Table 3

Estimated statistical powers required for parallel group trials for a 70% treatment effect using variable numbers of patients for the reference data set. The duration of follow up was 9 months and the tested response variable was the number of new enhancing lesions

Sample size		Number of patients used for simulations
Sample size		10	25	40	65
2×20	74	72	62	57
2×30	89	88	78	75
2×40	96	93	88	87
2×50	99	94	96	92