A consumer's guide to the pill and other drugs. John Wilks. Stafford VA: ALL Inc 1997 (xi + 346 pp.). ISBN: 1 890712 25 6. |
This is a
very difficult book to review in the present climate of emphasis on evidence-based medicine -- much of the material is emotive and many of the references are newspaper accounts of interviews with women and scientists.
Many of the data on contraceptive methods are quoted correctly but emphasise negative findings without a balanced account of benefits and risks. For instance, the author provides data related to the possible increase in incidence of thromboembolism in users of third-generation combined oral contraceptive pills, but fails to mention the possible role of these combinations in reducing the risk of myocardial infarction.
In relation to breast cancer and oral contraceptive use, Wilks concludes that "early-age use of the pill carries a greater risk of breast cancer, of developing larger tumours and having a worse prognosis". This flies in the face of a study published in the Lancet in 1996,1 regarded as the most definitive to date, while quoting correctly from smaller but less definitive studies. The 1996 study reanalysed data from 54 other studies comparing the incidence of pill use in 53 297 women with breast cancer with over 100239 women without breast cancer. These concluded that women taking the pill had a slightly increased risk of breast cancer during usage and in the 10 years after cessation (relative risk ranging from 1.24 in current users to 1.07 5 to 9 years after cessation); that this risk returned to the normal risk for age 10 or more years after stopping oral contraceptives; and that, if breast cancer occurred in women taking the pill, it had a significantly better prognosis than in women who had never used combined oral contraceptive pills. The group also concluded that, for women taking the pill between the ages of 20 and 24, there would be a likelihood of 1.5 extra cancers developing per 10 000 women during the whole period of pill use and in the 10 years after stopping the pill.
Similarly, Wilks quotes from Van der Vange's work in women taking combined low-dose oral contraceptives,2 but uses these data to promote his theory that, in many instances, the pill acts as an abortifacient (by preventing implantation), and that erratic timing of pill-taking decreases the effect of progestogens on the viscosity of cervical mucus. These are assertions for which there is no scientific basis.
Based on a number of recalls of faulty condoms, he also makes the claim that "condoms cannot be made without naturally occurring holes", and suggests that quality control is poor. One could equally interpret the recalls as good quality control, ensuring faulty condoms are detected and batches recalled. The manufacturing standards for condoms are in fact very high.
The author purports to provide users with true facts about contraception and fertility drugs, and to counteract the "incomplete" data presented by pharmaceutical companies and health professionals. However, given the biased slant of this information, I would not recommend this book.
Edith Weisberg
Director of Research
Sydney Centre for Reproductive Health Research
Family Planning NSW, Sydney, NSW
- Collaborative Group on Hormonal Factors in Breast Cancer. Breast cancer and hormonal contraceptives. Lancet 1996; 347: 1713-1727.
- Van der Vange N. Ovarian activity in low dose oral contraceptives. In: Chamberlain G (editor). Contemporary obstetrics and gynaecology. London: Butterworths 1988, 317-326.
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