Background: Although there are estimated to be nearly 1 million cases of herpes zoster diagnosed in the US each year, the economic costs associated with herpes zoster in the US have not been well described. Objective: To describe the healthcare resource utilisation and costs associated with physician-diagnosed acute/subacute herpes zoster, from a payer perspective, using a large US healthcare claims database. Methods: Data for the period 2000-1 were obtained from the Medstat Marketscan healthcare claims database. The duration of acute/subacute herpes zoster was considered to include the 21 days preceding, and 90 days following, the initial herpes zoster diagnosis. Resource utilisation was examined for individuals with newly diagnosed acute/subacute herpes zoster (n_=_8741) and compared, through regression analyses, with that observed for control individuals from the same population (n_=_50_000). Similar analyses were conducted for costs; the costs included reflected healthcare payments from patients, insurers and other sources. Regression analyses controlled for demographics (age, gender), conditions that have been observed with greater frequency among patients with acute/subacute herpes zoster in prior studies (cancer, HIV infection, organ transplantation, other immunosuppressive conditions and therapies) and the number of billed services within each of seven categories of care that were potentially related to acute/subacute herpes zoster and that were utilised within the 30-180 days prior to the diagnosis for affected patients, and over an analogous period for controls. Results: The acute/subacute phase of herpes zoster was estimated to result in an average of 1.7 (standard error [SE] 0.02) additional physician and hospital outpatient visits, 0.05 (SE 0.003) additional emergency room visits, 0.03 (SE 0.003) additional inpatient hospital admissions, 2.1 (SE 0.03) additional prescriptions filled and $US431 (SE 17.60) in additional healthcare costs per patient. Among patients with acute/subacute herpes zoster, 21.1% had a diagnosis code with a designation for a herpes zoster-related complication, and 9.4% had three or more outpatient visits with a diagnosis code for herpes zoster. The average estimated incremental costs per patient with acute/subacute disease increased with age, ranging from $US258 (SE 37.70) among patients aged <=19 years to $US805 (SE 106.30) among those aged >=80 years. The numbers of additional outpatient visits, inpatient admissions, prescriptions filled for pain medications and coded complications were also substantially higher among older than younger patients with acute/subacute herpes zoster. Conclusions: The management of acute/subacute herpes zoster was found to result in substantial healthcare costs, with outpatient care and prescription drugs comprising the majority of the cost burden. To more fully understand the overall cost of herpes zoster disease to society, future studies should examine the healthcare costs associated with post-herpetic neuralgia and productivity losses due to herpes zoster and post-herpetic neuralgia.
