Background: the identification of modifiable risk factors for preventing disability in older individuals is essential for planning preventive strategies.
Purpose: to identify cross-sectional correlates of disability and risk factors for the development activities of daily living (ADL) and instrumental ADL (IADL) disability in community-dwelling older adults.
Methods: the study population consisted of 897 subjects aged 65–102 years from the InCHIANTI study, a population-based cohort in Tuscany (Italy). Factors potentially associated with high risk of disability were measured at baseline (1998–2000), and disability in ADLs and IADLs were assessed both at baseline and at the 3-year follow-up (2001–03).
Results: the baseline prevalence of ADL disability and IADL disability were, respectively, 5.5% (49/897) and 22.2% (199/897). Of 848 participants free of ADL disability at baseline, 72 developed ADL disability and 25 of the 49 who were already disabled had a worsening in ADL disability over a 3-year follow-up. Of 698 participants without IADL disability at baseline, 100 developed IADL disability and 104 of the 199 who already had IADL disability had a worsening disability in IADL over 3 years. In a fully adjusted model, high level of physical activity compared to sedentary state was significantly associated with lower incidence rates of both ADL and IADL disability at the 3-year follow-up visit (odds ratio (OR): 0.30; 95% confidence intervals (CI) 0.12–0.76 for ADL disability and OR: 0.18; 95% CI 0.09–0.36 for IADL disability). After adjusting for multiple confounders, higher energy intake (OR for difference in 100 kcal/day: 1.09; 95% CI 1.02–1.15) and hypertension (OR: 1.91; 95% CI 1.06–3.43) were significant risk factors for incident or worsening ADL disability.
Conclusions: higher level of physical activity and lower energy intake may be protective against the development in ADL and IADL disability in older persons.