Physician tolerance for uncertainty. Use of liver-spleen scans to detect metastases

Abstract

To gain insight into diagnostic test use, 42 physicians who ordered 62 liver-spleen scans to detect possible metastases were interviewed. Before receiving the actual scan results, physicians gave pretest probability estimates for liver metastasis; probability estimates and management plans given the most common scan results; and probabilities above and below which they would stop the diagnostic workup (their decision thresholds). After learning the actual scan results, physicians gave their posttest probabilities and management plan. Thirteen physicians (31%) desired absolute certainty to rule in metastasis. Fifty % planned further evaluations even when probability estimates of metastasis reached one of their probability targets for ending the workup. Greater attention to decision thresholds may improve physicians'' understanding of their tolerance for diagnostic uncertainty and the ability of diagnostic tests to reduce it.