| Odds ratio (95% CI) | Sensitivity (%) (95% CI) | Specificity (%) (95% CI) | PPV (%) (95% CI) | NPV (%) (95% CI) | |
| Severity score 1 | 9.8 (5.1, 18.5) | 87.6 (79.6, 92.8) | 58.0 (52.7, 63.0) | 36.5 (30.6, 42.8) | 94.4 (90.5, 96.8) |
| Severity score 2 | 8.0 (4.6, 13.9) | 81.4 (72.6, 87.9) | 64.5 (59.4, 69.3) | 38.7 (32.3, 45.6) | 92.7 (88.7, 95.3) |
| Severity score 3 | 5.2 (3.2, 8.5) | 62.9 (53.0, 71.8) | 75.6 (70.8, 79.8) | 41.5 (33.8, 49,6) | 86.1 (83.9, 91.3) |
| Severity score 4 | 6.0 (3.7, 9.7) | 61.9 (51.9, 70.9) | 78.7 (74.1, 82.6) | 44.4 (36.3, 52.9) | 88.2 (84.2, 91.3) |
| Severity score 5 | 8.0 (4.8, 13.2) | 55.6 (45.8, 65.2) | 86.4 (82.4, 89.6) | 52.9 (43.3, 62.3) | 87.6 (83.7, 90.7) |
| Severity score 6 | 7.9 (4.7, 13.1) | 51.5 (41.7, 61.2) | 88.1 (84.3, 91.1) | 54.3 (44.2, 64.1) | 86.8 (82.9, 90.0) |
| Severity score 7 | 4.8 (2.6, 8.8) | 26.8 (19.0, 36.4) | 92.9 (89.7, 95.1) | 51.0 (37.7, 64.1) | 82.2 (78.1, 85.6) |
| Severity score 8 | 4.5 (2.5, 8.4) | 25.8 (18.1, 35.3 | 92.9 (89.7, 95.1) | 50.0 (36.6, 63.4) | 82.0 (77.9, 85.4) |
| Severity score 9 | 4.8 (2.9, 11.5) | 12.4 (7.2, 20.4) | 97.2 (94.9, 98.4) | 54.5 (34.7, 73.1) | 80.1 (76.0, 83.3) |
| Severity score 10 | 3.9 (1.6, 9.7) | 10.3 (5.7, 19.7) | 97.2 (94.9, 98.5) | 50.0 (29.9, 70.1) | 79.7 (75.7, 83.3) |
| Severity score 11 | 5.6 (0.91, 33.9) | 3.1 (1.1, 8.7) | 99.4 (98.0, 99.8) | 60.0 (23.1, 88.2) | 78.8 (74.8, 82.4) |
| Severity score 12 | 3.7 (0.51, 26.5) | 2.1 (0.6, 7.2) | 99.4 (98.0, 99.8) | 50.0 (15.0, 85.0) | 78.7 (74.6, 82.2) |
| Positive stringent index* | 6.4 (3.9–10.4) | 56.7 (46.8–66.1) | 83.0 (78.7–86.5) | 47.8 (38.9–56.9) | 87.4 (83.4–90.6) |
| Positive loose index* | 5.6 (3.5–9.0) | 59.8 (49.8–69.0) | 79.0 (74.4–82.9) | 43.9 (35.8–52.5) | 87.7 (83.6–90.9) |
*Data in the present study have been approximated to the criteria used in asthma indices (stringent and loose) suggested by Castro-Rodriguez et al.8
NPV, negative predictive value; PPV, positive predictive value.