title: The LAW index as an accurate indicator of the initiation of antiviral treatment in patients with chronic hepatitis B.
abstract: OBJECTIVE
  Considering that inflammation and fibrosis are major factors for the indication of antiviral treatment, liver stiffness measurements could help identify patients who require antiviral treatment. This study evaluated factors that best identify patients who require antiviral treatment and to develop a new indicator for chronic hepatitis B (CHB).
  
  
  METHODS
  Patients with CHB were randomly classified into a training or validation group, and a model for predicting necroinflammatory activity ≥ A3 or fibrosis grade ≥ F2 (A3F2) was established in the training group using binary regression analysis and validated in the validation group. Predictive efficacy was compared using area under the receiver-operating characteristics curve analysis.
  
  
  RESULTS
  Four-hundred ninety-two patients were enrolled. In the training group, female sex, aspartate aminotransferase-to-platelet count ratio index (APRI), and liver stiffness were independent predictors of A3F2 on multivariate analysis. These variables were used to construct a novel model, called the LAW (liver stiffness, APRI, woman) index, as follows: 1.5 × liver stiffness value (kPa) + 3.9 × APRI + 3.2 if female. The LAW index was a better predictor of A3F2 than the APRI or liver stiffness measurement in both training group (0.870; 95% confidence interval, 0.822-0.910) and validation group (0.862; 95% confidence interval, 0.813-0.903).
  
  
  CONCLUSIONS
  The LAW index was able to accurately identify patients with CHB who required antiviral treatment. A LAW index of >10.1 could be a strong indicator for the initiation of antiviral treatment in patients with CHB.
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Yeon Seok
authors.initials: YS
authors.lastname: Seo
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Tae Hyung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Jem Ma
authors.initials: JM
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Yim
authors.affiliation: Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung Up
authors.initials: SU
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Young Kul
authors.initials: YK
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Biostatistics, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hyunggin
authors.initials: H
authors.lastname: An
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Yim
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Jong Eun
authors.initials: JE
authors.lastname: Yeon
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hong Sik
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Byun
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Um
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Chang Duck
authors.initials: CD
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Ho Sang
authors.initials: HS
authors.lastname: Ryu
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage*; D015415:Biomarkers; D004334:Drug Administration Schedule; D005260:Female; D005355:Fibrosis; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000473:pathology*; D006801:Humans; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009336:Necrosis; D011237:Predictive Value of Tests; D012372:ROC Curve; D012044:Regression Analysis; D012720:Severity of Illness Index
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers
keywords: APRI; antiviral treatment; chronic hepatitis B; index; liver stiffness measurement