Jan P. Vandenbroucke, MD, PhD; Frans M. Helmerhorst, MD, PhD; Frits R. Rosendaal, MD, PhD
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
Vandenbroucke JP, Helmerhorst FM, Rosendaal FR. Epidemiology of Oral Contraceptives and Cardiovascular Disease. Ann Intern Med. 1998;129:747. doi: 10.7326/0003-4819-129-9-199811010-00018
Download citation file:
Published: Ann Intern Med. 1998;129(9):747.
TO THE EDITOR:
Chasan-Taber and Stampfer  present the “recency of market introduction” as a potential source of bias in evaluating the risk for venous thrombosis associated with new oral contraceptives containing desogestrel or gestodene. The argument is that women receiving these pills started using them more recently, those receiving older contraceptives had been using them for a longer time, and the risk for thrombosis is higher in the early periods of use. The straightforward solution is to compare “like with like”: women who are receiving different brands for similar time periods. This analysis was done by Jick and colleagues , who found that in the first 6 months of use, women receiving desogestrel and gestodene contraceptives have a sixfold to ninefold greater risk for venous thrombosis relative to women receiving levonogestrel contraceptives. In several other studies, separate analyses showed that relative risk was increased rather than decreased in the first period of use . The correct interpretation of these findings is that the excess risk of desogestrel and gestodene contraceptives cannot be explained by “recency of introduction bias” because the effect does not disappear upon stratification. The higher excess risk in the first period of use indicates effect modification and supports the decision of the British and German authorities to caution against first-time prescription of these pills to young women.
Learn more about subscription options.
Register Now for a free account.
Copyright © 2016 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use
This PDF is available to Subscribers Only