Nonparametric Bayesian covariate-adjusted estimation of the Youden index
| Autor: | Vanda Inacio de Carvalho, Miguel de Carvalho, Adam J. Branscum |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Statistics and Probability
Blood Glucose Youden's J statistic 01 natural sciences Sensitivity and Specificity General Biochemistry Genetics and Molecular Biology Statistics Nonparametric 010104 statistics & probability 03 medical and health sciences Bayes' theorem 0302 clinical medicine Covariate Statistics Econometrics Diabetes Mellitus Cutoff Humans Computer Simulation 030212 general & internal medicine 0101 mathematics Mathematics Models Statistical General Immunology and Microbiology Applied Mathematics Regression analysis Bayes Theorem General Medicine Nonparametric regression Medical test Skewness Regression Analysis General Agricultural and Biological Sciences Biomarkers |
| Zdroj: | Calhau Fernandes Inacio De Carvalho, V, de Carvalho, M & Branscum, A J 2017, ' Nonparametric Bayesian covariate-adjusted estimation of the Youden index ', Biometrics, vol. 73, no. 4, pp. 1279-1288 . https://doi.org/10.1111/biom.12686 |
| Popis: | A novel nonparametric regression model is developed for evaluating the covariate-specific accuracy of a continuous biological marker. Accurately screening diseased from nondiseased individuals and correctly diagnosing disease stage are critically important to health care on several fronts, including guiding recommendations about combinations of treatments and their intensities. The accuracy of a continuous medical test or biomarker varies by the cutoff threshold (c) used to infer disease status. Accuracy can be measured by the probability of testing positive for diseased individuals (the true positive probability or sensitivity, Se(c), of the test), and the true negative probability (specificity, Sp(c)) of the test. A commonly used summary measure of test accuracy is the Youden index, YI = max{Se(c) + Sp(c) − 1:c ∈ R, which is popular due in part to its ease of interpretation and relevance to population health research. In addition, clinical practitioners benefit from having an estimate of the optimal cutoff that maximizes sensitivity plus specificity available as a byproduct of estimating YI. We develop a highly flexible nonparametric model to estimate YI and its associated optimal cutoff that can respond to unanticipated skewness, multimodality, and other complexities because data distributions are modeled using dependent Dirichlet process mixtures. Important theoretical results on the support properties of the model are detailed. Inferences are available for the covariate-specific Youden index and its corresponding optimal cutoff threshold. The value of our nonparametric regression model is illustrated using multiple simulation studies and data on the age-specific accuracy of glucose as a biomarker of diabetes. |
| Databáze: | OpenAIRE |
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