Risk factors and outcomes of chronic opioid use following trauma.

Background The growing problem of opioid misuse has become a serious crisis in many countries. The role of trauma as a gateway to opioid use is currently not determined. The study was undertaken to assess whether traumatic injury might be associated with chronic opioid use and accompanying increased long-term mortality. Methods Injured patients and controls from Sweden were matched for age, sex and municipality. After linkage to Swedish health registers, opioid consumption was assessed before and after trauma. Among injured patients, logistic regression was used to investigate factors associated with chronic opioid use, assessed by at least one written and dispensed prescription in the second quarter after trauma. Cox regression was employed to study excess risk of mortality. In addition, causes of death for postinjury opioid users were explored. Results Some 13 309 injured patients and 70 621 controls were analysed. Exposure to trauma was independently associated with chronic opioid use (odds ratio 3 center dot 28, 95 per cent c.i. 3 center dot 02 to 3 center dot 55); this use was associated with age, low level of education, somatic co-morbidity, psychiatric co-morbidity, pretrauma opioid use and severe injury. The adjusted hazard ratio for death from any cause 6-18 months after trauma for chronic opioid users was 1 center dot 82 (95 per cent c.i. 1 center dot 34 to 2 center dot 48). Findings were similar in a subset of injured patients with no pretrauma opioid exposure. Conclusion Traumatic injury was associated with chronic opioid use. These patients have an excess risk of death in the 6-18 months after trauma.