Gold 1994.

Methods	CCT
Participants	Gold Skin Care Centre, USA 34 patients Inclusion criteria: Phase 1: hypertrophic or keloid scar Phase 2: 2 distinct keloids on same body part removed by CO2 laser Phase 3: scars from thermal burns Exclusion criteria: not stated Sex: not stated Age: not stated
Interventions	Phase 1 & 3: scar divided in half ‐ random allocation for each half to receive either silicone gel sheeting (minimum of 12 hours/day for 12 weeks); other half no treatment (control) Phase 2: one scar covered with silicone gel sheeting (as above) other scar untreated
Outcomes	Length of follow‐up: 12 weeks Clinical: Phase 1: patient and physician evaluation of overall improvement and colour Phase 2: recurrence of keloid Phase 3: scar thickness and colour Complications: none reported
Notes	Change rated on a 4‐point scale
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “lesions were divided in to two equal halves . . . sheeting was placed on half the scar for a minimum of 12 hours a day”. Comment: no information on randomisation was given in the study which we judged to be at unclear risk
Allocation concealment (selection bias)	Unclear risk	Comment: no information on allocation concealment was given in the study which we judged to be at unclear risk
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: “lesions were divided in to two equal halves . . . sheeting was placed on half the scar for a minimum of 12 hours a day”. Comment: due to the nature of the treatment, we judged that participants and personnel could not be blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: “Both patient and physician evaluated the following features: change in thickness and colour in the treated half of the scar and overall effectiveness of the product”. Comment: no further information was given on blinding of outcome assessor which we judged to be at high risk of bias
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: there was no loss to follow‐up in this study
Selective reporting (reporting bias)	Low risk	Comment: the study protocol was not sought, however all measurements discussed in the methods are reported in the results and clinically meaningful outcomes presented.
Other bias	High risk	Quote: “Supported by a research grant from Dow Corning Wright. The author has no financial interest in Dow Corning Wright or its parent company”. Comment: Dow Corning Wright was the brand of silicone gel used in the trial. We judged this to cause a high risk of bias.