Re: Risk of venous thromboembolism from use of oral contraceptives containing different progestogens and oestrogen doses: Danish cohort study, 2001-9
The authors of the Danish cohort study (1) would do well by using adequate style and content in their reply to the rapid responses. Serious arguments that challenge the validity of their results should not be dismissed in an apodictic and impolite style: The use of “accusations” for serious scientific concerns is not what the readers of the BMJ are entitled to.
As regards respect for your readers: I prefer to decide for myself whether information is relevant, rather than have it censored by authors. In the case of Shapiro’s request for a separate analysis comparing true first-ever users, the relevance of which is supported by the results of several scientific groups (2, 3), I concur with the principle attributed to John Tukey: “Far better an approximate answer to the right question, than an exact answer to the wrong question”.
1. Lidegaard O, Nielsen LH, Skovlund CV, Skjeldestad FE, Lokkegaard E. Risk of venous thromboembolism from use of oral contraceptives containing different progestogens and oestrogen doses: Danish cohort study 2001-9. BMJ 2011; 343: d6423.
2. Suissa S, Blais L, Spitzer WO, Cusson J, Lewis M, Heinemann L. First-time use of newer oral contraceptives and the risk of venous thromboembolism. Contraception 1997; 56(3):141-6.
3. Dinger J, Thai DM, Moehner S. The Risk of Venous Thromboembolism in OC Users: Time Patterns after Initiation of Treatment. Pharmacoepidemiology and Drug Safety, 2010; 19: S214-215
Competing interests: The author has consulted and worked for various scientific institutions, pharmaceutical companies, agricultural and medical device industry. Ongoing consultancy in sexual medicine, drug research methodology and epidemiology.