Screening ECG Yield in Primary Care (PPV NPV Calculator)

Screening ECG Yield in Primary Care: Explanation and Clinical Context The Screening ECG Yield in Primary Care calculator estimates the Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of routine electrocardiographic (ECG) screening programs based on population disease prevalence and test characteristics (sensitivity and specificity). PPV and NPV are essential for evaluating the clinical yield of screening, particularly in low-prevalence populations where even a test with good sensitivity and specificity may yield a high proportion of false positives. For example, in asymptomatic adults with an estimated disease prevalence of 5%, an ECG sensitivity of 85%, and specificity of 90%, the PPV would be approximately 31%, indicating that only about one-third of ECG-positive findings reflect true underlying cardiovascular disease.

Conversely, the NPV would exceed 98%, meaning a negative ECG effectively rules out clinically significant pathology. In practice, this tool helps clinicians quantify the expected diagnostic yield before implementing or interpreting screening ECG programs in community or primary care settings. It reinforces that the value of screening depends not only on test accuracy but also on the underlying disease prevalence within the screened population.