HEALTHCARE UTILIZATION AND COSTS ATTRIBUTABLE TO CLINICALLY IMPACTFUL IMMUNE-RELATED ADVERSE EVENTS AMONG OLDER ADULTS WITH ADVANCED NON-SMALL CELL LUNG CANCER TREATED WITH IMMUNE CHECKPOINT INHIBITORS
Author(s)
Olajumoke A. Olateju, BPharm, MS, PhD1, Rajender Aparasu, PhD1, Chan Shen, PhD2, Meera Patel, MD, MHA3, Tyler J. Varisco, PharmD, PhD4, Ekere J. Essien, MD, DrPH1, Meghana Trivedi, PharmD, PhD5, J. Douglas Thornton, PharmD, PhD1, Prachet J. Bhatt, M. Economics6.
1Pharmaceutical Health Outcomes and Policy, University of Houston, Houston, TX, USA, 2Division of Outcomes, Research and Quality, Penn State Cancer Institute, Hershey, PA, USA, 3Medicine - Hematology & Oncology, Baylor College of Medicine, Houston, TX, USA, 4Health Outcomes Division, The University of Texas at Austin, Austin, TX, USA, 5Pharmacy Practice and Translational Research, University of Houston, Houston, TX, USA, 6University of Houston, Houston, TX, USA.
1Pharmaceutical Health Outcomes and Policy, University of Houston, Houston, TX, USA, 2Division of Outcomes, Research and Quality, Penn State Cancer Institute, Hershey, PA, USA, 3Medicine - Hematology & Oncology, Baylor College of Medicine, Houston, TX, USA, 4Health Outcomes Division, The University of Texas at Austin, Austin, TX, USA, 5Pharmacy Practice and Translational Research, University of Houston, Houston, TX, USA, 6University of Houston, Houston, TX, USA.
OBJECTIVES: Immune checkpoint inhibitors (ICIs) are standard therapy for many patients with advanced non-small cell lung cancer (NSCLC) but can cause immune-related adverse events (irAEs). Despite their clinical importance, the downstream economic burden of clinically impactful irAEs, those requiring intensive medical management, among older adults remains unquantified. We estimated incremental healthcare utilization and costs attributable to clinically impactful irAEs among fee-for-service Medicare beneficiaries.
METHODS: Using SEER-Medicare data, we identified patients aged 66-85 years with advanced NSCLC who initiated nivolumab, pembrolizumab, or atezolizumab between 2015 and 2017, with follow-up through 2019. Clinically impactful irAEs were defined using irAE diagnosis codes plus evidence of systemic immunosuppressant use and/or treatment interruption and were modeled as a time-varying exposure. Healthcare utilization and costs were analyzed using marginal structural models with stabilized inverse-probability-of-exposure-and-censoring weights to address time-dependent confounding. Weighed two-part generalized estimating equations estimated per-patient-per-month (PPPM) and cumulative mean outcomes over 6, 12, and 24 months.
RESULTS: Among 4,867 beneficiaries, 1,667 (34.3%) experienced a clinically impactful irAE. Adjusted all-cause healthcare utilization was higher among patients with irAEs (mean [SE]:15.8[0.12] vs 12.0[0.12] visits PPPM; difference:3.9; 95% CI:2.9-4.8), with more than double the odds of inpatient hospitalization (OR:2.21; 95% CI:2.15-2.29). Adjusted all-cause medical costs averaged $16,042(14.7) vs $12,721(13.1) PPPM (difference: $3,322; 95% CI: $3,283-$3,361), driven primarily by inpatient care ($2,922; 95% CI: $2,903-$2,941). At 24 months, cumulative costs were $846,013(12,786) for patients with irAEs compared with $751,606(11,358) for those without (difference: $94,407; 95% CI: $91,606-$97,207). Findings remained robust in sensitivity analyses.
CONCLUSIONS: Clinically impactful irAEs are common among older adults receiving ICIs and are associated with substantial, sustained increases in healthcare utilization and downstream medical costs, primarily driven by inpatient care. These findings underscore the economic importance of early irAE detection and proactive adverse event management in immuno-oncology care.
METHODS: Using SEER-Medicare data, we identified patients aged 66-85 years with advanced NSCLC who initiated nivolumab, pembrolizumab, or atezolizumab between 2015 and 2017, with follow-up through 2019. Clinically impactful irAEs were defined using irAE diagnosis codes plus evidence of systemic immunosuppressant use and/or treatment interruption and were modeled as a time-varying exposure. Healthcare utilization and costs were analyzed using marginal structural models with stabilized inverse-probability-of-exposure-and-censoring weights to address time-dependent confounding. Weighed two-part generalized estimating equations estimated per-patient-per-month (PPPM) and cumulative mean outcomes over 6, 12, and 24 months.
RESULTS: Among 4,867 beneficiaries, 1,667 (34.3%) experienced a clinically impactful irAE. Adjusted all-cause healthcare utilization was higher among patients with irAEs (mean [SE]:15.8[0.12] vs 12.0[0.12] visits PPPM; difference:3.9; 95% CI:2.9-4.8), with more than double the odds of inpatient hospitalization (OR:2.21; 95% CI:2.15-2.29). Adjusted all-cause medical costs averaged $16,042(14.7) vs $12,721(13.1) PPPM (difference: $3,322; 95% CI: $3,283-$3,361), driven primarily by inpatient care ($2,922; 95% CI: $2,903-$2,941). At 24 months, cumulative costs were $846,013(12,786) for patients with irAEs compared with $751,606(11,358) for those without (difference: $94,407; 95% CI: $91,606-$97,207). Findings remained robust in sensitivity analyses.
CONCLUSIONS: Clinically impactful irAEs are common among older adults receiving ICIs and are associated with substantial, sustained increases in healthcare utilization and downstream medical costs, primarily driven by inpatient care. These findings underscore the economic importance of early irAE detection and proactive adverse event management in immuno-oncology care.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EE476
Topic
Economic Evaluation
Disease
SDC: Oncology, SDC: Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain), STA: Biologics & Biosimilars