After years of low baseline prevalence, substance use rose in Mexico during the last decade, according to nationally representative data from household surveys. This changing pattern is also evident among middle and high school students' surveys. Illicit drugs are now joining alcohol use as part of the substances currently found among the general public and the clients of health care services in the country In this context, alcohol and substance use and its consequences are now important parts of the current Mexican epidemiological profile. In the year 2000, among the population aged 15-64 years, alcohol was associated with the second leading cause of death (liver cirrhosis) in Mexico, the fourth leading cause (accidents, specially traffic-related), and the fifth leading cause (homicides). In turn, substance use was associated with the fifth leading cause of death (homicides) and with AIDS (the seventh leading cause). Some of the most important consequences of alcohol and substance use are the accidents and violence that they produce, either directly (i.e., drunken drivers) or indirectly through the channels of the illegal market of drug consumption. These consequences pose an important burden for the health system, specially for the emergency care delivered in emergency departments., (ED). Despite this, data to substantiate the impact of both substance use and alcohol is very limited in the country. Although during the last 15 years there have been several studies in Mexico to address the role of alcohol use in trauma and medical emergencies, similar studies for substance use are much scarcer. Therefore, new research to document the extension of substance and alcohol use and dependence, as well as its association with violence related ED episodes is needed. Due to the increase in substance use, it is specially important to present data on substance use on itself, and to reveal the pattern of, alcohol use in combination with substance use in the context of the ED consultation. In Mexico, among injured patients, alcohol use has been linked to violence-related episodes when compared to the general population. The relationship between substance use, other than alcohol, and violence-related injuries in the emergency room has been more inconsistent. A study of injured patients (n = 744) seeking care in the emergency department of a public general hospital in Mexico City is reported here. Prevalence of alcohol and substance use (habitual use and use within six hours prior to the injury) is reported. Additionally, the prevalence of substance use disorders (dependence) and the result of a rapid screening test for substance abuse among these patients are reported for the first time in the country. Alcohol and Substance use among violence-related injuries and the role of combined use of both alcohol and illicit substances on injury are addressed as well. The data reported here is part of the World Health Organization (WHO) Collaborative Study on Alcohol and Injuries, a multi-country epidemiological study carried out in 12 clinical settings in Argentina, Brazil, Belarus, Canada, China, Czech Republic, India, Mexico, Mozambique, New Zealand, South Africa, and Sweden. A sample of adult patients, 18 years and older, admitted to the emergency department and reporting an injury, was drawn from ED admission forms which reflected consecutive patient arrival in the ED over a six and a half-week period. All eligible patients attended at the ED during a 24 hour-period between January 15, 2002, and February 28, 2002, were approached to be breathalyzed and interviewed (with informed consent) as soon as po Patients,who were too severely injured to be interviewed in the ED were followed into the hospital and interviewed after their condition had stabilized. Data were collected using a questionnaire lasting about 25 minutes, administered by trained interviewers. Among other items, the interview obtained data on the condition which brought the patient to the ED, use of prescription or non-prescription medications within the six hours prior to the event, use of illicit or nonprescription drugs or use of alcohol within the six hours prior to the event, use of illicit drugs or non-prescription drugs during the last 12 months, alcohol consumption during the last 12 months and demographic characteristics. Patients who used alcohol or any other substance during the last 12 months were assessed for dependence in the last 12 months. A quantity-frequency (Q-F) typology for drinking during the last year was used as developed in prior studies in the emergency department; this is based on the frequency of usual drinking, and whether the patient reported consuming either 12 or more drinks or 5-11 drinks on one occasion. According to our results, most of the injured patients were males (60.0%) and under 30 years old (48.8%). The mean age was 35 years. Patients were fairly evenly, divided between married (39.4%) and single (37.6%). Almost one third of the sample had only an elementary school education or less, and most had few economical resources. Only 7.5% of the patients attending this ED used at least one drug in the last 12 months, 1.0% used these substances within six hours prior to the injury, 4.4% scored positively on a drug problem screener, and 1.7% met criteria for substance dependence in the last 12 months. Regarding alcohol, 17.4% reported alcohol use within six hours prior to the injury and 15.5% were positive on the breathalyzer rest. The prevalence of alcohol problems was 24.8% and 7.0% were positive for alcohol dependence in the last 12 months. Patients attending the ED with a violence-related injury were more likely to report substance use and substance use disorders, and to report alcohol use and alcohol use disorders than those with non-violent-related injuries. A close relationship was found between reporting substance use and/or substance use disorders and reporting alcohol use and/or alcohol use disorders, since patients who reported substance involvement were more likely to also report alcohol involvement. Finally, data on substance use and associated disorders in the ED, obtained for the first time in Mexico, suggest that drug dependence in ED patients may be higher than expected. This is an important topic that should be covered in future research. Screening patients and referring them to specialized treatment is an important step to be taken at ED scenarios in Mexico.
