Sexual function index adaptation for breast cancer patients (FSFI-BC)- translation and psychometric properties of Persian version

Background Effective interventions to improve sexual dysfunction in breast cancer survivors need screening of these dysfunctions with a suitable instrument. The aim of present study was translation and identifying psychometric properties of Female Sexual Function Index - Adapted for Breast Cancer (FSFI-BC) which has been specifically developed for breast cancer survivors. Method This methodological study was performed between February 2017 and October 2018. 200 breast cancer survivors in stage 1 or 2 who were selected through convenience sampling method, completed the questionnaire. Reliability was assessed by Cronbach's alfa and test re-test analysis and construct validity was performed through confirmatory (CFA) and exploratory factor analysis( EFA). Results Six factors were extracted in exploratory factor analysis (EFA). These factors explained 74.6% of the total variance in in NSA group and 0.821 in SA group. Reliability evaluation indicated high internal consistency and good test re-test reliability. Cronbach's alpha coefficient in all areas of the tool was above 0.7 (the lowest and the highest measures were 0.885 and 0.945, respectively), which is a good indicator for reliability of an instrument. Confirmatory factor analysis showed an acceptable fitness for seven factors of FSFI-BC questionnaire (Normed Fit Index or NFI = 0.9 for both groups, Comparative of Fit Index or CFI = 0.93 and 0.92,. 2/df = 1.68 and 1.71 for SA(Sexually Active) and NSA(No Sexually Active) individuals, respectively). Conclusion Study findings suggest that Persian version of FSFI-BC is a suitable instrument for sexual dysfunction screening in breast cancer survivors.