Objective

Dimension-specific objective measures are criticized for their limited perspective and failure to endorse subjective perceptions by respondents, but the validity and correlates of a subjective global measure of successful aging (SA) are still not well established. We evaluated the reliability and validity of a self-rated analogue scale of global SA in an elderly Singaporean population.

Design

Cross-sectional data analysis using a comprehensive questionnaire survey.

Participants and setting

489 community-dwelling Singaporeans aged 65 years and over.

Measurements

Self-rated SA on an analogue scale from 1 (least successful) to 10 (most successful) was analyzed for its relationship to criterion-based measures of five specific dimensions (physical health and function, mental well-being, social engagement, psychological well-being, and spirituality/religiosity), as well as outcome measures (life satisfaction and quality of life).

Results

Self-rated SA was significantly correlated to measures of specific dimensions (standardized β from 0.11 to 0.39), most strongly with psychological functioning (β = 0.391). The five dimension-specific measures together accounted for 16.7% of the variance in self-rated SA. Self-rated SA best predicted life satisfaction (R(2) = 0.26) more than any dimension-specific measure (R(2) from 0.05 to 0.17). Self-rated SA, vis-à-vis dimension-specific measures, was related to a different set of correlates, and was notably independent of chronological age, sex, education, socioeconomic status, and medical comorbidity, but was significantly related to ethnicity.

Conclusion

The self-rated analogue scale is a sensitive global measure of SA encompassing a spectrum of underlying dimensions and subjective perspectives and its validity is well supported in this study.

Introduction

Though consistent evidence suggests that physical activity may delay dementia onset, the duration and amount of activity required remains unclear.

Methods

We harmonized longitudinal data of 11,988 participants from 10 cohorts in eight countries to examine the dose-response relationship between late-life physical activity and incident dementia among older adults.

Results

Using no physical activity as a reference, dementia risk decreased with duration of physical activity up to 3.1 to 6.0 hours/week (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.67 to 1.15 for 0.1 to 3.0 hours/week; HR 0.68, 95% CI 0.52 to 0.89 for 3.1 to 6.0 hours/week), but plateaued with higher duration. For the amount of physical activity, a similar pattern of dose-response curve was observed, with an inflection point of 9.1 to 18.0 metabolic equivalent value (MET)-hours/week (HR 0.92, 95% CI 0.70 to 1.22 for 0.1 to 9.0 MET-hours/week; HR 0.70, 95% CI 0.53 to 0.93 for 9.1 to 18.0 MET-hours/week).

Discussion

This cross-national analysis suggests that performing 3.1 to 6.0 hours of physical activity and expending 9.1 to 18.0/MET-hours of energy per week may reduce dementia risk.

INTRODUCTION: The LIfestyle for BRAin Health (LIBRA) index yields a dementia risk score based on modifiable lifestyle factors and is validated in Western samples. We investigated whether the association between LIBRA scores and incident dementia is moderated by geographical location or sociodemographic characteristics. METHODS: We combined data from 21 prospective cohorts across six continents (N = 31,680) and conducted cohort-specific Cox proportional hazard regression analyses in a two-step individual participant data meta-analysis. RESULTS: A one-standard-deviation increase in LIBRA score was associated with a 21% higher risk for dementia. The association was stronger for Asian cohorts compared to European cohorts, and for individuals aged ≤75 years (vs older), though only within the first 5 years of follow-up. No interactions with sex, education, or socioeconomic position were observed. DISCUSSION: Modifiable risk and protective factors appear relevant for dementia risk reduction across diverse geographical and sociodemographic groups. HIGHLIGHTS: A two-step individual participant data meta-analysis was conducted. This was done at a global scale using data from 21 ethno-regionally diverse cohorts. The association between a modifiable dementia risk score and dementia was examined. The association was modified by geographical region and age at baseline. Yet, modifiable dementia risk and protective factors appear relevant in all investigated groups and regions.

INTRODUCTION: Sex differences in dementia risk, and risk factor (RF) associations with dementia, remain uncertain across diverse ethno-regional groups. METHODS: A total of 29,850 participants (58% women) from 21 cohorts across six continents were included in an individual participant data meta-analysis. Sex-specific hazard ratios (HRs), and women-to-men ratio of hazard ratios (RHRs) for associations between RFs and all-cause dementia were derived from mixed-effect Cox models. RESULTS: Incident dementia occurred in 2089 (66% women) participants over 4.6 years (median). Women had higher dementia risk (HR, 1.12 [1.02, 1.23]) than men, particularly in low- and lower-middle-income economies. Associations between longer education and former alcohol use with dementia risk (RHR, 1.01 [1.00, 1.03] per year, and 0.55 [0.38, 0.79], respectively) were stronger for men than women; otherwise, there were no discernible sex differences in other RFs. DISCUSSION: Dementia risk was higher in women than men, with possible variations by country-level income settings, but most RFs appear to work similarly in women and men.