Table S1. Numeric results for one-sided lower-limit confidence intervals for one proportion [confidence interval formula: exact (Clopper-Pearson)].

Variable	Confidence level	Sample size (N)	Target distance from P to lower limit	Actual distance from P to lower limit	Proportion (P)	Lower limit	Upper limit	Distance from P to limit if P=0.5
Outcome	0.999	505	0.073	0.073	0.538	0.465	1.0	0.073

A sample size of 500 produces a one-sided 99.9% lower-limit confidence interval with a distance from the sample proportion to the lower limit that is equal to 0.073 when the sample proportion is 0.538 (6) which is the incidence of preoperative hypoxemia of our previous study.