Evaluating research in cardiovascular medicine: citation counts are not sufficient.

Health research is often credited with driving improvements in health outcomes. However, there is much debate within universities and national funding organizations (such as the National Institutes of Health in the United States, the Canadian Institutes for Health Research, and the United Kingdom Research Assessment Exercise) about how best to evaluate and weigh the impact of different types of research.1 The bibliometric approach analyzes citation frequency and is the most popular method for judging the scientific impact of a study or an investigator.2 Although citation counts reflect the degree to which a study generates scientific discussion, they have many limitations as a metric,3 and it is unclear whether they reflect the quality and clinical importance of a study. Indeed, the findings of even highly cited articles are sometimes later proven to be incorrect.4