title: Factors associated with HBV virological breakthrough.
abstract: Little is known about non-adherence to HBV therapy. This study aimed to investigate the relationship between self-reported missed days of antiviral therapy and HBV virological breakthrough and factors associated with virological breakthrough.
  
  
  
  A cross-sectional survey of 211 HBV patients receiving oral antiviral therapies was undertaken at three tertiary hospitals in Sydney, Australia. Associations between 0 to >6 missed days in the last 30 days and virological breakthrough (defined as >10-fold rise in serum HBV DNA above nadir or after achieving virological response in the last 12 months) were examined. Logistic regression analyses determined the number of missed days most strongly associated with virological breakthrough and the associated factors. We report odds ratios (ORs) and relative risks (RRs).
  
  
  
  Of the 204, 32 participants (15.6%) had quantifiable HBV DNA levels (>20 IU/ml); 15 (46.8%) of them experienced virological breakthrough. Participants reported never missing medication (n=130, 63.7%) or missing 1 day (n=23, 11.3%), >1 day (n=23, 11.3%), 2-6 days (n=15, 7.3%) and >6 days (n=13, 6.4%). The most discriminating definition of non-adherence was missing >1 day of medication (RR=8.3; OR=10.2, 95% CI 3.1, 33.8, receiver operating characteristic curve 0.76). Factors independently associated with virological breakthrough included non-adherence (OR=9.0, 95% CI 2.5, 31.9) diagnosed with HBV ≤14 years (OR=5.3, 95% CI 1.0, 26.2) and age ≤47 years (OR=5.4, 95% CI 1.1, 26.9).
  
  
  
  Results provide an evidence-based definition of non-adherence to inform clinical practice and provide a basis for key patient education messages. Closer monitoring of groups at risk of viral breakthrough is required.
authors.affiliation: University of Technology Sydney, Faculty of Health, Broadway, NSW, Australia.|Sydney Children's Hospital Network, NSW, Australia.|The Kirby Institute, UNSW Australia, Wallace Wurth Building, Sydney, NSW, Australia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Sheppard-Law
authors.affiliation: The Kirby Institute, UNSW Australia, Wallace Wurth Building, Sydney, NSW, Australia.
authors.forename: Iryna
authors.initials: I
authors.lastname: Zablotska-Manos
authors.affiliation: Concord Repatriation General Hospital, Department of Gastroenterology and Liver Services, Concord, NSW, Australia.
authors.forename: Melissa
authors.initials: M
authors.lastname: Kermeen
authors.affiliation: Storr Liver Centre Westmead Hospital, Westmead, NSW, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Holdaway
authors.affiliation: Concord Repatriation General Hospital, Department of Gastroenterology and Liver Services, Concord, NSW, Australia.
authors.forename: Alice
authors.initials: A
authors.lastname: Lee
authors.affiliation: St George Hospital, Department of Gastroenterology & Hepatology, Kogarah, NSW, Australia.|St George Hospital Clinical Group School of Medicine, UNSW Australia, Kensington, NSW, Australia.
authors.forename: Amany
authors.initials: A
authors.lastname: Zekry
authors.affiliation: The Kirby Institute, UNSW Australia, Wallace Wurth Building, Sydney, NSW, Australia.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dore
authors.affiliation: Storr Liver Centre Westmead Hospital, Westmead, NSW, Australia.|Westmead Institute for Medical Research, University of Sydney, Sydney, NSW, Australia.
authors.forename: Jacob
authors.initials: J
authors.lastname: George
authors.affiliation: The Kirby Institute, UNSW Australia, Wallace Wurth Building, Sydney, NSW, Australia.
authors.forename: Lisa
authors.initials: L
authors.lastname: Maher
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001315:Australia; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000097:blood; D019317:Evidence-Based Medicine; D005260:Female; D006515:Hepatitis B virus / Q000187:drug effects / Q000302:isolation & purification; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D012307:Risk Factors; D057566:Self Report; D000072230:Sustained Virologic Response; D017211:Treatment Failure; D019562:Viral Load / Q000187:drug effects; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral