Study characteristics	Details of studies
Types of studies	Two arms (n = 35): Allman 1987; Aronovitch 1999; Beeckman 2019; Bennett 1998; Berthe 2007; Cassino 2013; Cavicchioli 2007; Conine 1990; Daechsel 1985; Feuchtinger 2006; Finnegan 2008; Gunningberg 2000; Hofman 1994; Inman 1993; Jiang 2014; Jolley 2004; Lazzara 1991; Malbrain 2010; McGowan 2000; Mistiaen 2009; Nixon 1998; Nixon 2019; Park 2017; Ricci 2013; Rosenthal 2003; Russell 2000; Russell 2003; Sauvage 2017; Schultz 1999; Takala 1996; Van Leen 2011; Van Leen 2013; Van Leen 2018; Vanderwee 2005; Vermette 2012. Three or more arms (n = 5): Andersen 1982; Laurent 1998; Sanada 2003; Sideranko 1992; Stapleton 1986. three studies contributing three separate arms to network meta‐analysis (Andersen 1982; Sideranko 1992; Stapleton 1986); Laurent 1998 with 2x2 factorial design contributing two separate comparisons in the analysis; two of three arms in Sanada 2003 were combined into one group, thus contributing one comparison to the analysis.
Follow‐up duration	Median 14 days (range: 5 days to 7 months)
Funding sources	Public funding (n = 9): Berthe 2007; Conine 1990; Jiang 2014; Mistiaen 2009; Nixon 1998; Nixon 2019; Stapleton 1986; van Leen 2011; Vermette 2012); Industries (n = 18): Allman 1987; Aronovitch 1999; Beeckman 2019; Bennett 1998; Cassino 2013; Daechsel 1985; Finnegan 2008; Gunningberg 2000; Inman 1993; Jolley 2004; Lazzara 1991; McGowan 2000; Ricci 2013; Russell 2000; Russell 2003; Schultz 1999; Takala 1996; van Leen 2018.
Age of participants	Average participant age: median 72.5 years (range 37.2 to 87.0 years)
Sex proportions	Male: 4702 (45.1%) in 38 studies Female: 5730 (54.9%) in 38 studies
Skin status at baseline	38 studies specified the skin status at baseline 34 studies (11,845 participants) with people at risk of having a new ulcer, with risk assessed largely using the Waterlow, Norton or Braden scales 28 studies (9018 participants) with people free of pressure ulcers at baseline; 6 studies (2827 participants) enrolling people with superficial ulcers. four studies (260 participants; Allman 1987; Cassino 2013; Finnegan 2008; Rosenthal 2003) recruited people with severe full‐thickness pressure ulcers alone.
Care settings	Acute care settings (including accident and emergency departments, and hospitals in general) (n = 21), Intensive care units (n = 4), Operating room (n = 3), and Community and long‐term care settings (including hospice, community, nursing homes, long‐term facilities) (n = 12)