The short form‐36 is preferable to the SIP as a generic health status measure in patients undergoing elective total hip arthroplasty

Open Access
Publisher Website
Google Scholar
Abstract
Objective. To assess the comparative usefulness of the Short Form‐36 (SF‐36) and the Sickness Impact Profile (SIP) as generic health status measures in total hip arthroplasty. Methods. Analysis of preoperative and 3‐month data of 54 consecutive patients undergoing total hip replacement for osteoarthritis or rheumatoid arthritis. Instruments were mailed to patients preoperatively and 3 months postoperatively. Results. In 10 of the 12 SIP subscales, but just 1 of the 8 SF‐36 subscales, more than 40% of the patients had scores of zero. On α 100‐point scale, the median global SIP was 12 (range 0–40) whereas the median global SF‐36 was 50 (range 10–85). This indicates that many items of the SIP were not germane to patients undergoing joint arthroplasty. The global and, particularly, the physical dimensions of the SF‐36 were more responsive than their SIP counterparts, as measured both by the standardized response mean (1.26 and 0.88, respectively) and the correlation with self‐perceived improvement in quality of life (r = 0.37 and 0.26, respectively). The SF‐36, but not the SIP, discriminated between patients with relatively good physical performance at 3 months with respect to their ability to work, to play sports, or to garden. Conclusion. The SF‐36 is briefer, more relevant, and more responsive than the SIP and is preferable as a generic health status measure in patients undergoing elective hip arthroplasty. The SF‐36 should be tested in other populations as well as other conditions to determine whether it is a superior generic health status instrument for evaluative research in orthopedic surgery.