Table 1.

Bias in epidemic metrics under low transmission rate.

Metric		Nonresponse bias (V-S)	Sample-size bias (S-S')	Total bias (V-S')
Attack rate
	Mean difference, %	7.90	2.13	10.03
	95% CI	7.88 to 7.91	1.58 to 2.68	9.47 to 10.58
	P value	<.001	<.001	<.001
Peak infection rate
	Mean difference, %	1.22	0.14	1.36
	95% CI	1.22 to 1.22	0.05 to 0.23	1.27 to 1.45
	P value	<.001	.003	<.001
Time to peak
	Mean difference, days	–1.76	0.76	–1
	95% CI	–1.96 to –1.56	0.16 to 1.36	–1.58 to –0.42
	P value	<.001	.02	.002