Study	Reason for exclusion
Ahmad 2011	Ineligible study design
Alexewicz 2007	Sample or analysis technique were not eligible
Amato 2015	Ineligible study design
Anon 2008	Ineligible study design
Ayuk 2016	Ineligible study design
Barros 2012	Sample or analysis technique were not eligible
Bernatchez 2012	Ineligible outcome
Bigliardi 1955	Study conducted before relevant techniques available
Bogaczewicz 2004	Ineligible study design
Bohórquez‐Sierra 2006	Ineligible study design
Budzyn‐Napierala 2016	Ineligible population; not people with venous leg ulcer
Caimi 2015	Sample or analysis technique were not eligible
Clark 2001	Ineligible study design
Cook 2000	Ineligible study design
Cook 2009	Ineligible prognostic factor
Cullen 2002b	Ineligible population
Da Silva 2014	Ineligible study design
Dalton 2005	Ineligible outcome
Derbyshire 2003	Ineligible study design
Duffy 2005	Ineligible study design
Eming 2006	Sample or analysis technique were not eligible
Eming 2008	Ineligible outcome
Failla 2008	Ineligible study design
Fernandez 2008	Sample or analysis technique were not eligible
Fisher 1998	Ineligible study design
Fray 2003	Preclinical animal study
Gacka 2004	Sample or analysis technique were not eligible
Gordon 1975	Ineligible study design; used as intervention
Grinnell 1992	Sample or analysis technique were not eligible
Grinnell 1998	Ineligible outcome
Hasmann 2011	Sample or analysis technique were not eligible
He 1999	Sample or analysis technique were not eligible
Herouy 2000a	Ineligible study design; used as intervention
Herouy 2000b	Ineligible study design
Herouy 2004	Sample or analysis technique were not eligible
Herrick 1997	Sample or analysis technique were not eligible
Hoffman 1998	Sample or analysis technique were not eligible
Honda 2011	Ineligible population
Huttunen 2000	Ineligible outcomes
Huttunen 2004	Ineligible outcomes
Huttunen 2005	Ineligible participants
Ibbotson 1994	Ineligible prognostic factor
Impola 2005	Ineligible outcomes
Ivins 2014	Ineligible study design
Karatepe 2010	Ineligible participants
Karim 2006	Ineligible outcomes
Kucharzewski 2005	Ineligible study design
Kucukguven 2013	Ineligible population
Körber 2006	Ineligible study design
Lantis 2011	Sample or analysis technique were not eligible
Ligi 2016	Ineligible study design
Lim 2010	Ineligible study design
Lotti 1995	Sample or analysis technique were not eligible
McCarty 2012	Ineligible study design
McCarty 2013	Ineligible study design
McInnes 2014	Ineligible outcome
Mirastschijski 2002	Ineligible population
Mirshahi 1995	Sample or analysis technique were not eligible
Moor 2009	Ineligible outcome
Moore 2007	Ineligible study design
Nielsen 1992	Sample or analysis technique were not eligible
Norgauer 2002	Sample or analysis technique were not eligible
Nwomeh 1999	Ineligible study design
Ovington 2001	Ineligible study design
Palolahti 1993	Ineligible outcome
Phillips 2007	Ineligible study design
Pirila 2007	Sample or analysis technique were not eligible
Raffetto 2014	Ineligible study design
Rayment 2008	Ineligible outcome
Rayment 2009	Ineligible study design
Rechardt 2000	Sample or analysis technique were not eligible
Rogers 1999	Ineligible study design
Saarialho‐Kere 1998	Sample or analysis technique were not eligible
Salgado 2017	Wound biopsy and proteases not investigated for clinical part of the study
Schmid 1999	Ineligible outcome
Schmidtchen 2000	Ineligible outcome
Schmidtchen 2003	Ineligible study design
Schultz 2004	Ineligible population
Senet 2003	Ineligible prognostic factor
Serena 2016	Healing rate measured before the start of the study; so cross‐sectional design
Serra 2014	Ineligible population
Serra 2015c	Ineligible study design
Serra 2016a	Ineligible study design
Serra 2016b	Sample or analysis technique were not eligible
Serra 2017	Sample or analysis technique were not eligible
Shields 1994	Ineligible population
Singh 2010	Ineligible study design
Stacey 1993	Sample or analysis technique were not eligible
Stacey 2000	Sample or analysis technique were not eligible
Stojadinovic 2014	Ineligible prognostic factor
Tarlton 1999	Ineligible study design
Tauzin 2014	Sample or analysis technique were not eligible
Turio 2002	Sample or analysis technique were not eligible
Ulrich 2005	Sample or analysis technique were not eligible
Vaalamo 1996	Sample or analysis technique were not eligible
Vaalamo 1997	Sample or analysis technique were not eligible
Vaalamo 1999	Sample or analysis technique were not eligible
Vahlquist 2000	Ineligible study design
Van Bergen 1996	Sample or analysis technique were not eligible
Varelias 2002	Ineligible population
Varelias 2006	Ineligible population
Weckroth 1996	Ineligible study design
Weckroth 2004	Sample or analysis technique were not eligible
Widgerow 2011	Ineligible study design
Wlaschek 1997	Ineligible prognostic factor
Wysocki 1993	Ineligible outcome
Wysocki 1996	Ineligible outcome
Zamboni 2005	Ineligible population
Zeegelaar 1997	Sample or analysis technique were not eligible
Zillmer 2011	Ineligible outcome