title: Predictors of response of US veterans to treatment for the hepatitis C virus.
abstract: The currently recommended treatment for hepatitis C virus (HCV) infection is pegylated interferon alfa (PEG-INF) and ribavirin, which can be difficult to tolerate. More information about predicting sustained virologic response (SVR) may allow more informed treatment decisions to be made. This retrospective observational cohort study identified predictors of SVR to PEG-INF and ribavirin in routine medical practice at 121 Department of Veterans Affairs facilities. Among 5,944 patients infected with HCV genotypes 1, 2, or 3 who had been treated with PEG-INF and ribavirin, SVR rates were 20%, 52%, and 43%, respectively, and discontinuation rates were 68% (prior to 48 weeks), 34% (24 weeks), and 41% (24 weeks), respectively. In multivariate analysis, significant predictors of decreased likelihood of genotype 1 patients having an SVR were being African American, clinical liver disease, diabetes, low cholesterol, low hemoglobin, low platelet count, and treatment at a low-volume facility. Predictors of increased likelihood of genotype 1 patients having an SVR were low-level HCV viremia, elevated ALT quotient, and receiving PEG-INF 2A (rather than 2B). For genotype 2 patients, increasing body mass index, prior use of interferon, and low platelet count were negative predictors; only low-level HCV viremia was a positive predictor. For genotype 3 patients, only receiving PEG-INF 2A affected the likelihood of an SVR; its effect was positive.
  
  
  CONCLUSIONS
  Among patients for whom HCV treatment is initiated during routine medical care, multiple factors including form of PEG-INF received affect the SVR rate for genotype 1 patients. Few of these factors affect the rate for genotype 2 patients, and even fewer do so for genotype 3 patients.
authors.affiliation: Center for Quality Management in Public Health, Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA. lisa.backus@va.gov
authors.forename: Lisa I
authors.initials: LI
authors.lastname: Backus
authors.forename: Derek B
authors.initials: DB
authors.lastname: Boothroyd
authors.forename: Barbara R
authors.initials: BR
authors.lastname: Phillips
authors.forename: Larry A
authors.initials: LA
authors.lastname: Mole
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D005260:Female; D005838:Genotype; D006526:Hepatitis C / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011092:Polyethylene Glycols / Q000627:therapeutic use; D011237:Predictive Value of Tests; D044469:Racial Groups; D011994:Recombinant Proteins; D012042:Registries; D012254:Ribavirin / Q000627:therapeutic use; D016896:Treatment Outcome; D014481:United States; D014728:Veterans
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C417083:peginterferon alfa-2b; C100416:peginterferon alfa-2a