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. 2011 Jan 5;11:1. doi: 10.1186/1471-2288-11-1

Table 4.

Coverage probability of the 95% confidence interval for the revised product-based estimator (ESRR) using a binomial variance

Low exposure probability (.05)/Low disease probability in unexposed (.02)
RR/ESR
Sample Size
(N1/N2)
1.0/.02 1.5/.03 2.0/.04 2.5/.05 3.0/.06 4.0/.08 5.0/.10

1,000/1,000 66.1 78.1 83.2 87.1 89.6 88.9 90.0
1,000/5,000 98.9 99.3 99.6 99.7 99.9 99.5 99.5
5,000/1,000 54.4 60.6 61.2 62.3 63.5 64.9 65.0
5,000/5,000 90.0 92.8 92.8 93.7 92.4 94.4 94.8

Low exposure probability (.05)/Moderate disease probability in unexposed (.09)
RR/ESR
Sample Size
(N1/N2)
1.0/.09 1.5/.14 2.0/.18 2.5/.23 3.0/.27 4.0/.36 5.0/.45

1,000/1,000 90.4 91.6 93.2 92.4 92.2 92.0 91.5
1,000/5,000 99.9 100 100 100 99.9 99.7 99.3
5,000/1,000 62.8 63.8 63.9 63.7 62.1 61.6 62.7
5,000/5,000 93.8 93.4 94.2 93.5 93.7 93.6 91.6

High exposure probability (.20)/Low disease probability in unexposed (.02)
RR/ESR
Sample Size
(N1/N2)
1.0/.02 1.5/.03 2.0/.04 2.5/.05 3.0/.06 4.0/.08 5.0/.10

1,000/1,000 89.1 91.2 91.8 92.6 91.5 92.5 93.8
1,000/5,000 99.7 99.1 99.4 99.0 98.0 98.8 98.1
5,000/1,000 63.9 68.0 64.7 69.3 70.7 70.5 71.9
5,000/5,000 92.1 94.0 95.1 94.8 94.3 94.5 93.5

High exposure probability (.20)/Moderate disease probability in unexposed (.09)
RR/ESR
Sample Size
(N1/N2)
1.0/.09 1.5/.14 2.0/.18 2.5/.23 3.0/.27 4.0/.36 5.0/.45

1,000/1,000 92.5 93.2 95.1 94.5 92.6 90.7 86.7
1,000/5,000 99.9 99.7 98.9 98.8 98.2 97.3 95.5
5,000/1,000 66.0 68.3 69.7 69.0 64.4 66.6 66.0
5,000/5,000 94.0 94.0 93.2 94.0 91.9 92.0 88.9

N1 is the sample the overall risk is derived from

N2 is the sample the relative risk is derived from

Relative Risk/Exposure-Specific Risk (RR/ESR) values are the hypothesized values

Italics denote coverage probabilities that did not attain 95%