Health status assessment in rheumatoid arthritis. II. Evaluation of a modified Shorter Sickness Impact Profile.

Abstract

To develop a shortened form of the Sickness Impact Profile (SIP) for routine practice. We used data from a study of health status in 99 women with rheumatoid arthritis (RA). A stepwise analysis model used physical discomfort (global rating), self-assessed pain (Body Symptom Scale), mental well-being (Mood Adjective Check List) and joint function (Keitel Index) to define important aspects of health. Short forms of the SIP for discrimination (53 items), evaluation (25 items) and prediction (28 items) compared well in validity to the original 136-item SIP. The discriminative short form showed excellent reliability (internal consistency), matching the level of the generic SIP. The evaluative and predictive short forms had acceptable but lower internal consistency than the original Profile. We suggest a 64-item core health status questionnaire (SIP-RA) to be included and further tested in the arsenal of routine measurements in outpatients with RA. The questionnaire should include physical (Body care and movement, Mobility), psychosocial (Emotional behavior, Social interaction, Alertness behavior, Communication) and free-standing (Sleep and rest, Home management, Recreation and past-times, Eating) SIP categories, and it will improve the description of patients with RA.