Measurement of Stigma in Men Who Have Sex with Men in Hanoi, Vietnam: Assessment of a Homosexuality-Related Stigma Scale.

Objective. To develop and assess a homosexuality-related stigma scale among men who have sex with men (MSM) in Hanoi, Vietnam. Methods. We conducted a cross-sectional study using respondent-driven sampling in Hanoi, Vietnam, in 2011. We used a cross-validation approach. Factor analysis was performed, and interitem correlation matrices were constructed to identify the latent factor structures, examine the goodness of fit, and assess convergent and discriminant validity of the determined scales. Internal consistency checks were performed in split samples and whole sample, and separately for each determined factor. Results. The findings were consistent in split samples. Three homosexuality-related stigma factors were identified: enacted homosexual stigma, perceived homosexual stigma, and internalized homosexual stigma. The fit indices of the confirmatory factor analysis in both split samples supported the hypothesized three-factor structures (in subsamples A and B: χ (2)/degrees of freedom ratio = 1.77 and 1.59, nonnormed fit index = 0.92 and 0.94, comparative fit index = 0.93 and 0.95, and the root mean square of approximation = 0.06 and 0.05, resp.). The interitem correlation supported the convergent and discriminant validity of the scales. The reliability of the three scales indicated good consistency (Cronbach's alpha: 0.79-0.84) across split samples and for the whole data. Conclusion. Our scales have good psychometric properties for measuring homosexuality-related stigma. These comprehensive and practical tools are crucial not only to assess stigma against MSM and its consequence, but also to guide the development of interventions targeting MSM, as well as to evaluate the efficacy of existing stigma reduction efforts in Vietnam and other countries with similar settings.