New article published: the relationship between ADAMTS13 and MI

2015-06-16 14_26_12-Plasma ADAMTS13 levels and the risk of myocardial infarction_ an individual pati

this article is a collaboration with a lot of guys. initiated from the Milan group, we ended up with a quite diverse group of researchers to answers this question because of the methods that we used: the individual patient data meta-analysis. The best thing about this approach: you can pool the data from different studies, even while you can adjusted for potential sources of confounding in a similar manner (given that the data are available, that is). On themselves, these studies showed some mixed results. But in the end, we were able to use the combined data to show that there was an increase MI risk but only for those with very low levels of ADAMTS13. So, here you see the power of IPD meta-analysis!

The credits for this work go primarily to AM who did a great job of getting all PI’s on board, analysing the data and writing a god manuscript. The final version is not online, but you find the pre-publication on pubmed




New article published – Conducting your own research: a revised recipe for a clinical research training project

2015-06-07 15_38_24-Mendeley Desktop

A quick update on a new article that was published on friday in the NTVG. This article with the title

“Conducting your own research: a revised recipe for a clinical research training project”

– gives a couple of suggestions for young clinicians/researchers on how they should organise their epidemiological research projects. This paper was written to commemorate the retirement of prof JvdB, who wrote the original article back in 1989. I am quite grew quite fond of this article, as it combines insights from 25 years back as well as quite recent insights (e.g. STROBE and cie Schuyt and resulted in a article that will help young research to rethink how they plan and execute their own research project.

There are 5 key suggestions that form the backbone of this article i.e. limit the research question, conduct a pilot study, write the article before you collect the data, streamline the research process and be accountable. As the article is in Dutch only at this moment, I will work on an English version. First drafts of this ms, each discussing each of the 5 recommendations might appear on this website. And how about a German version?

Anyway, it has to be mentioned that if it not was for JvdB, this article would have never come to light. Not only because he wrote the original, but mostly because he is one of the most inspiring teachers of epidemiology.

New publication: LTTE in the American Journal of Epidemiology

12.coverAt the department of Clinical Epidemiology of the LUMC we have a continuous course/journal in which we read epi-literature and books in a nice little group. The group, called Capita Selecta, has a nice website which can be found here. sometime ago we’ve read an article that proposed to include dormant Mendelian Randomisation studies in RCT, to figure out the causal pathways of a treatment for chronic diseases. This could be most helpful when there is a discrepancy between the expected effect and the observed effect. During the discussion of this article we did not agree with the authors for several reasons. We, AGCB/IP/myself, decided to write a LTTE with these points. The journal was nice enough to publish our concerns, together with a response by the authors of the original article. The PDF can be found via the links below which will take you to the website of the American Journal of Epidemiology. The PDF of our LTTE can also be found at my mendeley profile.

original article
letter to the editor
response by the author

Grant awarded to investigate the long term effects of cardiovascular disease at a young age

Today I got a letter from the Leiden University Fund (LUF) to inform me that the grant we requested was granted. This is great, because now we can investigate the long-term effects of young stroke, myocardial infarction and peripheral arterial disease. We will do this by linking our data from the RATIO to the several national databases (e.g. cause of death registries and hospital admissions) that are under control by the central bureau of statistics (CBS). I will perform this research together with AM and other Italian colleagues from Milan. 

The grant (11K) that was awarded is the Den Dulk Moermans Fonds, which exist since 2010, as we can read from the Dutch information the LUF website:

Het Den Dulk-Moermans Fonds is opgericht in 2010 na ontvangst van een erfenis van dhr. A.M. den Dulk. De doelstelling van het Fonds is het financieren van onderzoek naar gezondheid in de breedste zin van het woord.

The protective effects of statins on thrombosis recurrence: a letter to the editor of the European Heart Journal

Recently, Biere-Safi et al published the results from their analyses of the PHARMO database describing the relation between statin use and the recurrence of pulmonary embolism (pubmed). This article was topic of a heated debate on our department: is it really possible that statin use halves the risk of recurrence in this patient group? During this discussion we found some issues that could led to an overestimation of the underlying true protective effect. We described these issues in a letter to the editor which has been accepted as an e-letter. Some journals use e-letters to facilitate a faster and more vivid debate after a publication, but unfortunately, these e-letters are only to be found at the website of the publisher and not for example in Web Of Scienc or Pubmed. This could mean that these critical parts of the scientific debate could have a smaller reach, which is a pity.

Nonetheless, the text of our e-letter is to be found on the website of the Eur Heart J, or via my Mendeley account.

Grant awarded to investigate the role of coagulation FVIII in the aetiology of ischaemic stroke in RATIO study

I just received a letter from the KNAW stating that the grant proposal I sent to one of the fund of the KNAW, the van Leersumfunds, was awarded. From their website, we can only learn a little about this fund:

“The Van Leersum Fund supports neuro(bio)logical, radiological and pharmaceutical research by awarding a series of research grants.

The Fund was established in 1922 and is named after P. van Leersum. The assets of the fund are made up of his estate and the estate of Ms I.G. Harbers-Kramer.”

With this grant we will be able to measure coagulation favtor VIII in the ischaemic stroke substudy of the RATIO study. Coagulation factor FVIII is one of the most potent risk factors for venous thrombosis in the coagulation system, and were quite curious what effect it has on the risk of ischaemic stroke in young women.