Shalita 1989.

Study characteristics
Methods	Aim of study: to compare the efficacy of a widely used BPO wash with a product incorporating 2% SA in a detergent‐based vehicle system Design: cross‐over Unit of allocation: individuals Allocation: randomisation; no details Blinding: not described Duration of trial (from recruitment to last follow‐up): not described Dropouts: none
Participants	Population description: mild to moderate acne Setting: not mentioned Randomised number: 30 Age: 13 to 31 years Sex (M/F): 15/15 Severity of illness: mild to moderate
Interventions	Name of treatment group: SA; n = 15 Description: SA 2% Treatment period: 2 weeks Timing: once or twice daily Name of treatment group: BPO; n = 15 Description: 10% BPO wash Treatment period: 2 weeks Timing: once or twice daily
Outcomes	Primary outcomes Participants' global self‐assessment of acne improvement (e.g. measured by a 4‐point scale: excellent, good, fair, and poor). Authors did not report this outcome Withdrawal for any reason. No withdrawals Secondary outcomes Change in lesion counts (total or inflamed and non‐inflamed separately). Reduction of non‐inflamed and inflamed lesion counts, week 2 Physicians' global evaluation of acne improvement. Authors did not report this outcome Minor adverse events (assessed as total number of participants who experienced at least one minor adverse event). Authors did not report this outcome Quality of life. Authors did not report this outcome
Notes	Funding: this research was supported by a grant from GenDerm Corporation, Northbrook, Illinois
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details of random sequence generation were described
Allocation concealment (selection bias)	Unclear risk	No details of allocation concealment were described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants completed study, no missing outcome data
Selective reporting (reporting bias)	Unclear risk	Insufficient reporting data regarding change in inflammatory lesions
Other bias	High risk	No washout period between the first and second phases of the study