title: Estimation of quality-adjusted life expectancy in patients under prolonged mechanical ventilation.
abstract: OBJECTIVE
  The purpose of this study was to estimate the quality-adjusted life expectancy (QALE) and the expected lifetime utility loss of patients with prolonged mechanical ventilation (PMV).
  
  
  METHODS
  PMV was defined as more than 21 days of mechanical ventilation. A total of 633 patients fulfilled this definition and were followed for 9 years (1998-2007) to obtain their survival status. Quality of life of 142 patients was measured with the EuroQol five-dimensional (EQ-5D) questionnaire during the period 2008 to 2009. The survival probabilities for each time point were adjusted with a utility measurement of quality of life and then extrapolated to 300 months to obtain the QALE. We compared the age-, gender-matched reference populations to calculate the expected lifetime utility loss.
  
  
  RESULTS
  The average age of subjects was 76 years old. The life expectancy and loss of life expectancy were 1.95 years and 8.48 years, respectively. The QALE of 55 patients with partial cognitive ability and the ability to respond was 0.58 quality-adjusted life years (QALY), whereas the QALEs of 87 patients with poor consciousness were 0.28 and 0.29 QALY for the EQ-5D measured by family caregivers and nurses, respectively. The loss of QALE for PMV patients was 9.87 to 10.17 QALY, corresponding to a health gap of 94% to 97%.
  
  
  CONCLUSIONS
  Theses results of poor prognosis would provide stakeholders evidence for communication to facilitate clinical decisions. The estimation may be used in future studies to facilitate the cost-effectiveness and reduction of the health gap.
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Mei-Chuan
authors.initials: MC
authors.lastname: Hung
authors.forename: Yuan-Horng
authors.initials: YH
authors.lastname: Yan
authors.forename: Po-Sheng
authors.initials: PS
authors.lastname: Fan
authors.forename: Ming-Shian
authors.initials: MS
authors.lastname: Lin
authors.forename: Cheng-Ren
authors.initials: CR
authors.lastname: Chen
authors.forename: Lu-Cheng
authors.initials: LC
authors.lastname: Kuo
authors.forename: Chong-Jen
authors.initials: CJ
authors.lastname: Yu
authors.forename: Jung-Der
authors.initials: JD
authors.lastname: Wang
mesh_terms: D000368:Aged; D015897:Comorbidity; D003362:Cost-Benefit Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008017:Life Expectancy; D015993:Life Tables; D008297:Male; D009010:Monte Carlo Method; D009313:National Health Programs; D019057:Quality-Adjusted Life Years; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000191:economics / Q000523:psychology*; D016019:Survival Analysis; D013624:Taiwan; D013997:Time Factors