Impact of pill burden on adherence to hepatitis C medication.

Objective: To describe pill burden before and after hepatitis C virus (HCV) treatment initiation among patients newly treated for HCV infection, and to evaluate the association between HCV pill burden and gaps in HCV therapy. Methods: This was a retrospective administrative claims study of patients treated with direct-acting antivirals (DAAs) for HCV from 1 November 2013 to 31 July 2016. HCV pill burden was defined as the pill count per day for the index HCV regimen. Mean overall pill burden (HCV medications plus non-HCV medications) was calculated in the 90 days before and after DAA initiation. Gaps in the index HCV regimen were assessed in the 6 months after DAA initiation. Multivariable logistic regression was used to compare the odds of a gap in HCV therapy across HCV pill burden categories (1 pill/day, 2 pills/day, and ≥3 pills/day). Results: Among 9815 patients who met the study criteria, mean overall pill burdens before and after DAA treatment initiation were 5.4 and 7.7, respectively ( p  < .001). The adjusted odds ratio (OR) of a ≥15-day gap in HCV therapy was 1.75 (95% confidence interval [CI] = 1.38-2.22) for patients with 2 HCV pills/day and 2.11 (95% CI = 1.78-2.51) for patients with ≥3 pills/day, compared with patients with 1 HCV pill/day. Conclusions: Patients with HCV have a substantial pill burden even before initiating HCV treatment. As higher HCV pill burden was associated with lower medication adherence, pill burden should be an important consideration in HCV treatment selection.