Background: Research on the comparison of mental health services has identified the need for internationally standardised and reliable measurements.
Aims: To describe the strategies adopted in the European Psychiatric Services: Inputs Linked to Outcome Domains and Needs (EPSILON) Study for the translation and cross-cultural adaptation of five European versions of the instruments.
Method: A protocol was developed for translation of the outcome scales, describing each step in the translation procedure. Disputed items were discussed in focus groups, which faced seven tasks: a list of topics to be discussed; choosing where the group should meet; composition of participants; conducting the group; data collection; data completion afterwards; reporting results.
Results: Modifications made to instruments were: changes in the instrument structure, contents and concepts; adjustments to the instrument structure; and modifications to the instrument manual.
Conclusion: Use of focus groups is an adequate method to apply if concepts, constructs and translation issues are to be addressed; otherwise, less time-consuming methods should be considered.