Study	Reason for exclusion
Anonymous 1994	Not an RCT.
Anonymous 1997	Not an RCT.
Beldon 2009	Not an RCT.
Bolton 2008	Not an RCT.
Farina 1997	Hydrogel was not the only systematic difference between groups.
Flanagan 1995	Not an RCT.
Fonder 2008	Not an RCT.
Gibson 1995	Leg ulcers with mixed aetiology presenting < 75% of venous leg ulcer in each group of the study.
Hampton 2004	Not an RCT.
Hofman 2006	Not an RCT.
Hutchinson 1997	Not a treatment of interest.
JNMA 2007	Not an RCT.
Jull 2013	Not an RCT.
Karlsmark 2002	Not a treatment of interest.
Kerstein 2001	Not an RCT.
Kikta 1988	Hydrogel dressing was not the only systematic difference across treatment groups.
Lafferty 2011	Not an RCT.
Larsen 1997	Not a treatment of interest.
Lawall 2012	Not an RCT.
Milne 2014	Not an RCT.
Perez 2000	Not a treatment of interest.
Pirie 2009	Not an RCT.
Robinson 1988	Not a treatment of interest.
Robinson 1996	No separate report of data for participants with venous leg ulcers.
Sironi 2003	Hydrogel dressing was not the only systematic difference across treatment groups.
Timmons 2008	Not an RCT.
Werner‐Schlenzka 1994	Not a treatment of interest.
Young 2005	Not an RCT.

RCT: randomised controlled trial.