Evaluating translations of health status questionnaires. Methods from the IQOLA project. International Quality of Life Assessment.

There is growing demand for translations of health status questionnaires for use in multinational drug therapy studies and for population comparisons of health statistics. The International Quality of Life Assessment (IQOLA) Project is conducting a three-stage research program to determine the feasibility of translating the SF-36 Health Survey, widely used in English-speaking countries, into other languages. In stage 1, the conceptual equivalence and acceptability of translated questionnaires are evaluated and improved using qualitative and quantitative methods. In stage 2, assumptions underlying the construction and scoring of questionnaire scales are tested empirically. In stage 3, the equivalence of the interpretation of questionnaire scores across countries is tested using methods that closely approximate their intended use, and empirical results are compared. Data analyses from Sweden and the United Kingdom, as well as other research cited, support the feasibility of cross-cultural health measurement using the SF-36.