The Threshold Approach to Clinical Decision Making

Abstract

The physician's estimate of the probability that a patient has a particular disease is a principal factor in the determination of whether to withhold treatment, obtain more data by testing, or treat without subjecting the patient to the risks of further diagnostic tests. Using the concepts of decision analysis, we have derived expressions for two threshold probabilities involved in this choice: a "testing" threshold and a "test-treatment" threshold. Values can be assigned to these thresholds from data on the reliability and potential risks of the diagnostic test and the benefits and risks of a specific treatment. Treatment should be withheld if the probability of disease is smaller than the testing threshold, and treatment should be given without further testing if the probability of disease is greater than the test-treatment threshold. The test should be performed (with treatment depending on the test outcome) only if the probability of disease is between the two thresholds. The method exposes important principles of decision making and helps the clinician develop a rational, quantitative approach to the use of diagnostic tests.

A new simple risk score in patients with acute chest pain without existing known coronary disease

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“…The distance between the mark and the origin represented the value of the given outcome state. From those four values, I calculated treatment thresholds according to the method of Pauker and Kassirer [22,23], as described below.…”

“…With those equations, I derived the treatment threshold as defined by Pauker and Kassirer [22,23]. The treatment threshold represented a measure of clinical likelihood above which the surgical option had a greater value, and below it, nonoperative treatment was better.…”

“…However, Pauker and Kassirer [22,23] reported that variability in the values attributed to treatment outcomes affects the demanded degree of certainty that a treatment will attain its desired aims. They termed this requisite degree of certainty the ''treatment threshold''.…”