Alcohol intake and severity of injuries on highways in Mexico: a comparative analysis.

Aims: To analyze the association between alcohol intake and the severity of injuries sustained from traffic accidents on a Mexican highway.
Design: An observational unit evaluated drivers involved in auto accidents.
Setting: Mexico-Cuernavaca Highway, Mexico. A 60 km-long road with many altitude variations and sharp curves.
Participants: Three hundred and eighty-six drivers involved in traffic accidents between March and September, 1994.
Measurements: A questionnaire was applied to the driver, an occupant or witness at the site of the accident to collect information about the driver, vehicle characteristics, type of accident, day-night occurrence, road section (Mexico-Cuernavaca or Cuernavaca-Mexico) and weather conditions. A physical examination was carried out to determine the presence and severity of injuries.
Findings: There were 177 injured people, including 12 deaths, with rates of 67.5 injuries and 4.58 deaths per 10,000 km driven. Variables associated with alcohol intake (p < 0.05) included: severity of injuries, non-use of seat belt, vehicle size and occurrence at night. Risk factors for severe injuries were: alcohol intake (adjusted OR 6.1 CI 95% 1.6-24.0); non-use of seat belt (OR 4.9 CI 2.2-10.8), age < 25 years (OR 3.6 CI 1.0-12.7), age > 54 years (OR 6.0 CI 1.4-25.0), speed > 90 km/h (OR 2.6 CI 1.1-6.3) and occurrence at night (OR 2.6 CI 1.3-5.3).
Conclusions: Alcohol intake is a major risk factor for severe injuries from highway traffic accidents. Its association with other risk factors such as non-use of seat belt and excessive speed suggests the importance of designing interventions aimed at reducing alcohol intake among automobile drivers.