Aims: the aim of the study was to describe the phenomenon of pre-drinking (alcohol consumption before entering nightclubs or bars) and to identify factors associated with pre-drinking practices among patrons in the city of São Paulo, Brazil. Methods: Individual-level data were collected by a portal survey of 2422 patrons at the entrance and at the exit of 31 nightclubs. the nightclubs were selected by two-stage sampling using a probability proportional to the establishments' capacity in the first stage and a systematic sample of patrons in the second stage. Breath alcohol concentration (BrAC) was measured. Face-to-face interview identified pre-drinking characteristics and past-year risk behaviors. Analysis used sample weights to compensate for nightclubs or patrons that were possibly over- or under-represented. Results: of the study participants, 41.3% (95% confidence interval (CI) = 33.7-49.3) engaged in pre-drinking on the night of the interview. Being male (odds ratio (OR) = 1.98, 95% CI = 1.45-2.71), past-year binge drinking (OR = 2.28, 95% CI = 1.70-3.07), previous episodes of severe effects from drunkenness (OR = 1.77, 95% CI = 1.40-2.22) and sexual risk behavior (OR = 1.67, 95% CI = 1.20-2.33) were associated with recent pre-drinking. Pre-drinking predicted higher BrACs at the nightclub exit. Conclusion: Pre-drinking is prevalent among nightclub patrons and associated with risk behaviors, and is associated with alcohol intoxication at nightclub exits. Environmental prevention strategies must consider pre-drinking as a potential risk factor for alcohol intoxication in nightclubs.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Prevent Med, Epidemiol Sect, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Informat Hlth, Sect Stat, São Paulo, BrazilUniversidade Federal de São Paulo, Sect Bioestat, Dept Prevent Med, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Prevent Med, Epidemiol Sect, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Informat Hlth, Sect Stat, São Paulo, BrazilUniversidade Federal de São Paulo, Sect Bioestat, Dept Prevent Med, São Paulo, BrazilFAPESP: 2011/51658-0FAPESP: 2012/03832-4Web of Scienc
