Table 1. Construction of Cumulative Summation Charts with Varying Acceptable and Unacceptable Failure Rates.

Variables	Diagnostic Performance	Diagnostic Performance	Diagnostic Performance	Pneumothorax Occurrence
	p0 = 0.04	p0 = 0.06	p0 = 0.10	p0 = 0.25
	p1 = 0.08	p1 = 0.12	p1 = 0.20	p1 = 0.45
a = ln ([1 - β] / α)	2.20	2.20	2.20	2.20
b = ln ([1 - α) / β)	2.20	2.20	2.20	2.20
P = ln (p1 / p0)	0.69	0.69	0.69	0.59
Q = ln ([1 - p1] / [1 - p0])	0.04	0.07	0.12	0.31
H0 = b / (P + Q)	-2.99	-2.89	-2.71	-2.45
H1 = a / (P + Q)	2.99	2.89	2.71	2.45
s = Q / (P + Q)	0.06	0.09	0.15	0.35

H0 = lower decision limit, H1 = upper decision limit, p0 = acceptable failure rate, p1 = unacceptable failure rate, s = score, α = type I error level, β = type II error level