(C-055) Herpes Zoster Incidence Rates by Age for United States adults with Comorbid Conditions

Background: Certain comorbid conditions have a higher risk of Herpes Zoster (HZ), but it is unclear how recent incidence rates (IRs) for comorbidities compare to all adults and immunocompetent adults.

Objectives: 1) Evaluate age-specific HZ IRs in each selected comorbidity and the overall population, and 2) compare younger age groups (within 18-49 years old [YoA]) to immunocompetent 50-59.

Methods: We conducted a retrospective cohort study in the 2015-2022 US Merative MarketScan claims database. The overall population was ≥18 YoA, continuously enrolled for ≥15 months, no prior diagnosis of/vaccination against HZ. We excluded those with immunocompromising/autoimmune disease (IC/AID), then selected those with baseline comorbidities: diabetes, asthma, chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), depression, stress, or trauma. Immunocompetent population had no: IC/AID conditions/medications or selected comorbidities. Index date was defined as the 1st day of 16th month of continuous enrollment. Patients were censored at the earliest date of first HZ, first zoster vaccine, loss of coverage, or study end. We identified HZ as ICD-10 code B02.xx and antiviral ±7 days. ~10-year age groups were assigned, reassessed annually. We calculated age group-specific HZ IRs per 1000 person-years (PYs) in overall, immunocompetent, diabetes, and CKD and by number of comorbidities (1, 2 or 3+). We calculated adjusted IR ratios (aIRRs) using Poisson models and applied a non-inferiority (NI) margin of 95% CI lower limit (LL) >0.62; >0.62 but ≤1.0 was comparable, >1.0 was significantly higher.

Results: Around 20 million met overall inclusion criteria; 15% had one or more selected comorbidity, 57% were immunocompetent. HZ IRs per 1000 PYs by age group (18-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80+ YoA) increased with age within each comorbidity population and overall; age group specific IR is higher for each comorbidity (Diabetes: 2.55, 3.92, 4.90, 6.61, 7.85, 9.07, 10.23. CKD: 1.26, 3.37, 4.27, 6.36, 7.56, 10.12, 10.44) vs. overall population (1.16, 3.08, 3.99, 5.65, 6.78, 9.06, 9.42). HZ IRs appear higher with increasing number of comorbidities (1: 1.48, 4.15, 5.28, 6.87, 7.88, 9.34, 9.78; 2: 1.89, 5.02, 6.29, 8.59, 9.17, 10.73, 11.18; 3+: 2.41, 7.24, 7.38, 9.22, 10.30, 12.04, 12.92). The HZ IR for all comorbidities except CKD was significantly higher for 30-39 and 40-49 vs. 50-59 YoA immunocompetent; CKD 40-49 was comparable (aIRR 95% CI LLs all >1.0, except CKD 40-49 was >0.62 but ≤1.0).

Conclusions: Comorbidity HZ IRs appear higher than overall and appear higher with increasing number of comorbidities. Comorbidity HZ IRs 30-49 are generally significantly higher than immunocompetent 50-59.