A meta-analysis of marijuana, cocaine and opiate toxicology study findings among homicide victims.

ABSTRACT Aim To synthesize the results of marijuana, cocaine and opiate drug toxicology studies of homicide victims and examine variation in results across person and setting characteristics. Methods A meta-analysis of 18 independent studies identified from an extensive review of 239 published articles that met the inclusion criteria of reporting marijuana, cocaine and/or opiate toxicology test results for homicide victims. A total of 28 868 toxicology test results derived from 30 482 homicide victims across five countries were examined. Results On average, 6% of homicide victims tested positive for marijuana, 11% tested positive for cocaine, and 5% tested positive for opiates. The proportion of homicide victims testing positive for illicit drugs has increased over time. Age had a strong curvilinear relationship with toxicology test results, but gender differences were not apparent. Hispanic and African American homicide victims were more likely to test positive for cocaine; Caucasians were most likely to test positive for opiates. Cocaine use appeared to be related to increased risk of death from a firearm and was a greater risk factor for violent victimization in the United States than in Newfoundland and Scandinavia. Conclusion There are relatively few studies of illicit drug toxicology reports from homicide victims that allow for cross-cultural comparisons. This study provides a basis for comparing future local toxicology test results to estimates from existing research.