Sabine Loeffert

Oliver Ommen
email: oliver.ommen@uk-koeln.de

Nicole Ernstmann

Holger Pfaff

Changes in secondary pharmacological prevention of acute coronary syndromes and stroke after hospital discharge: a 6-month follow-up study of German primary care patients

Keywords: Acute coronary syndrome, Stroke, Secondary prevention, Primary care

Changes in secondary pharmacological prevention of acute coronary syndromes and stroke after hospital

discharge: a 6-month follow-up study of German primary care patients

Introduction

Changes in medications between ambulatory and stationary treatment have been examined in several publications with regard to interface problems. As a result, modifications in pharmaceutical treatment were found to various degrees and at different stages in the course of continued medical care [START_REF] Hach | Continuity of long-term medication use after surgical hospital stay[END_REF][START_REF] Himmel | Drug changes at the interface between primary and secondary care[END_REF][START_REF] Taxis | Frequency and predictors of drug therapy interruptions after hospital discharge under physician drug budgets in Germany[END_REF]. Inconsistency in prescription behaviour is especially problematic when dealing with medications with a proven benefit for preventing serious adverse health conditions. For example, the need for pharmaceutical approaches to secondary prevention of acute coronary syndromes (ACS) and stroke have increasingly gained recognition and acceptance during the last 2 decades [START_REF] Jamieson | Secondary Prevention of Ischemic Stroke: Evolution from a stepwise to a risk stratification approach to care[END_REF][START_REF] Phillips | New pharmaceutical approaches to stroke prevention, treatment[END_REF]. In this regard, national and international therapeutic guidelines for the prevention of secondary stroke and coronary events have been developed (e.g., Bundesärztekammer et al. 2006;[START_REF] Bertrand | Management of acute coronary syndromes in patients presenting without persistent ST-segment elevation[END_REF][START_REF] Braunwald | ACC/AHA 2002 guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarctionsummary article: a report of the American College of Cardiology/ American Heart Association task force on practice guidelines[END_REF]; Joint Guidelines issued by the German Neurological Society and the German Stroke Society 2005). As outlined in these therapeutic guidelines, antiplatelet, antihypertensive, and lipid-lowering therapies are known to significantly reduce the risk of recurrence of macrovascular diseases, such as coronary and cerebrovascular diseases. Contrary to this, national and international studies have shown that these guidelines are not yet fully implemented in primary and secondary prevention with respect to platelet aggregation inhibitors, angiotensin-converting enzyme (ACE) inhibitors, betablockers, and statins (EUROASPIRE I and II Group 2001;[START_REF] Krumholz | National use and effectiveness of beta-blockers for the treatment of elderly patients after acute myocardial infarction: National cooperative cardiovascular project[END_REF]Welterman et al. 1997) in the prevention of ACS. However, long-term secondary stroke prevention in Germany has revealed better findings, especially with regard to antithrombotic medications [START_REF] Hamann | Adherence to secondary stroke prevention strategiesresults from the German stroke data bank[END_REF]. Even though therapeutic guideline implementation has improved over the past years [START_REF] Mandelzweig | The second Euro Heart Survey on acute coronary syndromes: characteristics, treatment, and outcome of patients with ACS in Europe and the Mediterranean Basin in 2004[END_REF][START_REF] Wienbergen | Aktuelle Verordnungspraxis von CSE-Hemmern bei Entlassung aus der Klinik nach akutem Myokardinfarkt[END_REF], only few studies in Germany have examined whether treatment recommendations after hospital discharge were according to current guidelines and to what extent these recommendations were realised in subsequent primary care [START_REF] Zeymer | Sekundärprävention der koronaren Herzkrankheit in der Arztpraxis[END_REF]. The goal of this study was to compare treatment recommendations for secondary pharmacological prevention of ACS and stroke after hospital discharge with current guidelines and to examine changes in medication between initial hospitalisation and continued medical care.

Methods

Patients with ACS or stroke, who were treated in five hospitals in the Cologne area (Germany) between April 2005 and November 2005, were observed for 6 months after hospital discharge in a prospective study. Inclusion criteria for the study were as follows: admission diagnosis of ACS, as coded for by the hospital's administrative database (ICD-10 codes I20.0, I20.8, and I21); admission diagnosis of cerebral infarction or stroke (ICD-10 codes I63 and I64); and age >18 years with the cognitive and intellectual capability to participate in the study. Of the initially 970 hospitalised patients, 408 were excluded due to meeting the exclusion criteria: (1) very poor general health condition (35%), (2) low cognitive capability (14%), (3) lack of substantial knowledge of the German language (15%), (4) participation in other clinical studies (3%), and (5) other reasons (7%), or (6) due to early hospital discharge (26%). Of the remaining 562 potentially qualified patients, 216 (38%) gave their consent to participate in the study. The dropout rate of the included 216 patients totalled 41%. Patients`reasons for drop out were:

(1) "no longer interested" (69%), (2) "poor general health condition" (18%), (3) "too time-consuming" (8%), and (4) "too difficult" (6%). Thus, the remaining study population consisted of 127 patients (98 patients with ACS and 29 patients with stroke).

Data acquisition was pursued in three steps. During the initial hospitalisation or shortly after, patients completed a standardised questionnaire (step 1). The questionnaire captures socio-demographic data and information regarding the patient's general health. At the time of hospital discharge, each patient was given a questionnaire with a weekly health diary (step 2). The appropriate questionnaire was filled in by the patients on a weekly basis for 6 months following HD. The questionnaire covered aspects of general health, medications (brand name), dosing, change in medications, and the underlying reasons for medication changes. The third step of data acquisition was conducted by a study nurse for case documentation. Following a standardised procedure, information regarding admission and HD diagnosis (ICD-10), medications, stationary diagnosis and therapy, and follow-up treatments were obtained from the patient's medical records and HD summary.

The medication was classified according to the WHO's Anatomical Therapeutic Chemical (ATC) classification system [START_REF] Dimdi | Anatomisch-therapeutisch-chemische-Klassifikation mit Tagesdosen. Amtliche Fassung des ATC-Index mit DDD-Angaben für die Bundesrepublik Deutschland im Jahr[END_REF]. Over-the-counter (OTC) drugs, topical medications, acute medications (e.g., antibiotics, immunmodulatories, and antineoplastics), homoeopathic medications, herbal agents, and enzymes were not included in the study. Statistical analyses were performed using SPSS 12.0 and 15.0 (Statistical Package for the Social Sciences). Patient characteristics and medication data are presented in absolute and relative frequencies. In addition, for each medication a Cochran's Q test was performed to test for differences between the frequencies of prescription over time. An αadjustment (0.05) for multiple testing was performed by means of the Bonferroni procedure (Table 2). Due to the small sample size of this study, all available complete data sets were used for statistical analysis. Therefore, there were 104 ACS patients enclosed at hospital discharge and week 2 and 30 stroke patients from HD until week 12.

Results

The demographic characteristics of the patient groups are presented in Table 1. Patients with ACS took an average six medications per day within the observation period (minimum at week 24=0 and maximum at week 24=14), whereas patients with a stroke took five different medications per day (minimum at week 24=1 and maximum at week 24=10).

Of all patients with ACS, 100 (96%) received a betablocker, 16 (15%) used a vasodilator used for cardiac disease (organic nitrates and other vasodilators, e.g., molsidomine and trapidil), 83 (80%) used a lipid-lowering agent, and 67 (64%) used an ACE inhibitor at the time of HD. Eighty-nine (86%) of all study patients with ACS used acetylsalicylic acid and 58 (56%) clopidogrel as antiplatelet agents at the time of HD (Table 2). No change in medications was observed 2 weeks following HD. In week 24, a minor increase in the use of vasodilators 18% (p= 0.188) and a slight, however, due to the adjusted α-level (α*=0.003) not statistically significant decline in prescriptions of beta-blockers 93% (p=0.010) was observed. Furthermore, a significant decrease (p=0.002) of clopidogrel prescriptions [42 patients (43%)] and a non-significant decline (p=0.012) in the use of acetylsalicylic acid [76 patients (78%)] occurred in week 24. Of all ACS patients, 11% did not receive any antiplatelet agent at hospital discharge as well as 12% at week 2 and week 12 and 16% at week 24. However, 52% of the patients at HD and 2 weeks later were treated with acetylsalicylic acid and clopidogrel in combination. Furthermore, a decrease in the use of the combination therapy was observed in week 12 (43%) and week 24 (37%), respectively. Of all patients with stroke, 15 (50%) received a betablocker, 13 (43%) used an ACE inhibitor, 3 (10%) used a calcium channel blocker, 20 (67%) used a lipid-lowering agent, 17 (5%) used acetylsalicyclic acid, and 8 (27%) used clopidogrel at the time of hospital discharge (Table 2). No significant changes in medication were observed within 24 weeks. With regard to antiplatelet agent therapy, about 6 out of 30 patients did not receive any treatment throughout the observation time.

Data quality was assessed by comparing the prescribed medication as indicated on the physician questionnaires (n=28) with the medication documented in the health diaries (weeks 1-21). The data showed an agreement of 90.5% between the reports submitted by the patients and the physicians.

Discussion

The present study revealed a remarkably high number of ACS patients receiving antiplatelet medication (89%), betablockers (96%), lipid-lowering agents (80%), and ACE inhibitors (64%) when compared with earlier publications. Only the results from the Acute Myocardial Infarction (MITRA 1 + 2) and Myocardial Infarction (MIR) Registries showed a higher treatment rate of patients with ACE inhibitors (76%) at the time of HD [START_REF] Gottwik | Differences in treatment and outcome of patients with acute myocardial infarction admitted to hospitals with compared to without departments of cardiology[END_REF]. In contrast, EUROASPIRE-II reported that 84% of ACS patients received antiplatelet medication, 66% received beta-blockers, 63% received lipid-lowering agents, and 43% received ACE inhibitors (EUROASPIRE I and II Group 2001). Less positive, however, are the results of the DETECT-Study, reflecting the medication of patients with coronary artery disease in a German outpatient setting (Bischoff et al. 2006). Observed prescription rates for antiplatelet medication were 53%, for beta blockers 57%, for statins 43%, and for ACE inhibitors 50%. Furthermore, on closer examination, the apparently positive results of the present study concerning the antiplatelet medication of ACS patients are also less satisfactory. Only 52% of all ACS patients were treated with acetylsalicylic acid and clopidogrel in combination. These are insufficient results, since the combination of both antiplatelet agents was shown to be highly effective in secondary prevention of vascular events and in preventing coronary stent thrombosis.

Compared to acetylsalicylic acid alone, a combination of clopidogrel and acetylsalicylic acid decreases the number of cardiovascular events in patients with ACS by 20% (CURE Study Investigators 2001). In addition, a decline of the combination therapy was observed in week 12 (43%) and week 24 (37%), respectively. Therefore, for at least 9 months the guideline-recommended secondary medical prevention of ACS with the combination of acetylsalicylic acid and clopidogrel was not yet consistently implemented (Hamm et al 2004a(Hamm et al , 2004b;;Silber et al. 2005). Aside from some medical reasons (e.g., side effects), the cost-containment restrictions ("medication budget") for German physicians might explain the observed failure of guideline-oriented medication. Hypertensive, antiplatelet, and lipid-lowering therapies are also known to reduce the risk of recurrence of cerebrovascular disease [START_REF] Jamieson | Secondary Prevention of Ischemic Stroke: Evolution from a stepwise to a risk stratification approach to care[END_REF]. Based on these findings, the medications prescribed to patients with stroke seemed to be in concordance with current guideline recommendations. Specifically, >50% of patients received an antihypertensive medication, >80% of patients received an antithrombotic medication, and about 70% of patients were given a lipid-lowering agent. Several study patients had suffered a cerebral event coded as "unspecified stroke" (ICD-10: I64), which might have included cases of hemorrhagic stroke. This could be an explanation for why six patients (20%) did not receive any antithrombotic medication after HD. Except for antiplatelet medication, no changes in prescriptions were observed during the observation period for ACS patients. However, vasodilators used in cardiac diseases were prescribed more often (an increase of 3%), while beta-blockers had a lower prescription rate after 24 weeks (a decrease of 3%). This may indicate that some of the attending physicians focused on symptomatic treatment of the medical condition. Patients with ACS took an average of six medications and patients with stroke took an average of five medications, which is in the upper range reported in the literature [START_REF] Hach | Continuity of long-term medication use after surgical hospital stay[END_REF][START_REF] Harder | Structure and markers of appropriateness, quality and performance of drug treatment over a 1-year period after hospital discharge in a cohort of elderly patients with cardiovascular diseases from Germany[END_REF]. It was also found that polypharmacy can be caused by treatment according to evidence-based therapeutic guidelines, which is particularly problematic for elderly and multi-morbid patients [START_REF] Meinertz | Polypharmakotherapie ein Problem der Evidence-based Medicine[END_REF]. However, the administration of various drugs at various times of the day with different instructions can be very demanding and may result in low compliance, especially for geriatric patients [START_REF] Kidd | Adherence in social context[END_REF]. The employed method involving a health diary yielded sufficiently high data quality, as supported by the overall high agreement with regard to medication documentation by patients and physicians (>90%). However, it was difficult to motivate the physicians conducting further treatment to participate in this study (physician questionnaire: first contact after HD, n=28), and those who participated did not fully document medication-related infor-mation, e.g., reasons for a change in medications. The findings of this study are therefore limited to a small sample size. This must especially be kept in mind when interpreting the results of the patients with stroke (n=30). These data were obtained at five hospitals within the Cologne area and approximately 86% of the patients were hospitalised in a tertiary care hospital. Therefore, it is not known with certainty to what degree these results can be generalised. In conclusion, the results of our study as well as the results of the DETECTstudy (Bischoff et al. 2006) indicate an undersupply of ACS patient with antiplatelet agents, especially in outpatient care. In particular, the combination therapy with acetylsalicylic acid and clopidogrel seemed to not be sufficient in all cases. Future studies, particularly in German outpatient settings, with longitudinal design and representative samples should focus on this problem.

Table 2

 2 Prescriptions of medications with therapeutic guideline recommendations Patient characteristics at hospital discharge

		Acute coronary syndromes			Stroke
		Hospital	Week 2	Week 12	Week 24	p-	Hospital	Week 2	Week 12	Week 24	p-
		discharge	(n=104)	(n=98)	(n=98)	value a	discharge	(n=30)	(n=30)	(n=29)	value a
		(n=104)	%	%	%		(n=30)	%	%	%
		%					%
	Vasodilators	15.4	21.2	19.4	18.3	0.188	0	0	0	0	-
	Beta-blockers	96.2	91.3	90.8	92.9	0.010	50.0	46.7	50.0	48.3	0.875
	Calcium channel	9.6	8.7	11.2	11.2	0.629	10.0	6.7	13.3	13.8	0.194
	blockers
	ACE inhibitors b	64.4	65.4	60.2	60.2	0.380	43.3	40.0	43.3	44.8	0.572
	Angiotensin II	16.3	15.4	19.4	18.4	0.172	13.3	13.3	13.3	13.3	1.000
	antagonists
	Lipid-lowering agents	79.8	83.7	82.6	83.7	0.442	66.7	60.0	66.7	65.5	0.682
	Clopidogrel	55.8	54.8	52.0	42.9	0.002	26.7	23.3	16.7	20.7	0.479
	Ticlopidine	0	1,0	1,0	1,0	0.392	0	0	0	0
	Acetylsalicylic acid	85.6	85.6	78.6	77.6	0.012	56.7	50.0	60.0	65.5	0.525
	Adjusted α-level: α*=0.05/16=0.003

a Cochran's Q test; b (ACE) angiotensin-converting enzyme inhibitors

Table 1

Acknowledgements

The authors wish to thank all patients, physicians, and study nurses who participated in the study. We also are indebted to the staff and physicians of the participating hospitals: Klinik III für Innere Medizin der Universität Köln (Prof. Dr. Höpp), Klinik und Poliklinik für Neurologie der Universität Köln (Prof. Dr. Haupt), Dreifaltigkeits-Krankenhaus Wesseling (Dr. Göke), St. Elisabeth-Krankenhaus Köln (Prof. Dr. Pohl), Eduardus-Krankenhaus Köln (Dr. Witthöft), and St. Lukas Klinik Solingen (Dr. Leopold, Dr. Beckers). This study was supported financially by Sanofi-Aventis Germany GmbH.

Conflict of interest

The authors disclose any relevant associations that might pose a conflict of interest.


Barbara Niedźwiedzka

Katarzyna Czabanowska

Rafał Śmietana

Controlled vocabulary in public health. An overview of the achievements to date

come

Background Public health is a multidisciplinary field that has long been struggling with the need to develop comprehensive and exhaustive terminology that would cover all related disciplines, facilitate accurate understanding of terms, aid information search and processing, as well as permit an accurate scientific communication among public health professionals. This is not an easy task given the theoretical and practical scope of the discipline. Summary of the resources The following bibliographical databases were searched: LISA, PubMED, EMBASE, ERIC, as well as Internet websites devoted to public health issues, websites of the institutions operating in this area, and databases of projects financed by the European Union. All national and international reports in English, French, or German that dealt with the development of public health terminology in respective languages were included in the search. The glossaries, documents, databases, or web pages related to the activities of single institutions were excluded. Finally 13 glossaries were selected from among a number of different dictionaries, glossaries, and thesauruses that cover the terms used in public health discipline or its subdisciplines. The selected glossaries were developed in order to unify the terminology with their intended circulation exceeding the narrow aim of collecting terminology for the purpose of one project or for cataloguing the resources of a particular institution. Conclusion Until now, no one has developed one universal public health terminology, but various attempts related to its normalization are underway. The difficulties in communication, electronic collection, and transfer of information as well as differences in the understanding of public health terms have led to the process of unification. Such a process has been perceived not only in individual countries, but also internationally. There is hope that such works will finally result in the desired and internationally unified understanding of public health terms.

Keywords Public health . Vocabulary . Controlled . Dictionaries

Background

Public health as a multidisciplinary field on the one hand has special needs related to terminology development and on the other hand is confronted with major difficulties in its unification, unification that would greatly serve the processing of information and good communication among public health professionals. The task is not easy given how many disciplines contribute to the research related to the phenomena that have an impact on the health of populations. We are faced with a wide variety of activities and a multitude of data and data sources that stem from or crosscut: epidemiology, health policy, environmental re-search, health promotion and health education, health economics and management of organizations, psychology, and sociology, to name only some of the most important ones. Despite the difficulties, various attempts have been made to produce glossaries, thesauruses, or terminology lists that have tried to unify public health and health-related vocabulary.

The aim of the article is to present an overview, based on comprehensive literature and Internet sources review, related to the accomplishments in the area of development and unification of public health terminology. Included were vocabularies with a broad, national, or international scope of intended users. All dictionaries, thesauruses, and wordlists developed exclusively to cater for the needs of only a single institution, database, information center, or internet-based service have been disregarded.

Summary of the resources

A review of publications and available documents produced between the 1990s and June 2006 was conducted. Databases such as LISA, PubMED, EMBASE, and ERIC were searched using the following entries and keywords: PUB-LIC HEALTH, vocabular*, dictionar*, thesaurus*, glossar*. Also Internet websites devoted to public health issues and websites of institutions and organizations operating in the field of interest were reviewed as well as databases of projects financed by the European Union (found in Cordis and on the Public Health Portal) related to the development of glossaries in the area of public health. We also collated all the reports and information related to the development of nationwide or international terminology lists in English, French, and German. No reports or documents were consulted that referred to glossaries that were designated for use by a single institution, database, or website.

Studies devoted to the development of a universal terminology in the field of public health are not that numerous. The few that were found demonstrate that the beginnings of the efforts geared towards the establishment of a universal terminology go back to the mid 1990s. It was then that both in Europe and the in United States professionals started to compile locally available glossaries for broader use. They included terms from multidisciplinary language glossaries, wordlists developed for specific purposes, and in order to explain the terms, current definitions or contexts were provided.

The first example is the Public Health Information Network (PHIN), created by the Centers for Disease Control and Prevention in the USA, which implemented Public Health Vocabulary usage and made available standard dictionaries that contained a number of specialist terms. PHIN vocabulary is supposed to enable the cooperation of information systems in various organizations operating in the domain of public health. This is one of the PHIN activities, whose overall goal is to provide a uniform architecture for the exchange of information needed by professionals and clients in the field of public health through compliance of the institutions to the terminology standards, data exchange protocols, codes used, etc., across the USA. One of such glossaries is the PHIN Controlled Health Thesaurus, CHT, a polyhierarchic thesaurus, which provides definitions of individual terms, their synonyms and interrelationships, as well as contains references to dictionaries, from which the terms originate. It is mainly based on the terms used in the Unified Medical Language System, created by the US National Library of Medicine. The system comprises over 100 area-specific dictionaries and coding systems, and contains over a million terms in medicine and related sciences (UMLS Metathesaurus. Fact Sheet 2004). However, since the review of individual dictionaries has demonstrated that none of them actually exhausts the useful terminology in the domain of public health, CHT also contains terms outside UMLS, which are related to, e.g., environmental health, occupational health, accidents, and bioterrorism [START_REF] Almeida | Controlled Health Thesaurus for the CDC Web redesign Project[END_REF]. PHIN vocabulary is available at: PHIN Vocabulary Access and Distribution System.

In 1994, the International Union for Health Promotion and Health Education, Regional Office for Europe (IUHPE/ EURO), one of whose aims is to facilitate information exchange among member organizations, started to work on a multilingual thesaurus in the area of health promotion and health education [START_REF] Dorst | Restoring the tower of Babel: building a multilingual thesaurus on health promotion[END_REF]. This project was financed by the European Commission (DG V): the Program of Community Action for Health Promotion, Information, Education, and Training was implemented in cooperation with specialists in health terminology and health promotion, initially from four countries: the UK, France, Germany, and Holland. The thesaurus was based on the wordlist of the Netherlands Institute for Health Promotion and Disease Prevention (NGIZ), a thesaurus developed in Holland in 1982, and was used by the institutions that deal with health promotion and health education in this country. On completion of the first stage of work, the European Multilingual Thesaurus on Health Promotion comprised ca. 1,300 terms and allowed the use of databases in one of four languages in order to facilitate international cooperation and foster the dissemination and coordination of activities in the area of health promotion (Amis et al. 1996). The thesaurus contained the basic terms accepted at the international level and was developed in accordance with ISO recommendations on the creation of mono-and multilingual dictionaries, their form, arrangement, relationships, explanations, and references to other dictionaries [ISO 2788[ISO -1986(E)(E); ISO 5964-1985 (E)]. The thesaurus was tested in several institutions in the UK, Scotland, and Holland, and in 1997 work was expanded to include Italy and Sweden. At the moment, the thesaurus is available in 12 languages: French, Danish, Dutch, English, Finnish, German, Italian, Portuguese, Swedish, Spanish, Norwegian, and Greek. The thesaurus is available at: http://www. hpmulti.net.

The year 2001 saw the emergence of a glossary whose scope was broader, exceeding the scope of health promotion and education-the Glossaire des Termes de Santé Publique Internationaux. This multilingual glossary is available in English, French, German, and Spanish, and is a product of a project financed by the European Commission, implemented by 15 EU experts headed by Emmanuel Rusch. The glossary is made available by the Banque des Donnes Santé Publique (BDSP, France), and to a large extent, it is based on the Public Health Thesaurus (Thesaurus Santé Publique) developed by the Ecole Nationale de la Santé Publique (Rennes, France). The present, third review of the Thesaurus contains 6,186 terms, divided into 57 domains or the so-called microthesauruses, and 4,806 synonyms. The work on this thesaurus was started in the 1980s, with the key aim of the project being to develop a tool for indexing Public Health documents stored in the electronic Banque des Donnes Santé Publique (BDSP) and coordinated by the Ecole Nationale de la Santé Publique. The data collected by the BDSP came from a number of documenting institutions in France, hence the development of a uniform glossary of terms that describe documents maintained by individual institutions was crucial. The thesaurus is available at: http://www.bdsp.tm. fr/Glossaire/Default.asp.

Intensive work on controlled vocabulary in the area of public health is underway in the UK. The Health Development Agency [currently known as the National Institute for Health and Clinical Excellence (NICE)] developed the Public Health Information Thesaurus, based on the above-mentioned European Multilingual Thesaurus on Health Promotion. The thesaurus is used to index the publications listed in the Health Promotion Bibliographic Catalogue-HealthPromis, HDA's Evidence Base, as well as in the British portal Public Health Electronic Library. The HDA Public Health Information Thesaurus has been recently integrated with England's Public Health Observatories Public Health Information Tagging System (PHITS), and this way, a unified National Public Health Language (NPHL) was developed. The first version of this inventory of vocabulary was presented in December 2004. The National Public Health Language was created to permit uniform indexing and information search and to ensure efficient communication in the area of public health. This language, combining two important British terminologies, follows ISO recommendations and the APHO classification. It offers references to other glossaries operating in the public health subject area. NPHL comprises 1,571 terms in 10 thematic areas, as well as 340 synonyms. Work on the glossary is still underway and is geared towards its integration with the National Library's of Medicine MeSH (Medical Subject Headings), SNOMED (Systematized Nomenclature of Medicine), Government Category List and DoH Taxonomy. The NPHL is available at: http://www.nphl.nhs.uk or http://www.multites.com.

One should also mention glossaries that are narrowly specialized, yet very useful owing to the fact that their vocabulary is usually underrepresented in public health general dictionaries.

Among the multilingual thesauruses one needs to mention the General Multilingual Environmental Thesaurus, which was started in 1996 by the European Environment Agency (EEA) and its network-EIONET. GEMET was developed as a compilation of eight earlier multilingual glossaries and includes the basic environmental terminology. The 2001 revision is available in 17 European languages and has over 6,000 entries. The thesaurus is available through the European Environment Information and Observation Network website http://www.eionet.eu.int.

The National Information Center on Health Services Research and Health Care Technology (NICHSR) offers the "Terminology-A glossary of technical terms on the economics and finance of health services" http://www. nlm.nih.gov/nichsr/edu/healthecon/glossary.html.

The terminology related to the process of evaluating medical technologies-Health Care Technology Assessment-Glossary was developed by the National Information Center on Health Services Research and Health Care Technology (http://www.nlm.nih.gov/nichsr/ta101/ta10108.htm).

Many more or less extensive glossaries that may also be useful for Public Health professionals have been developed for the World Health Organization. Among them are the following:

- Assessment is available at http://www.who.int/hia/ about/glos/en/index2.html Numerous other WHO glossaries can be found using a search engine on the WHO website http://www.who.int/en/ by typing in the words "glossar," or "terminology," or "dictionar," each time adding a term that down-specifies a given area of interest.

-The most recent undertaking is: The Learners' Dictionary of Public Health for Students and Professionals. It has been developed in the framework of the European Leonardo da Vinci language competencies project by an international team of experts from Poland, Lithuania, the United Kingdom and Holland. The aim of the project was to develop a public health dictionary specifically targeted at the learners (the socalled learners' dictionary). Primary intended users of the glossary include students of public health, public health researchers and lecturers, teachers of specialist English, professionals and practitioners, who often work in international institutions, translators working for the EU and other international institutions, who should take into account the context of public health in their work. The definitions of terms, concepts, and expressions have been compiled in seven categories: epidemiology and biostatistics, environmental health and occupational health, health promotion, health policy, ethics and law, management, as well as economics and finance [START_REF] Czabanowska | Learner's dictionary for students and professionals[END_REF].

A word should also be said about terminology classifications that are also indispensable for the public health field and its professionals. They include, e.g., the International Classification of Diseases: 9th revision (ICD-9-CM_2005), containing commonly adopted names of diseases and medical conditions, the International Statistical Classification of Diseases and Related Health Problems: 10th revision (ICD-10), as well as the International Classification of Primary Care (ICPC) for primary health care terminology, the WHO International Classification of Functioning, Disability and Health (http://www3.who.int/icf/onlinebrowser/icf.cfm). Likewise, the terminology used in the Universal Medical Device Nomenclature System that covers medical equipment, systems, and materials, developed by the American Institute ECRI and translated into a number of languages, can also be useful. (http://www.ecri.org/Products_and_Services/ Products/UMDNS/Default.aspx -UMDNS.)

Conclusion

To date, a single universal public health terminology has not been produced yet. Actually this does not seem to be possible given the present stage of development of the domain, in which no international consensus exists as to the actual organization of public health services; diversity of concepts and systems, which entails a comparable diversity of public health terms that describe this complex reality.

The same reasons for which the unification of public health terminology appears to be a necessity, such as difficulties in communication, misunderstandings arising from different meanings of the same terms, and overlapping of various terms across disciplines, constitute the most serious obstacles. Multidisciplinarity blurs conceptual borders of the domain, and varying public health responsibilities contribute to serious problems at the lexical level, such as the different understanding of the same terms or shifting semantic fields. These observations were confirmed in 2004 by a review of Public Health terminology across eight EU countries (France, Germany, Italy, Holland, Poland, Spain, Sweden, and the United Kingdom), which showed substantial diversity in the use of crucial terms (Kaiser and Mackenbach 2004).

The expansion of the Internet and institutional networks and intensive implementation of IT in health care institutions may intensify work on the unification and standardization of terminology. In order to be effective, public health activities have to be supported by complete and upto-date information supported by a uniform, comprehensive, and universal terminology. Normalized vocabulary, among others, is also important for the purposes of classification and education in the field of foreign language teaching or translation work. Hence, all the efforts to develop public health terminology undertaken not only at the national, but also at the international level, with significant contribution on the part of international organizations, especially the European Commission, cannot be underestimated. It is to be hoped that such efforts will bring about the unification of this terminology, similar to that achieved in medicine.

  The Health Promotion Glossary developed by Don Nutbean of the WHO Collaboration Center for Public Health Promotion (University of Sydney, Australia) and published for the first time in 1986 is available at http://www.who.int/hpr/support.material.shtml -The European Observatory on Health Systems and Policies Glossary can be found at http://www.euro. who.int/observatory/glossary/toppage -The glossary of terms used in Health Impact

  International Organization forStandardization (1985) Guidelines for the establishment and development of multilingual thesauri. ISO 5964-1985 (E) International Organization for Standardization (1986) Guidelines for the establishment and development of monolingual thesauri. ISO 2788-1986(E) Kaiser S, Mackenbach JP (2004) Public Health in Eight European Countries -An International Comparison of Terminology (unpublished article), July Specialist English for European Public Health: Leonardo da Vinci Project no. PL/04/B/F/LA-174434 http://www.seeph.pro.mcg.pl/, and http://83.171.10.151/Zodynas/zodpakas/

Acknowledgements

Source of support Leonardo da Vinci Language Competencies Project: PL/04/B/F/LA-174434 financed by the European Commission.

Conflict of interest statement

The authors disclose any relevant associations that might pose a conflict of interest.


François-André Allaert

Antoine Blanc

Yves Megard

Isabelle Bertand

F.-A Allaert

F.-A Allaert

Parents' attitudes towards varicella vaccination acceptance in France and Germany: effect of vaccine recommendation and reimbursement (a survey)

Keywords: Varicella vaccination, General practice, Parents' attitude

Aims To ascertain physicians' and parents' attitudes towards varicella vaccination acceptance and to compare them between Germany (G), where routine varicella vaccination is recommended in children, and France (F), where it is not. Methods Study design: cross-sectional pharmacoepidemiological study conducted in pediatric practice. Data included descriptions of the vaccinated children by pediatricians and descriptions of the parents' attitudes using a self-administered questionnaire. The next five successive children, under 15 years old, vaccinated against varicella were included in the study. Results Six hundred ninety-five pediatricians (F: 186; G: 509) and 2,593 parents (F: 664; G: 1,929) were included in the study. Initially, 7.1% of the German parents and 15.3% of the French parents were reluctant to have their children inoculated with the varicella vaccine (p<0.0001). The main reason for their reluctance was the 'fear of complications due to the vaccination' in both countries (G: 60.0% vs 55.5%; p: ns). Fewer German parents thought that the varicella vaccine was too recent (5.9% vs 45.5%; p<0.0001), and they were also less reluctant due to the cost of the vaccination (G: 11.9% vs F:22.8%; p<0.02). In both countries, the most convincing arguments for parents who were initially reluctant were 'information on the potential seriousness of the disease,' which was reported by three-quarters of the parents (G: 70.0% vs F: 74.3%; p: ns), and 'availability of an effective, well-tolerated vaccine' (G: 59.4% vs F: 64.0%; p: ns). Conclusion Even in the absence of an official recommendation, French parents will accept varicella vaccine to the same extent as German parents where it is advisable if they receive appropriate information about the potential severity of the disease and the efficacy and safety of the vaccine.

Introduction

Many studies have shown that vaccines can protect children and adults from bacterial and viral infections. Vaccination has led to important reductions in the incidences of several diseases and even eradication in same instances, for example, small pox. Despite their proven effectiveness, many children do not receive vaccines because of their parents' philosophy or religious beliefs, their concerns about costs, or doubts about the usefulness, safety, or efficacy of vaccines [START_REF] Poland | Understanding those who do not understand: a brief review of the anti-vaccine movement[END_REF][START_REF] Taylor | Association between parents' preferences and perceptions of barriers to vaccination and the immunization status of their children: a study from Pediatric Research in Office Settings and the National Medical Association[END_REF][START_REF] Alfredsson | Why do parents hesitate to vaccinate their children against measles, mumps and rubella?[END_REF][START_REF] Fredrickson | Childhood immunization refusal: provider and parent perceptions[END_REF][START_REF] Freed | Parental vaccine safety concerns. The experiences of pediatricians and family physicians[END_REF]). Reluctance to use vaccines has been fueled by reports of alleged adverse events from vaccines spread by anti-vaccination web sites, as well as by recent vaccine recalls and modifications [START_REF] Freed | Safety of vaccinations: Miss America, the media and the public health[END_REF][START_REF] Wolfe | Content and design attributes of antivaccination websites[END_REF][START_REF] Flanagan-Klygis | Dismissing the family who refuses vaccines: a study of pediatrician attitudes[END_REF]). The situation is worse when the vaccine is not universally recommended, and even when a vaccine is recommended, not all physicians immediately adopt it in routine use. Varicella vaccine is one example for which these issues have slowed uptake. In the US, varicella vaccination has been recommended since 1996, but it took nearly 5 years to reach satisfactory coverage of more than 80% of children [START_REF] Sengupta | Varicella vaccination in Europe: are we ready for a universal childhood programme?[END_REF]. This vaccination has led to a reduction in the incidence of varicella of about 75% (CDC 2003). Doctors must be ready to answer parents' questions and address misconceptions since parental beliefs may be a major factor influencing whether a child receives the varicella vaccine [START_REF] Taylor | Parental attitudes toward varicella vaccination[END_REF].

The varicella vaccine is being increasingly used throughout Europe, although with different administrative and regulatory modalities. For example, in France, the varicella vaccine has been registered since December 2003, but there are no national recommendations for its routine use in children. Recommendations exist for health-care and childcare workers, those who have close contacts with immunocompromised people, and children requiring a solid organ transplant, and for people, at least 18 years old, within 3 days of contact with an infected person. In addition, this vaccine is not reimbursed by the health-care insurance system. In contrast, in Germany, routine administration to healthy children has been officially recommended since July 2004, and it is reimbursed in most administrative areas [START_REF] Rasch | Germany adds varicella vaccine to the National vaccination programme[END_REF]. Thus, Germany and France provide an interesting comparison for studying the effect of recommendations and funding on the attitudes of parents concerning varicella vaccination. For this we surveyed parents of children that were vaccinated against varicella by private pediatricians or general practitioners in Germany and France between March 2005 andMarch 2006.

Materials and methods

The purpose of this cross-sectional study conducted between March 2005 and March 2006 was to ascertain physicians' and parents' attitudes towards varicella vaccination acceptance and to compare them between Germany (G), where routine varicella vaccination is recommended in children, and France (F), where it is not. Two samples of 600 pediatricians (or GPs with essentially child-oriented practices) selected at random in France and Germany were involved. They were asked to include the next five successive children they vaccinated against varicella during the next month. These recruitment conditions led in each country to a sample of 3,000 cases providing a confidence interval of under 2% in case of an observed percentage under 5%. This choice was made due to the fact that we expected a low value for some questions, in particular for the spontaneous request for varicella vaccination, especially in France, where it is not reimbursed. These children had to be under 15 years of age and had to have no contraindications to the vaccine. Information on the main demographic and clinical characteristics of the vaccinated children as well as why the parents accepted the vaccination was recorded by the physician on the physician's questionnaire. Information on the parents' attitudes concerning the varicella vaccination was recorded on a self-administered questionnaire that the pediatrician gave them after having explained how to fill it in. This questionnaire was returned directly to the data analysis center in a prepaid envelope to protect anonymity. A common number included in the two documents allowed matching the pediatrician form with the self-administered questionnaire for the purposes of the statistical analysis.

Results are expressed as means with their standard deviations for quantitative variables and by numbers and frequency distributions for qualitative variables. Chi-square analysis and analysis of variance were respectively performed to compare qualitative and quantitative values between France and Germany. A P-value of less than 0.05 was considered to indicate statistical significance.

Results

Population and context of the vaccination

Between March 2005 andMarch 2006, 509 German pediatricians participated in the study and only 186 French pediatricians because of some recruitment difficulties in relation to the absence of varicella vaccination recommendations in France. This point will be discussed. The questionnaire was given to the parents of 3,033 vaccinated children. A total of 2,593 questionnaires was returned (85.6% response rate; 1,929 from Germany and 664 from France). The mean age, percentage of girls, family size, and rank of the vaccinated children were similar for the two countries (Table 1). The only variable that was significantly different was the parent's education level: 36.1% of parents in Germany vs. 55.3% of parents in France were university or advanced technical college graduates (P<0.0001).

The rate of spontaneously requested varicella vaccination was significantly higher for German parents than for French parents (20.9% vs 12.6%; P<0.0001). As shown in Fig. 1, except for 'avoid illness' and 'child living in close contact with other children,' which are the two main reasons for spontaneous requests for vaccination, nearly all the other reasons given by parents were significantly different between the two countries: 'Prevent complications' was mentioned more often in Germany than in France (51.4% vs 41.5%; P<0.01), and the difference was even larger for 'information on the varicella vaccine in the media' (42.3% vs 19.2%; P<0.0001). The reasons for a spontaneous request for varicella vaccination were less often in Germany than in France 'avoid social and professional impact of child's illness' (29.1% vs 47.7%; P<0.0001), 'child's relative currently has varicella' (5.6% and 21.5%; P<0.0001), and 'avoid scarring' (20.5% vs 29.6%; p<0.05).

Parents' opinions concerning varicella vaccination

The analysis of the parents' questionnaire (Fig. 2) reveals that 7.1% of the German and 15.3% of the French parents were initially reluctant to allow their children to receive the varicella vaccine (P<0.0001). The two main reasons for their reluctance were similar in the two countries, and both concerned the vaccination itself: 'Complications following vaccination' (G: 60.0% vs F: 55.5%; p: ns) and 'too many vaccinations' (G: 43.0% vs F: 40.6%; p: ns). The varicella vaccine was considered as being too recent by more French than German parents (G: 5.9% vs F: 45.5%; p<0.0001). Also, more French parents were reluctant due to the cost of the vaccination (G: 11.9% vs F: 22.8%; p<0.02) or because they considered their child too young (G: 5.9% vs F: 13.9%; p<0.05).

In both countries, the most convincing arguments for parents who were initially reluctant or who did not know that a varicella vaccine existed were 'information on the potential seriousness of the disease,' which was reported by three-quarters of the parents, and 'availability of an effective, well-tolerated vaccine,' which was mentioned by 59.4% and 64.0% of the parents in Germany and France, respectively (p: ns) (Fig. 3). The other reasons, in decreasing order of importance, were information that 'varicella is frequent and contagious' and 'prevention of varicella scars' and 'impact on the family of the disease.' Finally, the fact that vaccination is free of charge in Germany was indicated as an advantage by 23.4% of the German parents.

Discussion

In the current study, we investigated parents' attitudes to accepting varicella vaccination between France and Germany and the best way to convince them to have their children vaccinated.

The comparison with Germany was chosen because it was the first country in Europe that added varicella vaccination to the national routine vaccination schedule for all children; it was the first country in the European Union to do this. The Ständige Impfkommission (Standing Committee on Vaccination, STIKO) at the Robert Koch Institute in Germany announced the change in their published update to the national vaccine schedule (Robert Koch-Institut 2004a, b). According to these official recommendations, varicella vaccination is scheduled for infants aged between 11 and 14 months (given preferably at the same time as the MMR vaccine). Catch-up vaccination for children and adults is recommended, in particular for persons aged 9-17 years who have not had varicella infection. In France, no such recommendation exists, and the comparison with Germany was done in order to evaluate the impact of this recommendation and, moreover, to analyze if the existence a such recommendations was a sine qua non condition to the spreading of the varicella vaccine.

Potential biases should be considered before generalizing the results to all parents of young children. The most important possible bias is that the physicians who agreed to participate in the study may be those who are most in favor of varicella vaccination and therefore the most inclined to convince the parents. This bias is unavoidable, but its influence would be the same in both countries. This potential bias may also have had some impact on the parents' opinion, but the effect would have been minimal because the parents completed a strictly anonymous self-administered questionnaire that they sent directly to the data analysis center.

One other bias could be linked to the fact that the rate of pediatricians participating to the study in France was much lower than in Germany. The lack of a recommendation in favor of varicella vaccination in France (and consequently the absence of reimbursement) explains why many practitioners are still reluctant to propose it to parents and thus the difficulties we met recruiting regular varicella vaccine prescribers. These recruitment difficulties have an unavoidable effect on the precision of the results, providing an average confidence interval of 2% for the German data and of 4% for the French data rather than the initially expected <2%. However, taking into account that the lowest percentage described for the French sample is 12.6% of spontaneously requested varicella vaccination, this precision of 4% still appears satisfactory.

Another limit of our study is also due to the fact that we only considered vaccinated children, while it could have been interesting to describe the attitude and intentions from the parents who refused the vaccination of their child. This choice to focus our study on vaccination acceptance and eventual previous reluctance and not on refusal was dictated by the lack of recommendation for varicella vaccination in France. Also, a written inquiry about the patient's refusal could have been interpreted by the health authority as an unacceptable attempt to strongly influence them, and the rate of spontaneous answer would have been very low.

Despite potential biases and limits, our results revealed that the presence of a recommendation for the vaccination in Germany and its absence in France have a major impact on the parents' knowledge about the disease and its complications as well as on health-care promotion of the vaccine.

A first remark concerns the educational level of the parents of the vaccinated children, which was higher in France than in Germany. This reflects that in France, due to the lack of official recommendation and of reimbursement, the educational level and the level of income of parents has a strong influence on the acceptance of varicella.

Due to the availability of an official recommendation, more German parents were aware of the varicella vaccine and spontaneously requested vaccination. In addition, their reasons for requesting vaccination were different. German parents identified the main purpose of the vaccine as preventing complications and were convinced by information from the media, whereas the French parents' motivations were linked to the social and professional consequences of the disease, the prevention of infection of others, or the fear of scars. These findings suggest that even the French parents who spontaneously requested the vaccine were not aware of the seriousness of the complications of varicella. In Germany, the parents' attitudes are similar to those described for parents in the US [START_REF] Taylor | Parental attitudes toward varicella vaccination[END_REF]. In particular, when a recommendation exists, parents are more convinced about the advantages of the vaccine to prevent serious complications than its ability to reduce time lost from work.

The percentage of parents reluctant to accept varicella vaccination in the current study does not reflect the percentage in the global population; it reflects the initial rate of reluctance of parents who finally agreed to have their children vaccinated. Thus, the percentages reported here cannot be used as the basis for making conclusions about the reluctance for vaccination in the overall population. The parents' reluctance is mostly due to the fact that they consider varicella to be a harmless disease and, above all, fear of complications from the vaccine. The percentages of parents who were reluctant due to fear of complications of the vaccine (55.5% in France and 60.0% in Germany) are similar to that reported in the US (69%) [START_REF] Salmon | Factors associated with refusal of childhood vaccines among parents of school-aged children[END_REF]. The high proportion of French parents who said they were reluctant because the varicella vaccine is too recent (45.5%) is surprising, but is probably due to the fact that since varicella vaccine is not officially recommended in France, little information on varicella vaccination is targeted to the general population. This is illustrated by the fact that nearly half the French parents in our study were unaware that a varicella vaccine has been available for more than 10 years in the US, compared with 5.9% in Germany.

Differences in reluctance to have children vaccinated due to cost were not as big as expected. However, this finding may be biased by the socioeconomic profile of the French participants; on average, they have a higher educational level and therefore a higher income than their German counterparts. We cannot, therefore, conclude that French parents are probably more willing to pay than German parents. This finding could suggest that, in the absence of reimbursement, the use of the vaccine will be dependent on the parents' incomes.

Our results show that in both countries the most convincing argument in favor of the varicella vaccine is the information given by the practitioner regarding the seriousness of the disease and the availability of a welltolerated vaccine. The results from a study in the US, where the varicella vaccine has been recommended for more than 10 years, were similar; the most frequent factor influencing parents' decision was their doctor's advice [START_REF] Freeman | Parental knowledge, attitudes and demand regarding a vaccine to prevent varicella[END_REF].

In summary, our results show that both German and French parents readily accepted varicella vaccination when the practitioner recommended it and/or when they were appropriately informed about the potential severity of varicella disease and the safety of the vaccine, irrespective of an official recommendation and reimbursement for the vaccine. However, the absence of reimbursement may affect some parents' decision, due to the cost, and therefore, this may lead to social inequality.

Fig. 2

 2 Fig. 2 Reasons for parents' initial reluctance to accept varicella vaccination. Comparison between Germany and France

Table 1

 1 Family characteristics of vaccinated children

	Variable

Conflict of Interest

The authors Antoine Blanc, Yves Megard, and Isabelle Bertand are full-time employees of Sanofi Pasteur MSD. This study was funded by a grant from Sanofi Pasteur MSD.


Simone Becker
email: simone.becker@ok.uni-heidelberg.de

Monique Zimmermann-Stenzel

Physical activity, obesity, and educational attainment in 50-to 70-year-old adults

Keywords: Epidemiology, Socioeconomic factors, Telephone interview, Physical activity, Obesity

Aim The purpose of the study is to investigate, in subpopulations with varying levels of education, firstly, the extent to which older adults with an otherwise sedentary lifestyle perform simple everyday physical activities such as cycling for transport or taking a walk, and the extent to which older adults perform everyday physical activities in addition to exercise; and secondly, to explore correlations between physical activity and obesity. Methods The study is based on a representative, Baden-Württemberg State Foundation-funded study in 50-to 70-year-old residents of Baden-Württemberg (n=2,002). Results Subjects who say they ride a bike for transport or take a walk are significantly more likely to exercise than subjects who do not walk or cycle regularly. This holds even after controlling for sociodemographic and lifestylerelevant variables. However, the correlation between walking and exercise, and the positive correlation between walking and obesity, is retained only for subjects with a low level of education. Both for subjects with a low level of education and for subjects with a high level of education, multivariate analysis discloses a negative correlation between regular cycling and obesity. Conclusions People who do not exercise regularly are also less active on a day-to-day basis and are less likely to take a walk or ride a bike for transport. Given the healthpreserving effects attributed to leisure-time physical activity from a biological and medical point of view, it is particularly important to encourage older adults and disad-vantaged sectors of the population to be more physically active.

Background

Middle-aged and older adults take comparatively little exercise, as research shows [START_REF] Allender | Diet, physical activity and obesity statistics[END_REF][START_REF] Becker | Analysen zur Sportbeteiligung auf der Basis des repräsentativen Bundes-Gesundheitssurveys 1998[END_REF][START_REF] Boutelle | Associations between exercise and health behaviors in a community sample of working adults[END_REF][START_REF] Lamprecht | Soziale Lage, Freizeitstil und Sportaktivität in der Schweiz[END_REF][START_REF] Mensink | Bundes-Gesundheitssurvey: Körperliche Aktivität. Aktive Freizeitgestaltung in Deutschland[END_REF][START_REF] Rütten | Körperliche Aktivität[END_REF][START_REF] Schneider | Sportaktivität in Deutschland -Ergebnisse des Bundes-Gesundheitssurveys zu sozialmedizinischen Korrelaten der Verhaltensprävention[END_REF][START_REF] Sternfeld | Physical activity patterns in a diverse population of women[END_REF]. It is of interest to establish whether older adults replace exercising with everyday physical activity such as riding a bike for transport or taking a walk, or whether those who exercise regularly are also more likely to be more active in their everyday lives.

On the basis of the negative correlation between obesity and exercise reported for industrialized countries [START_REF] Boutelle | Associations between exercise and health behaviors in a community sample of working adults[END_REF][START_REF] Chen | Obesity and leisure time physical activity among Canadians[END_REF][START_REF] Mensink | Movement and circulation. Population studies on physical activities and cardiovascular risk[END_REF][START_REF] Sullivan | Obesity, inactivity, and the prevalence of diabetes and diabetes[END_REF]Vatten et al. 2006;Villegas et al. 2006), this study will also explore whether a negative correlation exists between everyday physical activity and obesity. A longitudinal study in Finland shows that men with high everyday activity levels (exercise and general physical activity combined) have a lower body mass index (BMI) than individuals with low levels of overall physical activity [START_REF] Sulander | Obesity and education: recent trends and disparities among 65-to 84-year-old men and women in Finland[END_REF]. Given that obesity is a medical risk factor for numerous chronic orthopedic and cardiovascular diseases [START_REF] Augestad | The association between physical activity and forearm bone mineral density in healthy premenopausal women[END_REF][START_REF] Cosman | The prevention and treatment of osteoporosis: a review[END_REF][START_REF] Hu | Dietary pattern analysis: a new direction in nutritional epidemiology[END_REF][START_REF] Lampert | Armut, soziale Ungleichheit und Gesundheit-Beiträge zur Gesundheitsberichterstattung des Bundes[END_REF][START_REF] Mayer | The relevance of sports for the onset, prevention and rehabilitation of osteoarthritis[END_REF]Wannamethee and Shaper 2001), this inadequately investigated correlation may be an important factor in terms of health policy-making for disease prevention. There is abundant evidence in the literature that individuals with a low level of education take less exercise [START_REF] Crespo | Prevalence of physical inactivity and its relation to social class in U.S. adults: results from the Third National Health and Nutrition Examination Survey, 1988-1994[END_REF][START_REF] Erlinghagen | Wer treibt Sport im geteilten und vereinten Deutschland. Eine quantitative Analyse sozio-ökonomischer Determinaten des Breitensports[END_REF][START_REF] Lampert | Armut, soziale Ungleichheit und Gesundheit-Beiträge zur Gesundheitsberichterstattung des Bundes[END_REF][START_REF] Sternfeld | Physical activity patterns in a diverse population of women[END_REF], are more likely to be obese [START_REF] Hachfort | Sportliche Aktivität -Ihre Bedeutung für die Lebensgestaltung und den Lebensstil im Alter[END_REF][START_REF] Lampert | Armut, soziale Ungleichheit und Gesundheit-Beiträge zur Gesundheitsberichterstattung des Bundes[END_REF][START_REF] Mensink | Übergewicht. In: Robert Koch Institut Was essen wir heute? Beiträge zur Gesundheitsberichterstattung[END_REF]), and have a higher overall risk of morbidity and mortality [START_REF] Helmert | Müssen Arme früher sterben? Soziale Ungleichheit und Gesundheit in Deutschland[END_REF][START_REF] Mielck | Soziale Ungleichheit und Mortalität[END_REF]. Obesity is associated with a large number of health problems in older adults in particular [START_REF] Sui | Cardiorespiratory fitness and adiposity as mortality predictors in older adults[END_REF]. Educational attainment impacts health behavior from an early age. Children whose parents have higher educational attainment have a healthier lifestyle through adulthood and are less likely to be obese than children whose parents have lower educational attainment (Wadsworthx 1997).

Exercise levels decline with increasing age, and conversely, the proportion of obese individuals increases steeply in the older population [START_REF] Sui | Cardiorespiratory fitness and adiposity as mortality predictors in older adults[END_REF]. Obesity in adulthood correlates positively with cardiovascular morbidity and mortality [START_REF] Oppert | The relationship between indicators of physical activity, indicators of sedentary behaviour and adiposity in French adults: the FLVS II study[END_REF][START_REF] Sui | Cardiorespiratory fitness and adiposity as mortality predictors in older adults[END_REF]). However, [START_REF] Sui | Cardiorespiratory fitness and adiposity as mortality predictors in older adults[END_REF] also demonstrated that individuals with a BMI of 30 or higher with a good level of fitness have a lower mortality rate than normal-weight individuals with a poor level of fitness [START_REF] Sui | Cardiorespiratory fitness and adiposity as mortality predictors in older adults[END_REF]). This paper looks at the impact of physical activity and correlations between physical activity and obesity against the backdrop of educational attainment.

Accordingly, this paper investigates (1) correlations between everyday physical activity (walking, cycling for transport) and exercise, (2) correlations between everyday physical activity (walking, cycling for transport) and obesity, and (3) these correlations versus educational attainment.

Method

Study population and data generation

The empirical basis of this study is composed of data from the Baden-Württemberg State Foundation-funded study "Living an active life-age and aging in Baden-Württemberg." This cross-sectional study provides representative, recent, and retrospective data on health, activity, and lifestyle in the population of 50 to 70 year olds.

A total of 2,002 subjects from the target population were surveyed by computer-assisted telephone interview (CATI) in the period from May to October 2006. The telephone sample for the data survey was drawn on the basis of the Gabler-Häder method (Gabler and Häder 1997). To ensure the representativeness of the study for the 50-to 70-year-old Baden-Württemberg population, the data set was weighted prior to the performance of statistical analysis according to variables of age, gender, and education on the basis of the 2004 Microcensus. The survey response rate was 21.23% (see [START_REF] Becker | Ein aktives Leben leben"-Sport, Bewegung und Gesundheit im mittleren und höheren Erwachsenenalter[END_REF]). 1 The fact that the data survey coincided with the soccer World Cup in Germany may have increased the nonresponse rate. It is likely that the response rate during this specific period was additionally impaired by the fact that many of the persons called stopped the discussion immediately and/or were unwilling to provide information on the presence of target persons in the household. In such cases, because of the lack of information on possible target persons among household members, these numbers had to be classified (erroneously, in some cases) as systematic noncoverage, which in turn may be a partial explanation for the low response rate. 2

Operationalizations

Dependent variables

Subjects who said they exercised at least once a week were defined as exercisers and compared with those who said they exercised less than once a week. Weekly exercise is the limit above which leisure-time physical activity starts to have a sustained health benefit. 3 In addition, the more often leisure-time physical activities are performed, the more likely it is that exercise is a lifestyle element, and, for the available data, a minimum exercise frequency of once weekly is the most effective basis for analysis.

The second dependent variable, obesity, is based on the WHO definition. Accordingly, all respondents with a BMI of at least 30 were defined as obese and were compared with respondents with a BMI below 30.

1 There is no uniform definition for calculating response rate (Schnell 1997: 19). In general, when calculating response rates, a distinction is made between sample-neutral and non-sample-neutral noncoverage. In this study, neutral noncoverage was defined as all instances of noncoverage where contact was not established despite achieving the maximum number of calls. Households with no 50-to 70-year-old target persons, households where the target person does not speak German, households with a non-Baden Württemberg phone number, and numbers used for technical purposes only (fax, modem) were classified as neutral noncoverage. Refusals and discontinuations were counted as systematic noncoverage. 2 This problem does not apply to the same extent for surveys among the general over-18 residential population, because even if the phone call is terminated immediately by the contact person, it can be assumed that a target person belongs to the household and the noncoverage is systematic in nature. 3 Although additional physical activity of any frequency may have health benefits (cf. [START_REF] Blair | How much physical activity should we do? The case for moderate amounts and intensities of physical activity[END_REF], more recent recommendations point to a higher cutoff point for frequency and intensity. For example, a Robert Koch Institute recommendation states: "A half hour of exercise at least 3 days a week has demonstrably positive effects on health" (Mensink 2003: 6).

Independent variables

Two everyday physical activitiestaking a walk and riding a bike for transportwere included in the analyses as independent variables. These everyday activities were queried using a dichotomous variable: "The next part is about riding a bike for transport, for example, to get the groceries, go to work, or a similar activity. Did you perform this activity on a regular basis within the past 12 months?" or "The next part is about taking a walk at a leisurely pace. Did you perform this activity on a regular basis within the past 12 months?" "Regularly" was defined as at least once a week.

Control variables

Overall health was queried by self-assessment on a scale from 1 (very good) to 5 (very poor) and subsumed into three categories ("good," "moderate," and "poor") for analysis purposes.

Diseases and risk factors were queried by asking subjects "Did you ever have any of the following diseases diagnosed by a doctor?" Medical risk factors including hypertension, hypercholesterolemia, and diabetes were defined according to WHO criteria and controlled for in the analyses performed.

Current tobacco use was defined according to the categories of "smoker" (daily and occasional) and "nonsmoker." Alcohol consumption was recorded on the basis of g/day and subsumed into the categories "low" (0-5 g/day), "moderate" (5-30 g/day), and "high" (>30 g/day).

Operationalization of eating habits was done by the typology proposed by [START_REF] Reime | Ernährungsgewohnheiten bei Beschäftigten in der Metallindustrie[END_REF]. Healthy eating was defined as daily consumption of whole grain bread, fruit, vegetables, and fish and non-daily consumption of meat, deep-fried foods, white bread, and confectionery. Subjects with three of these eight eating habits were rated as having an unhealthy diet, subjects with four or five of the eight were classified as having a moderately healthy diet, and subjects reporting more than six of the eight qualified as having a healthy diet.

Sociodemographic and socioeconomic variables were surveyed using a standardized questionnaire (Working Committee of the German Institutes for Marketing and Social Research et al. 2004) and likewise factored into the study as control variables.

Statistical design

The effects of everyday cycling/walking and of the control variables both on exercise and on obesity were determined bivariately, depending on scale level, by χ 2 test or unpaired t-test. Significant bivariate test results were followed by logistical regression to investigate the effects of cycling or walking on exercise and on obesity, whilst controlling for relevant covariates. The intention was to make the procedure as economical as possible in terms of the number of variables, by excluding from the multivariate analysis all variables and control variables found to be nonsignificant in the bivariate analysis. The purpose was to explore the extent to which cycling for transport or walking are in themselves determinants for the dependent variables, or whether individual associations disappear when other variables are factored in and held constant. Multiple regression models were calculated for the various correlations to be investigated. The overall model reported investigates the effects of the respective predictors on the dependent variable while including all the control variables that were significant in bivariate analysis. To determine educationspecific correlations, the overall model was calculated once again for the four central correlations, separately for the various education levels. The bi-and multivariate analyses were done in a standardized fashion incorporating full data sets only. All tests were two-tailed and the defined level of significance was p≤0.05. The analyses were done using the statistical program SAS for Windows, version 9.02 (SAS Institute Inc., Cary, NC, USA).

Results

Prevalences of exercise, obesity, and selected everyday physical activities

Of the older adult respondents in Baden-Württemberg, 61.7%4 said they engaged in leisure-time physical activity at least once a week. However, 12.9% of the respondents have a BMI of at least 30, which qualifies them as obese in accordance with the current WHO definition; 47.4% of the respondents ride a bike for transport, and 72.1% of the older adult respondents said they were regular walkers.

Bivariate analyses of exercise and obesity

The bivariate analyses revealed a highly significant positive correlation both between exercise and cycling for transport (χ 2 =97.989, p≤0.001) and between exercise and walking (χ 2 =38.171, p≤0.001).

This positive bivariate correlation between cycling for transport and exercise applies across all educational groups (results not presented in detail here). Bivariate analysis of the correlation between walking and exercise for different educational groups shows, however, that a significantly positive relationship between regular walking and leisuretime physical activity applies only to Hauptschule 5 graduates (χ 2 =37.712, p ≤0.001). For Realschule graduates and individuals with Abitur, regular walking does not have a significant effect on exercise.

In terms of bivariate analysis of the correlation between physical activity and obesity, however, contrary significant correlations are evident. Obese individuals are significantly more likely than non-obese individuals to be regular walkers (χ 2 =5.670, p=0.017). Separate analysis for the different educational groups shows that this correlation applies only to Hauptschule graduates (χ 2 =8.401, p=0.0037).

Obese subjects are significantly less likely to cycle for transport (χ 2 =6.813, p=0.009). Bivariate analysis for the different educational groups confirms this significant negative correlation only for Hauptschule graduates (χ 2 = 9.944, p=0.0020).

Multivariate analyses

Bike riding/regular walking and current exercise Logistical regression analysis shows that the significant correlation between bike riding and exercise holds even after controlling for all bivariately significant variables. Subjects who ride a bike for transport are 2.4 times more likely to be exercisers than subjects who do not (Table 1, model 1).

The statistically significant correlation between regular walks and exercise is retained in the bivariate analysis even after controlling for educational attainment. Individuals who walk regularly are 1.8 times more likely to be exercisers than subjects who do not. This correlation continues to apply whilst controlling for the additional lifestyle-relevant variables of tobacco use, nutrition, subjective state of health, obesity, and diabetes (Table 1).

Education-specific analysis reveals a positive correlation between cycling for transport and exercise across all educational attainment strata, whilst controlling for all the variables controlled in the overall model (see Table 2). Hauptschule graduates who cycle are 2.7 times more likely to be exercisers than Hauptschule graduates who do not. This significant correlation also applied for Realschule graduates [odds ratio (OR)=2.306, p=0.002] and those with Abitur (OR=1.979, p=0.004), albeit to a lesser extent (see Table 2).

The logistical regression models calculated separately for the various educational groups show thatwhen the controlled variables from the prior overall model are held constantthe positive relationship between regular walking and exercise applies only for subjects with lower educational attainment. Subjects with Hauptschule graduation, or with no school-leaving qualifications whatsoever, who take regular walks are 2.1 times more likely to be exercisers than Hauptschule graduates who do not (see Table 2). No statistically significant relationships are detected for subjects with higher educational attainment (see Table 2).

Cycling for transport/regular walking and obesity

The previously reported negative correlation between cycling for transport and obesity disappears for the overall population when controlled for other relevant variables (Table 3, model 1).

The odds ratio for being obese is 1.5 times higher for regular walkers when controlled for age, education, gender, and other lifestyle factors (Table 3, model 2).

The analyses for the individual educational groupsusing the same controlled variables as indicated in Table 3 showed no significant relationship between cycling for transport and obesity (see Table 4).

Education-specific analysis shows a positive correlation between regular walks and obesity only for Hauptschule graduates (Table 4). Regular walkers with low educational attainment are 1.8 times more likely to be obese than Hauptschule graduates who do not report regular walking. 5 The school forms in the three-tiered German secondary school system are Hauptschule, Realschule, and Gymnasium (9, 10, and 12-13 years of education, respectively). Gymnasium graduates pass an exam called Abitur which qualifies them to enter university, Hauptschule and Realschule qualifications are vocational rather than academic. In contrast, a significant correlation between frequent walking and obesity is not evident for Realschule graduates or those with Abitur qualifications.

Discussion

Are non-exercisers more physically active in everyday life to compensate for their lack of exercise?

Individuals aged 50-70 years who practice everyday physical activities such as cycling for transport and walking are also likely to take exercise. The significantly positive correlation between bike riding and exercise is evident in all three educational strata. Possibly, cycling for transport is perceived in all three educational strata as being an exercise-like activity and hence as being a component of an active lifestyle.

In contrast, breakdown by educational stratum shows that the positive correlation between walking and exercise applies only among Hauptschule graduates. These education-specific differences in the impact of regular walking on exercise may be because individuals with higher educational attainment would be unlikely to go for a simple walk when in need of physical and mental relaxation, opting instead for hikingwhich they would classify and report as exerciseor other leisure-time physical activity. Does everyday physical activity make up for a lack of exercise with respect to the risk factor of obesity? Individuals who take regular walks are significantly more likely to be obese than those who do not. Possibly, obese individuals choose a gentle walk as a spurious substitute for leisure-time physical activity (to assuage any "guilt" about not taking enough exercise). Broken down by educational attainment level, the walking-obese correlation applies only for Hauptschule graduates, however. This may be because a disproportionately high percentage of individuals with lower educational attainment are obese [START_REF] Sulander | Obesity and education: recent trends and disparities among 65-to 84-year-old men and women in Finland[END_REF] and unused to exercise and would perceive walking as non-strenuous. In addition, walking does not require expensive equipment. The lack of a financial barrier is a relevant factor for less well-off individuals with lower educational attainment.

Data set method limitations

With respect to the fairly low response rate, it is noteworthy that, although low response rates are generally associated with an increased risk of bias (Porst et al. 2007: 6;[START_REF] Koch | Teilnahmeverhalten beim ALLBUS 1994. Soziodemographische Determinanten von Erreichbarkeit, Befragungsfähigkeit und Kooperationsbereitschaft[END_REF][START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF][START_REF] Schnell | Nonresponse in Bevölkerungsumfragen[END_REF], a low response rate does not always equate with low data quality [START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF][START_REF] Porst | Strategien und Maßnahmen zur Erhöhung der Ausschöpfungsquoten[END_REF]. It is also worth questioning the extent to which a maximized response rate is useful if it involves "forcing" interviewees to respond through the massive deployment of response rate-enhancing measures. If such measures succeed in reducing the response rate but end up skewing the results, their impact may even be counterproductive in terms of survey quality [START_REF] Porst | Strategien und Maßnahmen zur Erhöhung der Ausschöpfungsquoten[END_REF]). Conversely, bias may be low even in the presence of a low response rate, provided that noncoverage is largely random [START_REF] Koch | Teilnahmeverhalten beim ALLBUS 1994. Soziodemographische Determinanten von Erreichbarkeit, Befragungsfähigkeit und Kooperationsbereitschaft[END_REF][START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF][START_REF] Porst | Strategien und Maßnahmen zur Erhöhung der Ausschöpfungsquoten[END_REF]). In the latter case, respondents would differ minimally if at all from nonrespondents and would hence represent no more than a random sample of the initial sample. In such a case, the only consequence of low response would be a larger standard error (Porst et al. 2007: 6). The risk of nonresponse bias exists, however, if noncoverage is not randomly distributed across the target population [START_REF] Koch | Teilnahmeverhalten beim ALLBUS 1994. Soziodemographische Determinanten von Erreichbarkeit, Befragungsfähigkeit und Kooperationsbereitschaft[END_REF][START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF]. In summary, it can be stated that response rate is only one attribute among many in determining survey quality [START_REF] Porst | Strategien und Maßnahmen zur Erhöhung der Ausschöpfungsquoten[END_REF]) and the focus on this particular feature is primarily because it can be measured objectively [START_REF] Porst | Strategien und Maßnahmen zur Erhöhung der Ausschöpfungsquoten[END_REF]).

As nonresponse bias is an attribute-specific variable, a low response rate (but also a high response rate) may be associated with marked bias in respect of one attribute, whereas the survey may be relatively bias-free in respect of another attribute [START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF]. A major problem in measuring nonresponse bias is that information on differences between respondents and nonrespondents is usually unavailable [START_REF] Koch | Wenn "mehr" nicht gleichbedeutend mit "besser" ist: Ausschöpfungsquoten und Stichprobenverzerrungen in allgemeinen Bevölkerungsumfragen[END_REF].

Because of the nature of the study, the data generated are based on subject self-assessment. Therefore, social desirability bias may be a factor [START_REF] Lautenschlager | Computer administration of questions: more desirable or more social desirability?[END_REF]. The fairly high percentage of exercisers may be partly attributable to social desirability effects. As past studies show, any investigation of behaviors deemed socially desirable is like to produce reporting bias in favor of the desirable behavior, resulting in this case in overreporting of exercise (Lamprecht and Stamm 1995). However, the potential social desirability problem is offset by the many advantages of the telephone interview method. The first of these is the representativeness of the data for the population studied. Unlike many other studies on the effects of ordinary physical activity on exercise and obesity, this study was not limited to a local, hospital-specific patient population. Although the results are representative for the 50-to 70-year-old Baden-Württemberg population only, the similarity in population structure between Baden-Württemberg and the whole of Germany allows the data to be applied to the overall German population (see Table 5). To illustrate the relevance of the representative dataset for the 50-to 70-year-old Baden-Württemberg population to the overall population of Germany, Table 5 compares key demographics for the 50-to 70-year-old national population with those of the 50-to 70-year-old Baden-Württemberg population. As can be seen, the population structure barely differs overall.

Another advantage of the study procedure is that it enabled us to analyze correlations between exercise, obesity, and physical activity in large sample sizes. Nevertheless, given the cross-sectional data employed, the results cannot be interpreted in terms of causation.

Conclusion

Given the economic importance of cardiovascular disease and orthopedic conditions such as back pain on the one hand and the reluctance of many middle-aged and older adults to practice leisure-time physical activity regularly on the other hand, targeted encouragement of ordinary physical activity is an important health policy objective. Ordinary physical activity such as regular walking/cycling gives broad, low-cost access to exercise. Campaigns appealing to sectors of the population with disproportionately low exercise participation and presenting physical activity as a means to a healthy lifestyle might be useful. More cycle lanes in cities and leisure areas might encourage more people to cycle for transport. Given the primary care physician's influence in encouraging physical activity [START_REF] Becker | Analysen zur Sportbeteiligung auf der Basis des repräsentativen Bundes-Gesundheitssurveys 1998[END_REF][START_REF] Schneider | Sportaktivität in Deutschland -Ergebnisse des Bundes-Gesundheitssurveys zu sozialmedizinischen Korrelaten der Verhaltensprävention[END_REF], doctors can play a major role in urging people to walk and cycle for transport on health grounds. Other authors report a significant correlation between everyday activity levels and the incidence of risk factors [START_REF] Hu | Television watching and other sedentary behaviors in relation to risk of obesity and type 2 diabetes mellitus in women[END_REF]. For sectors of the population with low exercise participation, including those with low educational attainment levels, leisure-time physical activity offerings should be low-threshold and not require high levels of fitness. They must be inexpensive, easily learned, and allow flexible scheduling; examples would be hiking, swimming, hill walking, and cycling. [START_REF] Abele | Wer ist der "typische[END_REF] cite keep fit courses as an ideal introduction to leisure-time physical activity for individuals unused to exercise.

Table 1

 1 Effects of everyday bicycle use and going for walks on an everyday basis on current sporting activity, controlled in both models for education, tobacco use, eating habits, overweight, state of health, and diabetes (logistical regression)

		Current sporting activity
		Everyday bicycle use	Going for walks
	Model	1	2
	Cycling a /going
	for walks a
	Odds ratio	2.441*	1.846*
	95% CI	1.992-2.991	1.487-2.292
	R 2	0.1082	0.0759
	n	1,805	1,805
	a Dichotomous variable coded with 1 in the presence of the
	characteristic and otherwise coded 0
	n number of subjects, CI confidence interval
	*p≤0.001

Table 2

 2 Education-specific analysis of the effects of everyday cycling and of going for walks on an everyday basis on current sporting activity, controlled for tobacco use, eating habits, overweight, subjective state of health, and diabetes (logistical regression)

		Current sporting activity
		Everyday bicycle use			Going for walks
	Model	Hauptschule 1	Realschule 2	Abitur 3	Hauptschule 4	Realschule 5	Abitur 6
	Cycling a /going for walks a
	Odds ratio	2.663*	2.306**	1.979**	2.089*	1.229	1.564
	95% CI	2.061-3.440	1.379-3.857	1.238-3.162	1.595-2.735	0.702-2.154	0.936-2.615
	R 2	0.1609	0.1365	0.0624	0.1192	0.1036	0.0452
	n	694	539	572	694	539	572
	a Dichotomous variable coded 1 in the presence of the characteristic and otherwise coded 0
	n number of subjects, CI confidence interval
	*p≤0.001; ** p≤0.01

Table 4

 4 Education-specific analysis of the effects of everyday cycling and going for walks on an everyday basis on overweight, controlled for age, gender, tobacco use, subjective state of health, diabetes, cholesterol, hypertension, and current sporting activity (logistical regression) Dichotomous variable coded 1 in the presence of the characteristic and otherwise coded 0 n number of subjects, CI confidence interval *p≤0.05

		Obesity
		Everyday bicycle use			Going for walks
	Model	Hauptschule 1	Realschule 2	Abitur 3	Hauptschule 4	Realschule 5	Abitur 6
	Cycling a /going for walks a
	Odds ratio	0.701	2.046	0.482	1.761*	1.090	0.957
	95% CI	0.480-1.024	0.907-4.617	0.146-1.591	1.132-2.740	0.428-2.776	0.278-3.293
	R 2	0.3240	0.1510	0.1386	0.3286	0.1342	0.1254
	n	694	539	572	694	539	572

a

Exercise in the respondents' definition of the term. There was no subsequent data cleaning to exclude exercise types/activities involving very little activity (e.g. bowling).

Acknowledgments

The "Living an active life-age and aging in Baden-Württemberg" project focuses on the leisure-time physical activity and health biographies, health behavior, and lifestyle of the 50-to 70-year-old age group. The study is conducted on behalf of the Baden-Württemberg State Foundation, with funding in place for the period from September 2005 to August 2007. Project contributors are: Prof. Dr. Klaus-Peter Brinkhoff, University of Stuttgart; Prof. Dr. Ansgar Thiel, University of Tübingen; Prof. Dr. Thomas Klein, University of Heidelberg; Dr. Uwe Gomolinsky, University of Stuttgart; Dr. Monique Zimmermann-Stenzel, University of Heidelberg; Christina Huy, University of Stuttgart; Simone Becker, University of Heidelberg.