Table 2 Sensitivity (sens), specificity (spec), positive predictive value (PPV) and negative predictive value (NPV) at different cut-off points (n = 160); unit of FENO is parts per billion
Asthma diagnoses | FENO | sens [%] (95%CI) | spec [%] (95%CI) | PPV [%] (95%CI) | NPV [%] (95%CI) | n |
|---|---|---|---|---|---|---|
Borderline BHR | > 12 | 85 (76–92) | 24 (16–34) | 50 (41–58) | 65 (47–79) | 126 |
mild BHR | > 20 | 64 (53–74) | 58 (47–77) | 57 (47–67) | 65 (53–74) | 82 |
moderate to severe BHR | > 35 | 32 (25–42) | 84 (74–90) | 63 (47–77) | 58 (49–67) | 38 |
positive bronchodilator reversibility | > 46 | 32 (23–43) | 93 (85–97) | 80 (63–91) | 61 (52–69) | 30 |
(n = 75)* | > 76 | 13 (7–23) | 100 (96–100) | 100 (72–100) | 57 (49–65) | 11 |
Mild BHR | > 12 | 90 (79–95) | 25 (17–34) | 40 (32–50) | 81 (64–91) | 126 |
moderate to severe BHR | > 20 | 67 (54–78) | 62 (52–71) | 50 (39–61) | 77 (67–85) | 82 |
positive bronchodilator reversibility | > 35 | 36 (25–49) | 83 (75–89) | 55 (40–70) | 70 (61–77) | 38 |
(n = 58)§ | > 46 | 36 (25–49) | 91 (84–95) | 70 (52–83) | 72 (63–79) | 30 |
> 76 | 17 (10–29) | 100 (96–100) | 100 (72–100) | 68 (60–75) | 11 |