Study Population

Patients with at least 1 diagnosis code for CHC (ICD-9-CM codes 070.44, 070.54, 070.70, and 070.71; ICD-10-CM codes B18.2, B19.20, and B19.21) and at least 1 claim for SIM, SOF, or LED/SOF prescriptions were selected. The date of the first claim for SIM, SOF, or LED/SOF was defined as the treatment initiation date or the index date. Patients with any diagnosis for hepatitis B (ICD-9-CM codes 070.20, 070.21, 070.22, 070.23, 070.30, 070.31, 070.32, and 070.33; ICD-10-CM codes B16.0, B16.1, B16.2, B16.9, B18.0, B18.1, B19.10, and B19.11) were excluded. To be eligible for the analysis, patients were required to have (a) continuous enrollment in a health plan at least 6 months before and after the index date; (b) paid claims for SOF + SIM ± RBV, SOF + PEG + RBV, SOF + RBV, or LED/SOF ± RBV regimens; and (c) at least 1 claim with DAA drug supply information following the index date (Appendix A, available in online article).

The 6-month period after the index date was selected because the longest treatment regimen in this study was 24 weeks or 5.6 months. The earliest possible index date for this analysis was November 2013, when SIM was approved by the FDA, and the latest possible index date was in early July 2015, to allow a minimum of 6 months continuous enrollment after the index date.