title: Cost per QALY (quality-adjusted life year) and lifetime cost of prolonged mechanical ventilation in Taiwan.
abstract: BACKGROUND
  Patients who require prolonged mechanical ventilation (PMV) are increasing and producing financial burdens worldwide. This study determines the cost per QALY (quality-adjusted life year), out-of-pocket expenses, and lifetime costs for PMV patients stratified by underlying diseases and cognition levels.
  
  
  METHODS
  A nationwide sample of 50,481 patients with continual mechanical ventilation for more than 21 days was collected during 1997-2007. After stratifying the patients according to specific diagnoses, a latent class analysis (LCA) was performed to categorise PMV patients with multiple co-morbidities into several homogeneous groups. The survival functions were estimated for individual groups using the Kaplan-Meier method and extrapolated to 300 months through a semi-parametric method. The survival functions were adjusted using an EQ-5D utility value derived from a convenience sample of 142 PMV patients to estimate quality-adjusted life expectancies (QALE). Another convenience sample of 165 patients was used to estimate the out-of-pocket expenses. The lifetime expenditures paid by the single-payer National Health Insurance (NHI) system and patients' families were estimated by multiplying average monthly expenditures by the survival probabilities and summing the values over lifetime.
  
  
  RESULTS
  PMV therapy costs more than 100,000 U.S. dollars (USD) per QALY for all patients with poor cognition. For patients with partial cognition, PMV therapy costs less than 56,000 USD per QALY for those with liver cirrhosis, intracranial or spinal cord injuries, and 57,000-69,000 USD for patients with multiple co-morbidities under age of 65. The average lifetime cost of PMV was usually below 56,000 USD. The out-of-pocket expenses were often more than one-third of the total cost of treatment.
  
  
  CONCLUSIONS
  PMV treatment for patients with poor cognition would cost more than 5 times Taiwan's GDP (gross domestic products), or less cost-effective. The out-of-pocket expenses for PMV provision should also be considered in policy decision.
authors.affiliation: Department of Public Health, National Cheng Kung University College of Medicine, Tainan, Taiwan.
authors.forename: Mei-Chuan
authors.initials: MC
authors.lastname: Hung
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Lu
authors.forename: Likwang
authors.initials: L
authors.lastname: Chen
authors.forename: Ming-Shian
authors.initials: MS
authors.lastname: Lin
authors.forename: Cheng-Ren
authors.initials: CR
authors.lastname: Chen
authors.forename: Chong-Jen
authors.initials: CJ
authors.lastname: Yu
authors.forename: Jung-Der
authors.initials: JD
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003365:Costs and Cost Analysis; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results; D012121:Respiration, Artificial / Q000191:economics* / Q000706:statistics & numerical data*; D016019:Survival Analysis; D013624:Taiwan / Q000453:epidemiology