Cannabis and other drug use among trauma patients in three South African cities, 1999-2001.

To assess the extent of cannabis and other drug use among patients presenting with recent injuries at trauma units in Cape Town, Port Elizabeth and Durban from 1999 to 2001. Cross-sectional surveys were conducted during a 4-week period at each of the above sites in 1999, 2000 and 2001. The concept of an idealised week was used to render representative samples. Cause of injury and biological markers to assess use of cannabis, methaqualone (Mandrax), opiates, cocaine, amphetamine, and methamphetamine. Over half of all patients tested experienced violent injuries. Excluding opiates, across sites and over time between 33% and 62% of patients tested positive for at least one drug (N = 1565). In most cases the drugs were cannabis and/or methaqualone. While no inter-city differences were found, male patients were typically more likely to test positive for drugs in general and specific drugs such as cannabis and the cannabis/methaqualone ('white pipe') combination than female patients. Drug positivity was higher in 2001 than in the previous 2 years in Cape Town, and patients injured as a result of violence in Cape Town and Durban were more likely to test positive for drugs than patients with certain other types of injuries. Drug use among trauma patients has remained consistently high for each of the 3 study periods. Efforts to combat the abuse of drugs such as cannabis and methaqualone would appear to be paramount in reducing the burden of injuries on health care services. The study has raised numerous issues requiring further research.