Male Genital Self-Image Scale (MGSIS): Cutoff Point, Cultural Adaptation and Validation of Measurement Properties in Brazilian Men

Background: Concerns about genital self-image (GSI) can influence sexual function and quality of life, and instruments that assess male GSI, such as the Male Genital Self-Image Scale (MGSIS), need to be adapted and validated in different cultures. Aims: To culturally adapt and validate the measurement properties of MGSIS in Brazilian men, according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline, and to create a cutoff point for satisfaction with male GSI. Methods: We assessed the validity of content through a committee of experts and cognitive interviews. The internal consistency and test-retest reliability were assessed using Cronbach's alpha and Intraclass Correlation Coefficient (ICC). We also calculate measurement errors using the Bland and Altman graph. The structural validity was investigated through exploratory and confirmatory factor analysis. The hypothesis test for construct validity was assessed using Spearman correlation from MGSIS with the International Index of Erectile Function (IIEF), Body Appreciation Scale (BAS-2) and Rosenberg Self-Esteem Scale (RSES). To create a cutoff point for satisfaction with the GSI, the item response theory and the classic test theory were used. Outcomes: Male's (i) GSI, (ii) sexual function, (iii) body appreciation, and (iv) self-esteem were assessed. Results: In this study, 518 men with a mean age of 33.90 (+/- 13.83) years participated. The Brazilian version of MGSIS demonstrated good content validity and a single factor that explained 64.57% of the variance. Cronbach's a and ICC values were 0.905 and 0.806, respectively. By assessing measurement errors, we found no systematic bias in the sample. MGSIS showed a moderate to weak correlation with IIEF, BAS-2 and RSES. A cut-off point of 23 in the MGSIS total score was found to rate satisfaction with the GSI. Clinical Translation: MGSIS is a valid and reliable measurement instrument for measuring male GSI in Brazil. Strengths and Limitations: This study evaluated the measurement properties of MGSIS according to COSMIN, which is a powerful and useful guideline for measurement properties. However, due to the lack of a gold standard for measuring the GSI, we have not assessed the criterion validity. Conclusion: MGSIS is valid, reliable and can be useful to assess the GSI and classify the satisfaction with the GSI of Brazilian men. Copyright (C) 2021, International Society of Sexual Medicine. Published by Elsevier Inc. All rights reserved.