Opioid-related adverse drug events in surgical patients: risk factors and association with clinical outcomes

Opioid analgesics are commonly used to treat acute post-operative pain. The primary objective of this study was to identify the risk factors for opioid-related adverse drug events (ORADEs) in surgical patients and the association between ORADEs and clinical outcomes.A retrospective cohort study was conducted using data from July 2016 to April 2020. ORADEs were defined using the International Classification of Diseases 10th Revision Australian Modification codes. Multivariate logistic regression was performed to identify ORADE risk factors. To investigate the association between ORADEs and clinical outcomes, propensity score matching was performed.Among 17,886 surgical patients who received opioid analgesics during hospital stay, 1,814 patients (10.2%) experienced ORADEs. Risk factors for general ORADEs included advanced age, comorbidities, concurrent use of benzodiazepines or gabapentinoids and a higher opioid daily dose. Patients who experienced ORADEs were associated with longer length of stay (Rate Ratio 3.00, 95% CI 2.97-3.04) but similar 28-day readmission rate (Odds Ratio 0.89, 95% CI 0.71-1.11).Risk factors for general ORADEs were advanced age, specific comorbidities, use of benzodiazepines or gabapentinoids and higher opioid dose. Routine use of opioids with gabapentinoids should be avoided and only used after careful consideration.