The Healthy Ageing Questionnaire Index: Validation in the Singapore Longitudinal Ageing Study.

INTRODUCTION: Healthy ageing (HA) indices typically use full questionnaire, performance- or blood-based assessment of functional ability which are time-consuming and resource-intensive. We developed and validated a simple and brief Healthy Ageing Questionnaire (HAQ) index with comparable measurement accuracy. METHODS: The 15-item HAQ (scored 0-100) was developed using data of 500 participants in the Singapore Study of Successful Ageing (SSOSA), a sub-cohort of the Singapore Longitudinal Ageing Study (SLAS-2). Its construct, concurrent, and predictive validity were evaluated in 2,161 participants in the SLAS-2 who were non-participants of the SSOSA. RESULTS: The HAQ index (mean = 64.0, SD = 11.8) showed a coherent 3-factor structure (Cronbach's alpha = 0.735). HAQ scores were higher among participants who were female, highly educated, not living alone, non-smoking, non-alcohol drinkers, not at risk of malnutrition, were robust or pre-frail, not disabled, had no or <5 medical conditions, and no recent fall or hospitalization. It was positively correlated with Mini-Mental State Examination and life satisfaction, and negatively correlated with age, logMAR vision, 5 times sit-and-stand, and timed-up-and-go. The HAQ index was significantly correlated but showed modest concordance with the Rowe-Kahn SA index. Increasing HAQ index quintiles were associated with decreased mortality risks from 40.6 to 9.7 deaths per 1,000 person-years; covariate-adjusted hazard ratio for the highest Q5 levels (HAQ score >70) was 0.44 (95% CI = 0.28-0.67). Using receiver operating characteristics analysis of predictive accuracy for survival, the area under the curve of HAQ was 0.675, and Rowe-Kahn SA index was 0.660 (p = 0.361). CONCLUSION: The HAQ is a brief and accurate HA index that is potentially useful across diverse settings and purposes in research, healthcare, and policy-making.

Tea Consumption and Risk of Chronic Obstructive Pulmonary Disease in Middle-Aged and Older Singaporean Adults.

Objective: The anti-oxidant and anti-inflammatory actions of phytochemicals and the smooth muscle relaxant actions of theophylline present in tea may confer pulmonary protection and reduce COPD risk. We investigated tea consumption (black, oolong, or green) association with COPD risks in a population-based cohort study of older adults aged ≥55. Methods: GOLD criteria was used to identify prevalent and incident cases of COPD (FEV1/FVC <0.70) among 4617 participants and 920 participants free of COPD at baseline who were assessed at follow-up 4.5 years later. Results: Prevalent cases of COPD consumed less tea than their non-COPD counterparts. Estimated odds ratio (OR) and 95% confidence intervals (95% CI) of association with prevalent COPD, adjusted for age, sex, ethnicity, housing type, smoking, alcohol, physical activity and BMI declined across tea consumption levels (p-trend=0.048), and was lowest for ≥3 cups/day (OR=0.77, 95% CI=0.61-0.96). The cumulated incidence of COPD declined across tea consumption categories (p-trend=0.012) and the lowest OR of association (OR=0.35, 95% CI=0.17-0.69) with consuming ≥3 cups/day after co-variate adjustment. Conclusion: Different kinds of tea showed similar non-significant trends of associations but appeared to be strongest for green tea. Tea consumption in this Asian population was associated with lowered COPD prevalence and incidence.

Physiological Dysregulation, Frailty, and Impacts on Adverse Health and Functional Outcomes.

Background: Multi-system physiological dysregulation (PD) may represent a biological endo-phenotype of clinical frailty. We investigated the co-occurrence of PD with physical frailty and its contributions to the known impact of frailty on adverse health outcomes. Methods: Data of 2,725 participants from the Singapore Longitudinal Aging Studies (SLAS-2), included baseline measures of physical frailty and PD derived from Mahalanobis distance (Dm) value of 23 blood biomarkers. We analyzed their concurrent association and their impacts on 9-year mortality, MMSE cognition, GDS depression, number of medications, disability, and hospitalization at baseline and follow up (mean 4.5 years). Results: Global PD (Log10Dm, mean = 1.24, SD = 0.24) was significantly but weakly associated with pre-frailty-and-frailty. Controlling for age, sex and education, pre-frailty-and-frailty (HR = 2.12, 95% CI = 1.51-3.00) and PD (HR = 3.88, 95% CI = 2.15-6.98) predicted mortality. Together in the same model, mortality HR associated with pre-frailty-and-frailty (HR = 1.83, 95% CI = 1.22-2.73) and PD (HR = 3.06, 95% CI = 1.60-5.85) were reduced after additionally adding global PD to the prediction model. The predictive accuracy for mortality were both approximately the same (PD: AUC = 0.62, frailty: AUC = 0.64), but AUC was significantly increased to 0.68 when combined (p < 0.001). Taken into account in the same model, frailty remained significantly associated with all health and functional outcomes, and PD was significantly associated with only MMSE, disability and medications used. In secondary analyses, there were mixed associations of system-specific PDs with frailty and different adverse outcomes. Conclusions: Co-existing PD and physical frailty independently predict mortality and functional and health outcomes, with increased predictive accuracy when combined. PD appears to be a valid representation of a biological endo-phenotype of frailty, and the potential utility of such subclinical measures of frailty could be further studied.

Physical and functional measures predicting long-term mortality in community-dwelling older adults: a comparative evaluation in the Singapore Longitudinal Ageing Study.

Measures of functional status are known to predict mortality more strongly than traditional disease risk markers in old adult populations. Few studies have compared the predictive accuracy of physical and functional measures for long-term mortality. In this prospective cohort study, community-dwelling older adults (N = 2906) aged 55 + (mean age 66.6 ± 7.7 years) were followed up for mortality outcome up to 9 years (mean 5.8 years). Baseline assessments included Timed Up-and-Go (TUG), gait velocity (GV), knee extension strength, Performance Oriented Mobility Assessment, forced expiratory volume in 1 second, Mini-Mental State Examination (MMSE), Geriatric Depression Scale, frailty, and medical morbidity. A total of 111 (3.8%) participants died during 16976.7 person-years of follow up. TUG was significantly associated with mortality risk (HR = 2.60, 95% CI = 2.05-3.29 per SD increase; HR = 5.05, 95% CI = 3.27-7.80, for TUG score ≥ 9 s). In multivariate analysis, TUG remained significantly associated with mortality (HR = 1.64, 95% CI = 1.20-2.19 per SD increase; HR = 2.66, 95% CI = 1.67-4.23 for TUG score ≥ 9 s). In multivariable analyses, GV, MMSE, Frailty Index (FI) and physical frailty, diabetes and multi-morbidity were also significantly associated with mortality. However, TUG (AUC = 0.737) demonstrated significantly higher discriminatory accuracy than GV (AUC = 0.666, p < 0.001), MMSE (AUC = 0.63, p < 0.001), FI (AUC = 0.62, p < 0.001), physical frailty (AUC = 0.610, p < 0.001), diabetes (AUC = 0.582, p < 0.001) and multi-morbidity (AUC = 0.589, p < 0.001). TUG's predictive accuracy shows surpassing predictive accuracy for long-term mortality in community-dwelling older adults.