Table 2

Effect of the baseline risk and relative risk reduction on the number needed to treat.^3,⁸ The results are shown as the number needed to treat

	Relative risk reduction by a new treatment (%)
Baseline risk*	50	40	30	25	20	15	10
*Risk of adverse event in control patients.
0.9	2	3	4	4	6	7	11
0.6	3	4	6	7	8	11	17
0.3	7	8	11	13	17	22	33
0.2	10	13	17	20	25	33	50
0.1	20	25	33	40	50	67	100
0.05	40	50	67	80	100	133	200
0.01	200	250	333	400	500	667	1000
0.005	400	500	667	800	1000	1333	2000
0.001	2000	2500	3333	4000	5000	6667	10000