title: A randomised controlled trial and cost-effectiveness analysis of high-frequency oscillatory ventilation against conventional artificial ventilation for adults with acute respiratory distress syndrome. The OSCAR (OSCillation in ARDS) study.
abstract: BACKGROUND
  Patients with the acute respiratory distress syndrome (ARDS) require artificial ventilation but this treatment may produce secondary lung damage. High-frequency oscillatory ventilation (HFOV) may reduce this damage.
  
  
  OBJECTIVE
  To determine the clinical benefit and cost-effectiveness of HFOV in patients with ARDS compared with standard mechanical ventilation.
  
  
  METHODS
  A parallel, randomised, unblinded clinical trial.
  
  
  METHODS
  UK intensive care units.
  
  
  METHODS
  Mechanically ventilated patients with a partial pressure of oxygen in arterial blood/fractional concentration of inspired oxygen (P : F) ratio of 26.7 kPa (200 mmHg) or less and an expected duration of ventilation of at least 2 days at recruitment.
  
  
  METHODS
  Treatment arm HFOV using a Novalung R100(®) ventilator (Metran Co. Ltd, Saitama, Japan) ventilator until the start of weaning. Control arm Conventional mechanical ventilation using the devices available in the participating centres.
  
  
  METHODS
  The primary clinical outcome was all-cause mortality at 30 days after randomisation. The primary health economic outcome was the cost per quality-adjusted life-year (QALY) gained.
  
  
  RESULTS
  One hundred and sixty-six of 398 patients (41.7%) randomised to the HFOV group and 163 of 397 patients (41.1%) randomised to the conventional mechanical ventilation group died within 30 days of randomisation (p = 0.85), for an absolute difference of 0.6% [95% confidence interval (CI) -6.1% to 7.5%]. After adjustment for study centre, sex, Acute Physiology and Chronic Health Evaluation II score, and the initial P : F ratio, the odds ratio for survival in the conventional ventilation group was 1.03 (95% CI 0.75 to 1.40; p = 0.87 logistic regression). Survival analysis showed no difference in the probability of survival up to 12 months after randomisation. The average QALY at 1 year in the HFOV group was 0.302 compared to 0.246. This gives an incremental cost-effectiveness ratio (ICER) for the cost to society per QALY of £88,790 and an ICER for the cost to the NHS per QALY of £ 78,260.
  
  
  CONCLUSIONS
  The use of HFOV had no effect on 30-day mortality in adult patients undergoing mechanical ventilation for ARDS and no economic advantage. We suggest that further research into avoiding ventilator-induced lung injury should concentrate on ventilatory strategies other than HFOV.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN10416500.
authors: Warwick Clinical Trials Unit, University of Warwick, Warwick, UK.
authors: Ranjit
authors: R
authors: Lall
authors: University of Leeds, Leeds, UK.
authors: Patrick
authors: P
authors: Hamilton
authors: John Radcliffe Hospital, Oxford, UK.
authors: Duncan
authors: D
authors: Young
authors: University of Leeds, Leeds, UK.
authors: Claire
authors: C
authors: Hulme
authors: University of Leeds, Leeds, UK.
authors: Peter
authors: P
authors: Hall
authors: Bristol Royal Infirmary, Bristol, UK.
authors: Sanjoy
authors: S
authors: Shah
authors: Queen Elizabeth Hospital, Birmingham, UK.
authors: Iain
authors: I
authors: MacKenzie
authors: Queen Elizabeth Hospital, Birmingham, UK.
authors: William
authors: W
authors: Tunnicliffe
authors: Intensive Care National Audit & Research Centre, London, UK.
authors: Kathy
authors: K
authors: Rowan
authors: Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
authors: Brian
authors: B
authors: Cuthbertson
authors: University of Leeds, Leeds, UK.
authors: Chris
authors: C
authors: McCabe
authors: Warwick Clinical Trials Unit, University of Warwick, Warwick, UK.
authors: Sallie
authors: S
authors: Lamb
mesh_terms: D000328:Adult; D000368:Aged; D002423:Cause of Death; D003362:Cost-Benefit Analysis; D005260:Female; D006612:High-Frequency Ventilation / Q000191:economics / Q000295:instrumentation / Q000401:mortality; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D019057:Quality-Adjusted Life Years; D012121:Respiration, Artificial / Q000191:economics / Q000295:instrumentation / Q000379:methods / Q000401:mortality; D012128:Respiratory Distress Syndrome / Q000191:economics / Q000401:mortality / Q000628:therapy*; D012720:Severity of Illness Index; D013222:State Medicine; D016019:Survival Analysis; D006113:United Kingdom