Level of Evidence for References Included in this Review

Level I–6 Articles

Evidence from a systematic review or meta-analysis of all relevant RCTs (randomized controlled trial) or evidence –based clinical practice guidelines based on systematic reviews of RCTs or three or more RCTs of good quality that have similar results

Hirsh et al., 2001; Ansell et al., 2008; Ansell et al., 2004; Eriksson et al., 2009; Suen et al., 2017; Salazar et al., 2014

Level II–7 Articles

Evidence obtained from at least one well-designed RCT (e.g., large multi-site RCT)

Raskob et al., 2012; Ginsberg et al., 2009; Fitzgerald et al., 2001; Wilson et al., 2016; Anderson et al., 2013; Weitz et al., 2017; An et al., 2016

Level III–2 Articles

Evidence obtained from well-designed controlled trials without randomization (i.e., quasi-experimental)

Parvizi et al., 2017; Pollock et al., 2016

Level IV–9 Articles

Evidence from well-designed case-control or cohort studies

Gillette et al., 2013; Nielen et al., 2016; Bloch et al., 2014; IJRCWC, 2012; Huang et al., 2016; Deirmengian et al., 2016; Cafri et al., 2017; Gutowski et al., 2015; Heller et al., 2016

Level V–12 Articles

Evidence from systematic reviews of descriptive and qualitative studies (meta-synthesis)

Cionac-Florescu et al., 2013; Leme et al., 2012; Cushman et al., 2007; Parvizi et al., 2017; Lu et al., 2010; Solayar et al., 2014; Mekaj et al., 2015; Turpie et al., 2007; Samama et al., 2011; Di Nisio et al., 2005; Lachiewicz et al., 2009; Stewart et al., 2013

Level VI–0 Articles

Evidence from a single descriptive or qualitative study

Level VII–9 Articles

Evidence from the opinion or authorities and/or reports of expert committees

Parvizi et al., 2007; Dalury et al., 2015; Kearon et al., 2012; Eikelboom et al., 2009; Johanson et al., 2009; Mont et al., 2011; Mont et al., 2011 Liberman et al., 2011; Markel et al., 2010