Validity and Reliability of Turkish Version of the Functional Assessment of Cancer Therapy-Brain Questionnaire.

Abstract

Assessing the quality of life (QOL) of patients with brain tumors is ever more important, given increasing survivorship and the higher likelihood of developing potential morbidities associated with new therapies. The aim of this study was to adapt the Functional Assessment of Cancer Therapy-Brain (FACT-Br) Questionnaire for Turkish populations and test its validity and reliability. The questionnaire was first translated into Turkish and back-translated, adapting it to the Turkish culture. This Turkish version of the FACT-Br was administered to 500 patients. Confirmatory factor analysis was conducted to examine the scale's construct validity. Test-retest and Cronbach's α reliability coefficients were calculated to determine reliability of the total questionnaire and all subdimensions. The questionnaire's factor structure demonstrated good fit, implying that it could be applied to the Turkish population. Interclass correlation coefficients were between 0.93 and 0.99. The 5 subscales demonstrated good internal consistency, with Cronbach's α ranging from .72 to .87. Overall, the reliability estimate for the total scale was 0.93. There was no difference between a 15-day test and retest coefficients for subscale and total scores, indicating stability. The Turkish version of the FACT-Br is a valid and reliable instrument that can be used to measure the QOL of patients with a brain tumor in Turkey. This assessment tool can be used in treatment evaluations and to evaluate other measures of QOL.