Psoriatic Arthritis Quality of Life Questionnaire: translation, cultural adaptation and validation into Brazilian Portuguese language

Introduction Psoriatic arthritis (PsA) is a multifaceted inflammatory disease that can cause joint destruction and impair quality of life. The Psoriatic Arthritis Quality of Life Questionnaire (PsAQoL) was the first disease-specific tool for determining the impact of the disease on the quality of life of people with PsA. Objectives The primary objective was to develop and validate a Brazilian Portuguese version of the PsAQoL. Methods The UK PsAQoL was translated into Brazilian Portuguese using two translation panels. This translation then checked for face validity and construct validity with new samples of patients. Finally, a test-retest validation study was conducted with 52 patients with PsA. The survey included the Nottingham Health Profile (NHP) as a comparator instrument. Results Internal consistency and reproducibility were both excellent for the new adaptation (0.91 and 0.90 respectively Scores on the PsAQoL were found to correlate as expected with the comparator measure and the instrument was able to detect differences in score related to perceived severity of PsA, general health status and presence of a flare. Conclusion The Brazilian PsAQoL was found easy to understand and complete and has excellent reliability and construct validity. The new measure will be a valuable new tool for use in routine PsA practice and clinical trials.