Towards Trustworthy Predictions of Conversion from Mild Cognitive Impairment to Dementia: A Conformal Prediction Approach

Predicting progression from a stage of Mild Cognitive Impairment to Alzheimer’s disease is a major pursuit in current dementia research. As a result, many prognostic models have emerged with the goal of supporting clinical decisions. Despite the efforts, the lack of a reliable assessment of the uncertainty of each prediction has hampered its application in practise. It is paramount for clinicians to know how much they can rely upon the prediction made for a given patient, in order to adjust treatments to the patient based on that information. In this exploratory study, we evaluated the Conformal Prediction approach on the task of making predictions with precise levels of confidence. Conformal prediction showed promising results. Using high confidence levels have the drawback of leaving a large number of MCI patients without prognostic (the classifier is not confident enough to give a single class). When using forced predictions, conformal predictors achieved classification performances as good as standard classifiers, with the advantage of complementing each prediction with a confidence value.

[1]  Alzheimer's Disease Neuroimaging Initiative,et al.  A point-based tool to predict conversion from mild cognitive impairment to probable Alzheimer's disease , 2014, Alzheimer's & Dementia.

[2]  Harris Papadopoulos,et al.  Reliable Probabilistic Prediction for Medical Decision Support , 2011, EANN/AIAI.

[3]  Vladimir Vovk,et al.  A tutorial on conformal prediction , 2007, J. Mach. Learn. Res..

[4]  M. Prince,et al.  World Alzheimer Report 2015 - The Global Impact of Dementia: An analysis of prevalence, incidence, cost and trends , 2015 .

[5]  G. Shafer,et al.  Algorithmic Learning in a Random World , 2005 .

[6]  Scott Boyer,et al.  Introducing Conformal Prediction in Predictive Modeling. A Transparent and Flexible Alternative to Applicability Domain Determination , 2014, J. Chem. Inf. Model..

[7]  Heikki Huttunen,et al.  Machine learning framework for early MRI-based Alzheimer's conversion prediction in MCI subjects , 2015, NeuroImage.

[8]  Alexander Gammerman,et al.  Conformal Predictors for Compound Activity Prediction , 2016, COPA.

[9]  Kristine Yaffe,et al.  A Clinical Index to Predict Progression from Mild Cognitive Impairment to Dementia Due to Alzheimer's Disease , 2014, PloS one.

[10]  Vladimir Vovk,et al.  Conformal predictors in early diagnostics of ovarian and breast cancers , 2012, Progress in Artificial Intelligence.

[11]  Carlos Guestrin,et al.  "Why Should I Trust You?": Explaining the Predictions of Any Classifier , 2016, ArXiv.

[12]  Ilia Nouretdinov,et al.  Prediction with Confidence Based on a Random Forest Classifier , 2010, AIAI.

[13]  Sethuraman Panchanathan,et al.  PyCP: An Open-Source Conformal Predictions Toolkit , 2013, AIAI.

[14]  João Maroco,et al.  Prediction of long-term (5 years) conversion to dementia using neuropsychological tests in a memory clinic setting. , 2013, Journal of Alzheimer's disease : JAD.

[15]  Harris Papadopoulos,et al.  Assessment of Stroke Risk Based on Morphological Ultrasound Image Analysis with Conformal Prediction , 2010, AIAI.