Proportion of studies reporting individual factors that affect vulnerability to HIV by region, overall and specifically among men who engage in transactional sex.

1Including syphilis, gonorrhea, chlamydia, human papilloma virus (HPV), and/or herpes simplex virus (HSV);
2Risk factor reported among any population in the study (i.e., men who have sex with men);
3Risk factor reported specifically among men who engage in transactional sex;
4Fisher’s exact test comparing frequency of reporting factors by geographic region of study, overall and among men who report transactional sex.