Screening is a crucial tool in epidemiology for the early detection of diseases, particularly those that are asymptomatic in the early stages. Effective screening programs can reduce morbidity and mortality. Sensitivity and specificity are key measures of a screening test's performance. Sensitivity measures the proportion of true positives correctly identified, while specificity measures the proportion of true negatives. Positive predictive value (PPV) and negative predictive value (NPV) are also important, indicating the likelihood that a positive or negative result is accurate.
