APPROVED OPIOID-INDUCED CONSTIPATION MEDICATION USE IN EMERGENCY DEPARTMENT PATIENTS WITH OPIOID-INDUCED CONSTIPATION

Background: Approved medications for opioid-induced constipation (OIC-Rx) are effective for patients with opioid-induced constipation (OIC).[1] Yet, there is little evidence on the real-world impact of OIC-Rx use in the emergency department (ED). This study aimed to compare health care resource utilization (HRU) in hospitals and healthcare costs between patients in the ED who did/did not receive OIC-Rx for OIC.

Methods: Adult ED OIC patients were evaluated retrospectively (4/2016-9/2019) and classified into cohorts based on if they received OIC-Rx in the ED. Cohorts were reweighted using entropy balancing—a reweighing technique to reduce selection bias—which balanced cohorts based on demographics, hospital characteristics, and OIC-related procedures/comorbidities. HRU was assessed in the ED and for 30 days post-discharge, and costs were compared using weighted regressions with random effects at the hospital level. Outcomes were also assessed among a subgroup of patients with cancer.

Results: Overall, 11,135 and 21,474 patients were identified in the OIC-Rx (93% given methylnaltrexone subcutaneous injection [SC]) and No-OIC-Rx cohorts, respectively. After balancing, overall characteristics were mean age 59 years, 60% female, 82% Caucasian, and 52% Medicare-insured. Most patients were from non-teaching, 300+ beds, or 10,000+ quarterly ED encounter hospitals, serving an urban population. OIC-Rx patients were 2.4 times more likely to be discharged home (OR [95% CI]=2.44 [2.14, 2.78]; p< 0.001) and 64% less likely to be admitted as an inpatient (OR [95% CI]=0.36 [0.31-0.41]; p< 0.001). Inpatient average length of stay was 1 day shorter (0.84-1.22; p< 0.001). Accounting for OIC-Rx drug costs, OIC-Rx patients had a mean of $1152 less in total health care costs per ED encounter, including the ED visit through 30 days post-discharge. The results were consistent among the cancer subgroup where OIC-Rx patients had a mean of $922 ($432-$1412; p< 0.001) less in total health care costs per ED encounter.

Conclusions: Patients receiving OIC-Rx (mostly methylnaltrexone SC) in the ED are more likely to be discharged home, less likely to be hospitalized, have a shorter stay, have a mean cost reduction of $1152 (cancer subgroup: $922 reduction), and save 0.7 inpatient days (cancer subgroup: save 1.0 inpatient days) per ED encounter than when patients do not receive OIC-Rx in the ED setting.