Onset and progression of chronic disease and disability in a large cohort of older Australian women

Abstract

ObjectiveTo estimate the probability of onset and progression of disease and disability, length of life with or without disease and/or disability, and incidence of mortality, and to identify factors associated with transitioning to disease and/or disability over time. Study designA prospective cohort study. Data were provided by 12,432 participants (born 1921–26) of the Australian Longitudinal Study of Women's Health linked with National Death Index data from 1996 (age: 70–75) to 2016 (age: 90–95). Main outcome measuresA five-state Markov model was fitted to estimate the transition probability, length of life with or without disease and/or disability, and the association between baseline characteristics and disease/disability/mortality risk. ResultsOver two-thirds of women had died by age 90–95, and only 3.8% of these had died with no chronic disease and disability. Those reporting chronic disease were more likely to have experienced disability (Transition Rate Ratio: 2•72, 95%CI= 2•52–2•93) than those who died without disability. At age 70–75, the expected life without chronic disease and disability was 7•68 (95%CI: 7•52–7•80) years, life with chronic disease but no disability was 4•39 (95%CI=4•23–4•49) years, and life with disability was 3.76 (95%CI=3•66–3•92) years. The factors difficulties managing on available income (HR=1•18, 95%CI=1•02–1•38), did not complete secondary school (HR=1•19, 95%CI=1•03–1•37), and overweight/obese (HR=1•36, 95%CI=1•20–1•55) were associated with an increased risk of disability. ConclusionsOur findings provide important insights on the onset and progression of disease and disability in older women, underscoring the importance of addressing mid-/early old-life risk factors, managing chronic conditions, and delaying disability onset and progression through targeted intervention programs.