Clinical meaning of the Stroke-Adapted Sickness Impact Profile-30 and the Sickness Impact Profile-136

Abstract

Background and purpose: Handicap or health-related quality of life (HRQL) measures are seldom used in stroke trials, although the importance of these measures has been stressed frequently. We studied the clinical meaning of the Stroke-Adapted Sickness Impact Profile-30 (SA-SIP30) and the original SIP136 for use in stroke research.

Methods: We included 418 patients who had had a stroke 6 months earlier. We studied the associations between the SA-SIP30 and SIP136 scores versus other frequently used outcome measures from the International Classification of Impairments, Disabilities, and Handicaps (ICIDH) (Barthel Index, Rankin Scale) and the HRQL model (health perception items, Euroqol). To interpret the continuous SA-SIP30 and SIP136 scores, we used receiver operating characteristic curve analysis with the aforementioned measures as external criteria.

Results: The psychosocial dimension scores of both SIP versions remained largely unexplained. The physical dimension and total scores of both SIP versions were mainly associated with the disability measures derived from the ICIDH model, as well as with the physical HRQL domains. Most patients with an SA-SIP30 total score >33 or an SIP136 total score >22 had poor health profiles. There were no major differences between the SA-SIP30 and the SIP136, although the SA-SIP30 scores were less skewed toward the healthier outcomes than the SIP136.

Conclusions: Our study showed that (1) both SIP total scores primarily represent aspects of physical functioning and not HRQL; (2) both SIP versions provide more clinical information than the frequently used disability measures; and (3) the SA-SIP30 should be preferred over the SIP136.