Validity and reliability of lung cancer quality of life Questionnaire from European Organization for Research and Treatment of Cancer (EORTC QLQ-LC13) in Iran

Introduction: Lung Cancer has a great impact on different aspects of quality of life of patients who are diagnosed with such cancer; therefore, conducting research on such patient's quality of life is essential. In this study we will examine the effects of lung cancer on quality of life of patients who are diagnosed with this cancer and propose a suitable questionnaire for the purpose of determining various scopes of quality of life of patients as well as the validity and reliability of such questionnaire. Objective: The aim of this study is to investigation of validity and reliability of lung cancer quality of life from European Organization for Research and Treatment of Cancer (EORTC QLQ - LC13) in Iran. Method: 75 lung cancer patients admitted to hospitals in Iran cancer Institute of Tehran University of medical science and Masih daneshvari hospital were chosen by nonrandom sampling. Demographic questionnaire EORTC QLQ - LC13 and EORTC QLQ - C30 were completed by the questioner. Descriptive data by frequency tables were analyzed and content validity we used translation for translating and internal consistencies were measured by the Cranach's alpha coefficient. Results: total Cranach's alpha coefficient (The reliability or internal consistency) was 0.720. Spearman correlation coefficient of symptom and side effect subscale was 0.0601 not showed any overlap between questions of these subscales and the high measure of spearman rank correlation between symptom subscale and its questions was in the range of 0.357-0.754 and side effect subscale and its questions was 0.366-0.708, that indicated subscales of LC13 have significant correlation. Conclusion: In general, the findings of this study indicated that the Iranian version of the EORTC QLQ-LC13 is a reliable and valid supplementary measure of the quality of life in lung cancer patients and can be used in clinical trials and studies of outcome research in oncology.