Clinical Edge

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Continuous Combined Oral Contraceptives & VTE Risk

JAMA Intern Med; ePub 2018 Oct 1; Li, et al

There was a slightly elevated risk for venous thromboembolism (VTE) in association with continuous/extended combined oral contraceptive (COC) use when compared to traditional cyclic COC use, a recent study found. Participants were women aged 18-50 years at the time of initiating a study COC between May 2007 and September 2015. Exposures were initiation of continuous/extended or traditional cyclic COCs containing ethinyl estradiol or levonorgestrel of any dose. Primary outcomes included first VTE hospitalization that occurred during the study follow-up. Researchers found:

  • 210,691 initiators of continuous/extended COCs (mean age 30.4 years) and 522,316 initiators of cyclic COC (mean age 28.8 years) were identified.
  • There was a slightly elevated VTE risk in association with continuous/extended COC use when compared with cyclic COC use.
  • However, due to the small absolute risk difference and potential residual confounding, the findings did not show strong evidence supporting a VTE risk difference between continuous/extended and cyclic COC use.


Li J, Panucci G, Moeny D, et al. Association of risk for venous thromboembolism with use of low-dose extended- and continuous-cycle combined oral contraceptives. A safety study using the Sentinel Distributed Database. [Published online ahead of print October 1, 2018]. JAMA Intern Med. doi:10.1001/jamainternmed.2018.4251.