Reliability and validity of the Functional Living Index-Cancer in Turkish cancer patients

The objective of this study was to test the reliability and validity of the Turkish version of the Functional Living Index-Cancer in Turkey. The English version of the Functional Living Index-Cancer was translated into Turkish following the standard translation methodology. The questionnaire was administered to 110 cancer patients who had been receiving chemotherapy. Internal consistency reliability was in the acceptable range for this instrument. Among cancer patients, the Cronbach alpha reliability for the total scale was .88, and subscale alpha coefficients ranged from .60 to .83, which is similar to the alpha of .79 observed in the Functional Living Index-Cancer, English version. The results of the principle components analysis and varimax rotation resulted in 5-factor structure: physical functioning, psychological functioning, current well-being, social functioning, and gastrointestinal symptoms. The results of this study suggest that the Turkish version of the Functional Living Index-Cancer is a reliable and valid supplementary measure of the quality of life in cancer patients in Turkey, and it can be used in clinical trials and studies of outcome research in oncology.