Cost-effectiveness of Out-of-Hospital Continuous Positive Airway Pressure for Acute Respiratory Failure.
OBJECTIVE
We determine the cost-effectiveness of out-of-hospital continuous positive airway pressure (CPAP) compared with standard care for adults presenting to emergency medical services with acute respiratory failure.


METHODS
We developed an economic model using a United Kingdom health care system perspective to compare the costs and health outcomes of out-of-hospital CPAP to standard care (inhospital noninvasive ventilation) when applied to a hypothetical cohort of patients with acute respiratory failure. The model assigned each patient a probability of intubation or death, depending on the patient's characteristics and whether he or she had out-of-hospital CPAP or standard care. The patients who survived accrued lifetime quality-adjusted life-years (QALYs) and health care costs according to their age and sex. Costs were accrued through intervention and hospital treatment costs, which depended on patient outcomes. All results were converted into US dollars, using the Organisation for Economic Co-operation and Development purchasing power parities rates.


RESULTS
Out-of-hospital CPAP was more effective than standard care but was also more expensive, with an incremental cost-effectiveness ratio of £20,514 per QALY ($29,720/QALY) and a 49.5% probability of being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold. The probability of out-of-hospital CPAP's being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold depended on the incidence of eligible patients and varied from 35.4% when a low estimate of incidence was used to 93.8% with a high estimate. Variation in the incidence of eligible patients also had a marked influence on the expected value of sample information for a future randomized trial.


CONCLUSIONS
The cost-effectiveness of out-of-hospital CPAP is uncertain. The incidence of patients eligible for out-of-hospital CPAP appears to be the key determinant of cost-effectiveness.
School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom. Electronic address: p.thokala@sheffield.ac.uk.
Praveen
P
Thokala
School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom.
Steve
S
Goodacre
West Midlands Ambulance Service National Health Service Foundation Trust, Brierley Hill, West Midlands, United Kingdom.
Matt
M
Ward
West Midlands Ambulance Service National Health Service Foundation Trust, Brierley Hill, West Midlands, United Kingdom.
Jerry
J
Penn-Ashman
Warwick Medical School and Heart of England National Health Service Foundation Trust, Coventry, United Kingdom.
Gavin D
GD
Perkins
D000208:Acute Disease; D000328:Adult; D045422:Continuous Positive Airway Pressure / Q000191:economics*; D003362:Cost-Benefit Analysis; D004632:Emergency Medical Services / Q000191:economics* / Q000379:methods; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008297:Male; D018803:Models, Economic; D019057:Quality-Adjusted Life Years; D012121:Respiration, Artificial / Q000191:economics / Q000379:methods; D012131:Respiratory Insufficiency / Q000191:economics / Q000628:therapy*; D006113:United Kingdom