Comparison 2. Topical azelaic acid versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Withdrawal for any reason	4		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.1.1 medium term	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.1.2 long term	3		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.2 Change in lesion counts ‐ > 50% inflamed reduction	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.2.1 long term	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.3 Change in lesion counts ‐ inflamed (percentage reduction from baseline)	3		Other data	No numeric data
2.3.1 short term	1		Other data	No numeric data
2.3.2 medium term	2		Other data	No numeric data
2.3.3 long term	2		Other data	No numeric data
2.3.4 long term (split‐face trials)	1		Other data	No numeric data
2.4 Change in lesion counts ‐ > 50% non‐inflamed reduction	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.4.1 long term	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.5 Change in lesion counts ‐ non‐inflamed (percentage reduction from baseline)	2		Other data	No numeric data
2.5.1 medium term	1		Other data	No numeric data
2.5.2 long term	1		Other data	No numeric data
2.5.3 long term (split‐face trials)	1		Other data	No numeric data
2.6 Change in lesion counts (percentage reduction from baseline)	3		Other data	No numeric data
2.6.1 medium term	1		Other data	No numeric data
2.6.2 long term	1		Other data	No numeric data
2.6.3 long term (split‐face trials)	1		Other data	No numeric data
2.7 Change in lesion counts (number of lesions post‐intervention)	1		Other data	No numeric data
2.7.1 short term	1		Other data	No numeric data
2.8 Change in lesion counts ‐ comedones (reduction in number of lesions post‐intervention)	1		Other data	No numeric data
2.8.1 long term	1		Other data	No numeric data
2.9 Physicians' global evaluation of acne improvement	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.9.1 Good to excellent improvement (long term)	1		Risk Ratio (M‐H, Random, 95% CI)	Totals not selected
2.10 Minor adverse events	3		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
2.10.1 burning	1	92	Risk Ratio (M‐H, Random, 95% CI)	4.56 [0.53, 39.24]
2.10.2 scaling	2	147	Risk Ratio (M‐H, Random, 95% CI)	1.49 [0.16, 13.48]
2.10.3 erythema	2	147	Risk Ratio (M‐H, Random, 95% CI)	1.96 [0.39, 9.78]
2.10.4 dryness	1	55	Risk Ratio (M‐H, Random, 95% CI)	2.92 [0.15, 57.90]
2.10.5 oiliness	1	55	Risk Ratio (M‐H, Random, 95% CI)	4.08 [0.22, 75.25]
2.10.6 itching	2	147	Risk Ratio (M‐H, Random, 95% CI)	5.45 [0.68, 43.53]
2.10.7 total events (medium term)	1	60	Risk Ratio (M‐H, Random, 95% CI)	19.00 [1.16, 312.42]