24 - Economic Burden of Herpes Zoster Among Individuals with Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study

Background: Previous studies have evaluated the risk of developing herpes zoster (HZ) in patients with chronic obstructive pulmonary disease (COPD), but little is known about the impact of an acute HZ episode on healthcare resource utilization (HCRU) and costs among patients with COPD in the US.

Methods: A retrospective cohort study of individuals ≥50 years of age was conducted using administrative claims data from Optum Clinformatics for commercially insured and Medicare Advantage members (01/01/2013 – 12/31/2018). Two cohorts of patients with COPD, with (Cohort A) and without (Cohort B) HZ episodes, were identified (Fig.1). COPD and HZ were identified using ICD-9 and ICD-10 diagnosis codes. All-cause HCRU rates were compared between cohorts using adjusted incidence rate ratios (IRRs), calculated using generalized linear models assuming a negative binomial distribution. Differences in all-cause costs were estimated by fitting a two-part model with a logit model in the first part and a gamma distribution for the second part. Potential differences between cohorts were accounted for by propensity scores, calculated using patients’ demographics and clinical characteristics at baseline and included as a covariate in multivariable regression analyses.Figure 1: Study Design Schematic


Results: Among patients with COPD, 3,415 patients with HZ (mean age [standard deviation]=73.2 [9.0] years) and 35,360 without HZ (72.4 [9.4] years) were identified. Compared to patients with COPD but without HZ, patients with COPD and HZ had an increased rate of all-cause outpatient visits (adjusted IRR=1.18; 95% confidence interval [CI]=1.15-1.22; p< 0.001) and Emergency Department visits (1.28; 1.20-1.35; p< 0.001) as well as higher all-cause total costs (adjusted cost difference, per patient per month [PPPM]=$313; 95% CI=$110-536; p< 0.004), in the first year of the observation period. All-cause mean costs PPPM and differences between cohorts were higher closer to the date of HZ diagnosis (or an imputed date for Cohort B, Fig.2).Figure 2: All-cause monthly costs


Conclusion: HCRU and cost burden is higher in patients ≥50 years old with COPD and HZ vs. without HZ. HZ vaccination may potentially reduce this burden among patients with COPD. 
Funding: GlaxoSmithKline Biologicals SA (GSK study identifier: HO-19-19749)