Healthcare costs of acute and chronic pain associated with a diagnosis of herpes zoster

Objectives: To determine the healthcare costs of acute and chronic pain associated with herpes zoster. Design: Retrospective cohort analysis. Setting: Inpatient and outpatient care. Participants: Patients were selected from Medicare, commercial insurance, and Medicaid claims databases if they had a diagnosis of herpes zoster or postherpetic neuralgia (PHN) or were prescribed analgesics after a diagnosis of herpes zoster (possible PHN) and were matched to controls for demographic and clinical factors using propensity scores. Measurements: One-year excess healthcare expenditures attributable to herpes zoster pain or PHN were calculated for inpatient, outpatient, and prescription drug services. Results: For the Medicare cohort, the average excess cost per patient was $1,300 in the year after a diagnosis of herpes zoster with 30 days or fewer of analgesic use and ranged from $2,200 to $2,300 per patient with PHN or possible PHN. Patients with possible PHN were 53% more prevalent than patients with PHN in the Medicare cohort and accounted for half of all excess expenditures. Findings were similar in the younger cohorts with commercial insurance and Medicaid except that costs attributable to PHN and possible PHN were higher, and patients with possible PHN were three to five times as prevalent as patients with PHN. Conclusion: Healthcare costs associated with PHN were substantially greater than those associated with herpes zoster pain that resolved within 30 days. The data suggest that as many as 80% of patients with PHN may not be diagnosed with PHN and that these patients account for at least half of PHN expenditures.