The Sickness Impact Profile: Development and Final Revision of a Health Status Measure

TLDR

The study presents the final development of the Sickness Impact Profile (SIP), a behaviorally based health status measure, and introduces a profile and pattern analysis technique for comparing group differences. The authors conducted large field trials and smaller disease‑specific studies to evaluate the SIP’s reliability and validity, using multitrait–multimethod and clinical measures, and finalized a 136‑item instrument with 12 categories whose overall, category, and dimension scores can be calculated. The SIP demonstrated high test‑retest reliability (r = 0.92) and internal consistency (r = 0.94), and its scores correlated moderately to highly with criterion measures in the expected direction.

Abstract

The final development of the Sickness Impact Profile (SIP), a behaviorally based measure of health status, is presented. A large field trial on a random sample of prepaid group practice enrollees and smaller trials on samples of patients with hyperthyroidism, rheumatoid arthritis and hip replacements were undertaken to assess reliability and validity of the SIP and provide data for category and item analyses. Test-retest reliability (r = 0.92) and internal consistency (r = 0.94) were high. Convergent and discriminant validity was evaluated using the multitrait–multimethod technique. Clinical validity was assessed by determining the relationship between clinical measures of disease and the SIP scores. The relationship between the SIP and criterion measures were moderate to high and in the direction hypotheszed. A technique for describing and assessing similarities and differences among groups was developed using profile and pattern analysis. The final SIP contains 136 items in 12 categories. Overall, category, and dimension scores may be calculated.