RESUMEN
BACKGROUND: Patient-reported quality of life (QOL) is an outcome measure in clinical trials in multiple sclerosis (MS), but translated QOL instruments may affect the actual comparability of data. OBJECTIVES: We aimed to investigate possible differences in QOL in MS between cultures and countries. We employed the Functional Assessment of Multiple Sclerosis (FAMS) Version 4 questionnaire, which is a state-of-the-art QOL instrument. METHODS: Some 484 MS patients from Austria (145), Germany (144), and Poland (195) aged 20-60 years, and stratified for sex and disease severity as measured by the Expanded Disability Status Scale (EDSS) score completed the respective FAMS translation and a socio-demographic questionnaire. RESULTS: Analysis of variance and post-hoc Scheffé-test showed that 64% of the FAMS items were answered significantly differently (p < 0.001) between the three countries. A multivariate regression analysis including all the available disease-related and socio-demographic variables revealed the factors age, EDSS score, employment, social contacts, MS course, and country to be significant predictors of both the total FAMS score and the score for items answered differently between the three countries. CONCLUSIONS: Differences exist in the QOL of MS patients from Austria, Germany, and Poland which seem to lie beyond the impact of disease severity. They appear to be related to culture or other country-specific factors, as country was an independent predictor of differently answered items of the FAMS and thus also of the whole FAMS. QOL instruments should consider this aspect to faithfully reflect subjective information such as patient-reported benefit of treatment in multinational clinical trials.