RESUMEN
Bars and nightclubs are main locations for sexual assault outcomes such as rape, attempted rape, stalking, and other forms of sexual harassment. Alcohol use is strongly associated with violence in nightlife settings. The present study aimed to identify individual and environmental factors, such as different types of nightclubs, music styles, and physical environment associated with nightclub patron's report of being victims of sexual aggression inside nightclubs in São Paulo, Brazil. Two levels of data were collected: observational data inside nightclubs and individual-level survey data of 2422 patrons at the entrance and 1822 patrons (1111 men; 711 women) at the exit of 31 nightclubs. Among patrons, 11.5% (95% CI 7.9-16.2%) reported being a victim of sexual aggression inside the venues in the night of the survey. Groping and forced kissing were the most prevalent forms of sexual aggression (9.8%; [7.2-13.1%]), which was more strongly associated with environmental factors such as crowding (OR = 2.9 [1.6-5.2%]), entrance consumption fee (OR = 4.2 [2.5-7.0%]), and music style than with individual-level factors. In funk (OR = 3.3 [1.6-6.9%]), electronic (OR = 3.2 [1.8-5.8%]), and pop dance (OR = 7.9 [2.2-29.1%]) nightclubs, patrons had higher chances of being a victim of sexual aggression compared to those ones at the eclectic nightclubs. Presence of reserved areas for sex increased the chances of reporting sexual aggression (OR = 1.8 [1.2-2.8%]). No significant gender differences for sexual aggression were detected. Results suggest a requirement of security improvement where environmental characteristics are potential predictors of victimization.