Table 1.

Summary of model parameters

Parameter	Mean	Distribution or 95% CI	Source
Baseline risks
Risk of mortality	0.257	Beta (9,26)	ACUTE
Risk of intubation	0.034	Beta (1,28)	ACUTE
OR for prehospital CPAP
Base case scenario (effectiveness parameters from ACUTE)
Log (Mortality OR)	0.145	Normal (0.145, 0.521)	ACUTE
Log (Intubation OR)	0.591	Normal (0.591, 1.403)	ACUTE
Scenario using effectiveness parameters from NMA
Log (Mortality OR)	−0.916	Samples	ACUTE, HTA meta-analysis [2]
Log (Intubation OR)	−1.050	Samples	ACUTE, HTA meta-analysis [2]
Life expectancy of patients
Lifetime years	2.67 years	Normal (2.67, 0.16)	3CPO trial [12], Clinical opinion
Health related quality of life
Utility	0.6	Beta (640,425)	3CPO trial [12], Clinical opinion
Costs (in £)
Prehospital CPAP	£33	Normal (£33, £3.3)	O-Two/SP [13], WMAS, Expert opinion
Hospitalisation	£3200	Gamma (80,40)	NHS Reference Costs [14]
Intubation	£3600	Gamma (90, 40)	HCHS index [15], Clinical opinion
Annual costs	£6000	Gamma (60, 100)	3CPO trial [12], HCHS index [15], Clinical opinion

HCHS Hospital and Community Health Services, WMAS West Midland Ambulance Service.