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

Abstract 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 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.