title: Alcohol and drug involvement in motorcycle driver injuries in the city of Sao Paulo, Brazil: Analysis of crash culpability and other associated factors.
abstract: BACKGROUND
  Earlier studies have already identified that a greater proportion of injured drivers are under the effects of illicit drugs than alcohol in Brazil, but the crash risk attributable to each substance is still unknown.
  
  
  METHODS
  Injured motorcycle drivers who were involved in traffic accidents in the West Zone of the city of Sao Paulo were recruited for a cross-sectional study based on crash culpability analysis. Alcohol and drug positivity among drivers was evaluated according to their responsibility for the crash. Culpability ratios were generated based on the proportion of drivers who were deemed culpable in relation to those considered not culpable according to the use of drugs and alcohol.
  
  
  RESULTS
  Of the 273 drivers recruited, 10.6% tested positive for alcohol. Among those who were also tested for drugs (n=232), 20.3% had consumed either alcohol and/or other drugs, 15.5% of whom were positive only for drugs other than alcohol, specifically cannabis and cocaine. Drivers who tested positive for alcohol were significantly less likely to possess a valid driver's license and to report driving professionally, whereas those who had consumed only drugs were more likely to drive professionally. The culpability ratio estimated for alcohol-positive drivers was three times higher than that for alcohol-free drivers, showing a superior ratio than drivers who had consumed only drugs other than alcohol, who presented a 1.7 times higher culpability ratio than drug-free drivers.
  
  
  CONCLUSIONS
  Substance use was overrepresented among culpable motorcycle drivers, with alcohol showing a greater contribution to crash culpability than other drugs.
authors.affiliation: Department of Preventive Medicine, University of Sao Paulo Medical School, Sao Paulo 01246-903, Brazil. Electronic address: heracc@usp.br.
authors.forename: Heraclito Barbosa
authors.initials: HB
authors.lastname: de Carvalho
authors.affiliation: Department of Preventive Medicine, University of Sao Paulo Medical School, Sao Paulo 01246-903, Brazil. Electronic address: gabriel.bio@usp.br.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Andreuccetti
authors.affiliation: Department of Traumatology and Orthopaedics, University of Sao Paulo Medical School, Sao Paulo 05403-010, Brazil. Electronic address: marcelo@marcelorosaderezende.com.br.
authors.forename: Marcelo Rosa
authors.initials: MR
authors.lastname: Rezende
authors.affiliation: Department of Surgery, University of Sao Paulo Medical School, Sao Paulo 01246-903, Brazil. Electronic address: cobernini@gmail.com.
authors.forename: Celso
authors.initials: C
authors.lastname: Bernini
authors.affiliation: Department of Surgery, University of Sao Paulo Medical School, Sao Paulo 01246-903, Brazil. Electronic address: jorge.ssilva@hc.fm.usp.br.
authors.forename: Jorge Santos
authors.initials: JS
authors.lastname: Silva
authors.affiliation: Department of Legal Medicine, University of Sao Paulo Medical School, Sao Paulo 01246-903, Brazil. Electronic address: vileyton@usp.br.
authors.forename: Vilma
authors.initials: V
authors.lastname: Leyton
authors.affiliation: Department of Traumatology and Orthopaedics, University of Sao Paulo Medical School, Sao Paulo 05403-010, Brazil. Electronic address: jgreve@usp.br.
authors.forename: Julia Maria
authors.initials: JM
authors.lastname: D'Andréa Greve
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D001334:Automobile Driving / Q000706:statistics & numerical data*; D001938:Brazil / Q000453:epidemiology; D002188:Cannabis; D003042:Cocaine / Q000032:analysis; D003430:Cross-Sectional Studies; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects / Q000032:analysis*; D008297:Male; D009049:Motorcycles; D019966:Substance-Related Disorders
chemical_list: D013287:Illicit Drugs; D003042:Cocaine
keywords: Alcohol; Culpability; Drivers; Drugs; Injuries; Motorcycle