Letters
Combined oral contraceptives and venous thromboembolism
Oral contraceptive study omitted several confounders
BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h3303 (Published 24 June 2015) Cite this as: BMJ 2015;350:h3303
- Samuel S Zagarella, dermatologist
- 1Concord Hospital, Sydney, Australia
- samuelzagarella{at}gmail.com
An important methodological problem may affect the findings of this otherwise well conducted case-control study.1
Although the authors included polycystic ovarian syndrome as a confounder, they did not include acne or hirsutism in the …
Log in
Log in using your username and password
Log in through your institution
Subscribe from £173 *
Subscribe and get access to all BMJ articles, and much more.
* For online subscription
Access this article for 1 day for:
£38 / $45 / €42 (excludes VAT)
You can download a PDF version for your personal record.