Do socioeconomic gradients in women's health widen over time and with age?

A population-based study was conducted to investigate changes over time in women's well-being and health service use by socio-economic status and whether these varied by age. Data from 12,328 mid-age women (aged 45–50 years in 1996) and 10,430 older women (aged 70–75 years) from the Australian Longitudinal Study on Women's Health were analysed. The main outcome measures were changes in the eight dimensions of the Short Form General Health Survey (SF-36) adjusted for baseline scores, lifestyle and behavioural factors; health care utilisation at Survey 2; and rate of deaths (older cohort only). Cross-sectional analyses showed clear socioeconomic differentials in well-being for both cohorts. Differential changes in health across tertiles of socioeconomic status (SES) were more evident in the mid-age cohort than in the older cohort. For the mid-aged women in the low SES tertile, declines in physical functioning (adjusted mean change of –2.4, standard error (SE) 1.1) and general health perceptions (−1.5, SE 1.1) were larger than the high SES group (physical functioning –0.8 SE 1.1, general health perceptions –0.8 SE 1.2). In the older cohort, changes in SF-36 scores over time were similar for all SES groups but women in the high SES group had lower death rates than women in the low SES group (relative risk: 0.79, 95% confidence interval 0.64–0.98). Findings suggest that SES differentials in physical health seem to widen during women's mid-adult years but narrow in older age. Nevertheless, SES remains an important predictor of health, health service use and mortality in older Australian women.