de Oliveira 2001.

Methods	RCT
Participants	Teaching Hospital, Brazil 26 patients (41 scars ‐ classified as either hypertrophic or keloid) Inclusion criteria: hypertrophic or keloid scars Exclusion criteria: radiation or corticosteroid therapy in last 12 months Sex: 5 male, 21 female Age: 15 to 53 years
Interventions	Patients with 2 scars: one scar received silicone gel sheet, the other non silicone gel sheet (both worn 24 hours/day) Patients with 3 scars: as above with one "control" scar with no treatment
Outcomes	Length of follow‐up: measurements made at 0, 30, 60, 90, 120 and 135 days Clinical: symptomatic relief of pain and itching, induration (hardness), length, width, colour of scar Intracicatrical pressure Complications: irritative contact dermatitis, which resolved with skin washing and removal of the gel for 5 hours
Notes	Intracicatrical pressure defined as "the necessary pressure to inject a 0.5 ml of triamcinolone solution into the scar tissue" Colour measured by 1000 colour paint chart
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “A clinical study was designed in which 26 patients with 41 hypertrophic or keloid scars were randomly chosen to receive silicone gel sheeting, non silicone gel sheeting or nothing”. Comment: no further information was given on how treatment areas were selected
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: “Every 2 days the [silicone gel] sheeting was removed, washed with water then reapplied to the underlying skin area . . . non silicone gel sheeting was removed after one week and replaced with fresh sheeting”.  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: “On days 0, 30, 60, 90, 120 and 135 the following parameters were evaluated by the same research, except for intracicatrical pressure which was measured blindly by two researchers on day 135." Comment: it is unclear whether the parameters other than intracicatrical pressure were measured by a blinded assessor
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: no information is given in the study on loss to follow‐up. Attrition bias was judged to be unclear. The scar was the unit of analysis and 27 scars were reported on, it is likely therefore that since 41 were randomised there were losses even though this was not reported.
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	Low risk	Comment: the study appears to be free of other sources of bias.