"SLAS is a community-based longitudinal epidemiologic study that aims to increase the understanding of ageing and health, and the factors that influence the ageing process. SLAS seeks to identify the cognitive, biomedical, lifestyle and behavioral, as well as psychosocial risk and protective factors that affect the transition from healthy ageing to functional impairment, illness and death. Participants recruited into SLAS are community-dwelling seniors, aged 55 and above, from various areas in Singapore. Study procedure includes a baseline survey upon enrollment, and participants are revisited on a 3-yearly basis thereafter. Enrolled subjects provide baseline data through structured interviews, physician assessments, laboratory testing, and self-reports of conditions, symptoms, and risk behaviors. Data in the study is collected by trained research staff and nurses." Source: US NLM Clinical Trial Registration