The Burden of Opioid-Related Adverse Drug Events on Hospitalized Previously Opioid-Free Surgical Patients

Objective Opioid analgesics are a mainstay for acute pain management, but postoperative opioid administration has risks. We examined the prevalence, risk factors, and consequences of opioid-related adverse drug events (ORADEs) in a previously opioid-free surgical population. Methods A retrospective, observational, cohort study using administrative, billing, clinical, and medication administration data from two hospitals. Data were collected for all adult patients who were opioid-free at admission, underwent surgery between October 1, 2015, and September 30, 2016, and received postoperative opioids. Potential ORADEs were determined based on inpatient billing codes or postoperative administration of naloxone. We determined independent predictors of ORADE development using multivariable logistic regression. We measured adjusted inpatient mortality, hospital costs, length of hospital stay, discharge destination, and readmission within 30 days for patients with and without ORADEs. Results Among 13,389 hospitalizations where opioid-free patients had a single qualifying surgery, 12,218 (91%) received postoperative opioids and comprised the study cohort. Of these, we identified 1111 (9.1%) with a potential ORADE. Independent predictors of ORADEs included older age, several markers of disease severity, longer surgeries, and concurrent benzodiazepine use. Opioid-related adverse drug events were strongly associated with the route and duration of opioids administered postoperatively: 18% increased odds per day on intravenous opioids. In analyses adjusted for several covariates, presence of an ORADE was associated with 32% higher costs of hospitalization, 45% longer postoperative length of stay, 36% lower odds of discharge home, and 2.2 times the odds of death. Conclusions We demonstrate a high rate and severe consequences of potential ORADEs in previously opioid-free patients receiving postoperative opioids. Knowledge of risk factors and predictors of ORADEs can help develop targeted interventions to minimize the development of these potentially dangerous and costly events.