1The Joanna Briggs Institute. Graduated compression stockings for the prevention of postoperative venous thromboembolism. Best Practice:evidence-based practice information sheets for health prefessionals,2001,5 (2):1-6.
2National Collaborating Centre for Acute Care. Venous thromboembolism: reducing the risk in surgical inpatients. Methods,evidence & guidance. National Institute for Health and Clinical Excellence. Engiand,April 2007.
3The Joanna Briggs Institute. Systematic reviews -the review process, Levels of evidence. Accessedon-line 2006.http://www.joannabriggs.edu. au/pubs/approach.php.
4Pearson A,Wiechula R,Court A,et al. The JBI model of evidencebased heahheare[J], Int J of Evidence-Based Healthcare,2005,3(8):207- 215.