Evaluation of diagnostic systems

Evaluation of Diagnostic Systems: Methods from Signal Detection Theory addresses the many issues that arise in evaluating the performance of a diagnostic system, across the wide range of settings in which such systems are used. These settings include clinical medicine, industrial quality control, environmental monitoring and investigation, machine and metals inspection, military monitoring, information retrieval, and crime investigation. The book is divided into three parts encompassing 11 chapters that emphasize the interpretation of diagnostic visual images by human observers. The first part of the book describes quantitative methods for measuring the accuracy of a system and the statistical techniques for drawing inferences from performance tests. The subsequent part covers study design and includes a detailed description of the form and conduct of an image-interpretation test. The concluding part examines the case study of a medical imaging system that serves as an example of both simple and complex applications. In this part, three mammographic modalities are used: industrial film radiography, low-dose film radiography, and xeroradiography. The case study focuses on the overall reliability of accuracy indices made by its main components, that is, the variabilities across cases, across readers, and within individual readers. The supplementary texts provide study protocols, a computer program for processing test results, and an extensive list of references that will assist the reader in applying those evaluative methods to diagnostic systems in any setting. This book is of value to scientists and engineers, as well as to applied, quantitative, or experimental psychologists who are engaged in the study of the human processes of discrimination and decision making in either perceptual or cognitive tasks.

Table of Contents:
Preface Acknowledgments Introduction The General Setting The General Problem The Proposed Solution Four Types of Evaluation General Issues in Test Design Some Application Vignettes Organization of This Book Part I Quantitative Methods Chapter 1 Fundamentals of Accuracy Analysis 1.1 Two Aspects of Performance 1.2 Analysis of Performance via the ROC Curve 1.3 Often Used, but Inadequate, Indices of Accuracy 1.4 Recommended Indices of Accuracy 1.5 A Computational Example 1.6 A Suitable Accuracy Index Based on One ROC Point 1.7 Indices of the Decision Criterion 1.8 Summary Chapter 2 Extensions of Accuracy Analysis 2.1 Multiple Alternatives 2.2 Other Interpretations of ROC Data 2.3 Combining Individual Results into a Group or Average ROC 2.4 Summary Chapter 3 Statistical Design of a Performance Test 3.1 Questions to Be Answered by the Reading Test 3.2 Logistic and Cost Constraints 3.3 General Approach to Statistical Analysis of Accuracy Data 3.4 The Degree of Statistical Power Required 3.5 Some Practical Rules for Study Design 3.6 Summary Chapter 4 Statistical Treatment of Accuracy Results 4.1 Standard Error of the Accuracy Index 4.2 Confidence Interval of the Accuracy Index 4.3 Statistical Significance of a Difference between Modalities 4.4 Statistical Analysis of True-Positive Probability at a Fixed False-Positive Probability 4.5 Assumptions Underlying the Recommended Statistical Procedure 4.6 Tests Comparing More Than Two Modalities 4.7 Summary Chapter 5 Forms of Efficacy Analysis 5.1 Cost-Benefit Analysis: A Conceptual Starting Point 5.2 Impediments to Cost-Benefit Analysis 5.3 Tailoring the Analysis to Suit the Situation 5.4 Setting the Efficacy Analysis at an Appropriate Level 5.5 SummaryPart II Experimental Methods Chapter 6 Elements of Study Design 6.1 Developing Study Goals 6.2 Outlining the End Product 6.3 Planning the Collection of Data 6.4 Summary Chapter 7 Procedure of a Performance Test 7.1 Case and Image Presentation 7.2 Response Format 7.3 Background Information Given Readers on Each Case 7.4 Timing of Trials and Sessions 7.5 Viewing Environment 7.6 Role of Test Administrator 7.7 Reader Orientation 7.8 Feedback to and from Readers 7.9 Summary Chapter 8 Drawing the Original Case Sample 8.1 Functions of the Original Case Sample 8.2 Types of Data Collected on Each Case 8.3 Selecting a Representative Case Sample 8.4 Bias in Case Data 8.5 Required Size of the Original Case Sample 8.6 Summary Chapter 9 Selection of Test Cases 9.1 Number of Cases for Adequate Representation 9.2 Proportional Representation of Case Types 9.3 Screening Out Inadequate Cases 9.4 Checking Representativeness of the Reading-Test Sample 9.5 Summary Chapter 10 Selection of Test Readers 10.1 Number of Readers for Adequate Representation 10.2 Type of Reader 10.3 Summary Part III A Methodological Case Study Chapter 11 Illustrative Evaluation of Imaging Systems 11.1 Case Selection 11.2 Response Format 11.3 Experimental Design 11.4 Test Procedures 11.5 Reader Ratings of Image Quality 11.6 Accuracy Results 11.7 Correlational Analyses 11.8 Obtaining Estimates of Pure Variance and Correlation Terms 11.9 Discussion: Sizing a Final Study from a Pilot StudyAppendixes Appendix A Sequence of Steps in Evaluation Appendix B Representativeness of a Performance-Test Sample Appendix C Illustrative Posttest Questionnaire Appendix D Computer Program for Accuracy Analysis Appendix E References to ROC Applications References Index