New patient-oriented summary measure of net total gain in certainty for dichotomous diagnostic tests
2006
New Measure for Diagnostic Tests
publication
Evidence: moderate
Author Information
Author(s): Linn Shai, Grunau Peter D
Primary Institution: Faculty of Social Welfare and Health Studies, School of Public Health, University of Haifa, and Unit of Clinical Epidemiology, Rambam Medical Center, Haifa, Israel
Hypothesis
To introduce a new, patient-oriented predictive index as a measure of gain in certainty.
Conclusion
PSI provides more information than J and the predictive values, making it more appropriate in a clinical setting.
Supporting Evidence
- The Predictive Summary Index (PSI) reflects the true total gain in certainty obtained by performing a diagnostic test based on knowledge of disease prevalence.
- PSI is a more comprehensive measure than the post-test probability or the Youden Index (J).
- The reciprocal of PSI is suggested as the number of persons who need to be examined in order to correctly predict a diagnosis of the disease.
Takeaway
This study introduces a new way to measure how much more certain we are about a diagnosis after a test, which helps doctors make better decisions.
Methodology
Algebraic equations were used to derive the Predictive Summary Index (PSI).
Digital Object Identifier (DOI)
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