Baum 1987.

Methods	Desing trial: parallel (2 groups). Study phase: not described. Baseline observation period: no (Dr Graham Serjeant, interviewed by one author of this review (JKM), on February 4, 2011). Follow‐up period: 8 weeks. Randomisation unit: patient. Unit of analysis: ulcers. Intention to treat: unclear.
Participants	Total: 30. Antibiotic therapy: 16. Placebo: 14. Withdrawals: 7% (2/30) (1 from each group). Reported leg ulcers at the start of the trial: 40 (data supplied by Dr Graham Serjeant, Jamaica, February 4, 2011). Age: median (range). Antibiotic therapy group: 29 years (14 ‐ 44 years); control group: 25 years (17 ‐ 49 years). Number of ulcers: 40 (antibiotic therapy: 20; placebo: 20). Duration (median): Antibiotic therapy group: 3.6 years (range: 0.3 to 15 years). Control group: 3.5 years (range: 0.3 to 12 years). Mean baseline ulcer area (cm2) ± SD. Antibiotic therapy group: 20.0 (14.9); placebo: 20.8 (19.0). Gender (male:female). Antibiotic therapy group: 4:9; control: 6:9. Inclusion criteria: 1. Hb SS; 2. leg ulceration of at least 3 months duration; 3. bacterial swabs revealed at least one of the skin pathogen; 4. to attend at 2‐weekly intervals; 5. to agree to the trial protocol; 6. multiple ulcers: yes, all used (data supplied by Dr Graham Serjeant, Jamaica, February 4, 2011). 7. new ulcers discussed: not information (Data supplied by Dr Graham Serjeant, Jamaica, February 4, 2011). Exclusion criteria: 1. large leg ulcers; 2. chronic renal failure.
Interventions	Antimicrobial therapy (aerosol preparation, twice daily): neomycin, bacitracin and polymyxin B. Control (aerosol dispenser, twice daily). Placebo: sterile normal saline with 1:1000 red food colouring. Co‐intervention: disinfectant (Eusol). Rest with elevation of the affected leg(s). Systematic antibiotics: not allowed. Oral zinc sulphate was allowed.
Outcomes	Primary: pain. Likely secondary outcomes (these end points were not described at 'methods section'): healing rate; bacteriological investigation. According with Dr Graham Serjeant, interviewed by one author of this review (JKM), 'ulcer area‐change' was the primary outcome (February 4, 2011).
Notes	1. This trial was described as "randomised controlled crossover trial" at Proceedings of the Commonwealth Caribean medical Research Council (31st Scientific Meeting, 1986, April 16‐19, Port Spain, Trinidad and Tobago. 2. Country: University Hospital of the West Indies, Kingston, Jamaica. 3. Study time: 10 June to 9 September 1993. 4. Sample size estimation a priori: not stated. 5. 3M Company Incorporated donated Rikospray®, an aerosol preparation of neomycin, bacitracin, and polymyxin B.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "patients were assigned, using size 4 block randomization" (page 847). Comments: there is an imbalance in two characteristics baseline: zinc therapy was only received by control patients and marked pain (14 placebo patients vs 8 patients treatment). Insufficient information about the sequence generation process to permit judgement of ‘low risk’ or ‘high risk’.
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement of ‘low risk’ or ‘high risk’.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to permit judgement of ‘low risk’ or ‘high risk’
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement of ‘low risk’ or ‘high risk’.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient reporting of attrition and exclusions to permit judgement of ‘low risk’ or ‘high risk’.
Selective reporting (reporting bias)	High risk	One or more clinically relevant and reasonably expected outcomes were not reported on; data on these outcomes were likely to have been recorded (i.e. safety). According with Dr Graham Serjeant, interviewed by one author of this review (JKM), 'ulcer area‐change' was the primary outcome (February 4, 2011).
Other bias	High risk	Ascertaiment bias and bias in the presentation of data (Appendix 2). Table of characteristics of patients at entry study only shows 28 patients. There is inconsistency relating to the study design and the healing rate end point. The inconsistency between 'Randomisation unit: patient' and 'Unit of analysis: ulcers' could generate the design and confusion bias (Appendix 2).