OBJECTIVES: To compare HRU and costs between ER patients who did/did not receive PAMORA for OIC.

METHODS: Adult ER OIC patients were evaluated retrospectively (4/2016-9/2019) and classified into cohorts based on if they received PAMORA in the ER. 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 during the ER encounter and costs were compared using weighted regressions with random effects at the hospital level.

RESULTS: Overall, 11,135 and 21,474 patients were identified in the PAMORA (93% given methylnaltrexone subcutaneous injection [SC]) and No-PAMORA cohorts, respectively. After balancing, overall characteristics were: mean age 59 years, 60% female, 82% Caucasian, and 52% Medicare-insured. Most patients were from large non-teaching hospitals (300+ beds and 10,000+ quarterly ER encounters) with an urban population (85%). PAMORA patients were 2.5 times more likely to be discharged home (OR=2.45;p-<0.001), 64% less likely to be admitted as an inpatient (OR=0.36;p<0.001)—of which 83% had a primary diagnosis for constipation. Inpatient average LOS was 1 day shorter (p<0.001). Accounting for PAMORA drug costs, PAMORA patients had a mean of $736 less in total healthcare costs per ER encounter (p<0.001).

CONCLUSIONS: Patients receiving PAMORA (mostly Methylnaltrexone SC) in the ER are more likely to be discharged home, less likely to be hospitalized, have a shorter stay, cost $736 less and save 0.7 inpatient days per ER encounter than when patients do not receive PAMORA in the ER setting.