Marshall 2001.

Methods	Multicentre, placebo‐controlled RCT.
Participants	159 participants with acute ST of leg, diagnosed on symptoms and signs only; 40 males, 116 females; mean age 53.8 years. Not reported if participants were hospitalised or non‐hospitalised.
Interventions	Wobenzym (4 tablets tid). Placebo. Study treatment given for 12‐16 days.
Outcomes	Reduction of pain to day 7 which had to amount to at least 4 points on the VRAS at baseline.
Notes	LMWH was allowed and administered to 4 participants. Paracetamol (maximal 2 g/day) + compression stockings were given to all participants. 9 participants had already been treated with other medications (no further details), which were stopped before the administration of study treatment. 4 participants had received LMWH before inclusion and continued LMWH throughout study. Funding: not stated. Disclosure of potential COI: not reported, no COI forms available.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐based. Participants assigned to treatment with a list generated by a computer.
Allocation concealment (selection bias)	Low risk	Participants assigned to treatment with a list generated by a computer. Concealment of allocation was present since randomisation took place with a computer program called "Random V.5" by Firma Wiedey GmbH Konstanz.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind study. Study medication described as "similarly looking study medication [placebo]."
Incomplete outcome data (attrition bias) All outcomes	High risk	1 participant withdrew consent postrandomisation; 10 (6%) participants lost to follow‐up.
Selective reporting (reporting bias)	Low risk	All prespecified outcomes reported.