7.3 3. Fisher's information: V(X) statistic under = =0)

Fisher's information V(X) will be: V (X) = -{ l^ (Q, a*) } -1 with:

{ l^ (Q,0 }-1 = l^ (Q,a*) -{ l^ (Q,a*) } { laa (Q,0 }-1 (Q,a*)

8 Appendix 2

8.1 Stopping boundaries for the one-sided SPRT and TT

The stopping boundaries, allowing to detect an effect size (ES) with working significance level a and power 1-3 (with ¡3 = a), are:

Z = -a + bV (lower boundary) and Z = a + bV (upper boundary) for the one-sided SPRT,

Z = -a + 3cV (lower boundary) and Z = a + cV (upper boundary) for the one-sided TT, with a = a' — 0.583V!, b = \ • ES, c = 4 • ES and I = Vi — Vi-1 where Vi is the information available at inspection i (Vo= 0) for both tests, and a' = eEs (^ar) for the one-sided SPRT, and a' = -¡2s for the one-sided TT. ° °

The correction 0.583VI is used to adjust for the discrete monitoring of the data (Siegmund, 1979). When ¡3 = a, a corrected value of the effect size ES must be used to compute the equations of the boundaries. In this case, the boundaries of the tests are computed from an exact formula.

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