Ishitobi 1991.

Methods	Study design: RCT
Participants	Country: Japan Setting: hospitalised and community Nº patients: 134 (55 with Buerger's disease; 25 in iloprost group and 30 in alprostadil group) Mean age: not specified. Gender: the proportion and numbers of participants with Buerger's disease were not specified Inclusion criteria: patients diagnosed with Buerger's disease Exclusion criteria: a) patients who had previous surgical treatment for chronic arterial obstructive disease; b) patients with necrosis, where the judgement of varicose ulcer is unclear; c) patients with haemorraghic events; d) patients with serious liver, kidney, or heart disease; e) hypersensitivity to medication or drugs; e) pregnancy
Interventions	Treatment: Iloprost group: iloprost 6 mcg in a liquid injection. One dose plus 3 doses PGE1 placebo/day; Alprostadil group (PGE1): liquid injection containing 20 mcg of alprostadil. Three doses plus 1 dose iloprost placebo/day Duration of treatment: 28 days No follow‐up
Outcomes	Primary: ulcer size, ulcer improvement Secondary: improvement of rest pain
Notes	Conflict of interest: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not described
Allocation concealment (selection bias)	Unclear risk	Method not stated
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double blind
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Does not describe if the outcome assessments were done by the same person responsible for recruitment
Incomplete outcome data (attrition bias) All outcomes	High risk	More drop‐out patients in the iloprost group than in the alprostadil group, actual numbers and possible reasons for drop‐out not provided
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	High risk	Does not described the proportion of smokers to non‐smokers in the groups