Supplementary Material for: VALIDITY AND RELIABILITY STUDY OF THE TURKISH VERSION OF THE BREAST CANCER STIGMA SCALE: A METHODOLOGICAL STUDY

IIntroduction: The purpose of this methodological and descriptive study was to conduct the validity and reliability study of the Breast Cancer Stigma Scale (BCSS) for the Turkish population of breast cancer patients. Methods: The sample of the study consisted of 150 female patients who were diagnosed with breast cancer, met the inclusion criteria, and applied to the oncology clinics and outpatient units of a university hospital. Data were collected through face-to-face interviews using a 13-item personal information form investigating patients’ sociodemographic and disease-related characteristics, the Breast Cancer Stigma Scale (BCSS), and the Patient Health Questionnaire-9 (PHQ-9). Language and content validity, criterion validity, construct validity, and reliability analyses of the scale were conducted sequentially. Descriptive statistical methods (number, percentage, mean, standard deviation), correlation analysis, Kruskal–Wallis test, Mann–Whitney U test, t-test, Cronbach’s alpha analysis, confirmatory factor analysis, and exploratory factor analysis were used for data analysis. Results: The Content Validity Index (CVI) value was found to be 1.0. The factor loadings of the scale ranged between 0.663 and 0.892, and the total explained variance was 73.89%. The Turkish version of the BCSS demonstrated excellent internal consistency (Cronbach’s α = 0.70-0.92) and good construct validity (CFA fit indices: CFI = 0.97, TLI = 0.96, RMSEA = 0.05, SRMR = 0.05). The Cronbach’s alpha coefficients for the subscales of the BCSS were 0.92 for the Body-image Impairment (BI) subscale, 0.70 for the Social Isolation (SI) subscale, 0.78 for the Discrimination (D) subscale, 0.89 for the Internalized Stigma (IS) subscale, and 0.90 for the total the BCSS score. The Turkish version of the scale showed a good fit with the original model, confirming its four-factor structure. Conclusion: The Turkish version of the BCSS was found to be valid and reliable. Keywords: Breast cancer, Stigma, Validity, Reliability