title: A cost-effectiveness analysis of "test" versus "treat" patients hospitalized with suspected influenza in Hong Kong.
abstract: BACKGROUND
  Seasonal and 2009 H1N1 influenza viruses may cause severe diseases and result in excess hospitalization and mortality in the older and younger adults, respectively. Early antiviral treatment may improve clinical outcomes. We examined potential outcomes and costs of test-guided versus empirical treatment in patients hospitalized for suspected influenza in Hong Kong.
  
  
  METHODS
  We designed a decision tree to simulate potential outcomes of four management strategies in adults hospitalized for severe respiratory infection suspected of influenza: "immunofluorescence-assay" (IFA) or "polymerase-chain-reaction" (PCR)-guided oseltamivir treatment, "empirical treatment plus PCR" and "empirical treatment alone". Model inputs were derived from literature. The average prevalence (11%) of influenza in 2010-2011 (58% being 2009 H1N1) among cases of respiratory infections was used in the base-case analysis. Primary outcome simulated was cost per quality-adjusted life-year (QALY) expected (ICER) from the Hong Kong healthcare providers' perspective.
  
  
  RESULTS
  In base-case analysis, "empirical treatment alone" was shown to be the most cost-effective strategy and dominated the other three options. Sensitivity analyses showed that "PCR-guided treatment" would dominate "empirical treatment alone" when the daily cost of oseltamivir exceeded USD18, or when influenza prevalence was <2.5% and the predominant circulating viruses were not 2009 H1N1. Using USD50,000 as the threshold of willingness-to-pay, "empirical treatment alone" and "PCR-guided treatment" were cost-effective 97% and 3% of time, respectively, in 10,000 Monte-Carlo simulations.
  
  
  CONCLUSIONS
  During influenza epidemics, empirical antiviral treatment appears to be a cost-effective strategy in managing patients hospitalized with severe respiratory infection suspected of influenza, from the perspective of healthcare providers in Hong Kong.
authors.affiliation: School of Pharmacy, Faculty of Medicine, Centre for Pharmacoeconomics Research, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Joyce H S
authors.initials: JH
authors.lastname: You
authors.forename: Eva S K
authors.initials: ES
authors.lastname: Chan
authors.forename: Maggie Y K
authors.initials: MY
authors.lastname: Leung
authors.forename: Margaret
authors.initials: M
authors.lastname: Ip
authors.forename: Nelson L S
authors.initials: NL
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000191:economics / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D005455:Fluorescent Antibody Technique / Q000379:methods; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000235:genetics; D007251:Influenza, Human / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D018803:Models, Economic; D009010:Monte Carlo Method; D053139:Oseltamivir / Q000191:economics / Q000627:therapeutic use*; D017063:Outcome Assessment, Health Care / Q000191:economics; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D019057:Quality-Adjusted Life Years; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir