Babayeva 2011.

Study characteristics
Methods	Aim of study: to evaluate the efficacy and safety of combination therapy with all‐TRA 0.05% cream plus CDP 1% lotion (all‐TRA + CDP group) in comparison with the combination of 3% alcohol‐based SA plus CDP 1% lotion (SA + CDP group) in the treatment of mild to moderate facial AV Design: parallel Unit of allocation: patients Allocation: randomised; no details of random methods were provided Blinding: single‐blinding; open label for assessors Duration of trial (from recruitment to last follow‐up): not described Dropouts: none
Participants	Population description: mild to moderate facial AV Setting: not described Randomised number: 46 Age: 18 to 31 in treatment group; 18 to 26 in control group Sex (M/F): 5/18 in treatment group; 5/18 in control group Severity of illness: mild to moderate Total lesion counts: 66.52 ± 8.04 in treatment group; and 66.52 ± 8.04 in control group; Inflammatory lesion counts: 21.95 ± 7.18 in treatment group; and 20.65 ± 7.73 in control group; Non‐inflammatory lesion counts: 44.78 ± 6.12 in treatment group; and 45.43 ± 6.38 in control group
Interventions	Name of treatment group: SA + CDP group n = 23 Description: combination of 3% alcohol‐based SA plus CDP 1% lotion Treatment period: 12 weeks Timing: twice‐daily Name of treatment group: all‐TRA + CDP group n = 23 Description: all‐TRA 0.05% cream plus CDP 1% lotion Treatment period: 12 week Timing: 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; week 12; 5‐point scale, 0: worsening or unchanged, 1: mild improvement, 2: moderate improvement, 3: good improvement and 4: excellent improvement) Withdrawal for any reason (no withdrawals) Secondary outcomes Change in lesion counts (total or inflamed and non‐inflamed separately) Percentage reduction in lesion counts, baseline and week 2, 4, 8, and 12 Physicians' global evaluation of acne improvement (week 12; 5‐point scale, 0: worsening or unchanged, 1: mild improvement, 2: moderate improvement, 3: good improvement and 4: excellent improvement) Minor adverse events (assessed as total number of participants who experienced at least one minor adverse event; symptoms evaluated using a 4‐point scale (0 = none, 1 = mild, 2 = moderate, 3 = severe; reported number of participants who experienced minor adverse event) Quality of life. AQOL questionnaire, week 12 Other outcomes that were not analysed in this review Time to 50% reduction in total lesion counts Skin surface barrier
Notes	Funding: not described
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "This 12‐week study was designed as a single‐blind, randomised, 1:1 parallel group and comparative investigation..."; Quote: "Patients were randomised to receive topical treatments for AV with one of two topical agent combinations..." Comment: no details of random methods were provided
Allocation concealment (selection bias)	Unclear risk	No detail of concealment approach was provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "This 12‐week study was designed as a single‐blind, randomised, 1:1 parallel group and comparative investigation...", Comment: unclear which side was blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "Evaluations were performed by an investigator aware of the treatment allocation at baseline and after 2, 4, 8 and 12 weeks of treatment." Comment: outcome assessment was not blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "The 12‐week treatment periods were completed by all subjects." Comment: no missing outcome data
Selective reporting (reporting bias)	Low risk	Results reported for all prespecified outcomes in the methods section
Other bias	Low risk	No other potential bias identified