Reproducibility of the Brazilian Portuguese version of the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire used in conjunction with its lung cancer-specific module

Objective: The assessment of the quality of life in patients with lung cancer has become one of the main goals in current clinical trials. To assess the quality of life of these patients, the most widely used instrument is the 30-item European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) in conjunction with its supplemental 13-item lung cancer-specific module (QLQ-LC13). The objective of this study was to assess the reproducibility of the Brazilian Portuguese version of these questionnaires. Methods: A prospective study involving 30 stable outpatients with rung cancer who completed the instruments on the first day of the study and two weeks later. Results: The test-retest reproducibility using the intraclass correlation coefficient for the EORTC QLQ-C30 and the QLQ-LC13 ranged from 0.64 to 1.00 and from 0.64 to 0.95, respectively. No correlations were found between the domains of the instruments and clinical parameters. Conclusions: Our findings show that these instruments were reproducible in this sample of patients with lung cancer in Brazil.