Brazilian-Portuguese validation of the University of Washington Quality of Life questionnaire for patients with head and neck cancer

Background. The University of Washington Quality of Life (UW-QOL) questionnaire is an English-language survey instrument used worldwide to assess the quality of life of patients with head and neck cancer. To be used in other cultures, such instruments require careful translation and psychometric validation in other languages. Methods. The translation and cultural adaptation of the questionnaire were performed following accepted international guidelines. The psychometric validation was performed on a consecutive series of patients with at least 1 year of disease-free survival after treatment for squamous cell carcinoma of the upper aerodigestive tract, recruited from October 2004 to January 2005 from a tertiary cancer center hospital. Eligible subjects were invited to complete the Portuguese version of the UW-QOL questionnaire during routine clinical consultation and complete it again within 15 days. They also completed a validated Portuguese version of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and a questionnaire to evaluate anxiety and depression symptoms (Hospital Anxiety and Depression Scale [HADS]). Results. A Portuguese version of the questionnaire was developed in iterative fashion. In the psychometric validation process, a total of 109 patients were analyzed. Reliability was excellent, including both internal consistency (Cronbach's alpha [α] of 0.744) and test retest reliability (intraclass correlation coefficient [ICC] of 0.882). Construct validity was supported by statistically significant relationships between the SF-36 and HAD questionnaires and the translated UW-QOL questionnaire. Conclusions. The Brazilian-Portuguese version of the UW-QOL questionnaire appears to be culturally appropriate and psychometrically valid. This version is a valuable tool to evaluate accurately the quality of life of Brazilian patients with head and neck cancer.