Socio-economic status and major trauma in a Scandinavian urban city: A population-based case-control study

Epidemiological studies of patients with major trauma, including both hospitalized and immediately deceased whom are undergoing medico-legal autopsy, are very rare. We studied the incidence and mortality of major trauma in all 10 districts in the Scandinavian city of Malmö, Sweden, and the association between socio-economic status and major trauma.

Major trauma was defined as a New Injury Severity Score > 15, or a lethal outcome due to trauma. Cases with a registration address in Malmö between 1 January 2011 and 31 December 2013 were identified from the red trauma alarm list in the hospital and the autopsy register in the Forensic Department. Statistics Sweden matched each case with four randomly selected age-, gender- and district-matched controls. Social assistance within the household, level of education, income and capital income were compared.

We identified 117 cases (80 men and 37 women) with a median age of 48.0 years (IQR 28.5-65.0). The incidence of major trauma in Malmö was 12.7 (95% CI 10.4-15.0) per 100,000 person-years; and 69 died due to major trauma, with 8.4 (95% CI 6.4-10.4) per 1000 deaths. Lower income (p = 0.024), no income (OR 1.6; 95% CI 1.0-2.4; p = 0.037) and social assistance (OR 2.3; 95% CI 1.3-4.1; p = 0.003) were associated with major trauma. The level of education was not found to be related to major trauma (p = 0.47).

Low income and social assistance within the household were associated with major trauma in the city of Malmö, but not the level of education; in this age-, gender- and district-matched case-control study of major trauma.