The general purpose of the Australian [Adelaide] Longitudinal Study of Aging (ALSA) is to gain further understanding of how social, biomedical, and environmental factors are associated with age-related changes in the health and well-being of persons aged 70 years and older. Emphasis is given to the effects of social and economic factors on morbidity, disability, acute and long-term care service use, and mortality. The aim is to analyze the complex relationships between individual and social factors and changes in health status, health care needs, and service utilization dimensions. Components of Wave 6 (1999-2000) (Part 1) include a comprehensive personal interview conducted via the Computer-Assisted Personal Interview (CAPI) system, a home-based assessment of physiological functions, self-completed questionnaires, and additional clinical studies. In Part 2, Wave 6 Clinical Data, information about the health histories of the respondents was elicited, including information on medication, blood pressure, and physical and mental disabilities.