Pre-injury dispensing of psychoactive prescription drugs in a ten years trauma population: a retrospective registry analysis

BACKGROUND: The use of psychoactive prescription drugs is associated with increased risk of traumatic injury, and has negative impact on clinical outcome in trauma patients. Previous studies have focused on specific drugs or subgroups of patients. Our aim was to examine the extent of psychoactive drug dispensing prior to injury in a comprehensive population of trauma patients. METHODS: The Oslo University Hospital Trauma Registry provided data on all trauma patients admitted to the trauma centre between 2005 and 2014. We linked the data to Norwegian Prescription Database data from 2004. Opioids, benzodiazepines, z-hypnotics, gabapentinoids, and centrally acting sympathomimetics dispensed during the year before trauma of each patient were identified. We determined the pre-trauma annual prevalence of dispensing and mean annual cumulative defined daily doses (DDD) for each drug class, and compared results with corresponding figures in the general population, using standardised ratios. For each drug class, dispensing 14 days preceding trauma was analysed in patients sustaining severe injury and compared with patients sustaining non-severe injury. RESULTS: 12,713 patients (71% male) were included. Median age was 36 years. 4891 patients (38%) presented with severe injury (Injury Severity Score > 15). The ratio between annual prevalence of dispensed prescriptions for trauma patients and the general population, adjusted for age and sex, was 1.5 (95% confidence interval 1.4–1.6) for opioids, 2.1 (2.0–2.2) for benzodiazepines, 1.7 (1.6–1.8) for z-hypnotics, 1.9 (1.6–2.2) for gabapentinoids, and 1.9 (1.6–2.2) for centrally acting sympathomimetics. Compared with the general population, mean annual cumulative DDD of opioids and benzodiazepines dispensed to trauma patients were more than two and three times as high, respectively, in several age groups below 70 years. The prevalence of dispensing 14 days pre-trauma was higher in severely injured patients for opioids, benzodiazepines, and z-hypnotics compared with patients without severe injury. CONCLUSIONS: Our results support previous findings that the prevalence of psychoactive drug use is high among trauma patients. In terms of both frequency and amounts, the pre-injury dispensing of psychoactive drugs to trauma patients supersedes that of the general population, especially in younger patients.