OBJECTIVES: To describe patient characteristics and treatment duration among patients initiating telaprevir (T) or boceprevir (B) combination treatments with pegylated interferon and ribavirin (T/PR; B/PR) using administrative claims data. METHODS: A retrospective analysis of data from patients initiating T/PR or B/PR (index date) was conducted (MarketScan Research Databases 2011-2012). Study criteria included 7 months of continuous enrollment pre-index, 6 months post-index, diagnosis of chronic HCV and claim for PR within 40 days of index date. Pre-index comorbidities were ascertained using ICD-9-CM codes. Indicated T duration is 12 weeks (84 days); and minimum indicated B duration is 24 weeks (168 days; maximum 44 weeks). Medication Possession Ratios (MPR, adherence indicator) and persistence were estimated over the indicated duration of treatment for each drug respectively. RESULTS: A total of 3288 patients met the study criteria (T/PR, n=2582 [79%]; and B/PR, n=706 [21%]). Age (mean±SD) and gender were similar between cohorts (T/PR=53.7±8.4 years, 35% female; B/PR=53.7±8.7 years, 39% female). Patients treated with T/PR were more likely to have a claim for liver cirrhosis in the pre-index period (T/PR=24%; B/PR=18%, p=0.002).  Prevalence rates of other comorbidities were similar between cohorts: diabetes (T/PR=14%; B/PR=13%), hypertension (T/PR=12%; B/PR=12%), and anxiety or depression (T/PR=11%; B/PR=11%). MPR (mean±SD) was 0.91±0.2 for T/PR patients in the first 84 days post-index and 0.78±0.3 for B/PR in the first 168 days post-index (p<0.001). At 84 days, 82% (95% confidence interval [CI]: 80%-83%) of T/PR patients were on therapy compared with 84% (CI: 81%-87%) of B/PR patients; 54% (CI: 51%-58%) of B/PR patients were still on therapy at 168 days. CONCLUSIONS: Chronic HCV-infected patients initiating telaprevir or boceprevir combination treatment had similar demographic characteristics and non-liver comorbidities. Cirrhosis was more prevalent among patients receiving telaprevir combination treatment. Data suggest adherence to indicated duration of treatment was higher among telaprevir patients than boceprevir patients.