A comprehensive method for the translation and cross-cultural validation of health status questionnaires.

The FACIT (Functional Assessment of Chronic Illness Therapy) translation methodology has been in use for nearly 10 years and, during the course of that time, has emphasized a universal translation approach that includes multicountry review, the use of qualitative and quantitative methods in testing, and the exploration of new methods such as differential item functioning (DIF) analysis using item response theory to evaluate item equivalence. The FACIT translation methodology aims to establish equivalence of meaning and measurement between different country versions through the use of the decentered model of translation and advanced statistical methods.