Association between chronic diseases and disability in elderly subjects with low and high income: the Leiden 85-plus Study

BACKGROUND: Disability in activities of daily living (ADL) might be more prevalent among elderly with low income due to higher prevalence of chronic diseases and impairments, as well as stronger associations of these factors with ADL-disability. METHODS: In the Leiden 85-plus Study, we defined disability as being unable to perform one or more basic ADL activities. Presence of chronic diseases was obtained from medical records, impairments were assessed with performance-tests. RESULTS: Elderly with low income had higher prevalence of ADL-disability (23% versus 12%; odds ratio 2.0; 95% confidence interval 1.3-3.2), higher prevalence of impairments and equal prevalence of chronic diseases, except for dementia and co-morbidity. Associations of these factors with ADL-disability were not stronger. CONCLUSIONS: We conclude that ADL-disability is more prevalent in elderly with low income. Neither prevalence of chronic diseases nor the association with disability could explain this