NilFroushzadeh 2009.

Study characteristics
Methods	Aim of study: to compare the efficacy of combination treatment of clindamycin + SA, versus clindamycin + tretinoin versus Design: parallel Unit of allocation: individuals Allocation: randomisation; no details Blinding: single‐blind Duration of trial (from recruitment to last follow‐up): recruited from September 06 to August 07 Dropouts: none
Participants	Population description: mild‐to moderate AV Setting: Skin Disease and Leishmaniasis Research Center and Isfahan University of Medical Sciences clinics, Iran Randomised number: 42 Age: 15 to 25 years Sex: (M/F): 0/42 Severity of illness: mild to moderate
Interventions	Name of treatment group: 1% clindamycin + 2% SA lotion; n = 14 Description: 1% clindamycin + 2% SA lotion Treatment period: 12 weeks Timing: twice daily Name of control group 1: 1% clindamycin + 0.025% tretinoin; n = 14 Description: 1% clindamycin + 0.025% tretinoin Treatment period: 12 weeks Timing: once nightly Name of control group 2: 1% clindamycin lotion; n = 14 Description: 1% clindamycin Treatment period: 12 weeks Timing: twice daily
Outcomes	Primary outcomes Participants' global self‐assessment of acne improvement (e.g. measured by a four‐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). Week 12, only summary statistics were reported. 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). Reported number of participants who experienced minor adverse event Quality of life. Authors did not report this outcome Other outcomes that were not analysed in this review Acne Severity Index
Notes	Funding: not mentioned
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	This was a single‐blinded clinical trial, no details of randomisation methods were provided
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Patients were blinded to the type of treatment". Comment: It did not describe how "blinding" method was used. This study was 'single‐blinded', blinding of personnel probably insufficient
Blinding of outcome assessment (detection bias) All outcomes	High risk	This was a 'single‐blinded' (patient‐blinded) trial, blinding of investigator probably insufficient
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "All patients completed the study." Comment: no missing outcome data
Selective reporting (reporting bias)	Unclear risk	No baseline data for each group reported
Other bias	Low risk	No other potential bias identified