Koshkin 2001.

Methods	Placebo‐controlled, double‐blinded RCT.
Participants	119 participants with acute ST confirmed by duplex ultrasonography; mean age 54.5 years. Not reported if participants were hospitalised or non‐hospitalised.
Interventions	Systemic enzyme therapy (Wobenzym) (10 tablets tid). Placebo. Study treatment given for 16 days.
Outcomes	Positive changes for a combined outcome including pain, redness, oedema.
Notes	Funding: not reported. Disclosure of potential COI: not reported, no COI forms available.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of random sequence generation not reported.
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not reported.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Double‐blind study; however, not reported who was blinded and how blinding was obtained.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information provided. Unclear if all included participants were evaluated for study outcomes.
Selective reporting (reporting bias)	Low risk	All prespecified outcomes were reported.