Translation, validation, and norming of the Dutch language version of the SF-36 Health Survey in community and chronic disease populations

The primary objectives of this research were to translate; validate, and generate normative data on the SF-36 Health Survey for use among Dutch-speaking residents of the Netherlands. Translation of the SF-36 into Dutch followed the stepwise, iterative procedures developed by the IQOLA Project. Following extensive pilot testing, the SF-36 was administered to: (1) a random sample of adult residents of Amsterdam (n = 4172); (2) a random, nationwide sample of adults (n = 1742); (3) a sample of migraine sufferers (n = 423); and (4) a sample of cancer patients undergoing active anti-neoplastic treatment (n = 485). Data quality across the four studies was consistently high. The rates of missing data ranged from 1% to 5% at the item level, and from 1.2% to 2.6% at the scale level. Multitrait scaling analysis confirmed the hypothesized scale structure of the SF-36 and associated scale scoring in all four samples. Cronbach's alpha coefficients surpassed the 0.70-criterion for group comparisons in all but one case (the Social Functioning stale in the cancer sample), with a mean alpha coefficient across all scales and samples of 0.84. Known-group comparisons yielded consistent support for the validity of the SF-36. In the two community samples, statistically significant differences in SF-36 mean scale scores were observed as a function of age, gender, and the prevalence of chronic health conditions. In the migraine and cancer samples, mean SF-36 scale scores varied significantly as a function of Various indicators of disease severity. The SF-36 profiles for the two community samples were highly similar. The cancer sample yielded the lowest SF-36 scores, with the migraine sample holding an intermediate position. On-going studies will generate data on the responsiveness of the SF-36 to within-group changes in health over time. Efforts are underway to translate and validate the questionnaire for use among ethnic minority groups in the Netherlands. (C) 1998 Elsevier Science Inc.