Change in lesion counts (counts or %)
Study	Subgroup	Salicylic acid	Placebo	P value
Eady 1996	Number of whitehead reduction (short, medium and long term)	Unclear, not reported	Unclear, not reported	no difference; no difference; < 0.002
Eady 1996	Number of total counts reduction (short, medium and long term)	Unclear, not reported	Unclear, not reported	no difference; < 0.043; < 0.001
Eady 1996	Number of papules reduction (short, medium and long term)	Unclear, not reported	Unclear, not reported	no difference; no difference; 0.022
Shalita 1981	Percent reduction ‐total (long term: 12 weeks after start of treatment)	38.4%	24.6%	not report and the author did not state whether this difference is significant
Techapichetvanich 2011	Percent reduction ‐ noninflamed (long term: 10 weeks after start of treatment)	83.77%	25.83%	0.001
Techapichetvanich 2011	Percent reduction ‐ total counts (long term: 10 weeks after start of treatment)	83.97%	35.94%	0.001