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.