Association of Opioid-Related Adverse Drug Events With Clinical and Cost Outcomes Among Surgical Patients in a Large Integrated Health Care Delivery System

Abstract

Importance: Opioids are commonly used for pain control during and after invasive procedures. However, opioid-related adverse drug events (ORADEs) are common and have been associated with worse patient outcomes. Objectives: To examine the incidence of ORADEs in patients undergoing hospital-based surgical and endoscopic procedures and to evaluate the association of ORADEs with clinical and cost outcomes. Design, Setting, and Participants: In this retrospective study of clinical and administrative data, ORADEs were identified using International Classification of Diseases, Ninth Revision diagnosis codes for known adverse effects of opioids or by opioid antagonist use. Multivariable regression analysis was used to measure the association of ORADEs with outcomes after adjusting for potential confounding factors. The setting was 21 acute care hospitals in a large integrated health care delivery system. Participants were 135 379 patients (aged ≥18 years, admitted from January 1, 2013, to September 30, 2015) who underwent surgical and endoscopic procedures and were given opioids. Exposure: Opioid use, reported as morphine milligram equivalent doses. Main Outcomes and Measures: Opioid-related adverse drug events and their association with inpatient mortality, discharge to another care facility, length of stay, cost of hospitalization, and 30-day readmission. Results: Among 135 379 adult patients in this study (67.5% female), 14 386 (10.6%) experienced at least one ORADE. Patients with ORADEs were more likely to be older, of white race/ethnicity, and male and have more comorbidities. Patients with ORADEs received a higher total dose of opioids (median morphine milligram equivalent dose, 46.8 vs 30.0 mg; P < .001) and for a longer duration (median, 3.0 vs 2.0 days; P < .001). In adjusted analyses, ORADEs were associated with increased inpatient mortality (odds ratio [OR], 28.8; 95% CI, 24.0-34.5), greater likelihood of discharge to another care facility (OR, 2.9; 95% CI, 2.7-3.0), prolonged length of stay (OR, 3.1; 95% CI, 2.8-3.4), high cost of hospitalization (OR, 2.7; 95% CI, 2.4-3.0), and higher rate of 30-day readmission (OR, 1.3; 95% CI, 1.2-1.4). ORADEs were associated with a 2.9% increase in absolute mortality, an $8225 increase in cost for the index hospitalization, and a 1.6-day increase in length of stay for the index hospitalization. Conclusions and Relevance: Opioid-related adverse drug events were common among patients undergoing hospital-based invasive procedures and were associated with significantly worse clinical and cost outcomes. Hospital-acquired harm from ORADEs in the surgical patient population is an important opportunity for health systems to improve patient safety and reduce cost.