Pre-admission opioid use disorder as a new predictor of in-hospital mortality and six-month outcomes in traumatic brain injury patients: a retrospective longitudinal cohort study.

BACKGROUND

The present study aimed to investigate the effect of pre-admission Opioid Use Disorder (OUD) on in-hospital mortality and 6-month follow-up TBI outcomes.

DESIGN

This study included 2804 patients with TBI admitted to the Intensive Care Unit of Emtiaz (Rajaee) Hospital, a referral trauma center in Shiraz, Iran. Finally, 1087 eligible participants were selected from included patients. Then, 872 discharged patients were followed for six months. Subsequently, unfavorable neurological outcomes (Glasgow Outcome Scale-Extended ≤ 4) and the mortality rate were compared among the patients with and without OUD.

RESULTS

The mean age of the patients was 38.0 ± 18.9 years old (84.7% men). About 9.2% of patients had OUD. Opioid users had a slightly lower risk of in-hospital mortality (OR = 0.62, 95% CI = [0.328, 1.183], P-value = 0.148). In contrast, 6-month follow-up mortality significantly increased in the survived patients with a history of pre-admission OUD (OR = 2.49, 95%CI= [1.29, 2.80], P-value = 0.007). Moreover, 6-month unfavorable outcomes were raised in OUD, though it was not significant (OR = 1.59, 95%CI= [0.89, 2.84], P-value = 0.121).

CONCLUSIONS

Our results revealed that patients with OUD are at increased risk of 6-month follow-up complications and also death following moderate to severe TBI. Although OUD decreased in-hospital mortality, 6-month follow-up indicated that mortality and unfavorable outcomes were increased in the OUD group. Based on the existing evidence, this effect is probably not only due to the destructive impact of pre-admission OUD on brain physiology. However, it may also be due to an increase in opioid consumption to alleviate pain and withdrawal symptoms after hospital discharge.