Public Transportation Use and Cognitive Function in Older Age: A Quasiexperimental Evaluation of the Free Bus Pass Policy in the United Kingdom

The impact of free subway passes on the social relationships and mental health of urban older people: A segmented regression analysis

OBJECTIVE

This study aimed to examine the impact of free subway passes (FSP) on the social relationships and mental health of urban older people.

STUDY DESIGN

Segmented regression analysis METHODS: We studied data from the 2019 Korea Community Health Surveys, looking at 38,205 participants aged over 45 in metropolitan areas without activity limitations. The intervention group comprised residents of Ulsan, a city without a subway system and thus not eligible for the FSP policy. The control group included residents of five metropolitans and capital city with subway systems where FSP are available. We used controlled segmented regression analysis to explore how FSP influenced satisfaction with public transportation, social connections, social participation, and mental health (measured by Patient Health Questionnaire-9, PHQ-9 as a proxy variable).

RESULTS

Satisfaction of transportation and social participation of people who reside in metropolitan without FSP was likely to decrease more than people in metropolitan with FSP and capital city (model 1: satisfaction of transportation estimate 0.941; 95 % CI 0.909-0.974, social participation estimate 0.983; 95 % CI 0.969-0.998, model 2: satisfaction of transportation estimate 0.935; 95 % CI 0.899-0.973, social participation estimate 0.979; 95 % CI 0.964-0.994). And people who reside in metropolitan without FSP had marginally increasing PHQ-9 score compared to metropolitan with FSP and capital city (model 1: PHQ-9 score estimate 1.009; 95 % CI 0.999-1.018, model 2: PHQ-9 score estimate 1.007; 95 % CI 0.997-1.018).

CONCLUSION

FSP use might promote social participation and be marginally associated with reduced depressive symptoms among older adults. Further research is needed to explore the effects of FPS and other public transportation subsidies. The findings of this study might serve as important evidence for developing public transportation policies in other communities.

Cognitive Health Costs of Poor Housing for Women: Exploring Executive Function and Housing Stress in Urban Slums in India

An increasing body of literature has investigated the implications of housing quality on health, confirming the negative consequences of poor housing quality on physical and mental health. Despite this increased focus on the salutogenic impacts of housing, the relationship between housing quality and cognitive health remains understudied. This study examined how the housing quality in urban informal settlements, where living conditions are often substandard, affects women's cognitive functioning, with a specific focus on executive function (EF) skills. EF is a decision-making system that enables us to make decisions using working memory and attentional control. This study addressed two key questions: (1) Is housing quality associated with EF skills? (2) Does perceived housing stress experienced by women mediate the housing-EF relationship? A standardized observer-based tool assessed housing quality, psychometric instruments measured EF skills, and a 12-item questionnaire evaluated perceived housing stress. Results indicated that better housing quality is positively associated with higher EF skills, with housing stress acting as a mediating factor in this relationship. These findings have important implications for both health and housing policies. Investments in improving housing conditions can yield cognitive health benefits for women, and addressing stress-inducing housing factors could further enhance cognitive outcomes.

Impacts of zero-fare transit policy on health and social determinants: protocol for a natural experiment study

Population-level efforts are needed to increase levels of physical activity and healthy eating to reduce and manage chronic diseases such as obesity, cardiovascular disease, and type 2 diabetes. Interventions to increase public transit use may be one promising strategy, particularly for low-income communities or populations of color who are disproportionately burdened by health disparities and transportation barriers. This study employs a natural experiment design to evaluate the impacts of a citywide zero-fare transit policy in Kansas City, Missouri, on ridership and health indicators. In Aim 1, comparison to 9 similar cities without zero-fare transit is used to examine differential changes in ridership from 3 years before to 4 years after the adoption of zero-fare. In Aim 2, Kansas City residents are being recruited from a large safety net health system to compare health indicators between zero-fare riders and non- riders. Longitudinal data on BMI, cardiometabolic markers, and economic barriers to health are collected from the electronic health record from 2017 to 2024. Cross-sectional data on healthy eating and device-measured physical activity are collected from a subsample of participants as part of the study procedures (N = 360). Numerous baseline characteristics are collected to account for differences between Kansas City and comparison city bus routes (Aim 1) and between zero-fare riders and non-riders within Kansas City (Aim 2). Evidence on how zero-fare transit shapes population health through mechanisms related to improved economic factors, transportation, physical activity, and healthy eating among low-income groups is expected.

Gaps in the usage and reporting of multiple imputation for incomplete data: findings from a scoping review of observational studies addressing causal questions

BACKGROUND

Missing data are common in observational studies and often occur in several of the variables required when estimating a causal effect, i.e. the exposure, outcome and/or variables used to control for confounding. Analyses involving multiple incomplete variables are not as straightforward as analyses with a single incomplete variable. For example, in the context of multivariable missingness, the standard missing data assumptions ("missing completely at random", "missing at random" [MAR], "missing not at random") are difficult to interpret and assess. It is not clear how the complexities that arise due to multivariable missingness are being addressed in practice. The aim of this study was to review how missing data are managed and reported in observational studies that use multiple imputation (MI) for causal effect estimation, with a particular focus on missing data summaries, missing data assumptions, primary and sensitivity analyses, and MI implementation.

METHODS

We searched five top general epidemiology journals for observational studies that aimed to answer a causal research question and used MI, published between January 2019 and December 2021. Article screening and data extraction were performed systematically.

RESULTS

Of the 130 studies included in this review, 108 (83%) derived an analysis sample by excluding individuals with missing data in specific variables (e.g., outcome) and 114 (88%) had multivariable missingness within the analysis sample. Forty-four (34%) studies provided a statement about missing data assumptions, 35 of which stated the MAR assumption, but only 11/44 (25%) studies provided a justification for these assumptions. The number of imputations, MI method and MI software were generally well-reported (71%, 75% and 88% of studies, respectively), while aspects of the imputation model specification were not clear for more than half of the studies. A secondary analysis that used a different approach to handle the missing data was conducted in 69/130 (53%) studies. Of these 69 studies, 68 (99%) lacked a clear justification for the secondary analysis.

CONCLUSION

Effort is needed to clarify the rationale for and improve the reporting of MI for estimation of causal effects from observational data. We encourage greater transparency in making and reporting analytical decisions related to missing data.

Associations of Cognitively Active Versus Passive Sedentary Behaviors and Cognition in Older Adults

BACKGROUND

Cognitively stimulating sedentary behavior (SB) may positively impact cognition. This study aimed to (1) describe participation across types of SB among older adults with and without cognitive impairment and (2) examine how baseline SB participation impacts cognition, longitudinally.

METHODS

We used National Health and Aging Trends Study data from rounds 6 to 11 for cross-sectional and longitudinal analyses. Participants were 2244 community-dwelling older adults who were selected for the SB module in round 6. The SBs were categorized as active (eg, hobbies) and passive (eg, television). Participants were also categorized as having intact or impaired orientation, memory, and executive function based on tests of orientation, recall, and the clock-drawing test. We calculated descriptive statistics characterizing SB by cognitive status. Aim 2 involved competing risks proportional hazard models of participants with intact cognition (n = 1574) to identify associations between baseline SB and changes in cognition, moves to institutional care, and death over 6 years.

RESULTS

Participants (40% ≥ 80 years, 55% female, 77% White non-Hispanic) averaged 8.75 (SD = 4.42) hours of daily SB, including 4.05 (SD = 2.32) hours of passive SB and 4.75 (SD = 3.13) hours of active SB. Active SB >3 hours per day was associated with a lower risk of impaired orientation (subdistribution hazard models = 0.60; P = .048) and memory (subdistribution hazard models = 0.62; P = .02). Baseline participation in passive SB did not impact the risk of having a change in cognition during rounds 7 to 11.

CONCLUSION

Cognitive decline was lower among older adults who participated in more active SB. Thus, type of SB should be considered in examining the impact on cognition.

Public transport use and mortality among older adults in England: A cohort study

BACKGROUND

Most evidence on transport use and mortality has focused on the commute to work. This study aims to fill a gap by assessing relationships between public transport use and mortality among older adults.

METHODS

Data come from a cohort of 10,186 individuals aged 50 or older who participated in the English Longitudinal Study of Ageing (ELSA), with survey data linked to mortality records over 16 years (2002-2018). We assessed a binary measure of public transport use and frequency of use from 'every day or nearly every day' to 'never'. Cox proportional-hazards regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for associations between public transport use and mortality. Analyses were adjusted for a range of covariates including socio-demographic factors, chronic disease, and self-reported problems with daily living activities.

RESULTS

Overall, 3371 participants (33.1%) died within the study period. Mortality was lower among public transport users (21.3%) compared with non-users (64.2%). Adjusted analyses found that users had 34% lower mortality than non-users (HR 0.66 (95% CI 0.61;0.71)). Adjusted analyses showed similar association sizes across frequencies of public transport use, with those using public transport every day or nearly every day having 41% lower mortality than never users (HR 0.59 (0.49;0.71)). Associations were similar among those with and without a longstanding illness.

CONCLUSION

The use of public transport among older adults is linked to lower levels of mortality. Reductions in provision of public transport services could be detrimental to both transportation and population health.

Implementing age-friendly policies in China: Assessing the impact on older adults' self-rated health

Using prefecture-level policy documents (2008-2018) and the China Health and Retirement Longitudinal Study (2011-2018), this study used fixed-effects regressions to examine the associations between the maturity of two age-friendly policies, i.e., old age care (OAC) and preferential treatment (PT) policies for older adults, and the self-rated health (SRH) of older adults. We use policy duration and policy density to measure policy maturity. The results showed positive relationships exist between the density of OAC and PT policy and older adults' SRH, whereas long policy duration often relates to lower SRH. Policy duration and policy density work synergistically. Furthermore, heterogeneity analyses indicated that older adults aged over 75 years, male, those with physical or mental impairment, and living in rural areas and in the first- and second-tier cities benefit significantly from denser OAC policy. The SRH of older adults suffering from physical disabilities or mental problems and living in rural areas is positively associated with denser PT policy. From a policy perspective, our findings suggest that age-friendly policies should be updated over time and be place- and characteristic-tailored.

Association of Perceived Neighborhood Environments With Cognitive Function in Older Adults

The current study examined the associations between perceptions of the social and physical neighborhood environments and cognitive function in older adults. This cross-sectional study analyzed 821 adults aged ≥65 years from the Adult Changes in Thought study. Perceived neighborhood attributes were measured by the Physical Activity Neighborhood Environment Scale. Cognitive function was assessed using the Cognitive Ability Screening Instrument. The associations were tested using multivariate linear regression. One point greater perceived access to public transit was associated with 0.56 points greater cognitive function score (95% confidence interval [CI] [0.25, 0.88]), and an additional one point of perceived sidewalk coverage was related to 0.22 points higher cognitive function score (95% CI [0.00, 0.45]) after controlling for sociodemographic factors. The perception of neighborhood attributes alongside physical infrastructure may play an important role in supporting older adults' cognitive function. [Journal of Gerontological Nursing, 49(8), 35-41.].

Neighborhood built environments and cognition in later life

Objectives: Maintaining good cognition is crucial in later life. However, most existing research has focused on individual factors impacting cognition, and few studies have investigated the association between neighborhood built environment and older adults' cognition. This study examined the association between neighborhood built environment and cognition among community-dwelling older adults and identified variations in this association between different age groups in the older population.Methods: Data were derived from a cross-sectional survey of 1873 people aged 65 years and above in Hong Kong. We merged individual data from the survey with neighborhood built environment data based on community auditing and geographical information system. After controlling for individual covariates, we used multivariable linear regression to examine the association between neighborhood built environment and cognition.Results: Residents aged 80 and younger in neighborhoods with a higher land-use mix and more public transport terminals exhibited better cognition. Only the number of community centers in a neighborhood was positively associated with cognition for people older than 80.Conclusion: The built environment creates diverse impacts on different age groups among older adults. Our findings provide useful information for urban planners and policymakers for planning community facilities and built environments that consider the needs of different age groups within the older population.

The Revolution Will Be Hard to Evaluate: How Co-Occurring Policy Changes Affect Research on the Health Effects of Social Policies

Extensive empirical health research leverages variation in the timing and location of policy changes as quasi-experiments. Multiple social policies may be adopted simultaneously in the same locations, creating co-occurrence that must be addressed analytically for valid inferences. The pervasiveness and consequences of co-occurring policies have received limited attention. We analyzed a systematic sample of 13 social policy databases covering diverse domains including poverty, paid family leave, and tobacco use. We quantified policy co-occurrence in each database as the fraction of variation in each policy measure across different jurisdictions and times that could be explained by covariation with other policies. We used simulations to estimate the ratio of the variance of effect estimates under the observed policy co-occurrence to variance if policies were independent. Policy co-occurrence ranged from very high for state-level cannabis policies to low for country-level sexual minority-rights policies. For 65% of policies, greater than 90% of the place-time variation was explained by other policies. Policy co-occurrence increased the variance of effect estimates by a median of 57-fold. Co-occurring policies are common and pose a major methodological challenge to rigorously evaluating health effects of individual social policies. When uncontrolled, co-occurring policies confound one another, and when controlled, resulting positivity violations may substantially inflate the variance of estimated effects. Tools to enhance validity and precision for evaluating co-occurring policies are needed.

What to Do When Everything Happens at Once: Analytic Approaches to Estimate the Health Effects of Co-Occurring Social Policies

Social policies have great potential to improve population health and reduce health disparities. Increasingly, those doing empirical research have sought to quantify the health effects of social policies by exploiting variation in the timing of policy changes across places. Multiple social policies are often adopted simultaneously or in close succession in the same locations, creating co-occurrence that must be handled analytically for valid inferences. Although this is a substantial methodological challenge for researchers aiming to isolate social policy effects, only in a limited number of studies have researchers systematically considered analytic solutions within a causal framework or assessed whether these solutions are being adopted. We designated 7 analytic solutions to policy co-occurrence, including efforts to disentangle individual policy effects and efforts to estimate the combined effects of co-occurring policies. We used an existing systematic review of social policies and health to evaluate how often policy co-occurrence is identified as a threat to validity and how often each analytic solution is applied in practice. Of the 55 studies, only in 17 (31%) did authors report checking for any co-occurring policies, although in 36 studies (67%), at least 1 approach was used that helps address policy co-occurrence. The most common approaches were adjusting for measures of co-occurring policies; defining the outcome on subpopulations likely to be affected by the policy of interest (but not other co-occurring policies); and selecting a less-correlated measure of policy exposure. As health research increasingly focuses on policy changes, we must systematically assess policy co-occurrence and apply analytic solutions to strengthen studies on the health effects of social policies.

Adverse childhood experiences and cognitive function in adulthood: examining the roles of depressive symptoms and inflammation in a prospective cohort study

PURPOSE

Adverse childhood experiences (ACEs) have been associated with cognitive decline in adulthood. However, the underlying mechanisms implicated remain unclear. This study investigated depressive symptoms and systemic inflammation as potential mediators of the association between ACEs and later cognitive function.

METHODS

Participants were adults aged 50 + from the English Longitudinal Study of Ageing (N = 3029; 54.8% female). Measures included self-reported ACEs at wave 3 (2006-2007), C-reactive protein (CRP) and depressive symptoms at wave 4 (2008-2009), and cognitive function at waves 3 and 7 (2014-2015). Mediation analyses examined the direct associations between ACEs and cognitive function at wave 7 and the indirect associations via depressive symptoms and CRP at wave 4. In a first set of analyses, models were adjusted for sociodemographic factors and baseline cognitive function. In a second set of analyses, models were additionally adjusted for BMI and health behaviours (n = 1915).

RESULTS

Cumulative ACEs exposure positively predicted depressive symptoms (b = 0.184, s.e. = 0.034, p < .001), which in turn predicted poorer cognitive function at wave 7 (b =  - 0.035, s.e. = 0.008, p < .001). ACEs also positively predicted systemic inflammation as measured by CRP (b = 0.031, s.e. = 0.01, p = 0.0016). However, CRP did not mediate the association between ACEs and later cognitive function (b =  - 0.0002, 95% CI: - 0.002, 0.002).

CONCLUSION

These findings suggest that ACEs may be related to cognitive decline partly via depressive symptoms and corroborate prior research linking ACEs with systemic inflammation in adulthood.

Which Occupation is Highly Associated with Cognitive Impairment? A Gender-Specific Longitudinal Study of Paid and Unpaid Occupations in South Korea

Background: To examine the associations between paid and unpaid occupations and the risk of cognitive impairment with respect to gender in a middle-aged population using the dataset of a nationally representative longitudinal survey. Methods: Overall, 24,925 observations of 5865 participants aged 45–64 years were sampled from the seven waves of the Korean Longitudinal Study of Ageing (2006–2018). A dichotomous outcome variable was derived based on the Korean version of the Mini-Mental State Examination scores, and occupations were grouped into 12 categories, including three unpaid ones. Sociodemographics, lifestyle, and medical conditions were included as covariates in the mixed logistic regression models. Adjusted odds ratios and predicted probabilities of cognitive impairment were estimated. Results: In the longitudinal models with all-studied covariates, the risk of cognitive impairment was similar between genders but differed across occupation categories for each gender. Moreover, the association between occupation and cognitive impairment varied between genders. Regarding the predicted probability, in men, the retired category exhibited the highest risk of cognitive impairment. However, in women, the highest risk was related to the homemakers category, with the risk being more than five times higher than those in the professionals and related workers category. Conclusions: Public health policies to reduce the risk of cognitive impairment in the middle-aged population need to be designed and implemented with respect to both gender and occupation.

Associations between dehydroepiandrosterone sulphate (DHEAS) and cognitive function in 5,061 older men and women in the English Longitudinal Study of Ageing

Despite extensive observational and intervention research, the association between concentrations of dehydroepiandrosterone sulfate (DHEAS) and cognition at older ages remains unclear. This study investigated cross-sectional and longitudinal relationships between plasma DHEAS and cognitive function in a large nationally-representative cohort of men and women aged 50 and older. Data were analysed from 5061 participants (mean age 65.1, standard deviation 8.61) who completed memory, verbal fluency and processing speed tests at baseline and two years later. Age, education, marital status, paid employment, depressive symptoms, mobility impairment, coronary heart disease and diabetes were included as covariates, and analyses were stratified by gender. We found positive associations at baseline between DHEAS concentration and aggregate cognition after adjustment for covariates in men (β = 0.049, standard error (s.e.) 0.020, p = 0.015). Longitudinally, DHEAS at baseline predicted cognition two years later in men (β = 0.052, s.e. 0.020, p = 0.010), but not after baseline cognition was taken into account (β = 0.022, s.e. 0.016, p = 0.17), indicating that DHEAS was not associated with rate of cognitive decline. Similar associations were recorded at 6 year follow-up. No significant relationships between DHEAS and cognition were observed among women. We conclude that greater DHEAS concentrations are associated with cognition level at older ages in men, but are unlikely to play a functional role in cognitive decline.

Public transit and depression among older adults: using agent-based models to examine plausible impacts of a free bus policy

BACKGROUND

Daily transport is associated with mental health. A free bus policy (FBP) may be effective in promoting the use of public transit in older adults and be associated with reductions in depressive symptoms.

METHODS

We developed an agent-based model and grounded it using empirical data from England to examine the impact of an FBP on public transit use and depression among older adults. We also used the model to explore whether the impact of the FBP bus use and depression is modified by the type of income segregation or by simultaneous efforts to improve attitudes towards the bus, to reduce waiting times or to increase the cost of driving via parking fees or fuel price.

RESULTS

Our model suggests that improving attitudes towards the bus (eg, campaigns that promote bus use) could enhance the effect of the FBP, especially for those in proximity to public transit. Reducing wait times could also significantly magnify FPB impacts, especially in those who live in proximity to public transit. Contrary to expectation, neither fuel costs nor parking fees significantly enhanced the impact of the FBP. The impact of improving attitudes towards the bus and increasing bus frequency was more pronounced in the lower-income groups in an income segregation scenario in which destination and public transit are denser in the city centre.

CONCLUSION

Our results suggest that the beneficial mental health effects of an FBP for older adults can be magnified when combined with initiatives that reduce bus waiting times and increased spatial access to transit.