Community v. non-community assault among adults in Khayelitsha, Western Cape, South Africa: a case count and comparison of injury severity.

BACKGROUND Community assault (CA) or vigilantism is widespread in the township of Khayelitsha, Cape Town, South Africa (SA). Anecdotal evidence suggests that victims of CA are worse off than other assault cases. However, scientific data on the rate and severity of CA cases are lacking for SA. OBJECTIVES To contribute to CA prevention and management strategies by estimating the rate of CA among adults in Khayelitsha and comparing the injury severity and survival probability between cases of CA and other assault (non-CA) cases. METHODS We studied four healthcare centres in Khayelitsha during July - December 2012. A consecutive case series was conducted to capture all CA cases during this period. A retrospective folder review was performed on all cases of CA and on a control group of non-CA cases to compare injury severity and estimate survival probability. RESULTS A total of 148 adult cases of CA occurred (case rate 1.1/1 000 person-years) over the study period. The Injury Severity Scores (ISSs) in the CA group were significantly higher than in the non-CA group (p < 0.001), with a median (interquartile range) ISS of 3 (2 - 6) in CA cases v. 1 (1 - 2) in non-CA cases. Comparison between the CA v. non-CA groups showed that a Glasgow Coma Scale < 15 (20.1% v. 5.4%, respectively), referral to the tertiary hospital (33.8% v. 22.6%, respectively), and crush syndrome (25.7% v. 0.0%, respectively) were all more common in CA cases. Survival probabilities were similar in both groups (CA v. non-CA 99.2% v. 99.3%, respectively). CONCLUSION The rate of CA among adults in Khayelitsha is high, and the severity of injuries sustained by CA victims is substantially higher than in other assault cases.