The Impact of Adverse Events on Health Care Resource Utilization, Costs, and Mortality Among Patients Treated with Immune Checkpoint Inhibitors

Abstract

Background: We investigated the association between adverse events (AEs) suspected to be immune-related and health care resource utilization, costs, and mortality among patients receiving programmed cell death 1/programmed cell death ligand 1 immune checkpoint inhibitor (ICI) monotherapy for urothelial carcinoma, renal cell carcinoma, non-small cell lung cancer, or Merkel cell carcinoma. Patients and Methods: We conducted a retrospective cohort study using medical and pharmacy claims and enrollment information from U.S. commercial and Medicare Advantage with Part D enrollees in the Optum Research Database from March 1, 2014, through April 30, 2019. Claims were linked with mortality data from the Social Security Death Index and the National Death Index. Eligible patients had at least one ICI claim between September 1, 2014, and April 30, 2019. Results: After adjusting for potential confounding variables, we found patients with AEs had more than double the risk of an inpatient stay (hazard ratio [HR], 2.2; 95% confidence interval [CI], 1.9–2.5) and an 80% higher risk of an emergency visit (HR, 1.8; 95% CI, 1.6–2.1) than patients without AEs. Adjusted 6-month total costs were $24,301 higher among patients with an AE versus those without ($99,037 vs. $74,736; 95% CI, $18,828–29,774; p