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Analysis of Predictive Values Based on Individual Risk Factors in Multi-Modality Trials
Department of Medical Statistics, University of Göttingen, Humboldtallee 32, 37073 Göttingen, Germany
* Author to whom correspondence should be addressed.
Received: 23 January 2013; in revised form: 25 February 2013 / Accepted: 13 March 2013 / Published: 15 March 2013
Abstract: The accuracy of diagnostic tests with binary end-points is most frequently measured by sensitivity and specificity. However, from the clinical perspective, the main purpose of a diagnostic agent is to assess the probability of a patient actually being diseased and hence predictive values are more suitable here. As predictive values depend on the pre-test probability of disease, we provide a method to take risk factors influencing the patient’s prior probability of disease into account, when calculating predictive values. Furthermore, approaches to assess confidence intervals and a methodology to compare predictive values by statistical tests are presented. Hereby the methods can be used to analyze predictive values of factorial diagnostic trials, such as multi-modality, multi-reader-trials. We further performed a simulation study assessing length and coverage probability for different types of confidence intervals, and we present the R-Package facROC that can be used to analyze predictive values in factorial diagnostic trials in particular. The methods are applied to a study evaluating CT-angiography as a noninvasive alternative to coronary angiography for diagnosing coronary artery disease. Hereby the patients’ symptoms are considered as risk factors influencing the respective predictive values.
Keywords: positive predictive value; negative predictive value; diagnostic trials; coronary artery disease
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MDPI and ACS Style
Lange, K.; Brunner, E. Analysis of Predictive Values Based on Individual Risk Factors in Multi-Modality Trials. Diagnostics 2013, 3, 192-209.
Lange K, Brunner E. Analysis of Predictive Values Based on Individual Risk Factors in Multi-Modality Trials. Diagnostics. 2013; 3(1):192-209.
Lange, Katharina; Brunner, Edgar. 2013. "Analysis of Predictive Values Based on Individual Risk Factors in Multi-Modality Trials." Diagnostics 3, no. 1: 192-209.