The Economic Burden of Thromboembolic Events Among Patients with Immune-Mediated Diseases

Introduction Thromboembolic events (TEs) are associated with considerable costs. However, there is a paucity of evidence quantifying the economic burden associated with TEs among patients with immune-mediated diseases (IMDs). Methods This retrospective cohort study used the IBM MarketScan(R) Commercial and Medicare Supplemental Claims databases (2014-2018). Commercially insured adults with IMDs were classified into two cohorts based on diagnosis of TEs (deep vein thrombosis, pulmonary embolism, ischemic stroke, myocardial infarction). Patients in the TE cohort were matched on type of IMD, age, sex, and year of diagnosis to patients in the no TE cohort. In the TE cohort, the index date was the date of first TE following first IMD diagnosis. In the no TE cohort, the index date was assigned so the duration from first IMD diagnosis to index date matched the duration for the corresponding patient in the TE cohort. All-cause total healthcare costs were compared between cohorts in the 30-day and 1-year periods following the index date (inclusive). Unadjusted comparisons were conducted using Wilcoxon signed-rank tests. Adjusted results were estimated using generalized estimating equations with robust sandwich estimator. Results Overall, 9681 matched patients were included in each cohort (mean age 61.1 years; 63.7% female). The TE cohort had higher proportions of comorbidities than the no TE cohort (Charlson Comorbidity Index [1.5 vs. 0.9]; p < 0.0001). Adjusted all-cause total healthcare costs were significantly greater in the TE cohort versus no TE cohort in the 30-day and 1-year periods following the index date (cost difference: 30-day, $17,574; 1-year, $36,459; both p < 0.0001) and were driven by inpatient costs (cost difference: 30-day, $14,864; 1-year, $23,360; both p < 0.0001). TE-related healthcare costs were $15,955 and $20,239 in the 30-day and 1-year periods, respectively. Conclusion Among patients with IMDs, TEs are associated with substantial economic burden within 30-days and 1-year following the event.