The structure of affective symptomatology in older adults with osteoarthritis.

Objective: To examine the structure of symptoms of affective disorder among older adults with a chronic health problem (osteoarthritis) and to explore cross-sectional and longitudinal associations of obtained affective symptom clusters with key health outcomes (pain, functional disability, perceived health).

Methods: One-year longitudinal study of older adults with diagnosed osteoarthritis of the knee. Symptoms of DSM depression and anxiety were assessed in a research diagnostic interview by using a DSM-IV symptom checklist; self-reports captured demographic characteristics, objective health, pain, disability, and perceived health. Confirmatory factor analysis tested comparability of affective symptom structure in this sample to findings of previous research; ordinary least squares regression examined cross-sectional and longitudinal associations of affective symptoms with health outcomes, controlling for demographics and objective health.

Results: The current sample displayed an affective symptom structure comparable with that observed in previous research, with symptoms clustering into depressed mood (DM), somatic symptoms (SS), and psychic anxiety (PA) factors. DM was cross-sectionally associated with pain and disability and marginally with perceived health; SS predicted current pain and perceived health. Only DM predicted 1 year change in disability and perceived health (but not pain).

Conclusions: This research confirms the role of SS of distress in fueling disability and perceived ill health among older adults who are chronically ill. However, it is DM that drives changes in perceived health and functional ability.