Health-related quality of life in Switzerland: normative data for the SF-36v2 questionnaire.

Purpose: Health-related quality of life (HRQOL) is an important concept to describe well-being of the general population and persons with diseases. The short form-36 (SF-36) is a widely used questionnaire assessing self-reported HRQOL in eight health domains. The aims of this study were to provide normative data for the SF-36 version 2 (SF-36v2) for all language regions in Switzerland and weighting coefficients to calculate two summary measures for physical and mental health. Methods: A random representative (regarding age, sex, and language region) sample of people living in Switzerland aged 18-75 years in 2015 was eligible for our questionnaire survey. We calculated the eight health domain subscales for different subsamples based on sociodemographic characteristics. Two summary measures for physical and mental health were derived using data-based factor score coefficients and calculated for the subsamples. Results: A total of 1209 persons completed the SF-36v2 (mean age 48.7 years, 58.1% women). The SF-36v2 was valid and reliable in Switzerland. Physical health was better in men (p = 0.012) and younger persons (p < 0.001). Mental health was better in men (p < 0.001) and older persons (p < 0.001). Regarding regional differences, we found better physical (p = 0.002) and mental (p < 0.001) health in German speaking persons compared to French and Italian speaking persons. Conclusions: This paper presents the first SF-36v2 normative data for Switzerland, which are based on a recent study in a representative sample. Our normative data and weighting coefficients will enable future studies to compare HRQOL assessed by the SF-36 in healthy and diseased persons to a representative Swiss sample.