We developed a two-pronged approach for establishing alerting thresholds for prospective monitoring within the proposed framework. First, for monitoring activities for which relevant clinical trial data are available on the active comparator, we adapted an approach that borrows concepts from margin setting in NI trials for efficacy (“NI approach”). In the second approach, we summarized NI margins used in published
randomized trials and reviewed publicly available data available on the US FDA’s website to identify the type and magnitude of evidence used in regulatory decisions involving withdrawals and black box warnings between 2009 and 2013 (“benchmark approach