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Biomedical subjects

L B Lusted

Publications and source records attributed to L B Lusted.

At least 19 recordsLinked to original sources

General problems in medical decision making with comments on ROC analysis.

Medical decision-making studies continue to focus on two questions: How do physicians make decisions? How should physicians make decisions? Researchers pursuing the first question emphasize human cognitive processes and the programming of symbol systems to model observed human behavior. Those researchers concentrating on the second question assume that there is a standard of performance against which the physician's decisions can be judged, and to help the physician improve his performance, an array of tools is proposed. These tools include decision trees, Bayesian analysis, decision matrices, receiver operating characteristics (ROC) analysis, and cost-benefit considerations including utility measures. Medical decision-making questions must be answered in an ethical context where ethics and decision analysis are interviewed.

Bayes Theorem↗

Observer performance in detecting multiple radiographic signals. Prediction and analysis using a generalized ROC approach.

The theories of decision processes and signal detection provide a framework for evaluation of observer performance. Some radiological procedures involve a search for multiple similar lesions, e.g., plain radiographic examinations for gallstones or pneumoconiosis. Presuming knowledge of the conventional ROC curve for detection of a single radiographic signal, a model is presented which is used to predict observer performance in an experiment requiring detection of more than one such signal. An experiment tests the validity of this model for detecting radiographically the presence of zero, one, or two low-contrast, 2-mm diameter, Lucite beads. Results confirm the validity of the model and suggest that observer performance in relatively complex detection tasks can be predicted from simpler experiments.

Decision Making↗

Visual detection and localization of radiographic images.

In conventional receiver-operating-characteristic (ROC) curve analysis of visual detection performance, the observer is credited with a true-positive response if a visual signal is present somewhere in a radiograph called "positive" by the observer; however, the measured true-positive rate can be different for a given false-positive rate if the observer is required to identify the correct location of the visual signal in order to receive credit for a true-positive response. The authors describe and have confirmed experimentally a model which can be used to predict observer performance in an experiment requiring both detection and localization on the basis of the conventional ROC curve determined in a detection experiment. Implications for the use of signal detection theory in the assessment of radiographic image quality are discussed.

Humans↗