Table 3 Calculated sample size needed under different sample allocation scenarios to reach 80% non-inferiority power.Sample size is the total number of samples available in the new trial. \(p_{NC}\) is the probability of retreatment after beef cattle being treated with negative control. ENFO is enrofloxacin; Z is the new treatment. Sample allocation is the number of samples assigned to each treatment. For example, (87, 1687, 1785) means the number of samples assigned to NC, ENFO, and Z are 87, 1687, and 1785
total sample size | \(p_{NC}\) | \(p_{ENFO}\) | \(p_{Z}\) | sample allocation (NC, ENRO, Z) | allocation type | with existing network | non-inferiority power |
|---|---|---|---|---|---|---|---|
5355 | 0.681 | 0.2229 | 0.2229 | (1785, 1785, 1785) | even | No | 80.01% |
4584 | 0.681 | 0.2229 | 0.2229 | (1528, 1528, 1528) | even | Yes | 80.00% |
3559 | 0.681 | 0.2229 | 0.2229 | (87, 1687, 1785) | uneven | Yes | 80.02% |