Sheehan‐Dare 1989.

Methods	This was a double‐blind, double‐dummy RCT in a hospital setting. The duration of the trial was 12 weeks. Randomisation was stated to be by matched pairs on the basis of age, sex, acne grade, and numbers of both inflamed and non‐inflamed lesions, but no details were given about the method of sequence generation. Industrial support came from Upjohn. UV control was used in the winter months. Previous acne treatment was stopped 30 days before the start of the trial, which included all acne therapy, antibiotics, corticosteroids, and antiandrogens. Evaluation was at 0, 4, 8, and 12 weeks. The area evaluated was the face. The assessor was not stated. All participants who completed the trial according to the protocol were included in the analysis. The following statistical tests were used: student's t‐test for differences from baseline, and the second trial publication also reported that analysis of variance and Newman‐Keuls techniques were used, and an analysis of variance for between group differences was undertaken.
Participants	66 participants were enrolled. 33 participants were randomised to the minocycline group; 33 participants were randomised to the clindamycin group. There was 1 (6%) dropout in the minocycline group and 6 (18%) in the clindamycin group. The age range was 14 to 35. Recruitment was fulfilled by hospital out‐patients. There was baseline comparability (age, sex, grade, and count). Inclusion criteria of the trial Moderate to severe facial acne, 10 to 120 IL with a maximum of 6 NOD/cyst on the face Exclusion criteria of the trial PREG, BF, SENS, started or stopped OC within 90 days of the study, history of chronic bowel disease or diarrhoea
Interventions	Minocycline 50 mg bd Clindamycin phosphate 1% topical solution bd Appearance: standard but double‐dummy used Concomitant therapy: not specified Instructions: capsules to be taken before meals, apply lotion to whole face Skin hygiene: not specified Empty stomach: not specified Compliance: not specified
Outcomes	Outcomes of the trial NIL (Cc, Co) and IL count (PA, PU, NOD, MAC) Grade: Leeds (0 to 10) (Burke 1984) Mean changes in NILC and ILC, and grade from baseline (primary outcome) Adverse drug reactions as reported by the participants
Notes	Country: United Kingdom Language: English Review version: 2002 Data were presented in graphical form only. Macules were included in the ILC. Grades and counts were log transformed prior to analysis. The manufacturers or authors couldn't supply further information. The numbers of participants in each group were not reported. There were differences between the 2 reports of the same trial, including whether or not there was a statistically significant reduction in non‐inflamed lesion counts, and in the type of statistical tests used. There were differences between 2 publications of this trial.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation was stated to be by matched pairs on the basis of age, sex, acne grade, and numbers of both inflamed and non‐inflamed lesions, but no details were given about the method of sequence generation.
Allocation concealment (selection bias)	Unclear risk	This was unclear; no details were given.
Blinding (performance bias and detection bias) All outcomes	Low risk	It was stated to be "double blind, double dummy" (page 25 of the published report). No further details were given.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	66 participants were enrolled, but there were no details on how many participants were randomised to each group: It was assumed to be 33 due to matched pairs. 6 dropped out from the clindamycin arm and 1 from the minocycline arm, but it was unclear at which time point these dropouts occurred.
Selective reporting (reporting bias)	Low risk	All outcomes, including adverse events, were reported at each time point. No data were reported (graphical only).