Net Reclassification Improvement: Computation, Interpretation, and Controversies A Literature Review and Clinician’s Guide

The net reclassification improvement (NRI) is an increasingly pop-ular measure for evaluating improvements in risk predictions. This article details a review of 67 publications in high-impact general clinical journals that considered the NRI. Incomplete reporting of NRI methods, incorrect calculation, and common misinterpretations were found. To aid improved applications of the NRI, the article elaborates on several aspects of the computation and interpretation in various settings. Limitations and controversies are discussed, in-cluding the effect of miscalibration of prediction models, the use of the continuous NRI and “clinical NRI, ” and the relation with decision analytic measures. A systematic approach toward present-ing NRI analysis is proposed: Detail and motivate the methods used for computation of the NRI, use clinically meaningful risk cutoffs for the category-based NRI, report both NRI components, address is-sues of calibration, and do not interpret the overall NRI as a percentage of the study population reclassified. Promising NRI find-ings need to be followed with decision analytic or formal cost-effectiveness evaluations. Ann Intern Med. 2014;160:122-131. www.annals.or