Assessing health in musculoskeletal disorders – the appropriateness of a German version of the Sickness Impact Profile

Abstract

The Sickness Impact Profile (SIP) is gaining increasing popularity in clinical and epidemiological studies, assessing health status or the impact of therapeutic interventions. The SIP was created as a global measure, assessing generic dimensions of health. As there were only a few such methods available in our country, we decided in 1990 to validate a German version of the SIP and to test its appropriateness in patients with musculoskeletal disorders. Due to the up-to-dateness of our results, we decided to publish now the data of this German version of the SIP. Reliability, validity and sensitivity to change of the German version of the SIP were tested in 299 patients with musculoskeletal disorders. The test-retest correlation was high for the overall score (r = 0.81), as well as for Cronbach's alpha (r = 0.83). Results for categories were significantly lower. Validity was tested by comparing the SIP to the Keitel Index (r = 0.6) and to the Measurement of Patient Outcome Scale (r = 0.72), as well as to a control group, which showed significant differences in all categories and in the overall score. Furthermore, the SIP was able to demonstrate therapy-related improvements in health in all our patients. We concluded that the german version of the SIP fulfilled statistical test criteria. The results were comparable to those achieved in the original American version. A cross-cultural comparison using the SIP is justified for at least those patients with musculoskeletal disorders.