Table 2

Diagnostic accuracy of FENO in different patient collectives

Pneumologists practice (n=393)
p(asthma)=39.2%
General practice (n=160)
p(asthma)=46.9%
NO [ppb]SensitivitySpecificitySensitivitySpecificity
≥4100 (97.6 to 100)0 (0 to 1.6)100 (95.1 to 100)0 (0 to 4.3)
≥699.4 (96.5 to 99.9)2.1 (0.9 to 4.8)96.0 (88.9 to 98.6)7.1 (3.3 to 14.6)
≥997.4 (93.5 to 99.0)7.5 (4.8 to 11.6)92.0 (83.6 to 96.3)15.3 (9.2 to 24.4)
≥1095.5 (91.0 to 97.8)13.0 (9.3 to 17.9)89.3 (80.3 to 94.5)16.5 (10.1 to 25.8)
≥1190.9 (85.3 to 94.5)18.8 (14.4 to 24.2)88.0 (78.7 to 93.6)20.0 (12.9 to 29.7)
≥1285.1 (78.6 to 89.9)28.5 (23.2 to 34.5)85.3 (75.6 to 91.6)23.5 (15.8 to 33.5)
≥1569.3 (76.6 to 82.6)36.4 (30.6 to 42.7)76.0 (65.2 to 84.3)37.6 (28.1 to 48.2)
≥1769.5 (61.8 to 76.2)47.3 (41.1 to 53.6)69.3 (58.1 to 78.6)52.9 (42.4 to 63.2)
≥1965.6 (57.8 to 72.6)55.2 (48.9 to 61.4)64.0 (52.7 to 73.9)57.6 (47.0 to 67.6)
≥2159.7 (51.8 to 67.1)63.2 (56.9 to 69.1)60.0 (48.7 to 70.3)61.2 (50.6 to 70.9)
≥2648.7 (40.9 to 56.5)75.3 (69.5 to 80.3)49.3 (38.3 to 60.4)72.9 (62.6 to 81.2)
≥3138.3 (31.0 to 46.2)83.3 (78.1 to 87.5)37.3 (27.2 to 48.6)76.5 (66.5 to 84.3)
≥3632.5 (25.6 to 40.2)87.9 (83.2 to 91.4)32.0 (22.5 to 43.2)83.5 (74.2 to 89.9)
≥4128.6 (22.1 to 36.2)90.8 (86.5 to 93.8)32.0 (22.5 to 43.2)88.2 (79.6 to 93.5)
≥4823.4 (17.4 to 30.7)92.5 (88.4 to 95.2)30.7 (21.4 to 41.9)92.9 (85.4 to 96.7)
≥5122.7 (16.8 to 29.9)93.7 (89.9 to 96.1)28.0 (19.1 to 39.0)92.9 (85.4 to 96.7)
≥5720.8 (15.1 to 27.9)95.4 (92.0 to 97.4)25.3 (16.8 to 36.2)94.1 (86.9 to 97.5)
≥6518.8 (13.4 to 25.7)95.8 (92.5 to 97.7)20.0 (12.5 to 30.4)98.8 (93.6 to 99.8)
≥7217.5 (12.3 to 24.3)97.1 (94.1 to 98.6)14.7 (8.4 to 24.4)98.8 (93.6 to 99.8)
≥9912.3 (8.0 to 18.4)99.2 (97.1 to 99.8)10.7 (5.5 to 19.7)100 (95.7 to 100)
  • FENO, fractional exhaled nitric oxide; ppb, parts per billion.