Cost of Herpes Zoster in Patients With Selected Immune-Compromised Conditions in the United States.

Background.  This retrospective study investigates the healthcare costs of herpes zoster (HZ) in patients with selected immune-compromised (IC) conditions in the United States (US). Methods.  Patients with incident HZ diagnosis (index date) were selected from nationwide administrative claims databases from 2005 to 2009. Baseline IC groups, analyzed separately, included adults aged 18-64 years with the following: human immunodeficiency virus infection (HIV), solid organ transplant (SOT), bone marrow or stem cell transplant (BMSCT), or cancer; and older adults (aged ≥65 years) with cancer. Herpes zoster patients (n = 2020, n = 1053, n = 286, n = 13 178, and n = 9089, respectively) were 1-to-1 matched to controls without HZ (with randomly selected index date) in the same baseline group. The healthcare resource utilization and costs (2014 US dollars) during the first 2 postindex quarters were compared between matched cohorts with continuous enrollment during the quarter. Results.  Herpes zoster patients generally had greater use of inpatient, emergency room and outpatient services, and pain medications than matched controls (P < .05). The incremental costs of HZ during the first postindex quarter were $3056, $2649, $13 332, $2549, and $3108 for HIV, SOT, BMSCT, cancer in adults aged 18-64 years, and cancer in older adults, respectively (each P < .05). The incremental costs of HZ during the second quarter were only significant for adults aged 18-64 years with cancer ($1748, P < .05). The national incremental costs of HZ were projected to be $298 million annually across the 5 IC groups. Conclusions.  The healthcare cost associated with HZ among patients with studied IC conditions was sizable and occurred mainly during the first 90 days after diagnosis.