Table 4:
Critical values and exact alpha levels for those combinations of T, D and M for which there does not exist a critical value for α = 0.05. T is the upper limit on the sample size (length of surveillance), expressed in terms of the expected number of events under the null. D is the sample size at which the sequential analyses start, also expressed in terms of the expected number of events under the null. M is the minimum number of events required to signal. CVcons and CVlib are the conservative and liberal critical values, respectively, while αcons and αlib are their corresponding alpha levels.
| T | D | M | CV cons | α cons | CV lib | α lib |
|---|---|---|---|---|---|---|
| 5 | 1 | 1,4 | 2.545178 | 0.04587 | 2.545177 | 0.05323 |
| 10 | 2 | 1,4 | 2.591675 | 0.04998 | 2.591674 | 0.05478 |
| 10 | 4 | 1,4 | 2.298373 | 0.04924 | 2.298372 | 0.05379 |
| 10 | 8 | 1,4 | 1.834622 | 0.04373 | 1.834621 | 0.05001 |
| 15 | 10 | 1,4 | 2.020681 | 0.04755 | 2.020680 | 0.05124 |
| 20 | 3 | 1,4 | 2.846635 | 0.04712 | 2.846634 | 0.05001 |
| 60 | 4 | 1,4 | 3.162908 | 0.04922 | 3.162907 | 0.05094 |
| 60 | 6 | 1,4 | 3.051470 | 0.04953 | 3.051469 | 0.05101 |
| 80 | 8 | 1,4 | 3.090356 | 0.04906 | 3.090355 | 0.05023 |
| 800 | 3 | 1,4 | 3.887512 | 0.04992 | 3.887511 | 0.05091 |
| 1000 | 1 | 1,4 | 4.047191 | 0.04944 | 4.047190 | 0.05094 |
| 1000 | 8 | 1,4 | 3.814122 | 0.04944 | 3.814121 | 0.05002 |