Lindgren 1998.

Methods	RCT with 8 weeks' treatment. Method of randomisation: unclear.
Participants	27 participants with venous ulcers treated in outpatient department Groups matched at baseline for age, sex, ulcer duration and mean ulcer area
Interventions	Group 1: (n = 15) cryopreserved allografts, dressing (Mepitel) and compression Group 2: (n = 12) dressing (Mepitel) and compression
Outcomes	a) Number with ulcer healed at 8 weeks: Group 1: = 2/15 Group 2: = 2/12 b) Number with a reduction in ulcer area: Group 1: = 8/15 Group 2: = 6/12
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “…randomised to two groups” Comment: randomisation mentioned however no method outlined
Allocation concealment (selection bias)	Unclear risk	Comment: not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "two patients in each group were excluded as the end stage of healing produced multiple small wounds not allowing analysis with this method" Comment: 4 patients excluded which comprises 12% of the total sample. Assumed to be low risk due to small proportion of the total.
Selective reporting (reporting bias)	Low risk	Comment: all primary outcomes reported adequately (wound healing as percentage of initial wound area)
Other bias	Unclear risk	Comment: all variables balanced except mean initial wound area (4.4 cm² vs 7.9 cm²). It is unclear what impact, if any, this can have on the data.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: not stated
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: not stated