A NT-proBNP threshold of 400 pg/mL in people with AF would maintain a test sensitivity (93.2%, 95% CI [92.4, 93.9]) and NPV (94.3%, 95% CI [93.6, 94.9]) above 90% but reduce referrals by 18.3% with a 7.4% increase in missed or delayed diagnoses compared to the 125 pg/mL threshold. Here, NPPB is linked to atrial fibrillation.