The authors found no significant association between marijuana use and the risk for injury. This is a unique study approach, but several bias’ may influence the results. One, the study population are members of an HMO, and may have a higher SES than the general population. Two, the assessment of marijuana exposure was crude and was by self-report. Three, no measures of marijuana use are available at the time of the injury.

Source: Braun BL, Tekawa IS, Gerberich SG, Sidney S. Marijuana use and medically attended injury events. Annals of Emergency Medicine 32:353-360, 1998.