Determination of clinical efficacy: nuclear medicine as applied to lung scanning

This paper describes a Society of Nuclear Medicine sponsored study of 2023 patients which compares two methods, logistic regression (LR) and entropy minimax pattern detection (EMPD), to evaluate efficacy. Lung scans, used in determining or excluding a diagnosis of pulmonary embolism (PE), were utilized to create the data set. The LR analysis, presented here, shows that lung scan findings have significant influence on the referring physician's diagnostic thinking. Models were developed for the probability of a signout diagnosis of PE, and equal patient groups tested the validity of these regression equations. A comparison of the sensitivity, specificity, and predictive values of EMPD and LR was done. EMPD predicts a signout diagnosis on only 41% of cases before lung scan and 71% after lung scan; LR provides a prediction of the signout diagnosis on 100% of cases. An advantage of EMPD is that it does not require poor probability estimates