eff.arm.infofract function

information-fraction based arm efficacy stop

allows stopping an arm for efficacy at a given look when the probability of the corresponding target parameter being greater or smaller (depending on the argument 'alternative' of batss.glm ) than delta.eff is greater than a function of the information fraction at that look.

eff.arm.infofract(posterior, b, n, N, p)

Arguments

• posterior: the 'BATSS' ingredient 'posterior' corresponding, in this context, to the (posterior) probability of the target parameter being greater or smaller (depending on the argument 'alternative' of batss.glm ) than 'delta.eff'.
• b: a tuning parameter (to be defined in eff.arm.control).
• n: the 'BATSS' ingredient 'n' corresponding to the vector of number of recruited participants per arm including the control group.
• N: the 'BATSS' ingredient '`N' corresponding to the maximum (planned) sample size.
• p: a tuning parameter (to be defined in eff.arm.control).

Returns

eff.arm.infofract returns a logical constant.