Burden of Herpes Zoster Among Patients with Psoriatic Arthritis in the United States

David Singer,1 Philippe Thompson-Leduc,2 Siyu Ma,1,3 Deepshekhar Gupta,4 Wendy Y Cheng,5 Selvam R Sendhil,6 Manasvi Sundar,6 Ella Hagopian,5 Nikita Stempniewicz,1 Mei Sheng Duh,5 Sara Poston1 1GSK, US Health Economics and Outcomes Research, Philadelphia, PA, USA; 2Analysis Group, Inc., Health Economics and Outcomes Research, Montreal, QC, Canada; 3Tufts Medical Center, Boston, MA, USA; 4Analysis Group, Inc., Health Economics and Outcomes Research, Menlo Park, CA, USA; 5Analysis Group, Inc., Health Economics and Outcomes Research, Boston, MA, USA; 6Analysis Group, Inc., Health Economics and Outcomes Research, Los Angeles, CA, USACorrespondence: Nikita Stempniewicz, GSK, US Health Economics and Outcomes Research, FMC Tower Suite 1700, 2929 Walnut Street, Philadelphia, PA, 19104, USA, Tel +1 203 803 9909, Email nikita.x.stempniewicz@gsk.comPurpose: Patients with psoriasis (PsO) and psoriatic arthritis (PsA) are at increased risk of herpes zoster (HZ), but healthcare resource use (HRU) and costs relating to HZ in adults with PsA are unknown. We aimed to estimate the incidence of HZ among adults with PsA vs without psoriatic disease and the additional HRU and costs among patients with PsA with vs without HZ.Patients and Methods: This retrospective, longitudinal, cohort study estimated HZ incidence in PsA+ vs PsO–/PsA– cohorts and HRU and medical/pharmacy costs among PsA+/HZ+ vs PsA+/HZ– cohorts comprised of adults from Optum’s de-identified Clinformatics Data Mart Database during 2015– 2020. For the HRU/cost analyses, index was the date of first HZ diagnosis (PsA+/HZ+ cohort) or was randomly assigned (PsA+/HZ– cohort). Generalized linear models were used for adjusted comparisons between cohorts.Results: HZ incidence was higher in the PsA+ (n = 57,126) vs PsO–/PsA– (n = 23,837,237) cohort (14.85 vs 7.67 per 1000 person-years; adjusted incidence rate ratio [aIRR]: 1.23; 95% confidence interval [CI]: 1.16– 1.30). Numbers of outpatient visits, emergency department visits, and inpatient admissions were significantly higher in the PsA+/HZ+ (n = 1045) vs PsA+/HZ– (n = 36,091) cohorts during the first month after HZ diagnosis (outpatient: aIRR: 1.74; 95% CI: 1.63– 1.86; emergency department: 3.14; 95% CI: 2.46– 4.02; inpatient: aIRR: 2.61; 95% CI: 1.89– 3.61). Mean all-cause per-patient costs were significantly higher in the PsA+/HZ+ vs PsA+/HZ– cohorts during the first month after index ($6493 vs $4521; adjusted cost difference: $2012; 95% CI: $1204–$3007). HRU and costs were numerically higher in the PsA+/HZ+ cohort during the first 3 and 12 months.Conclusion: These findings, which provide evidence on the increased incidence and HRU and economic burden associated with HZ among adults with PsA, could be used to inform clinical practice and decision-making.Plain Language Summary: Why was the study done?Psoriatic arthritis affects the joints of around 20% of patients with the skin condition, psoriasis.Patients with psoriatic arthritis are at increased risk of shingles, which can cause a painful skin rash and complications.This study aimed to provide information on how many patients with psoriatic arthritis get shingles and the healthcare use and costs of caring for patients with psoriatic arthritis and shingles.What did the researchers do and find?Using data from a large US health plan database, we estimated that for every 1000 patients with psoriatic arthritis observed for 1 year, 15 will develop shingles.Patients with psoriatic arthritis were 23% more likely to develop shingles than people without psoriatic disease.Patients with psoriatic arthritis and shingles had 2– 3 times as many healthcare visits in the month after a shingles diagnosis as patients with psoriatic arthritis but no shingles.This resulted in an average additional cost of approximately $2000 per patient.What do these results mean?Psoriatic arthritis increases the risk of shingles.The costs associated with shingles in patients with psoriatic arthritis are substantial.Measures to prevent shingles in this population could be beneficial. Keywords: claims database, costs, healthcare resource use, incidence, psoriatic arthritis, United States