Age-related injury patterns resulting from knife violence in an urban population

Interpersonal violence involving knives is a major public health problem. The majority of patients are young people in urban areas, but little is known about age-specific patterns of injury and recent trends in injury characteristics. We performed a retrospective cohort study of all patients presenting to an urban major trauma centre with stab injuries resulting from assault between 2012 and 2018. A total of 3583 patients were included. Young people (age under 25) were more likely to have sustained multiple stab wounds compared to older people (43% vs 35%, p < 0.001) and had significantly higher rates of stab injuries involving the lower limbs, groin and buttocks. The annual number of injuries increased steadily during the study period in patients aged under 25 (r(2) = 0.82, p = 0.005) and those over 25 (r(2) = 0.95, p < 0.001). Over time, limb and junctional injuries accounted for an increasing proportion of stab wounds in young people, overtaking torso injuries as most common pattern of injury by the end of the study period. These findings illustrate the influence of age on injury patterns resulting from knife violence, and support the expansion of outreach initiatives promoting bystander-delivered haemorrhage control of extremity wounds.