Skip to content

Research on outcomes of medical malpractice litigation suggest expert witnesses with higher levels of scholarly impact may have an edge

Research conducted at the Rutgers New Jersey Medical School, Newark and published in the American Journal of Ophthalmology, has highlighted a statistical association between scholarly productivity among expert witnesses and the outcome of medical malpractice litigation. The research analyzed a range of ophthalmic-related medical malpractice lawsuits in the US heard between January 2006 and June 2014. Among the almost 100 cases reviewed, the research found that cases were more likely to resolve on the side of the expert witness with the higher “h-index” – a summary statistic reflecting scholarly output. In addition, defendants were also found to call expert witnesses with a higher h-index more often than plaintiffs (a person who brings an action in a court of law), potentially reflecting an asymmetry in access to experts between defendants and plaintiffs.


According to the research study, approximately 1 in 6 US physicians is estimated to face a malpractice claim every year and surgeons, relative to other specialties, tended to face such claims more often. Such a growing risk of litigation creates an upward pressure on the cost of malpractice insurance premia, recently underscored by a US Department of Health and Human Services (HHS) report indicating that “Americans spend far more per person on the costs of litigation than any other country in the world.” Invariably, medical malpractice cases often involve significant technical details requiring the input of expert testimony to establish the standard of care and provide an opinion on causation.


In reviewing 8 years of malpractice cases the Rutger Medical School research group found that the defendant and plaintiff expert witnesses had a comparable number of years experience, 32.9 years vs. 35.7 years, respectively. In addition, experts for both the defendant and the plaintiff had a similar scholarly impact (h-index) of 8.6 and 8.3, respectively. The h-index, although an imperfect measure, aims to capture a degree of scholarly output by counting the number of works published by a particular author and then counting the number of publications that cite the author’s work. This measure can then be argued to reflect an individual’s productivity or contribution to a field, including some measure of how an expert is rated by their peers. An expert with an h-index of 5 has published 5 papers that have been cited by peers at least 5 times.   Malpractice cases in which the defendant expert witnesses had a higher h-index than their plaintiff counterpart appeared to resolve in the defendant’s favor 72.7% of the time. Similarly, when the plaintiff’s expert witnesses had a higher h-index than their respective defendant witness, the case appeared to resolve in the plaintiff’s favor 75% of the time. According to the research paper, “the jury may view expert witnesses with a significant publication history as more credible, which can affect their decisions in litigation proceedings. An expert practicing in an academic setting with greater number of years of professional experience, higher h-index, and fellowship training is more likely to be recruited by defendant attorneys.”