Iranian Version of the Quality of Life in Adult Cancer Survivors (QLACS) Questionnaire: Examining Face and Content Validity, Exploratory Factor Analysis and Reliability

Abstract

Background: Quality of life among cancer patients after diagnosis and treatment steps is an important factor in preventing further cancer complications. Thus, appropriate tools to evaluate the quality of life among this group are required. Quality of life in Adult Cancer Survivors (QLACS) questionnaire is a suitable tool which evaluates different aspects of life among cancer survivors. Objectives: This study evaluated the Persian version of the QLACS questionnaire among Iranian short-survivors of breast cancer by assessing its validity and reliability. Methods: The QLACS was translated to Persian for this study. The questionnaire's face and content validity were assessed by a panel of experts by the impact score, content validity ratio, and index methods. In the next step, the questionnaire was filled out by 150 women with breast cancer who were diagnosed 1.5 - 5 years before this study. Explanatory factor analysis was performed to assess factors. Reliability was evaluated using Cronbach’s alpha. Results: Overall, 37 items were selected for explanatory factor analysis that had an impact score of more than 1.5, content validity ratio (CVR) more than 0.99, and a suitable content validity index (CVI). In factor analysis, 10 factors were extracted via varimax rotation, accounting for 75.8% of the total variance. Cronbach’s alpha of all the factors was more than 0.7, that was similar to the original questionnaire. Conclusions: We conclude that the Persian version of the QLACS questionnaire has optimal properties for the assessment of quality of life among Iranian short-survivors of breast cancer.