Cohort Profile: The Australian Longitudinal Study of Ageing (ALSA)

Abstract

In response to the expressed need for more sophisticated and multidisciplinary data concerning ageing of the Australian population, the Australian Longitudinal Study of Ageing (ALSA) was established some two decades ago in Adelaide, South Australia. At Baseline in 1992, 2087 participants living in the community or in residential care (ranging in age from 65 to 103 years) were interviewed in their place of residence (1031 or 49% women), including 565 couples. By 2013, 12 Waves had been completed; both face-to-face and telephone personal interviews were conducted. Data collected included self-reports of demographic details, health, depression, morbid conditions, hospitalization, gross mobility, physical performance, activities of daily living, lifestyle activities, social resources, exercise, education and income. Objective performance data for physical and cognitive function were also collected. The ALSA data are held at the Flinders Centre for Ageing Studies, Flinders University. Procedures for data access, information on collaborations, publications and other details can be found at [http://flinders.edu.au/sabs/fcas/].

A loyal participant “Sheila” is shown on three occasions over her 21 years of continuous involvement in the ALSA. She was 80 years of age at Wave 3, shown doing the Clinical Assessment; 95 at Wave 11 doing her home interview and 99 years at Wave 12. In 2014 she celebrated her 100th birthday.

Figure 1.

Mode of interview and number of participants over time in the ALSA study. SW1¹, since Wave 1.

Figure 2.

Illustration of the differential magnitude of dynamic partner effects between wives’ and husbands’ perceptual speed (Top Panel) and subjective well-being (Bottom Panel) Top Panel A represents model-implied sample (of average age and education) means on wives’ cognition (perceptual speed) from a bivariate Dual Change Score Model (Full Dynamics) for the hypothetical case that the initial sample means for husbands’ cognition were varied by half a standard deviation (i.e., 5 T-score units). Under the assumption of comparable wives’ cognition at T1, wives with cognitively fit husbands (husbands_T1 +0.5 SD) showed relatively shallow perceptual speed decline, whereas those with cognitively less fit husbands (husbands_T1 –0.5 SD) showed relatively steeper perceptual speed decline. In contrast, the lines in Top Panel B indicate that husbands’ cognitive trajectories of change over time were minimally changed as a function of different initial levels of wives’ perceptual speed. Bottom Panel B shows model-implied change in subjective well-being (SWB: morale) for participants (of average age and education, adjusted also for health constraints, length of marriage, and number of children) assuming that all husbands reported similar morale at T1, but their wives differed in initial morale. On average, morale declined for husbands; but husbands whose wives reported low SWB (wives_T1 –0.5 SD) showed relatively stronger SWB decline, whereas those husbands whose wives reported high SWB (husbands_T1 +0.5 SD) showed relatively shallow decline. In contrast, Bottom Panel A shows wives’ decline was altered modestly as a result of varying initial husbands’ SWB.