This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)
All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.
Recently, improving the prediction model performance by adding a new prognostic marker is being studied intensively. The
purpose of this study is to compare the properties of a number of novel and a traditional measure (ROC) to evaluate the
predictive performance of a new marker. In addition, we specifically focused on quantifying the improvement in predictive
performance of an existing model after the addition of the new marker. For that purpose, we analyzed data, which contains age,
gender, hypertension, hyperlipidemia, smoking and tc/hdl as the clinical risk factors for the initial model, obtained from 293
patients having a risk of Coronary Artery Disease (CAD). Afterwards, the Mean Platelet Volume (MPV) was added to this initial
model as a new prognostic marker. The results showed that the addition of MPV improved the model performance; the AUC
increased from 0.76 to 0.81 (p = 0.011) and the accuracy range increased from 0.67 to 0.74. Then, in order to assess the relative
classification power of the MPV to predict CAD events, the data was analyzed by logistic models and risk reclassification indices
such as Net Reclassification improvement Index (NRI) and Integrated Discrimination improvement Index (IDI). NRI was found
to be 0.1039 (SE = 0.0364, p = 0.004) and value of NRI being almost the same as IDI (IDI= 0.10388 SE=0.0358 p=0.003). As a
result, the model including the mentioned clinical risk factors and the MPV performed better than that without MPV and also,
the ratio of the correctly classified individuals after the addition of MPV increased more than the increase of the AUC. Moreover,
the novel statistical metrics such as NRI and IDI were found to be more sensitive than the traditional AUC measures.
Yasemin Yavuz has completed her Ph.D. at the age of 29 years from Ankara University and postdoctoral studies from The University of Reading,
Medical and Pharmaceutical Statistics Research Unit. She is the director of Evidence Based Medicine unit of Ankara University, Faculty of Medicine.
She has published more than 30 papers in various journals and serving as an editorial board member of some national and international journals
in the field of health.
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals