Economic and Clinical Burden of Herpes Zoster Among Patients With Inflammatory Bowel Disease in the United States

Lay Summary Herpes zoster is associated with increased healthcare resource utilization and costs in patients with inflammatory bowel disease, especially during the time shortly after diagnosis. Background Patients with ulcerative colitis (UC) or Crohn's disease (CD) are at increased risk of herpes zoster (HZ); however, relevant cost and healthcare resource utilization (HCRU) data are limited. Methods We estimated HCRU (hospitalization, emergency department [ED], and outpatient visits) and costs in patients with UC or CD, with and without HZ, using administrative claims data (October 2015-February 2020). HCRU and costs (2020 US dollars) were compared at 1 month, 1 quarter, and 1 year after the index date, using propensity score adjustment and generalized linear models. Results In total, 20 948 patients were included: UC+/HZ+ (n = 431), UC+/HZ- (n = 10 285), CD+/HZ+ (n = 435), and CD+/HZ- (n = 9797). Patients with HZ had higher all-cause HCRU rates and all-cause total healthcare costs relative to those without HZ. In the first month, adjusted incidence rate ratios (aIRRs) for hospitalizations and ED visits for patients with UC and HZ compared with UC alone were 2.87 (95% confidence interval [CI], 1.93-4.27) and 2.66 (95% CI,1.74-4.05), respectively; for those with CD and HZ, aIRRs were 3.34 (95% CI, 2.38-4.70) and 3.31 (95% CI, 2.32-4.71), respectively, compared with CD alone (all P < .001). Adjusted cost differences in UC and CD cohorts with HZ over the first month were $2189 and $3774, respectively, chiefly driven by higher inpatient costs. The incremental impact on HCRU and costs in cohorts with HZ predominantly occurred during the first quarter following diagnosis. Conclusions HZ is associated with increased HCRU and costs in patients with UC and CD, especially shortly after diagnosis.