Validation of the BODY-Q Chest module in Finnish trans men undergoing chest wall masculinization

The aim of gender affirmation surgery is to ease gender dysphoria. In transgender men, chest wall masculinization is the most common gender affirmation surgery. The BODY-Q Chest module is currently the only instrument developed to measure health-related quality of life (HRQL) in men undergoing chest wall surgery. Linguistic validation and cultural adaption to Finnish were performed previously. The study aims to validate the BODY-Q Chest module in transgender men who have undergone surgical chest wall masculinization.All transgender patients who underwent chest wall masculinization at Helsinki University Hospital between 2005 and 2018 were invited to the study. The BODY-Q Chest module comprises two scales-chest and nipple. Data were obtained using the BODY-Q Chest module, the 15D questionnaire, and specifically targeted items designed by the authors. The statistical analyses were conducted to exclude selection bias, evaluate validity of the instrument, and compare it to other instruments.Of the 220 patients invited, 123 participated in the survey (response rate 56%). Ceiling effects were observed with 18.9% and 20.5% scoring maximum points. Cronbach's alpha was 0.92 and 0.88 for the chest and nipple scales, respectively. In exploratory factor analysis, both scales loaded to one factor confirming unidimensionality. Correlation with the generic 15D questionnaire was low.The BODY-Q Chest module provides valid scores with sufficient consistency and reliability when measuring HRQL in transgender men undergoing chest wall masculinization. Moreover, it offers specificity that existing or generic instruments cannot provide. Ceiling effect was expected due to the postoperative status of participants.