The Fagan nomogram displays the relationship between the pre-test probability, likelihood ratios, and post-test probability for Schistosoma haematobium detection. Assuming a baseline pre-test probability (prevalence) of 20%, a positive AI result (LR-Positive = 8) increases the post-test probability of infection to 66%. Conversely, a negative AI result (LR-Negative = 0.14) reduces the post-test probability of infection to 3%.