High rates of early treatment discontinuation in hepatitis C-infected US veterans.
BACKGROUND
Patients with chronic hepatitis C (HCV) frequently discontinued dual therapy with pegylated interferon alfa (Peg-IFN) plus ribavirin (RBV) before reaching the recommended duration of 48 or 24 weeks for genotypes (G) 1/4 or 2/3, respectively. We quantified rates of discontinuation despite efficacy (non-LOE) versus lack of efficacy (LOE) versus discontinuation for unknown reasons in a national database of United States veterans.


METHODS
We identified a population-based cohort of U.S. veterans with encounters from 2004 through 2009 who had lab-confirmed HCV infection and initiated therapy with Peg-IFN plus RBV in Veterans Health Administration medical centers. Pharmacy data were used to determine therapy duration, defined as the sum of Peg-IFN days supplied. Patients "discontinued" if they failed to receive at least 44 (G1/4) or 20 weeks (G2/3) of therapy. We classified discontinuations as due to non-LOE, LOE, or unknown reasons using a classification rule based on treatment duration and laboratory confirmed response.


RESULTS
Of 321,238 diagnosed HCV patients during the evaluation period, 9.7% initiated therapy and 6.4% met all other inclusion criteria. 54.9% of patients discontinued early; of these, 41.2% discontinued due to non-LOE reasons, 12.5% discontinued for LOE reasons, and 46.3% discontinued for unknown reasons. Among non-LOE discontinuers, most (60.1%) discontinued in the first 4 weeks of therapy, which constitutes 13.6% of all treated patients.


CONCLUSIONS
We observed a high proportion of early discontinuations with dual-therapy regimens in a national cohort of HCV-infected veterans. If this trend persists in the triple-therapy era, then efforts must be undertaken to improve adherence.
Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA. joanne.lafleur@pharm.utah.edu.
Joanne
J
LaFleur
Robert
R
Hoop
Timothy
T
Morgan
Scott L
SL
DuVall
Prashant
P
Pandya
Eli
E
Korner
Kristin
K
Knippenberg
Candace
C
Hayden
Richard E
RE
Nelson
D005260:Female; D005838:Genotype; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009323:Natural Language Processing; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014728:Veterans / Q000706:statistics & numerical data*; D028761:Withholding Treatment