Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study

Introduction: The relationships between falls, fear of falling, poor mobility, and PA avoidance occur in a cyclic, multi-directional fashion. Aim: This study investigates the concomitant associations of fall history, fear of falling, and physical performance (SPPB) on physical activity using a cross-national sample of community-dwelling older adults from middle and high-income countries. Methods: Linear mixed-effects models looking at the influence of individual and environmental factors were used and participants were nested within each study site. Results: Estimated walking minutes was 52% lower for those with low SPPB compared to high SPPB, 20% lower for those with medium level fear of falling compared to low levels, and 50% lower for those with high level fear of falling compared to low levels. Conclusion: An individual’s


Introduction
Falls are a major public health concern for older adults globally.It is estimated that 30% of community-dwelling older adults (>65 years) will fall at least once per year [1].Across the globe, 80% of fatal falls occur in low-or middle-income countries [2].Non-fatal falls often lead to serious medical injuries that result in loss of disability-adjusted life years, which can be costly for the individual and his/her community [3].Overall, it is estimated that significant injuries occur in 4-15% of falls and 23-40% of injury-related deaths in older adults are due to falls [4].
Fear of falling (FoF) is observed in 50%-60% of community-dwelling individuals who have fallen [2] and is identified as a significant health concern because of its

Results
Table      In Page 17 health promotion efforts can increase walking among older adults by addressing their fear of falling and improving physical performance.

Strengths & Limitations
This study takes into account environmental close association with falls and other mobility-related measures.Correlates to FoF, such as low mobility [5], frailty, and low physical activity (PA) behavior [6, 7] overlap with fall risk factors.Thus, falls, fear of falling, poor mobility, and PA avoidance occur in a cyclic, multidirectional fashion [8] and should be considered together.There is limited research that considers falls, FoF, physical function, and PA together and at the same time accounts for individuals and environmental influences.The socioecological model has been successfully used as a framework to understand mobility limitations in older adults in the past [9, 10] and may prove useful for conceptualizing the complex relationship between falls and PA.This framework provides a broader perspective on the determinants of PA behavior by considering the context of a health behavior within different social and physical environments, thus bridging the gap between individual and environmental constructs [11].In this article, we propose to use the socioecological model as a framework to investigate the concomitant associations of fall history, FoF, and physical performance on PA using a cross-national sample of community-dwelling older adults from middle and high-income countries.This study examined models that included individual risk factors commonly associated with falls, such as sex, age, fall history, and FoF, and perceived environmental risk factors such as, uneven sidewalks, community safety, and community barriers.
Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 4 Results from this study help better identify how individual and environmental-level fall risks affect an older adult's PA levels in diverse populations in order to improve falls related interventions.Methods Data Source Data were collected as part of the International Mobility in Aging Study (IMIAS) at the following study sites: Kingston (N=398) and St. Hyacinthe (N=401), Canada; Tirana, Albania (N=394); Natal, Brazil (N=407); and Manizales, Colombia (N=402).Each site sampled near equal proportions of men and women, with the total sample containing 955 men and 1047 women.These diverse sites were chosen because the varying demographic factors maximize the spectrum of exposures that participants face across the life-course, allowing for exploration of distributional tails that would have been impossible with a single site [12].Baseline data were obtained in 2012, with follow-up collections in 2014 and 2016.Only baseline data for the five sites were used for this study.Participants comprised of communitydwelling older adults aged 65 to 74 at baseline.University ethics committees did not allow researchers to recruit or contact potential participants directly in Kingston and St. Hyacinthe.Thus, participants were recruited through their physicians in these sites.In Tirana, Natal, and Manizales, participants were randomly sampled and recruited from health center registries.Potential participants were then approached directly by interviewers to participate in the study [1].All interviewers were trained according to a standardized protocol.Response rates were 90% in Tirana and nearly 100% in Manizales and Natal.While 30% of invited participants in Kingston and St. Hyacinthe contacted the field coordinator, 95% agreed to participate in this study.Individuals who had four or more errors on the Leganes Cognitive Test orientation scale [13] were excluded from the study, as low scores indicated an inability to complete study procedures.Gomez et al compiled a cohort profile to describe recruitment and retention details [14].Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 5 Principal Exposures Principal exposures for this analysis were personal level factors: fall history in the last year, physical performance, and FoF.Fall history (yes/no) was assessed by asking participants whether or not they had fallen within the past 12 months.Physical performance was evaluated with the extensively validated Short Performance Physical Battery test (SPPB), which includes tests of balance, gait speed, and chair stand.Each component has a maximum score of four.Total possible SPPB score 0-12 and the battery is described in detail elsewhere [15].To simplify results' interpretation, we recoded the total SPPB score into a binary variable of high versus low physical function.SPPB scores of less than eight indicate low or limited physical performance, and SPPB scores of eight of more indicate higher physical performance [16].FoF was assessed with the Falls Efficacy Scale International (FES-I) questionnaire (Yardley et al. 2005).FES-I quantifies the fall concerns of older persons related to 16 activities that occur inside and outside of the home.The level of falling concern was measured on a four-point Likert scale (1 = not at all concerned to 4 = very concerned).
Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 7 Analysis STATA/SE (version 14.0; StataCorp LP, College Station, TX USA) was used to conduct the analyses.One-way ANOVA analyses were performed to test differences in average minutes walking per day for all variables.Multivariate linear mixed-effects models were used to examine the strength and direction of the relationship between covariates and outcome measures aggregated by study site (Kingston and St. Hyacinthe, Canada; Tirana, Albania; Manizales, Colombia; and Natal, Brazil).

Figure 1
Figure 1 depicts the conceptual model underpinning our analyses.The linear mixed-effects models were used because of the hierarchical structure of the data with IMIAS participants nested within study sites.Four models were generated to test whether individual-level and perceived environmental-level exposures affect the relationship between walking and falls, fear

Figure 1 :
Figure 1: Conceptual Framework Depicting the Inter-relatedness of Physical Activity with Fear of Falling, Physical Performance, and Fall History Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 10 Natal 296(20.7)105(18.9)312(18.0)90(34.2) 134(15.0)136(21.1)132(29.0)Missing values--Fall History: n=17, SPPB: n=3, Fear of Fall: n=10, Uneven Sidewalk: n=85, Community Barrier Scale: n=47, Perception of Safety: n= 110, Average Minutes Walking per Day: n=80 a Community barrier scale ranges from 3 to 9, higher score indicates more community barriers b Perception of safety scale ranges from 8 to 24, higher score indicates higher perceived safetyIn Table2, the outcome measure, average minutes walking per day, is displayed by fall history, physical performance, fear of falling, and covariates.The results are stratified by site location to depict sitespecific differences.Individuals with higher physical performance, lower fear of falling, who are males, with higher education, and who are younger walked significantly more.For site location, the highest average daily walking time was in Kingston (m=38.3),followed by Tirana (m=35.6),St. Hyacinthe (m=29.5),Manizales (m=28.3),and Natal (m=16.8).Although not statistically significant with all sites combined, there was a significant difference in walking time by fall history in Tirana and uneven sidewalks in Kingston.In Tirana, individuals who had not fallen within the past 12 months had higher mean daily walking minutes (m=37.8)compared to those who reported a recent fall (m=24.6).In Kingston, individuals who reported having uneven sidewalks in their neighborhoods walked more (m=43.1)compared to individuals who reported no uneven sidewalks (m=30.5).Those who perceived low community barriers had the highest daily mean walking minutes (m=33.6),followed by high barriers (m=29.1)and middle barriers (m=25.3).Those with middle levels of perceived safety had the highest daily mean walking minutes (m=33.8),followed by high perceived safety (m=31.2) and low perceived safety (m=24.5).
*One-way ANOVA test of difference in average walking time for the whole sample and by each study site, p <0.05.Missing values--Fall History: n=17, SPPB: n=3, Fear of Fall: n=10, Uneven Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 12 Sidewalk: n=31 a CBS reported by tertiles with all site combined, low indicates low levels of perceived community barriers b PoSS reported by tertiles with all sites combined, high indicates high levels of perceived safety Table 3 displays the results of four mixedeffects models clustered by site location, along with the ICC for each model.Model coefficients and 95% confidence intervals are exponentiated for easier interpretation.In Model 1, only SPPB and fear of falls are significant correlates to average minutes walking per day.Estimated walking minutes are 52% lower for those with low SPPB compared to high SPPB, 20% lower for those with medium level fear of falling compared to low levels, and 50% lower for those with high level fear of falling compared to low levels.There was little change observed in coefficients and confidence intervals for principal exposures across the four models.In Model 3, which included only perceived environmental-level factors, high CBS was associated with less walking compared to low barriers, and middle PoSS was associated with more walking compared to high-perceived safety.The ICC is presented at the bottom of each model and is a measure of the total variance in walking time that is attributable to clustering by study site.The ICCs for all models were low (less than 0.06) Thus, less than 6% of the variation in walking time can be attributed to how individuals within site resemble each other.
Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 14 Discussion Using the socioecological model, we examined the role of individual-level and perceived environmental-level exposures on the relationship between falls, fear of falling, and physical performance (SPPB) on walking.This study is one of the first to examine multilevel factors using crossnational data.Fall history was not associated with walking times, but SPPB and fear of falling were associated with them.Although individual and environmental level factors such as sex, age, education, CBS, and PoSS had a significant relationship with minutes walking in all 4 models, these individual and environmental factors had little influence on the relationship between the principal exposures and outcome.In other words, the relationship between fall history, fear of falling, and SPPB on walking did not change despite adding individual and environment level factors into the models.These findings reflected Davis et al.'s findings that, within middle income countries, individual and interpersonal level factors were associated with older adults meeting physical activity guidelines, and not community or organizational level factors [24].As expected, lower physical performance and higher fear of falling were associated with less walking time.The relationship between these variables remained relatively constant even with the addition of individual and environmental level covariates.Although this study did not identify the causal pathway of these variables, it supports the results of previous studies that observed similar variables separately.Cooper et al is of the many authors who demonstrated that increased physical activity levels improve physical performance and other health outcomes [25].Delbere et al demonstrated that fear-related avoidance of physical activity in Belgium could have negative effects on physical ability due to the lack of physical activity and training [8].Surprisingly, fall history (whether the individual has experienced falls), was not associated with minutes walking in all four models.Based on previous studies, fall history was expected to influence minutes walking.One explanation may be that the difference in culture, government structure, and health policies among the different high and middle income sites affect and cancel out the relationships observed between the variables.Although the low ICC in the Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 15 mixed models clustered by site suggests low influence from the site, bivariate analysis shows that the high income site, Kingston, has the highest proportion of those who reported falls history, yet the lowest proportion of those who have high fear of falling.The opposite was observed in Tirana.One explanation could be that illness is often overreported in higher income households.For example, an individual with higher income and education, who is generally healthy most of the time, may be able to identify if she or he is ill more than an individual with lower income and education [26].Furthermore, Foster argues that higher income individuals have the means to dampen the impacts of poor health, whereas lower income individuals do not, thus the impacts of poor health should be observed more closely among lower income individuals.
and individual level factors to PA in a crossnational sample of participants from middle and high income countries.The analysis strategy applied to this study was grounded in a well-established theoretical foundation, the socioecological model.Four mixedeffects models were used to test the interactions between individual and environmental level factors.A nested model was used based on the theory that was applied.Despite sampling from four very different study sites, the variance of walking was not due primarily to study site, or geographical location.Instead, SPPB and fear of falling, along with other individual characteristics such as sex, were strong predictors.While their study has many strengths, there are limitations too.First, we are unable to determine etiology with a cross-sectional data set.However, since the benefits of walking for older adults are wellestablished, the purpose of this paper was to identify any correlates to walking that can potentially be of public health value.Second, the accuracy of the self-reported environmental exposures may affect the results.Participants would have to be outdoors in order to accurately report environmental factors, CBS and PoSS.If participants are already outdoors, then they may already be engaging in PA.Furthermore, there might be a possibility of misclassification error as mentioned in the discussion above.Nonetheless, studies have shown that the perceived environment is a stronger predictor of PA compared to objective environment (20).Lastly, although the effects of site location have been statistically accounted for, examining the relationship between safety and walking may be a bit more complicated and depend on unmeasured factors unaccounted for in this study.For instance, theoretically speaking, sex and gender play a role in how an individual perceives their environmental safety [35].Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.Page 18 Conclusion Many older adults remain or become increasingly physically inactive over time.An individual's fall concern and physical performance may be important to consider when making recommendations to increasePA; however, fall history doesn't seem to affect minutes walking.Individual and environmental level factors do not seem to affect the relationship.Identifying and addressing barriers to PA in older adults may be useful for health care practitioners and health policy advocates to generate a .H., World report on ageing and health.2015: World Health Organization.5. Auais, M., et al., Fear of falling as a risk factor of mobility disability in older people at five diverse sites of the IMIAS study.Archives of gerontology and geriatrics, 2016.66: p. 147-153.6. Lachman, M.E., et al., Fear of falling and activity restriction: the survey of activities and fear of falling in the elderly (SAFE).The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 1998.53(1): p. P43-P50.7. Wang, H., et al., Analysis on the characteristics and factors associated with avoidance of activity induced by fear of falling in the communitydwelling elderly.Zhonghua liu Xing Bing xue za zhi= Zhonghua Liuxingbingxue Zazhi, 2015.36(8): p. 794-798.8. Delbaere, K., et al., Fear-related avoidance of activities, falls and physical frailty.A prospective community-based cohort study.Age and ageing, 2004.33(4): p. 368-373.9. Webber, S.C., M.M. Porter, and V.H. Menec, Mobility in older adults: a comprehensive framework.The gerontologist, 2010.50(4): p. 443-450.10.Yeom, H.A., J. Fleury, and C. Keller, Risk factors for mobility limitation in community-dwelling older adults: a social ecological perspective.Geriatric nursing, 2008.29(2): p. 133-140.11.King, A.C., et al., Theoretical approaches to the promotion of physical activity: forging a transdisciplinary paradigm.American Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.
Total FES-I scores range between 16 and 64, with higher scores medium, and low education by site to obtain a variable called "relative education".Thus, a participant can have high educational attainment relative to his/her community, but medium or low attainment compared to another site in IMIAS.Sex is an interviewer reported categorical variable (male/female).Age is a self-reported continuous variable re-coded into a binary categorical variable (64-69/70-75).

Table 1 .
Individual and environmental level covariates fall history, physical performance, and 1 displays individual-level and environmental-level covariate frequencies by fall history, physical performance, and of falling compared to the other sites.Both low SPPB and fear of falling were more Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX. frequent among women than men and among those with low educations.While there was a greater proportion of the older age group with low SPPB scores, their

Table 2 .
Average minutes walking per day by fall history, physical performance, fear of falls, and covariates, stratified by site location Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.

Table 3 .
Mixed linear regression models for geometric mean minutes walking for reference group, ratio of geometric mean minutes by principal exposures, individual-level exposures, and perceived environmental level exposures clustered by site location Phoebe W. Hwang, Mohammad Auais, Afshin Vafaei, Nicole T.A. Rosendaal, Yan Yan Wu, Catherine M. Pirkle, Disentangling the relationship between falls, fear of falling, physical function and walking by applying a socioecological framework to the International Mobility in Aging Study.SEEJPH 2023.Posted: 09-04-2023, Vol.XX.