Table 2.

Risk-adjusted minimum positive airway pressure usage threshold and incremental benefit

	3 months		12 months		24 months
	Hospitalization	ER visits	Hospitalization	ER visits	Hospitalization	ER visits
Predicted event rate per 1,000 patients	32	119	109	471	202	930
Reduction per additional hour of PAP usage, % (95% CI)*	9.7 (8.7–10.6)	7.4 (6.9–8.0)	6.8 (6.2–7.4)	5.8 (5.5–6.1)	5.4 (4.9–5.8)	5.1 (4.9–5.4)
Absolute reduction in events per additional hour of PAP usage, per 1,000 patients (95% CI)†	3.1 (2.8–3.4)	8.9 (8.2–9.5)	7.4 (6.7–8.0)	27 (25.9–29.0)	10.9 (9.9–11.8)	48 (45.5–50.3)
Minimum usage for benefit, h/night‡	3	1	3	1	2	1

Definition of abbreviations: CI = confidence interval; ER = emergency room; IRR = incidence rate ratio; PAP = positive airway pressure.

^*Calculated as 1 − IRR.

^† Based on the percent reduction and lower/upper confidence limits applied to the predicted event rate.

^‡ Divided into usage categories (i.e., 0 = <1, 1 = 1 to <2, 2 = 2 to <3, through to ⩾9).