FAP and stroke disorder: Subsequent analysis of Youdens index determined discriminators of FAP for the presence of stroke as follows: 101 ng/ml [sensitivity 72% (95% CI 67.36–84.38%); specificity 77% (95% CI 59.86–89.58%); Positive Predictive Value 81% (95% CI 69.28–88.9%); Negative Predictive Value 68% (95% CI 55.84–77.33%)].