Table 2

Return on investment (ROI) sensitivity analysis: variation of number of subjects, sites, and counterfactual studies used to calculate ROI

ParametersVariationsCompared with ROI 555%
SubjectsPlus 10%603
Plus 5%579
Minus 5%531
Minus 10%507
Study sitesPlus 10%559
Plus 5%557
Minus 5%553
Minus 10%551
Counterfactual cases>counterfactual studies 22, maximum, no combined studies682
<counterfactual studies than 10, combining 12 studies368