Francesco Dentali, MD; James D. Douketis, MD; Monica Gianni, MD; Wendy Lim, MD; Mark A. Crowther, MD, MSc
Acknowledgments: The authors thank Dr. Qilong Yi for his helpful review of and contribution to the manuscript.
Grant Support: Dr. Crowther is a Career Investigator of the Heart and Stroke Foundation of Ontario. Dr. Lim holds a Mentorship award from the Canadian Institutes of Health Research.
Potential Financial Conflicts of Interest: Consultancies: J.D. Douketis (Agen Biomedical), M.A. Crowther (Sanofi-Aventis, Pfizer Inc., Leo Laboratories, GlaxoSmithKline, Organon, Artisian Therapeutics); Honoraria: J.D. Douketis (Sanofi-Aventis, Pfizer Inc., Leo Pharma), M.A. Crowther (Sanofi-Aventis, Pfizer Inc., Leo Laboratories, GlaxoSmithKline, Organon Artisian Therapeutics); Grants received: M.A. Crowther (Sanofi-Aventis, Pfizer Inc., Leo Laboratories, GlaxoSmithKline, Organon, Artisian Therapeutics).
Requests for Single Reprints: James D. Douketis, MD, St. Joseph's Hospital, Room F-544, 50 Charlton Avenue East, Hamilton L8N 4A6, Ontario, Canada; e-mail, email@example.com.
Current Author Addresses: Drs. Dentali and Gianni: Inusbria University, Viale Borri 57, 21100 Varese, Italy.
Drs. Douketis, Lim, and Crowther: McMaster University, 50 Charleton Avenue East, Hamilton L8N 4A6, Ontario, Canada.
Underutilization of anticoagulant prophylaxis may be due to lack of evidence that prophylaxis prevents clinically important outcomes in hospitalized medical patients at risk for venous thromboembolism.
To assess the effects of anticoagulant prophylaxis in reducing clinically important outcomes in hospitalized medical patients.
MEDLINE, EMBASE, and Cochrane databases were searched to September 2006 without language restrictions.
Randomized trials comparing anticoagulant prophylaxis with no treatment in hospitalized medical patients.
Any symptomatic pulmonary embolism (PE), fatal PE, symptomatic deep venous thrombosis, all-cause mortality, and major bleeding. Pooled relative risks and associated 95% CIs were calculated. For treatment effects that were statistically significant, the authors determined the absolute risk reduction and the number needed to treat for benefit (NNTB) to prevent an outcome.
9 studies (n = 19 958) were included. During anticoagulant prophylaxis, patients had significant reductions in any PE (relative risk, 0.43 [CI, 0.26 to 0.71]; absolute risk reduction, 0.29%; NNTB, 345) and fatal PE (relative risk, 0.38 [CI, 0.21 to 0.69]; absolute risk reduction, 0.25%; NNTB, 400), a nonsignificant reduction in symptomatic deep venous thrombosis (relative risk, 0.47 [CI, 0.22 to 1.00]), and a nonsignificant increase in major bleeding (relative risk, 1.32 [CI, 0.73 to 2.37]). Anticoagulant prophylaxis had no effect on all-cause mortality (relative risk, 0.97 [CI, 0.79 to 1.19]).
2 of 9 included studies were not double-blind.
Anticoagulant prophylaxis is effective in preventing symptomatic venous thromboembolism during anticoagulant prophylaxis in at-risk hospitalized medical patients. Additional research is needed to determine the risk for venous thromboembolism in these patients after prophylaxis has been stopped.
Francesco Dentali, James D. Douketis, Monica Gianni, Wendy Lim, Mark A. Crowther. Meta-analysis: Anticoagulant Prophylaxis to Prevent Symptomatic Venous Thromboembolism in Hospitalized Medical Patients. Ann Intern Med. 2007;146:278–288. doi: 10.7326/0003-4819-146-4-200702200-00007
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Published: Ann Intern Med. 2007;146(4):278-288.
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