Impact of chronic systemic and neurological disorders on disability, depression and life satisfaction

To assess the effects of a range of chronic systemic and neurological disorders on three life quality indicators: disability, depressive symptoms and life satisfaction.

As part of the Sydney Older Persons Study, a community survey was carried out with 434 non-demented people aged 75 or over living in Sydney, Australia. Subjects were given a medical examination covering the following disorders: heart disease, chronic lung disease, bone and joint disease, stroke, visual loss, peripheral vascular disease, obesity, other systemic diseases, gait ataxia, gait slowing (including Parkinsonism) and cognitive impairement short of dementia. They were also assessed on a clinician-rated disability scale and given self-report depression and life satisfaction scales.

Gait slowing affected all three indicators of life quality. Heart disease and chronic lung disease affected disability and depressive symptoms, but not life satisfaction. These associations were present when the effects of age, sex, education and all other disorders were controlled in multiple regression analyses. However, when disability was also controlled, none of the physical disorders predicted life satisfaction and only heart disease continued to predict depressive symptoms.

Of the physical disorders considered in the study, gait slowing, heart disease and chronic lung disease had the greatest impact on life quality. These disorders affect depressive symptoms and life satisfaction largely because they increase disability.