Table 4. Performance of the Firefly technology as a screener for a clinical threshold of AHI ≥15.

Performance (AHI ≥15)	Training set	Test set
Sensitivity (%) (CI)	89.7 (75.4–97.3)	88.3 (77.3–95.1)
Specificity (%) (CI)	86.5 (77.9–92.3)	80.0 (67.8–88.7)
PPV (%) (CI)	74.5 (59.5–85.7)	81.5 (70.9–89.6)
NPV (%) (CI)	95.1 (88.5–98.7)	87.3 (76.1–94.4)
Accuracy (%) (CI)	87.5 (81.3–92.3)	84.2 (75.8–89.2)
ROC AUC (CI)	0.95 (0.91–0.98)	0.92 (0.85–0.95)
PR AUC (CI)	0.87 (0.78–0.94)	0.89 (0.80–0.94)

Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and AUC of the ROC and PR curves are provided for the training and testing sets respectively. The 95% confidence intervals are shown in parenthesis. AHI, apnea hypopnea index; ROC, receiver operating characteristic; AUC, area under the curve; PR, precision recall.