The prevalence of a disease in a population significantly impacts the predictive values of a test. Positive Predictive Value (PPV) is the probability that individuals with a positive test result actually have the disease, and Negative Predictive Value (NPV) is the probability that individuals with a negative result are disease-free. In low-prevalence settings, even tests with high sensitivity and specificity can yield a high number of false positives, affecting the PPV.
