Table 2.

Pooled data on adverse events

		Outcome achieved
		with
		Active		Placebo
Outcome	Number of trials	Number/total	Percent (95% CD)	Number/total	Percent (95% CI)	Relative (95% CI)	NNH (95% CI)
Adverse event withdrawal (all concentrations of imiquimod)	4	5/284	1.8 (0.2 to 3.4)	0/186	0 (0 to 0)	1.7 (0.4 to 9.9)	not calculated
Adverse event withdrawel (imiquimod 5%)	3	4/164	2.4 (0.0 to 4.8)	0/156	0 (0 to 0)	1.9 (0.4 to 10)	not calculated
Lack of efficacy withdrawal (imiquimod 2% or 5%)	5	5/303	1.7 (0.3 to 3.1)	21/285	7.4 (4.3 to 11)	0.3 (0.1 to 0.7)	-18 (-11 to -48)

The number needed to harm (NNH) describes the number of patients who have to be treated for one to have treatment-specific harm compared with placebo. Negative figures indicate that the harm occurs less frequently with treatment than placebo. NNH was not calculated when there was no significant difference between imiquimod and placebo. CI = confidence interval; NNH = number needed to harm