Cardiff Wound Impact Schedule-Validity, Reliability and Dimensionality of the Norwegian Version

The objective of this study was to test the validity, reliability and dimensionality of the Norwegian version of the Cardiff Wound Impact Schedule (CWIS), a measure for wound-specific health-related quality of life. The Norwegian CWIS and a 36-item short form health survey (SF-36) were completed by 204 patients with hard-to-heal wounds on the lower extremity. The questionnaires were filled in at three time points over 8-14 weeks (T0, T1, T2). The Patients Global Impression of Change (PGIC) was completed at T1 and T2. Demographic and clinical data were collected at T0 and T2. The three-factor model of the CWIS showed an acceptable fit to the observed data, and the dimensionality was clear as long as two correlated error terms were accepted and four items were removed (χ² = 426.64, p = 0.000, df = 204, χ²/df = 2.09, RMSEA = 0.074, SRMR = 0.066, CFI = 0.900, TLI = 0.880). Correlation analyses showed significant associations between the CWIS and SF-36 (0.350**-0.766**), PGIC (-0.277**), wound size (-0.156**), general wound pain intensity (-0.371**) and pain intensity at wound change (-0.240**); all aligned with the expected directions. The intraclass correlations indicated good to excellent test-retest reliability (0.724**-0.951**). The internal consistency ranged from acceptable to excellent (α = 0.78-0.89, ρc = 0.79-0.89). While the questionnaires' ability to detect wound-related change was low, it was adequate for differentiating between healed and non-healed ulcers. The Norwegian version of the CWIS demonstrated good reliability and construct validity, making it suitable for evaluating HRQoL in patients with hard-to-heal wounds. However, some modifications were made to achieve an acceptable model fit.