Rachel L Knight

Aïna Chalabaev

Melitta A Mcnarry

Kelly A Mackintosh

Joanne Hudson
email: joanne.hudson@swansea.ac.uk

Do Age Stereotype-Based Interventions Affect Health-Related Outcomes in Older Adults? A Systematic Review and Future Directions

Keywords: ageism, physical activity, quality of life, psychological well-being

Purpose

-Developing interventions that target population-specific motivational barriers to promote health behaviours is crucial, especially for older adults who are confronted with negative age stereotypes. This systematic review evaluates randomised and non-randomised field studies that tested the effects of age stereotype-based interventions on health outcomes, in adults aged 50 years and over. Methods -MEDLINE, SPORTDISCUS, Scopus, Web of Science Core Collection and PsychINFO were searched to identify articles published up until May 2019. Data were extracted from all articles independently and assessed for risk-of-bias using Cochrane Collaboration tools. Results -Ten articles met the inclusion criteria. Health-related outcome measures were identified across three domains: physical, psychological/psychosocial well-being, and quality of life/subjective health, with age stereotypes reported as an additional outcome. Intervention structure varied substantially between studies regarding content, duration, frequency, and length of follow-up. Conclusions -Most studies showed that age stereotype-based interventions significantly improved physical function or physical activity, as well as self-perceptions of ageing. However, more rigorous studies are needed. Indeed, given the detrimental health effects of age stereotypes, the potential for impact of interventions designed to challenge them is important. Future research should explore: the implications of intervening on different stereotype mechanisms; whether intervention effects are comparable across health domains; and whether age stereotype-based interventions are more effective than non-age-specific interventions. PROSPERO Registration CRD42018094006.

Do Age Stereotype-Based Interventions Affect Health-Related Outcomes in Older

Adults? A Systematic Review and Future Directions. The world's population is ageing. By 2030, it is predicted that 25% -30% of the European population will be at least 65 years old [START_REF] Mamolo | Population projections for forty-four European countries: The ongoing population ageing[END_REF]. Despite globally reported statistics indicating that average life expectancy is continuing to increase, 10% -13% of life years are still lived in poor health (World Health Organization [WHO], 2019). The consistent engagement of older adults with behaviours known to positively influence physical and mental health, such as physical activity, provides one of the biggest contemporary challenges [START_REF] Forberger | How to tackle key challenges in the promotion of physical activity among older adults (65+): The AEQUIPA network approach[END_REF]. Indeed, older adults remain one of the least active population segments, with 60% of adults aged 65 years and older not reaching adequate physical activity levels worldwide [START_REF] Hallal | Global physical activity levels: Surveillance progress, pitfalls, and prospects[END_REF].

Combatting physical inactivity and promoting health behaviours in older adults requires the development of behavioural interventions that effectively promote healthy habits.

However, many behaviour change techniques used with younger adults, such as goal setting, self-monitoring, or providing feedback, are not effective for older adults (for a review see [START_REF] French | Which behaviour change techniques are most effective at increasing older adults' self-efficacy and physical activity behaviour? A systematic review[END_REF]. This is due, at least in part, to older adults having distinct, populationspecific, motivational barriers with suggestions that such barriers may be partially subjective and result from the influence of age stereotypes [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF].

Age stereotypes are characteristics, generalisations or assumptions about how individuals at a particular age are viewed and should behave [START_REF] Ory | Challenging ageing stereotypes: Strategies for creating a more active society[END_REF]. They often negatively depict later life (e.g., ill health, decreased functional ability). Importantly, longitudinal prospective studies show negative age stereotypes are associated with adverse effects on older adults' physical and functional health [START_REF] Levy | Longitudinal benefit of positive self-perceptions of aging on functional health[END_REF][START_REF] Wurm | On the importance of a positive view on ageing for physical exercise among middle-aged and older adults: Cross-sectional and longitudinal findings[END_REF] and longevity [START_REF] Kotter-Grühn | Self-perceptions of aging predict mortality and change with approaching death: 16-year longitudinal results from the Berlin Aging Study[END_REF]. Moreover, controlled, experimental studies have shown that inducing negative stereotypes may increase autonomic responses to stress [START_REF] Levy | Reducing cardiovascular stress with positive self-stereotypes of aging[END_REF], inhibit cognitive function and memory [START_REF] Barber | How stereotype threat affects healthy older adults' performance on clinical assessments of cognitive decline: The key role of regulatory fit[END_REF][START_REF] Haslam | When the age is in, the wit is out": Age-related self-categorization and deficit expectations reduce performance on clinical tests used in dementia assessment[END_REF], and reduce physical function [START_REF] Chiviacowsky | Age stereotypes' effects on motor learning in older adults: The impact may not be immediate, but instead delayed[END_REF].

Several mechanisms could explain the effects of age stereotypes on older adults' health. Stereotype embodiment theory [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF] proposes that age stereotypes are internalised into self-perceptions of ageing in later life, which affect health behaviours [START_REF] Levy | Preventative health behaviours influenced by self-perceptions of aging[END_REF], and subsequently health outcomes, such as recovery from acute myocardial infarction [START_REF] Levy | Physical recovery after acute myocardial infarction: Positive age self-stereotypes as a resource[END_REF], dementia development [START_REF] Levy | Positive age beliefs protect against dementia even among elders with high-risk gene[END_REF], or longevity [START_REF] Levy | Longitudinal benefit of positive self-perceptions of aging on functional health[END_REF]. Stereotype threat theory [START_REF] Steele | Stereotype threat and the intellectual test performance of African Americans[END_REF] proposes that individuals underperform or disengage when they feel at risk of confirming negative views about their abilities. In a meta-analysis of 22 published and 10 unpublished studies, [START_REF] Lamont | A review and meta-analysis of age-based stereotype threat: Negative stereotypes, not facts, do the damage[END_REF] identified that age-based stereotype threat significantly affected performance across health domains in older adults (mean d = 0.32) regardless of gender, age or underlying health status. Finally, stereotypes may also influence health outcomes more directly. Ideomotor theory applied to age stereotypes [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF] suggests that priming stereotypes (usually implicitly) may directly affect behaviours, without mediation by selfperceptions of ageing, or concerns of being negatively stereotyped. For example, subliminally presented positive age stereotypes have improved older adults' physical function [START_REF] Levy | stereotype-matching effect: Greater influence on functioning when age stereotypes correspond to outcomes[END_REF] and influenced their will to live (Levy et al., 1999[START_REF] Levy | Reducing cardiovascular stress with positive self-stereotypes of aging[END_REF].

Overall, this literature indicates that age stereotypes can be a barrier to older adults' engagement in health behaviours. Thus developing interventions which reduce the negative impact of stereotypes on health outcomes may offer a promising approach to promote healthy ageing. Whilst previous reviews have investigated how manipulating age stereotypes affects health outcomes, these only included laboratory-based studies (see [START_REF] Armstrong | Stereotype threat effects on older adults' episodic and working memory: A meta-analysis[END_REF][START_REF] Lamont | A review and meta-analysis of age-based stereotype threat: Negative stereotypes, not facts, do the damage[END_REF]. To our knowledge, no systematic review has examined the effects of field interventions targeting age stereotypes on health outcomes in older adults. The current review investigates this question in community dwelling older adults aged  50 years.

Methods

This review was designed and conducted in line with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA, [START_REF] Liberati | The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: Explanation and elaboration[END_REF] and registered with PROSPERO; registration number CRD42018094006 available at: https://www.crd.york.ac.uk/prospero/.

Article Selection Criteria

Table 1 provides a full breakdown of article inclusion/exclusion criteria. Although older adults are defined by WHO (2015) as aged ≥ 65 years, initial literature scoping identified that previous research has used an inconsistent age range to define someone as an "older adult", varying from 50 years of age upwards. To ensure a comprehensive overview of all relevant studies targeting "older adults", the age range criterion was defined as any study including participants aged ≥ 50 years. Studies meeting this criterion, but which also included participants under 50 years, were excluded.

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Data Sources, Searches and Study Selection

Electronic databases (EBSCOhost MEDLINE, EBSCOhost SPORTDiscus, Scopus, Web of Science Core Collection and EBSCOhost PsychINFO), limited to academic journals published in English from 1995 -April 2018, were searched by RLK. Database alerts were set, and new citations screened, until May 2019. Search terms were verified by a subject librarian and agreed by the review team. The Boolean terms used included, but were not limited to, ("older adul*" OR "senio*" OR "elderly") AND ("age stereotyp*" OR "ageism" OR "positive priming" OR "stereotype prejudice") AND ("memory" OR "physical activity" OR "quality of life" OR "views-on-ageing").

One author (RLK) screened all retrieved citations and abstracts; JH independently reviewed 10% of articles screened and all those coded "maybe" to ensure there were no discrepancies. The reviewers independently reviewed all articles retrieved in full text against the pre-defined inclusion/exclusion criteria. Disagreements were resolved through discussion.

For details of secondary and grey literature search strategies, database specific restrictions, an example of the full search terms applied, and full details of the study selection process, see the online Supplementary Material.

Data Extraction

A form based on a Cochrane Collaboration template [START_REF] Higgins | Cochrane Handbook for Systematic Reviews of Interventions version 6.0[END_REF], was used to extract data by RLK, including: authors; publication year; study design, setting, aim, hypothesis and methodology; sample size, participant demographics and baseline characteristics; outcome measure(s); exposure and follow-up time-point measurement; empirical results, and, risk-of-bias assessment information. Where applicable, The Behaviour Change Technique Taxonomy V1 [START_REF] Michie | The Behavior Change Technique Taxonomy (v1) of 93 hierarchically clustered techniques: Building an international consensus for the reporting of behavior change interventions[END_REF], a nomenclature that classifies intervention components into 93 different behaviour change techniques, was used independently by two appropriately trained reviewers (RK and JH) to characterise the 'active' elements of interventions. A third unblinded reviewer (MM) independently reviewed all extracted data. No discrepancies were identified.

Quality Assessment

Two reviewers (RK, and MM or AC) independently assessed risk-of-bias and study quality for each reported outcome measure using the ROB 2.0 tool for randomised studies [START_REF] Sterne | RoB 2: a revised tool for assessing risk of bias in randomised trials[END_REF] and the ROBINS-I tool for non-randomised studies [START_REF] Sterne | ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions[END_REF].

In line with guidance, algorithms were followed to obtain a judgement for each assessed domain using the published article and available supplementary material. Studies with at least one domain scored as high risk-of-bias or with four or more domains of some concerns, were subsequently classified overall as high risk-of-bias. Studies were classified overall as low risk-of-bias only if all domains achieved this criterion [START_REF] Sterne | RoB 2: a revised tool for assessing risk of bias in randomised trials[END_REF]. Disagreements were resolved through discussion. No studies were excluded due to low quality or risk-ofbias, rather, all issues were considered when interpreting the results.

Data Synthesis

A descriptive summary and explanation of evidence robustness for each study is presented as a lack of homogeneity between studies in terms of design, interventions and outcome measures precludes a meta-analysis from being conducted. Themes focus on the effect of different intervention types on specific outcome domains. Findings are collated in a tabulated summary, grouped and synthesised according to study design and characteristics.

Results

Electronic database searching identified 14,236 articles, with a further 21 identified from secondary searches. Following removal of duplicates, 9,742 articles were screened, with 9,655 that did not meet the inclusion criteria excluded. The remaining 87 articles were retrieved in full text and assessed for eligibility, with 10 articles retained for the final analysis (Figure 1). An overlap between four articles was identified1 , indicating the 10 articles represented the results of eight independently conducted studies. For clarity, the characteristics, results and risk-of-bias for each individual article are presented separately, but, where appropriate, findings between those linked are discussed together.

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Study Characteristics and Participants

All articles included in the review were published in English between 2009 and 2019, six were randomised control trials (RCTs) and four were non-randomised. The summation of participant data was deemed inappropriate due to the potential overlap between articles [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF][START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF].

Individual data for each article is presented with the study characteristics in Table 2. The REPRINTS study [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF] and AgingPlus Program [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF] included some participants aged < 65 years old, however, normal distribution analysis showed at least 94% and 83% of participants, respectively, were aged > 64 years old. Although all studies provided demographic information on participant age and sex, only some provided further details, such as ethnicity [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF][START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] or health status [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF][START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF].

Intervention structure (content, duration, session frequency) and where utilised, control group parameters, varied substantially between the eight independent studies (see Table 2). Follow-up periods ranged from two-weeks to seven years. Concerning content, two independent studies reviewed the impact of providing positive experiences through intergenerational contact [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF][START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF], a concept that it has been proposed could challenge age stereotypes, leading to positive health gains, through the provision of positive experiences and reductions in stereotype threat and negative attitudes (Abrahms et al., 2008;[START_REF] Pettigrew | A meta-analytic test of intergroup contact theory[END_REF]. One study reviewed the impact of implicit and explicit priming of positive age stereotypes [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF], one the impact of inducing positive views-on-ageing coupled with non-age-specific behaviour change techniques [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] and four based their intervention around exercise provision. Whilst in [START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF] exploring the implicit impact of exercise was the only intervention strategy, others targeted an additional componentperceptions of participants' own ageing [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF], suppressing negative attitudes and general thoughts about ageing [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]Emile et al., 2014). Health-related outcomes from three domains were identified: physical, psychological/psychosocial well-being and quality of life/subjective health, with age stereotype domain outcomes additionally categorised.

Six independent studies stated or implied their intervention was theoretically underpinned by a stereotype model. All relied on the stereotype internalisation process proposed by [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF] within stereotype embodiment theory. Specifically, Beyer et al.

Risk-of-Bias

The risk-of-bias summaries for the six RCTs and four non-randomised articles are presented in Figures 2 and3, respectively. Despite multiple domain assessments of some concerns indicating that the overall article risk-of-bias should be considered high, following discussion between authors, [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] and [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] were instead deemed to have an overall risk-of-bias of some concerns. This classification was based on the level of identifiable concern within each domain and partial provision of evidential support between the articles and within the study, that decreased, but did not nullify, these concerns.

The online Supplementary Material presents the supporting justification for each study's individual outcomes.

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Study Descriptions

Non-Randomised Studies

Four articles presenting three independent studies used non-randomised designs. [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF] measured generativity and self-esteem in older adults following participation in an intergenerational music therapy intervention, compared with a usual-routine control group. During 10 sessions over a 12-week period, participants formed dyads with different children (mean age 9.5 years). [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF] and [START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF] also explored the effects of intergenerational contact during the REPRINTS study. Usual walk speed, handgrip strength and self-rated health were measured nine months from baseline, with maximal walk speed, functional reach, one-leg stand, depression level and self-esteem additionally measured at a seven-year follow-up. Intervention group participants volunteered at Education or Child Care facilities once every one or two weeks. The control group continued life as usual. Participants who withdrew or changed groups/engaged in associated activities were excluded from analysis.

Conversely, [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF] used a case-series design to establish the preliminary effects of an eight-week multi-component experimental personalised goal achievement programme. The intervention, based on the Health Action Process Approach (HAPA; [START_REF] Schwarzer | Modelling health behaviour change: How to predict and modify the adoption and maintenance of health behaviours[END_REF], aimed to challenge negative views-on-ageing, operationalised as a composite of awareness of age-related change, age stereotypes, expectations regarding one's own ageing, and subjective age. Views-on-ageing, self-perceptions of ageing, and selfreported physical activity levels were measured four-weeks post-intervention. Additional measurements of views-on-ageing and self-perceptions of ageing were taken at week four.

The moderation of age on training effect was also examined.

RCTs

Six articles, including five independent studies, used randomised designs. [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF] embedded a psychological intervention into an exercise session for older adults.

Information targeting self-perceptions of ageing in losses and gains domains was provided once a week for 12 weeks. Differences in physical function and depression level were measured at baseline and at a four-week follow-up and compared to an exercise-only control group. Effects on self-perceptions of ageing were measured at baseline, mid-intervention, post-intervention and at a four-week follow-up. Similarly, Emile et al. (2014) examined the effects of providing counter-stereotypical information to sedentary older women during a twice weekly individualised, supervised walking programme. Post-intervention, quality of life, self-reported physical activity (supported by a six-minute walk test, classified by the authors as measures of physical capacity), and views-on-ageing were measured and compared with non-intervention controls. [START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF], as part of a wider cognitive ageing study, evaluated how an exercise-only intervention, delivered three times a week for six months, affected selfperceptions of ageing and age dissatisfaction in females. Comparisons were made with an active control group undertaking an equal length computer course and a passive nonintervention control group. The authors also tested whether direct approach (defined as the most emotionally gratifying orientation by [START_REF] Mees | Goals of action and emotional reasons for action: A modern version of the theory of ultimate psychological hedonism[END_REF]) mediated the relationship between exercise and age stereotypes.

Taking a different approach, [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] investigated whether subliminally presenting positive age stereotypes four times over an eight-week period could: improve physical function, strengthen positive and decrease negative views-on-ageing, and, increase positive and decrease negative self-perceptions of ageing. Comparisons were made with a group that received an explicit-positive prime only and a control group that received neutral versions of both priming techniques. No data or results are presented for an additionally stated implicit-positive plus explicit-positive prime group, however the study used a 2x2 design, and the findings presented address the three study hypotheses. [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] and [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] developed a brief single session intervention based on a battery of behaviour change techniques underpinned by the HAPA [START_REF] Schwarzer | Modelling health behaviour change: How to predict and modify the adoption and maintenance of health behaviours[END_REF]. Aiming to induce positive views-on-ageing, five weeks after baseline assessment, intervention group participants received additional information about positive aspects of ageing and the association between positive views-on-ageing and health outcomes.

Change in self-reported physical activity levels (supplemented by accelerometery data in [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] was compared with an alternate intervention group that received an additional planning sheet of comparable length, an active control group targeting volunteering and a passive control group. [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] additionally measured attitudes towards older adults as a participant outcome but did not present data for any outcome measure for the passive control group. For details of reported outcome measures, their associated follow-up periods, and presented statistical results see Appendices A and B.

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Study Findings

Physical Domain

Within this domain, results are split between two separate constructs: physical function and physical activity. Physical Activity. A significant direct effect on physical activity was reported by two studies; one RCT (Emile et al., 2014) and one case-series design [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]. In Emile and colleagues' study ( 2014), both self-reported physical activity, and capacity for physical activity significantly improved from baseline to three-month follow-up in the intervention group, in comparison to the control group, where they remained stable. A positive correlation was identified between stereotypes of the perceived benefits of exercise for older adults and physical activity score and a negative correlation between stereotypes of the perceived exercise risks for older adults and physical activity score. [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF] also found a significant trend for increased physical activity throughout their study. Participants doubled their mean weekly minutes of physical activity from baseline (M = 84.95; SD = 91.17) to a four-week follow-up (M = 171.55; SD = 97.26). However, using a much briefer intervention, an RCT reported by [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] and [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] found no significant direct group effects on physical activity for the main intervention plus views-on-ageing group. The only significant effect evident in the two intervention groups was at a 14-month follow-up, in favour of the intervention plus planning group. [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] also explored the indirect effect of different components of attitudes towards older adults (measured by the German Semantic Differential) on changes in physical activity. Despite an overall non-significant effect, they identified a marginally significant indirect effect to change physical activity from the intervention plus views-onageing (versus active control) via changes in integrity. For mean change in integrity, physical activity levels were predicted to increase by 42 minutes per week.

Physical Function. Two out of three studies, one RCT [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] and one non-randomised control trial [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF], found a notable effect on any measure of physical function. Although [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF] reported a significant latent change from baseline to a four-week follow-up across their whole sample, embedding a positive self-perceptions of ageing component into an exercise intervention did not lead to physical function changes between baseline and at four-week follow-up or the intercept at mid-intervention. [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] reported that only the implicit-positive intervention had a significant strengthening effect. Improved physical function at week eight was predicted by level of positive self-perceptions at week six. Additionally, the implicit intervention had a direct impact on physical function in the predicted direction. The only significant group effect found by the REPRINTS study [START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF] was on functional reach at a seven-year follow-up, with observed decline in reach distance significantly less in the intervention group.

Quality of Life/Subjective Health

A single RCT by Emile et al. (2014) found a trend for group effect between the exercise plus counter-stereotypical information and non-intervention control group in the WHOQoL-26 domains of physical health, and psychological health. Additionally, a positive correlation was identified between stereotypes of the perceived benefits of exercise for older adults and psychological health. The main effect of group in a non-randomised intergenerational contact versus usual-routine control study found no reportable effect on mean subjective self-rated health at nine-month or seven-year follow-up [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF].

Psychological/Psychosocial Well-Being

In [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF], the group variable significantly predicted the change between baseline and four-week follow-up; only participants randomised to the exercise plus selfperceptions of ageing intervention demonstrated a decrease in mean depression level. The group variable also significantly predicted the intercept at a four-week follow-up.

Conversely, depression and self-esteem level at seven-year follow-up did not change significantly between groups in a study where participants were given the option to join the intergenerational intervention or usual-routine control group [START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF]. These findings mirrored those of [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF] in a prior non-randomised 12-week intergenerational study. Differences between post-intervention scores for generativity and self-esteem were not significant.

Age Stereotypes

Within this domain, results are split between two separate constructs: self-perceptions of ageing and views-on-ageing. While self-perceptions of ageing refer to people's satisfaction with their own ageing; this is not the case for views-on-ageing, which refer to individuals' general beliefs about older adults. The latter was included in the review as a manipulation check indicating whether the intervention has been effective in changing age stereotypes.

Self-Perceptions of Ageing. Significant effects were reported by three RCTs [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF][START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] and one-case series design [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]. Implicit priming with positive stereotypes significantly strengthened positive, and weakened negative, self-perceptions of ageing, when compared with the neutrally primed control group [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF]. Using a completely different intervention strategy, [START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF] found that dissatisfaction with ageing was lower immediately following a six-month exercise intervention compared to both the passive and active control groups. The authors additionally concluded the significant effect on exercise was mediated through direct approach, and that age had a significant partial effect on age dissatisfaction.

The positive self-perceptions of ageing component embedded by [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF] into their exercise intervention, again, had a significant effect on measured self-perceptions of ageing from baseline to intervention completion for ongoing development (i.e., ageing as a time of growth) and physical losses (i.e., ageing as a time of decline). Nevertheless, this effect was not fully sustained four weeks later, decreasing but remaining significant for ongoing development factors and no longer maintaining the group effect for physical losses.

Brothers and Diehl (2017) observed a similar effect pattern when utilising strategies designed to target the suppression of negative attitudes and general thoughts about ageing. Whilst significant improvements in self-perceptions of ageing were observed during the intervention period, a significant decline in sustained effect was observed at a 12-week follow-up.

Views-on-Ageing. Some significant effects were presented by four studies; three RCTs (Emile et al., 2014;[START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] and one case-series design [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]. A significant intervention effect was observed on attitudes toward older adults, and more particularly the integrity scale of the German Semantic Differential [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF]. From baseline to six-week follow-up study participants who received the additional views-on-ageing component had more positive attitudes towards older adults at the end of the intervention compared to the active control group. The group effect significantly increased perceived benefits of exercise for older adults, and decreased perceived risks of exercise for older adults, when views-on-ageing and exercise were targeted via a three-month supervised walking programme (Emile et al., 2014). No group effect was reported for the psychological barriers component of views-on-ageing. [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF] reported a significant effect of the intervention for all views-on-ageing measures: age stereotypes/views-on-ageing scale, awareness of age-related change (gains), and awareness of age-related change (losses). However, age stereotypes and gains-related factors demonstrated a significant decline between the end of the formal education component and a four-week follow-up. Implicit priming with positive stereotypes also significantly strengthened positive, and weakened negative, views-on-ageing when compared with a neutrally primed control group [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF]. Whilst the explicitpositive intervention also strengthened positive views, the effect of the implicit intervention was reported to be 30% greater.

Discussion

This systematic review examined the effects of interventions that have targeted age stereotypes on health outcomes in community-dwelling older adults. Six of the eight independent studies focused on health outcomes within the physical domain [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF][START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]Emile et al., 2014;[START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF][START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF], five of which reported significant [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]Emile et al., 2014;[START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF], or marginal [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF], improvements in physical function or physical activity due to the intervention. However, only three studies [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] did not present an overall high risk-of-bias. As such, although the results are generally consistent, they should be interpreted with caution given the low number of studies and the varied risk-of-bias.

Other health outcomes investigated relate to psychological well-being. Half of the independent studies examined at least one dimension of this domain: quality of life (Emile et al., 2014), subjective health [START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF], generativity [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF], depression [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF], and self-esteem [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF]. Results consistently demonstrated no impact by the interventions (with the exception of depression in [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF].

It is noteworthy that most independent studies (six out of eight) were theoretically underpinned [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF][START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]Emile et al., 2014;[START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF][START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF]. These studies focused exclusively on one specific mechanism of stereotype influence: the internalisation of stereotypes into self-perceptions of ageing (stereotype embodiment theory; [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF]. All seven studies found significant effects on either age stereotype endorsement or selfperceptions of ageing, providing support to stereotype embodiment theory [START_REF] Levy | Stereotype embodiment: A psychosocial approach to aging[END_REF].

Although these results are promising, two studies had a high overall risk-of-bias [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF]Emile et al., 2014), thus their results need to be considered with caution. Additionally, interpretation is limited by the fact that studies have used different operationalisations of stereotype internalisation. They examined intervention effects on self-perceptions of ageing [START_REF] Beyer | Are self-perceptions of ageing modifiable? Examination of an exercise programme with vs. without a selfperception of ageing-intervention for older adults[END_REF][START_REF] Klusmann | Views on ageing and emotional benefits of physical activity: Effects of an exercise intervention in older women[END_REF], on endorsement of age stereotypes [START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF]Emile et al., 2014), or on both [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF][START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF], whilst mostly using the same terminology of views-on-ageing.

Future Directions

The present review reveals consistent effects of age stereotype-based interventions on health outcomes in the physical domain. These results are promising, and more research is needed to better understand when, and how, such interventions may be effective. First, although the physical health domain is important, other health outcomes, (e.g., cognitive abilities), deserve further investigation. Interestingly, cognitive outcomes have been the main focus in laboratory-based studies investigating the effects of experimental manipulations of stereotypes (for a review see [START_REF] Lamont | A review and meta-analysis of age-based stereotype threat: Negative stereotypes, not facts, do the damage[END_REF]. The generalisability of these laboratorybased findings to real-life settings remains to be elucidated.

Second, age stereotype-based intervention effects have mostly been examined on selfperceptions of ageing, within the stereotype internalisation hypothesis. More research is needed to investigate whether such interventions may also affect stereotypic concerns, as per stereotype threat theory [START_REF] Steele | Stereotype threat and the intellectual test performance of African Americans[END_REF]. Again, this question has only been investigated in laboratory-based studies. Addressing this unknown is important, as intervening on stereotypic concerns might require different techniques to intervening on selfperceptions of ageing. Indeed, suppressing the endorsement of negative age stereotypes, as is typically done in stereotype internalisation-based interventions, might not be effective on stereotypic concerns. Susceptibility to stereotype threat effects may occur simply because individuals are aware of the existence of negative stereotypes about their group, even if they do not endorse them [START_REF] Steele | A threat in the air: How stereotypes shape intellectual identity and performance[END_REF]. Techniques that help individuals to adopt a malleable conception of their competence (e.g., Emile et al., 2017) or that stimulate intergenerational contact (e.g., [START_REF] Abrams | Threat inoculation: Experienced and imagined intergenerational contact prevents stereotype threat effects on older people's math performance[END_REF], may represent a promising approach to reduce stereotypical concerns, but these need to be tested further in real-world settings.

Third, concerning the stereotype internalisation hypothesis, given that studies have used different operationalisations of this concept, future research should endeavour to disentangle the constructs of interest. Intervening on older adults' age stereotypes (i.e., the underlying cause) may have different implications than intervening on their self-perceptions of ageing (i.e., the proximal mechanism). Adopting a mechanistic approach towards the influence of stereotypes could therefore be useful, by testing the mediating role of selfperceptions of ageing in the effect of a stereotype-based intervention on health outcomes. The study of [START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF] demonstrates promise in this regard, however more research is needed to further support the mediating role of self-perceptions of ageing.

Finally, other potential avenues for future research include investigating whether: i) age-specific behaviour change techniques are more effective than non-age-specific techniques. Only one RCT has examined this question [START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF][START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF]; ii) some components of stereotype-based interventions are more effective than others.

Studies have used different ones (i.e., exercising, challenging negative stereotypes, presenting positive stereotypes, avoiding negative thoughts and attitudes about one's own ageing, or a combination of these); iii) interventions are equally effective irrespective of sex. A significant proportion of participants in previous studies were female (75% -100%), and, iv) the effects of stereotype-based interventions depend on intervention duration, and if these effects are sustained over longer time-periods. Indeed, the preliminary work of [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF] suggests this may not be the case.

Limitations

A rigorous, systematic approach, following a pre-defined protocol and using validated risk-of-bias tools, was employed within this review. Whilst every effort was made to identify all relevant articles during the screening process, a lack of standardisation within the nomenclature of terms used by authors when describing age stereotype constructs, and the diversity of potential 'health-related' outcomes, may have resulted in some studies not being captured. It is also important to acknowledge, only studies published in English were included. The moderate-to-high risk-of-bias within studies, heterogeneous nature of the interventions, and inclusion of some studies that involved participants < 65 years old, limited the interpretation of findings, and strength of conclusions that could be drawn.

Conclusion

Age stereotypes are detrimental to older adults' health. Whilst some postive effects were identified on components of physical function or physical activity, and self-perceptions of ageing, this review highlights a paucity of high quality research on the use of real-world interventions that endeavour to positively impact health outcomes by directly or indirectly targeting stereotypes of ageing. Nevertheless, the potential for impact should not be dismissed as the range and robustness of available studies is limited. Given that more subtle strategies, implemented over longer time-periods may be needed [START_REF] Brothers | Feasibility and efficacy of the Aging Plus program: Changing views on ageing to increase physical activity[END_REF]Emile et al., 2014;[START_REF] Levy | Subliminal strengthening: Improving older individuals' physical function over time with an implicit-age-stereotype intervention[END_REF], the role of intergenerational contact should not be overlooked on the basis of the reported null findings [START_REF] Belgrave | The effect of a music therapy intergenerational program on children and older adults' intergenerational interactions, cross-age attitudes, and older adults' psychosocial well-being[END_REF][START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF][START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF]. Increasing life expectancy and the current lack of consensus on how to effectively influence healthy ageing indicates taking a pragmatic approach towards intervention development, and, that research in real-world settings could be vital. Note: AARC = awareness of age-related change; cm = centimetres; kg = kilograms; M = mean; m = metres; min = minutes; n = number; NVoA = negative view-on-ageing; SD = standard deviation; SPA = self-perceptions of ageing; VoA = views-on-ageing.

Appendix B

Outcome Data and Results of RCTs

Supplementary Data 1

Example of Search Strategy for SportDiscus TI "older adul*" OR AB "older adul*" OR TI "elderly" OR AB "elderly" OR TI "aged" OR AB "aged" OR TI "retired" OR AB "retired" OR TI "geriatric" OR AB "geriatric" OR TI "older peopl*" OR AB "older peopl*" OR TI "older populatio*" OR AB "older populatio*" OR TI "older perso*" OR AB "older perso*" OR TI "older wom?n" OR AB "older wom?*" OR TI "older men" OR AB "older men*" OR TI "mature" OR AB "mature" OR TI "senio*" OR AB "senio*" AND TI "age stereotyp*" OR AB "age stereotyp*" OR TI "aging stereotyp*" OR AB "aging stereotyp*" OR TI "ageing stereotyp*" OR AB "ageing stereotyp*" OR TI "ageism" OR AB "ageism" OR TI "agism" OR AB "agism" OR TI "priming" OR AB "priming" OR TI "positive priming" OR AB "positive priming" OR TI "negative priming" OR AB "negative priming" OR TI "implicit priming" OR AB "implicit priming" OR TI "explicit priming" OR AB "explicit priming" OR TI "positive stereotyp*" OR AB "positive stereotyp*" OR TI "negative stereotyp*" OR AB "negative stereotyp*" OR TI "implicit stereotyp*" OR AB "implicit stereotyp*" OR TI "counterstereotyp*" OR AB "counterstereotyp*" OR TI "counter stereotyp*" OR AB "counter stereotyp*" OR TI "counterstereotyp*" OR AB "counter-stereotyp*" OR TI "self regula*" OR AB "self regula*" OR TI "selfregula*" OR AB "self-regula*" OR TI "views on aging" OR AB "views on aging" OR TI "views on ageing" OR AB "views on ageing" OR TI "stereotype boost" OR AB "stereotype boost" OR TI "stereotype threat" OR AB "stereotype threat" OR TI "stereotype embodiment" OR AB "stereotype embodiment" OR TI "stereotype internali?ation" OR AB "stereotype internali?ation" OR TI "positive vie*" OR AB "positive vie*" OR TI "negative vie*" OR AB "negative vie*" OR TI "imagery" OR AB "imagery" OR TI "imagined contact" OR AB "imagined contact" OR TI "intergenerational contact" OR AB "intergenerational contact" OR TI "intergroup contact" OR AB "intergroup contact" OR TI "self perceptio* of aging" OR AB "self perceptio* of aging" OR TI "self perceptio* of ageing" OR AB "self perceptio* of ageing" OR TI "self-perceptio* of aging" OR AB "self-perceptio* of aging" OR TI "self-perceptio* of ageing" OR AB "self-perceptio* of ageing" OR TI "subjective aging" OR AB "subjective aging" OR TI "subjective ageing" OR AB "subjective ageing" OR TI "stereotype prejudice" OR AB "stereotype prejudice" OR TI "stereotype discrimination" OR AB "stereotype discrimination" OR TI "social interactio*" OR AB "social interactio*" OR TI "social support" OR AB "social support" AND TI "physical activity" OR AB "physical activity" OR TI "exercise" OR AB "exercise" OR TI "physical function" OR AB "physical function" OR TI "physical performance" OR AB "physical performance" OR TI "motor performance" OR AB "motor performance" OR TI "motor learning" OR AB "motor learning" OR TI "well-being" OR AB "well-being" OR TI "wellbeing" OR AB "wellbeing" OR TI "well being" OR AB "well being" OR TI "quality of life" OR AB "quality of life" OR TI "cognition" OR AB "cognition" OR TI "cognitive functio*" OR AB "cognitive functio*" OR TI "memory" OR AB "memory" OR TI "functional capacity" OR AB "functional capacity" OR TI "health related variabl*" OR AB "health related variabl*" OR TI "health-related variabl*" OR AB "health-related variabl*" OR TI "self-worth" OR AB "self-worth" OR TI "self worth" OR AB "self worth" OR TI "anxiety" OR AB "anxiety" OR TI "physical recovery" OR AB "physical recovery" OR TI "self related health" OR AB "self related health" OR TI "self-related health" OR AB "self-related health" OR TI "self esteem" OR AB "self esteem" OR TI "self-esteem" OR AB "self-esteem" OR TI "self efficacy" OR AB "self efficacy" OR TI "self-efficacy" OR AB "self-efficacy" OR TI "motivation" OR AB "motivation" OR TI "obesity" OR AB "obesity" OR TI "subjective aging" OR AB "subjective aging" OR TI "subjective ageing" OR AB "subjective ageing" OR TI "age stereotyp*" OR AB "age stereotyp*" OR TI "aging stereotyp*" OR AB "aging stereotyp*" OR TI "ageing stereotyp*" OR AB "ageing steretyp*" OR TI "views on aging" OR AB "views on aging" OR TI "views on ageing" OR AB "views on ageing" OR TI "self perceptio* of aging" OR AB "self perceptio* of aging" OR TI "self perceptio* of ageing" OR AB "self perceptio* of ageing" OR TI "self-perceptio* of aging" OR AB "self-perceptio* of aging" OR TI "self-perceptio* of ageing" OR AB "self-perceptio* of ageing" OR TI "perceptio* of aging" OR AB "perceptio* of aging" OR TI "perceptio* of ageing" OR AB "perceptio* of ageing"

Database Specific Restrictions

Scopus -Subject headings -Medicine, Nursing, Psychology, Social Sciences, Health Professions, Undefined. MEDLINE -MeSH terms and keyword searches were explored during preliminary searches, however, due to the quality of citations generated and the number of specific terms not covered by MeSH, a combined keyword and MeSH term search was run.

Secondary and Grey

Literature Search Strategies

Google Scholar and Ethos were searched for grey literature; full text articles retrieved were hand searched via reference checking and forward and backwards citation screening/snowballing, and members of the Society for Personality and Social Psychology group were contacted to identify any additional studies.

Study Selection Process

All database and secondary searches were conducted by RK, who, following the removal of duplicates via Endnote X8 (Clarivate Analytics, US), uploaded the retrieved articles to Covidence and screened the titles and abstracts, coding "yes", "no", "maybe". A screening tool developed by RK, based on the inclusion criteria, was piloted on 5% of the articles; a second reviewer (JH) independently reviewed the screened titles for discrepancies to ensure there was no discordance between reviewers, or with regards to inclusion/exclusion criteria application. On completion of the screening process, a further 5% of studies and all articles coded "maybe" were reviewed by JH. The two reviewers independently reviewed all articles retrieved in full text against the pre-defined inclusion/exclusion criteria. Disagreements regarding were resolved by discussion with a third reviewer (AC) (initially k = 0.75, following discussion k = 1).

(

  2019); Brothers and Diehl (2017); Emile et al. (2014); Klusmann et al. (2012); Levy et al. (2014); Warner et al. (2016), and Wolff et al. (2014), based their studies on this theory.

Figure 3

 3 Figure 1

  ASES = age stereotype and exercise scale; CES-D = Center for Epidemiologic Studies Depression Scale; CI = confidence interval; cm = centimetres; CSI = counter-stereotypical information; GSD = German Semantic Differential; kg = kilograms; m = metres; min = minutes; MET = metabolic equivalent; MVPA = moderate-to-vigorous physical activity; n = number; PA = physical activity; QoL = quality of life; SE = standard error; SPA = self-perceptions of ageing; SPPB = short physical performance battery; VoA = views-on-ageing; WHO = World Health Organization; 6MWT = six minute walk test. a Levy et al. 2014 figure in parenthesis = SE not SD, no mean data presented for the explicit-positive prime group, no mean data or results presented for implicit-positive plus explicit-positive prime group

Table 1

 1 Study Inclusion/Exclusion Criteria

	Variable	Inclusion Criteria	Exclusion Criteria
	Population, or participants	Older adults -Aged ≥ 50 years	Studies with participants aged 50
	and condition or interest	Any gender	and over, that also included
		Not restricted to the UK	participants under 50 years of age
	Intervention or exposures	Interventions that incorporate or are	Laboratory-based studies that only
		based on processes that either	induced and reported the immediate
		promote positive, or suppress	or very short-term effects of a
		negative, views-on-ageing and/or self-	single stereotype priming session
		perceptions of ageing, or reduce the	(e.g., the next day, Chivacowsky et
		impact of stereotype threat, and were	al., 2018)
		designed to elicit positive effects on
		either health-related variables and
		behaviours, or any age stereotype
		construct
	Comparisons or control	No restrictions were placed on the
	groups	alternative intervention, control group
		or pre/post intervention outcome
		measurement
	Outcomes of interest	A change in any health-related	Studies that do not have at least 1
		outcome (i.e., cognitive function, PA)	outcome measure that can be
		or measured age stereotype construct	directly or indirectly associated
		(i.e., attitudes towards own ageing)	with participant health, their age
		from baseline to any available follow-	stereotypes or views-on-ageing
		up, with no restriction on intervention
		length or type, measurement tool or
		minimum length of follow-up period
	Setting	Any community or research facility	Hospital/inpatient settings
		setting
	Study designs	Any intervention-based study design	Observational studies where no
		(RCT, non-randomised control trials,	intervention or manipulation occurs
		cohort, intervention comparison,	Studies not providing original
		controlled before-and-after	results such as systematic reviews,
		intervention studies	meta-analysis, general reviews or
			editorials
	Note. PA = physical activity; RCT = randomised control trial; UK = United Kingdom

Table 2

 2 Study Characteristics

	Author (Location)	Design	Participants	Intervention description	Intervention length	Control group (s)	Stereotype prime	Target stereotype construct	BCTs intervention group	BCTs Control group
	Belgrave	CBA	n = 27	Intergenerational music therapy -	10-weeks	Passive control group -	Implicit	N/A	12.2 Restructuring the social	None
	(2011)		Age range not reported	dyadic pairings (not the same every	10 x 30 min sessions	Maintained ordinary routine			environment (++)
	(USA)		Mean age = 84.75 years	week) with children from local	1x week over 12-week period	& attended other normal non-
			SD not reported	school. Activities included singing,	(2-week vacation)	intergenerational activities at
			Female = 88.89%	structured conversations, instrument		their living facility
				playing, moving to music.
	Beyer et al.	RCT	n = 89	Group exercise training sessions	12-weeks	Active control group -	Explicit	SPA	3.1 Social support (unspecified) (+)	4.1 Instruction on
	(2019)		Age range 65-88 years	targeting improving balance,	60 min sessions	Exercise only			4.1 Instruction on how to perform a	how to perform a
	(Germany)		Mean age = 76.54 years	strength, endurance, flexibility &	1x week				behaviour (+)	behaviour (+)
			SD = 5.4	reducing fear of falling					6.1 Demonstration of behaviour (+)	6.1 Demonstration of
			Females = 34.8%	+ 4x 20-30 min psychological					8.1 Behavioral practice/rehearsal (+)	behaviour (+)
				intervention, aimed at changing					13.2 Framing/Reframing (++)	8.1 Behavioural
				SPA, embedded in the second half					5.1 Information about health	practice/rehearsal (+)
				of the exercise sessions at weeks 2,					consequences (+)
				5, 8 & 11					3.3 Social support (emotional) (++)
	Brothers &	Case	n = 62	Multi-component program	8-weeks	N/A	Explicit	VoA	1.2 Problem solving (++)	N/A
	Diehl	Series	Age range 52-82 years	targeting NVoA	Weeks 1-4: 4x 120 min				1.3 Goal setting (outcome) (++)
	(2017)		Mean age = 65.26 years	Educational component (weeks 1-4)	education sessions 1x week				2.3 Self-monitoring of behaviour
	(USA)		SD = 6.62	-attitudinal & motivational pieces	Weeks 5-8: 4x 10-15 min				(++)
			Females = 83.9%	for enacting behaviour change	semi-structured interview +				3.1 Social support unspecified (+)
				Experiential component (weeks 5-8)	telephone support 1x week				5.3 Information about social and
				-worked towards personalised PA					environmental consequences (+)
				goal & completed daily PA logs					13.2 Framing/Reframing (++)
	Emile et al.	RCT	n = 52	Individualised non-standardised	12-weeks	Passive control group -	Implicit &	VoA	1.3 Goal setting outcome (+)	N/A
	(2014)		Age range 67-97 years	supervised walking program &	40-60 min sessions	Maintained normal daily	Explicit		2.4 Self-monitoring of outcome(s)
	(France)		Mean age = 78.54	education component that	2x week	routine			of behaviour (+)
			SD = 7.37	incorporated strategies to suppress					3.3 Social support (emotional) (++)
			Females = 100%	negative age stereotypes & activate					5.3 Information about social and
				positive ones					environmental consequences (+)
	Fujiwara et al.	NRCT n = 143	Intensive training sessions followed		Passive control group -	Implicit	N/A	12.2 Restructuring the social	None
	(2009)		Age range not reported	by group activity sessions with		Maintained normal daily			environment (++)
	(Japan)		Mean age = 68.46 years	school children. Activities included		routine
			SD = 5.3	pre-group meeting to share
			Females = 62.23%	information, playing hand games &
				with toys, picture book reading,
				additional monthly meetings with
				area wide group/time to engage with
				further training

Table 2

 2

	Continued
	Author (Location)	Design	Participants	Intervention description	Intervention length	Control group (s)	Stereotype prime	Target stereotype construct	BCTs intervention group	BCTs Control group
	Klusmann et	RCT	n = 259	Intensive multi-faceted group exercise	6-months	Passive control group -	N/A	SPA	3.1 Social support unspecified (+)	Active control group
	al.		Age range 70-93 years	targeting aerobic, strength &	90 min sessions	Maintained normal daily			4.1 Instruction on how to perform a	3.1 social support
	(2012)		Mean age = 73.6 years	flexibility training	3x week	routine			behaviour (+)	unspecified (+)
	(Germany)		SD = 4.2			Active control group -			6.1 Demonstration of behaviour (+)
			Females = 100%			computer course designed			8.1 Behavioural practice/rehearsal
						for seniors dealing with			(+)
						common software
	Levy et al.	RCT	n = 100	Group 1 -Implicit subliminal priming	4-weeks	Neutral control group -	Implicit &	VoA & SPA	N/A	N/A
	(2014)		Age range 61-99 years	via computer with words depicting	4x sessions	Implicit neutral -primed	Explicit
	(USA)		Mean age = 81 years	positive stereotypes of ageing plus	1x week over 8-week period	via same method as
			SD = 10	Explicit neutral -asked to imagine	(weeks 2, 3, 4 & 5)	implicit prime but with
			Females = 78%	neutral topics		random series of letters,
				Group 2 -Explicit positive asked to		plus Explicit neutral -
				"imagine a senior citizen who is		asked to imageing neutral
				mentally and physically healthy" (one		topics
				of 3 versions) plus Implicit neutral -
				primed via same method as implicit
				prime but with random series of letters
				Group 3 -Exposed to both implicit
				and explicit positive interventions
	Sakurai et al.	NRCT n = 349	Intensive training sessions followed by	12-week intensive training	Passive control group -	Implicit	N/A	12.2 Restructuring the social	None
	(2016)		Age range not reported	group activity sessions with school	Unspecified x 30 min sessions	maintained normal daily			environment (++)
	(Japan)		Mean age = 67.7 years	children. Activities included pre-group	1x every 1-2 weeks	routine but 38% were
			SD = 5.7	meeting to share information, playing	Unspecified x 120mins	involved in volunteering
			Females = 82.8%	hand games & with toys, picture book	meetings/additional training	activities i.e., at welfare
				reading, additional monthly meetings	1x week	facility every week & 42%
				with area wise group/time to engage		a few times a month
				with further training.		(Mean time per week
						1.5hours, SD = 1.7)

Table 2

 2

	Continued

RCT = randomised control trial; SPA = self-perceptions of ageing; VoA = views-on-ageing; (+) = BCT present in all probability; (++) = BCT present beyond all reasonable doubt.

[START_REF] Fujiwara | REPRINTS: Effects of an Intergenerational Health Promotion Program for Older Adults in Japan[END_REF] and[START_REF] Sakurai | Long-term effects of an intergenerational program on functional capacity in older adults: Results from a seven-year follow-up of the REPRINTS study[END_REF][START_REF] Warner | Revisiting selfregulatory techniques to promote physical activity in older adults: Null-findings from a randomised controlled trial[END_REF] and[START_REF] Wolff | What do targeting positive views on ageing add to a physical activity intervention in older adults? Results from a randomised controlled trial[END_REF] present different outcome data components and/or time-points from the same overall studies

Acknowledgements:

This work was supported by a Cotutelle PhD Scholarship from Swansea University and Université Grenoble Alpes. We have no known conflict of interest to disclose. No part of the content of this manuscript has been presented elsewhere. Our thanks to Parisa Eslambolchilar for assistance with the development of the initial review protocol.

Data availability statement:

The data that supports the findings of this study are available in the supplementary material of this article.

Supplementary Data 2

Information to Support Risk of Bias Assessments Non-Randomized Articles