Frequently Asked Questions

Frequently Asked Questions about HepaTop

Table of content

What does HepaTop mean ?

HepaTop is a contraction for Hepatology Top. We are willing to build a reference ranking for authors in hepatology.

Who is behind hepatop.com ?

hepatop.com is built and maintained by BioPredictive R&D. BioPredictive R&D cutting edge results are published on BioPredictive Labs.
The objective of BioPredictive is to discover and develop non-invasive liver diagnostic tests in order to facilitate the management and treatment of patients. BioPredictive is the company behind the famous "FibroTest", the non-invasive test for the liver fibrosis (based on a simple blood sample at your local laboratory). learn more

Is HepaTop really transparent ?

Yes. Full methodology is published on the website.

What is h-index ?

H-index is an index proposed by Jorge E. Hirsch that aims to provide a robust single-number metric of an academic's impact, combining quality with quantity.
h = the number of papers with citation number higher or equal to h : a scientist with an h-index of 25 has published 25 articles that have each attracted at least 25 citations.
More about h-index :
• Hirsch JE. An index to quantify an individual's scientific research output. Proc Natl Acad Sci U S A. 2005;102:16569-72.
• Ball P. Achievement index climbs the ranks. Nature 2007;448:737.
• Jacso ́ P. Testing the calculation of a realistic h-index in Google Scholar, Scopus and Web of Science for F.W. Lancaster, Library Trends 2008.
• WikiPedia

Why did you choose h-index ?

h-index is not perfect, but has a lot of qualities :
• it is (quite) simple to understand
• it is easy to reproduce
• it's a single number
• it is feasible to compute it for thousands of authors

However, we know it has drawbacks :
• self-citations might increase h-index
• the older the author, the higher the h-index (but we did split population into 4 to fight this drawback)

Why did you choose Google Scholar ?

There are mainly 4 databases available to build the h-index :
• MedLine (PubMed's database) : very very nice database with a very good conception. However, as the DB only accesses abstracts, it is not aware of citations nor references. And therefore can not be used to build h-index. However it's our source to list publications of authors.
• ISI Web Of Science (WOS) : limited to ISI publications, and merely inactive since 2004-2005
• Scopus : database with limited rights, non accessible. Nice scope of journals, but non exhaustive. Indexation started in 1996 only, which is a no-go for hepatop.com project
• Google Scholar : very large (some say too large) database, public (so that h-index is repeatable for transparency)

Even if it may be improved, we did choose Google Scholar as the citation database. We use PubMed too for other features like publications count or country detection.

What about false positive ?

Given that in litterature, authors are known by their author name (i.e : "Friedman, Scott L.") and mostly using initials (i.e : "Friedman, SL"), there is a risk of false positive for common names. We try to sort this issue with several strategies :
• we use full initials, with second last name, if exists
• we only scope medical articles, so no collision with other sciences (physic, economy, mathematics, etc.)
• we do not accept authors with high risk of false positive : more than a mean of 80 publications a year for the last 50 years or the last 5 years. Their h-index is calculated but not shown, and these authors do not appear in ranking.
• we try to focus only on "hepatology" and generalist journals. The list of journals we use is listed on this page.

Is HepaTop perfect ?

Of course not ! Hepatop.com is mostly automated, in a world without a perfect gold standard : as long as authors will be identified by their name (rather than by an unique ID) this kind of tool will remain imperfect. We use very advanced algorihtms in order to lower false positives (articles attributed to the wrong author). If you think an author file contains errors, just contact the webmaster.

Why can't I find my name in hepatop.com ?

hepatop.com is only computed for hepatologists. Our definition of an hepatologist is a physician subscribing to a liver association (might be international, like AASLD, EASL or APASL - or national).
If you think you should be added please just contact the webmaster.

This is not serious : I can't even find <you name it> ?

Several top-hepatologists have been already identified as False Negative (mostly due to homonyms or algorithms errors in Liver Scientific Society identification algorithms) and will be integrated in following upgraded versions.
Waiting for a global identification number we apologize for these imperfections. If you want to express yourself about this, just contact the webmaster.

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Due mainly to homonyms, errors are possible and if you detect "false positives" or "false negatives" don't be too frustrated and please contact the webmaster.