The NP must differentiate between screening tests (applied to asymptomatic populations to detect disease early) and diagnostic tests (applied to symptomatic individuals to confirm or exclude a specific disease). These test categories have fundamentally different operating requirements, clinical applications, and error implications. Screening tests are applied to apparently healthy, asymptomatic individuals in defined populations. They must meet the Wilson-Jungner criteria: the condition must be an important health problem, there must be a recognizable early/latent stage, there must be an accepted treatment, and early treatment must improve outcomes compared to treatment after clinical presentation. Screening tests prioritize HIGH SENSITIVITY to minimize false negatives (missing a case of disease in an asymptomatic person has greater consequences because the person has no symptoms to prompt later detection). Acceptable false positive rates are tolerated because positives proceed to confirmatory diagnostic testing. Diagnostic tests are applied to symptomatic individuals to confirm or exclude a suspected diagnosis. They prioritize HIGH SPECIFICITY to minimize false positives (incorrectly labeling a patient with a disease they do not have leads to unnecessary treatment, psychological harm, and healthcare costs). Diagnostic...