title: Risk of venous thromboembolism in women with polycystic ovary syndrome: a population-based matched cohort analysis.
abstract: BACKGROUND
  There is an increased risk of venous thromboembolism among women taking oral contraceptives. However, whether there is an additional risk among women with polycystic ovary syndrome (PCOS) is unknown.
  
  
  METHODS
  We developed a population-based cohort from the IMS LifeLink Health Plan Claims Database, which includes managed care organizations in the United States. Women aged 18-46 years taking combined oral contraceptives and who had a claim for PCOS (n = 43 506) were matched, based on a propensity score, to control women (n = 43 506) taking oral contraceptives. Venous thromboembolism was defined using administrative coding and use of anticoagulation. We used Cox proportional hazards models to assess the relative risk (RR) of venous thromboembolism among users of combined oral contraceptives with and without PCOS.
  
  
  RESULTS
  The incidence of venous thromboembolism among women with PCOS was 23.7/10 000 person-years, while that for matched controls was 10.9/10 000 person-years. Women with PCOS taking combined oral contraceptives had an RR for venous thromboembolism of 2.14 (95% confidence interval [CI] 1.41-3.24) compared with other contraceptive users. The incidence of venous thromboembolism was 6.3/10 000 person-years among women with PCOS not taking oral contraceptives; the incidence was 4.1/10 000 person-years among matched controls. The RR of venous thromboembolism among women with PCOS not taking oral contraceptives was 1.55 (95% CI 1.10-2.19).
  
  
  CONCLUSIONS
  We found a 2-fold increased risk of venous thromboembolism among women with PCOS who were taking combined oral contraceptives and a 1.5-fold increased risk among women with PCOS not taking oral contraceptives. Physicians should consider the increased risk of venous thromboembolism when prescribing contraceptive therapy to women with PCOS.
authors.affiliation: Department of Pharmaceutical Outcome and Policy, University of Florida College of Pharmacy, Gainesville, FL, USA. bird.steven@gmail.com
authors.forename: Steven T
authors.initials: ST
authors.lastname: Bird
authors.forename: Abraham G
authors.initials: AG
authors.lastname: Hartzema
authors.forename: James M
authors.initials: JM
authors.lastname: Brophy
authors.forename: Mahyar
authors.initials: M
authors.lastname: Etminan
authors.forename: Joseph A C
authors.initials: JA
authors.lastname: Delaney
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D016012:Poisson Distribution; D011085:Polycystic Ovary Syndrome / Q000150:complications*; D057216:Propensity Score; D016016:Proportional Hazards Models; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000209:etiology*
chemical_list: D003277:Contraceptives, Oral, Combined