We've been developing intuitive high-quality statistical software at an affordable price, backed up by fast friendly customer service for over 25 years...
Office hours: 9am-5pm GMT Mon-Fri
It's Tuesday 5:02 PM and the office is closed - e-mail us and we'll get back to you as soon as possible.
A decision threshold is a value that dichotomizes the result of a quantitative test to a simple binary decision.
The test result of a quantitative diagnostic test is dichotomized by treating the values above or equal to a threshold as positive, and those below as negative, or vice-versa.
There are many ways to choose a decision threshold for a diagnostic test. For a simple screening test, the decision threshold is often chosen to incur a fixed true positive or false positive rate. In more complex cases, the optimal decision threshold depends on both the cost of performing the test and the cost of the consequences of the test result. The costs may include both financial and health-related costs. A simple formula to determine the optimal decision threshold (Zweig &
Campbell, 1993) maximizes: Sensitivity - m * (1- Specificity) where m = (Cost FP - Cost TN) / (Cost FN - Cost TP).