I want to calculate the required sample size for an equivalence trial, which is a sub-trial within the already clustered randomized trial for another main outcome. However, I haven’t seen any syntax so far to calculate sample size for an equivalence trial in a cluster.
The hypothesis is: there is no difference (at least no increased difference) between intervention and control groups. The aim is to rule out the potential side-effect of an intervention
The parameters are:
Mean difference between the intervention and control is not greater than 1 (two-sided), while the mean control value is 2.6.
No. of clusters available for each arm=25
ICC=0.05, Coefficient of variation of cluster size (not equal cluster size) is 1.6
Power = 90% and alpha 0.05.
(or you can give me examples for proportions as well if the above scenario doesn't make sense)
Any help?
Thank you in advance