Discriminant and convergent validity of self-report measures of affective distress in patients with rheumatoid arthritis.

The discriminant and convergent validity of several self-report measures of affective distress commonly administered to patients with rheumatoid arthritis (RA) were examined. Fifty-two patients with RA completed the Arthritis Helplessness Index, the Beck Depression Inventory, Spielberger's State Anxiety and Trait Anxiety Inventories, and the Arthritis Impact Measurement Depression and Anxiety Scales. Correlational and factor analyses revealed that the measures of anxiety and depression demonstrated adequate convergent validity but poor discriminant validity. Our results suggest that these measures index a general feeling of distress rather than discrete affective difficulties. The ability of these measures to assess separate problems of anxiety and depression among RA patients is questioned.