Limitations
nonadherence
This trial also has some limitations. The inclusion of patients in our trial stopped prematurely due to futility as already explained in the Materials and methods section. Because of this premature study termination, our study is likely to be underpowered. However, as stated before, our interim analysis was possibly too early in the follow-up and not representative of the actual outcome of the trial. Therefore, the use of an interim analysis should be thought through more thoroughly in future trials before executing this analysis.Second, our method to identify nonadherence has one drawback and that is the absence of all available AHDs in the method. Currently, only 12 out of more than 50 AHDs can be accurately measured with this method. This is mainly due to the validation process. If accurate measurements are needed, the amount of drugs in a method is limited [