The US FDA convened a public Advisory Committee meeting to review evidence from a study commissioned by the agency. An analysis of findings derived from four databases was published on the FDA website and presented at the meeting. Among users of combined hormonal contraceptives containing EE plus DRSP, the risks of VTE and ATE were higher than among users of older reference contraceptives containing other progestogens. The findings have now been published in a peer-reviewed journal.
The researchers conducted this study to evaluate the published evidence on the use of combined hormonal contraceptives and the risk of thromboembolism and cardiovascular death. Generally accepted epidemiological principles of causality are applied.
The findings did not satisfy the criteria of time order, bias, confounding, statistical stability and strength of association, duration-response, internal consistency, external consistency, or biological plausibility.
The study concluded that the increased risk of VTE in combined hormonal contraceptive users is dependent on the dose of estrogen, and independent of the progestogen used. The best evidence also suggests that DRSP does not increase the risk of ATE, and may reduce it.