New oral contraceptives and the risk of venous thrombosis

Jenny, a 20-year-old university student, saw me recently to inquire about starting the pill. She mentioned that her friend was on Yaz, but got worried when she looked it up on the internet.

She asked, “Is it true that it causes more blood clots than other pills?”

What does the research evidence say?

Step 1: The Cochrane Library

The Cochrane Library contains a recent 2014 systematic review and network meta-analysis (up to date to December 2013) that examines the risk of venous thrombosis in women using different combined oral contraceptive pills (COCPs).]

A PICO search using the Trip Database (search term: P: “women”, I: “drospirenone”, C: “levonorgestrel”, O: “venous thrombosis