De 2011.

Methods	Parallel design, randomised controlled trial
Participants	41 participants from Postgraduate Institute of Medical Education and Research, Chandigarh, India.Inclusion criteria: participants with severe grade 4 acne according to the FDA global score Exclusion criteria: not provided Age: not provided Gender: not provided Duration of acne: not provided Acne severity: severe
Interventions	Group A (n = 21): daily low dose isotretinoin (0.3 mg/kg/day) and azithromycin pulse (500 mg daily on three consecutive days fortnightly) Group B (n = 20): standard dose isotretinoin (0.5 mg/kg/day) in a total cumulative dose of 120 mg/kg Participants in both groups received interventions for eight months
Outcomes	Improvement in severity of acne assessed by participants themselves using a 10‐point visual analogue scale (VAS) on each visit, fortnightly for the first two follow‐ups, and subsequently monthly until treatment completion* Occurrence of any side effects assessed on each visit, with assessments of liver function tests and lipidogram only every 2 months* * Indicates outcomes which matched those prespecified for this review
Funding body	None stated
Notes	Only a preliminary report of this study was available as a conference proceeding
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: The trial did not provide any information about random sequence generation
Allocation concealment (selection bias)	Unclear risk	Comment: There was no statement regarding methods of allocation concealment in the study
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: The study did not provide any information to permit judgement
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: The study did not provide any information to permit judgement
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: The high level of loss to follow‐up in the study could lead to a considerable attrition bias (33% in Group A and 45% in Group B)
Selective reporting (reporting bias)	Low risk	Comment: No protocol available; however, there was an adequate report of outcomes listed in methods section
Other bias	Low risk	Comment: There were no other apparent sources of bias