EDITOR,--It is understandable that last week's BMJ should devote considerable space to the Committee on Safety of Medicines' recent advice1 on combined oral contraceptives and venous thromboembolism.2 3 4 5 6 I doubt, however, whether your readers will be enlightened by some of the views expressed in it. In particular, the excess risk of venous thromboembolism with combined oral contraceptives containing desogestrel or gestodene is 15 per 100000 users per year, not 15 per 100000 women.

The committee's decision to advise doctors, pharmacists, and the public about the increased risk of thromboembolism with combined oral contraceptives containing desogestrel or gestodene was based on the results of three studies. Contrary to assertions in the BMJ and elsewhere, none were preliminary findings. The World Health Organisation's study and that of Dr Hershel Jick (based on the general practice research database) have been submitted for publication; Professor Spitzer provided the committee with an abstract prepared for the December meeting of the British Pharmacological Society. None of the authors have retracted their publications. All indicate that there is an increased risk of venous thromboembolism associated with combined oral contraceptives containing desogestrel or gestodene compared …