Evidence-based medicine and guidelines.

Journal of Family Planning and Reproductive Health Care 2004: 30(4) Evidence-based medicine and guidelines Madam I feel it necessary to join the discussion about evidence-based medicine (EBM) and guidelines. I am dismayed about the constant negative attitude towards new contraceptives that are badly needed. I do not believe (serious safety issues aside) that contraceptives should be viewed in entirely the same light as drugs used for a medicinal purpose; in the latter some minor adverse side effects are tolerated provided the overall risk/benefit balance is acceptable for the condition being treated. With contraception, both efficacy and minor side effects are equally important. Indeed, for some women, the balance is reversed with a poorer efficacy being tolerated in favour of lesser or more acceptable side effects. The proponents of EBM have lost sight of the fact that most of what we do in family planning is not based on what would now be considered good evidence, and that it is reasonable to make certain assumptions. Last year the Clinical Effectiveness Unit’s Product Review of Cerazette®1 stated: “... an evidence-based recommendation cannot be made that the desogestrel pill is different from other POPs in terms of efficacy ....”, while the Drug and Therapeutics Bulletin2 went further: “...there is insufficient evidence on whether it is a more effective contraceptive than other POPs...” and “... we believe the company’s claim that Cerazette has the ‘efficacy of a combined pill’ is unsubstantiated and should be withdrawn”. Less than a year later, the product licence for Cerazette has been officially altered to allow a 12-hour pilltaking leeway3 – the same as for the combined pill. To most of us, this had been obvious from the start: while acknowledging a lack of good evidence, why could those writing the product reviews not have been less scathing, more willing to use a little common sense? Similar attacks have been made on both Evra® and Yasmin®, which should be welcomed as providing alternatives for women who may not have found a method that suits them. Choice is extremely important: a woman may wish to use a product simply because her friend is happy with it. This may not be evidencebased, but if it will improve her compliance then it may be less expensive than paying for her termination of pregnancy. Most modern contraceptives are very good: should we only have the one and tell women there is so little difference between them that it will do? Perhaps the Drug and Therapeutics Bulletin should learn from how people use its sister publication Which? When I want to buy a washing machine, I might not chose their evidence-based top product if it doesn’t match my kitchen, however well it washes my clothes.