Diagnostic performance of four LTx referral policies.

The policy of FEV1 ≤ 30% predicted and a FEV1-based policy derived from a 2019 guideline were used as two baselines. Apart from the original AutoPrognosis policy developed on the studied UK CF cohort, an augmented AutoPrognosis policy with two additional criteria developed from the Canadian CF data was included in the evaluation as well. As a balanced measurement of prognostic accuracy, a high F1 score comes with high PPV and TPR scores. Decrease in either PPV or TPR score leads to a lower F1 score. Desirable LTx referral policies ought to have a high F1 score. All evaluation results were reported with 95% CI.