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Venous thrombosis in users of non-oral hormonal contraception: follow-up study, Denmark 2001-10

BMJ 2012; 344 doi: (Published 10 May 2012) Cite this as: BMJ 2012;344:e2990

Re: Venous thrombosis in users of non-oral hormonal contraception: follow-up study, Denmark 2001-10

Thank you to Dr. Anne L Connolly for her considerations. Let me start with a citation by George Monbiot (The Guardian, November 22, 2011):

“One of the most widespread human weaknesses is our readiness to accept claims that fit our beliefs and reject those that clash with them. We demand impossible standards of proof when confronted with something we don't want to hear, but will believe any old cobblers if it confirms our prejudices.”

From time to time scientific findings are inconvenient, sometimes even unpalatable. Faced with such findings, a clinician or decision maker may follow one of two strategies: The first one (which is obviously followed by some clinicians working with contraceptive counselling and by the marketing holders of hormonal contraceptive products) is to deny the evidence. The second one is to put the new evidence into perspective, and integrate the new findings with other aspects of contraceptive counselling, qualifying our advice to patients.

The majority - fortunately - seems to choose the latter strategy. A few, however – despite how much evidence they might be up against – will continue to deny scientific evidence. The naysayers promoting George Monbiot’s observation were the continued deniers of human made global warming, who cannot be convinced about this very well documented scientific fact, despite the wealth of scientific evidence provided.

Sometimes I see concerning similarities between the scientific climate debate and the scientific debate about serious side effects of hormonal contraceptives. The similarity is the rejection of sound scientific studies due to minor or imaginary limitations, versus the reliance upon poor quality junk science.

Competing interests: The author has within the last three years received honoraria for speeches in pharmacoepidemiological issues, including fees from Bayer Pharma Denmark, MSD Denmark, and Theramex, Monaco, and has been expert witness for plaintiff in a legal US case in 2011.

25 May 2012
Øjvind Lidegaard
Gynaecological Clinic, Rigshospitalet, University of Copenhagen
Blegdamsvej 9, 2100 Copenhagen