How reliable is prognostic research? A case study of C-reactive protein in coronary artery disease

Jun 01, 2010

Prognostic markers provide tools for discriminating between groups of patients who are at different risks of a particular outcome, and therefore should help clinicians to manage disease. In a comprehensive overview of studies looking at one such proposed marker, C-reactive protein (CRP) in coronary artery disease, Harry Hemingway and colleagues, from University College London, show that despite the inclusion of many tens of thousands of patients in research on this specific question, the published record is so inadequate that no clear clinical recommendations can be made.

In the study, published in PLoS Medicine, the authors carried out a detailed systematic review to identify all prospective studies reporting risk of a coronary, cardiovascular, or outcome among patients in whom the CRP values had been measured. They identified 83 studies in the published scientific literature, in which data was reported for 61,684 patients, and 6,485 outcomes. A straightforward analysis of the results of these studies suggested overall evidence for a fairly strong increase in risk associated with higher CRP levels. However, the authors found strong evidence of publication bias. This occurred owing to non-publication of studies with contradictory findings to those which did get published. In an attempt to adjust for publication bias, the researchers estimated that CRP would have a much smaller strength of association with coronary or death outcomes. Finally, the authors also identified a low standard of repor ting quality for many of the published studies, and multiple types of reporting bias in the literature.

Given these biases, the authors conclude that the data "preclude firm conclusions about the magnitude and independence of the association between higher CRP levels and higher risk of subsequent death and nonfatal cardiovascular events". They propose that improvements are needed in the design and reporting of this type of research. Critically, in reporting of these studies it is unclear whether analyses are being included in a publication because the direction of the result suggests something interesting, or because the original study plan specified it; a proposal included in the paper is that study protocols for prognostic research should be registered in advance.

Explore further: A look at latest Ebola developments

More information: Hemingway H, Philipson P, Chen R, Fitzpatrick NK, Damant J, et al. (2010) Evaluating the Quality of Research into a Single Prognostic Biomarker: A Systematic Review and Meta-analysis of 83 Studies of C-Reactive Protein in Stable Coronary Artery Disease. PLoS Med 7(6): e1000286. doi:10.1371/ journal.pmed.1000286

add to favorites email to friend print save as pdf

Related Stories

More 'good' cholesterol is not always good for your health

May 25, 2010

(PhysOrg.com) -- We've all heard about the importance of raising HDL, or the so-called "good" cholesterol, and lowering LDL, or "bad" cholesterol, to improve heart health. While we've come to assume HDL cholesterol ...

Blood test for inflammation may be sign of colon cancer

Apr 19, 2010

A blood test used to determine the level of inflammation in the body may offer some help in assessing colon cancer risk, according to results of a study to be presented by Vanderbilt-Ingram Cancer Center's Gong Yang, M.D., ...

Recommended for you

Routines most vital in avoiding Ebola infection: WHO

15 hours ago

Meticulously following stringent routines when putting on and removing protective equipment is more important than the kind of gear health care workers use to ward off Ebola infection, the World Health Organization said Friday.

A look at latest Ebola developments

16 hours ago

No African countries are on the United Nations list of contributors to fight Ebola. With few exceptions, African governments and institutions are offering only marginal support as the continent faces its ...

Liberia opens one of largest Ebola treatment centers

16 hours ago

Remembering those who have died in the world's deadliest Ebola outbreak, Liberia's president opened one of the country's largest Ebola treatment centers in Monrovia on Friday amid hopes that the disease is ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.