positive predictive value
The probability that a newborn with a positive screening result actually has the condition being tested for.
Full Definition
Positive predictive value (PPV) in newborn screening represents the proportion of positive screening results that correspond to truly affected infants. PPV is calculated as the number of true positive cases divided by the total number of positive screening results (true positives plus false positives). This metric is heavily influenced by disease prevalence, with rare conditions typically having lower PPVs even with highly specific tests. PPV is a critical measure for counseling families, allocating follow-up resources, and evaluating the clinical utility of screening tests.
Usage
Usage note: Often abbreviated as PPV; express as a percentage in reporting contexts.
In Context
- "The positive predictive value for congenital hypothyroidism screening was 89% in this population." — performance evaluation
- "Low positive predictive values necessitate improved counseling protocols for families receiving abnormal results." — program improvement plan