title: Risk of recurrence after venous thromboembolism in men and women: patient level meta-analysis.
abstract: OBJECTIVE
  To determine the effect of sex on the risk of recurrent venous thromboembolism in all patients and in patients with venous thromboembolism that was unprovoked or provoked (by non-hormonal factors). Data source Comprehensive search of electronic databases (Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials) until July 2010, supplemented by review of conference abstracts and contact with content experts.
  
  
  METHODS
  Seven prospective studies investigating an association between D-dimer, measured after anticoagulation was stopped, and disease recurrence in patients with venous thromboembolism.
  
  
  METHODS
  Patient level databases were obtained, transferred to a central database, checked, and completed with further information provided by authors.
  
  
  RESULTS
  2554 patients with a first venous thromboembolism had follow-up for a mean of 27.1 (SD 19.6) months. The one year incidence of recurrent venous thromboembolism was 5.3% (95% confidence interval 4.1% to 6.7%) in women and 9.5% (7.9% to 11.4%) in men, and the three year incidence of recurrence was 9.1% (7.3% to 11.3%) in women and 19.7% (16.5% to 23.4%) in men. Among patients with unprovoked venous thromboembolism, men had a higher risk of recurrence than did women (hazard ratio 2.2, 95% confidence interval 1.7 to 2.8). After adjustment for women with hormone associated initial venous thromboembolism, the risk of recurrence remained higher in men (hazard ratio 1.8, 1.4 to 2.5). In patients with provoked venous thromboembolism, occurring after exposure to a major risk factor, recurrence of disease did not differ between men and women (hazard ratio 1.2, 0.6 to 2.4). In women with hormone associated venous thromboembolism and no other risk factors, recurrence was lower than that in women with unprovoked venous thromboembolism and no previous hormone use (hazard ratio 0.5, 0.3 to 0.8).
  
  
  CONCLUSIONS
  In patients with a first unprovoked venous thromboembolism, men have a 2.2-fold higher risk of recurrent venous thromboembolism than do women, which remained 1.8-fold higher in men after adjustment for previous hormone associated venous thromboembolism in women. In patients with a first provoked venous thromboembolism, risk of recurrence does not differ between men and women with or without hormone associated venous thromboembolism. Indefinite anticoagulation may be given greater consideration in men than in women after a first venous thromboembolism.
authors.affiliation: St Joseph's Healthcare Hamilton, Hamilton, ON, Canada. jdouket@mcmaster.ca
authors.forename: James
authors.initials: J
authors.lastname: Douketis
authors.forename: Alberto
authors.initials: A
authors.lastname: Tosetto
authors.forename: Maura
authors.initials: M
authors.lastname: Marcucci
authors.forename: Trevor
authors.initials: T
authors.lastname: Baglin
authors.forename: Benilde
authors.initials: B
authors.lastname: Cosmi
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
authors.forename: Paul
authors.initials: P
authors.lastname: Kyrle
authors.forename: Daniela
authors.initials: D
authors.lastname: Poli
authors.forename: R Campbell
authors.initials: RC
authors.lastname: Tait
authors.forename: Alfonso
authors.initials: A
authors.lastname: Iorio
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D012737:Sex Factors; D054556:Venous Thromboembolism / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D