Stata version 12.1 for windows

The frequency distributions of all data sets were determined. Bivariate analyses using the Chi-square test were performed to examine the associations between willingness to participate with and sociodemographic characteristics, perceptions, and knowledge concerning HIV vaccine studies, sexual behavior, and social support. Logistic regression models were employed to control for cofounders as follows: all bivariate analyses of willingness to participate with a p-value of <0.2 were included in multivariate logistic regression analyses and were considered to be statistically significant if the resulting p-value was <0.05 (16 (link)). The Hosmer–Lemeshow goodness of fit test was applied to assess the logistic regression model, and a final p-value of >0.05 taken as indicating good fit. The frequency of missing data was 3.3%. All statistical analyses were two-sided and performed using Stata Version 12.1 for Windows (StataCorp 1985–2011, College Station, Texas).