Predictive values of ILO chest X-ray and respiratory function parameters for identifying silicosis when compared with respiratory physician assessments with HRCT for secondary screening participants
| No silicosis from secondary screening | Silicosis from secondary screening | Sensitivity % (95% CI) | Specificity % (95% CI) | NPV% (95% CI) | PPV% (95% CI) | LR+ (95% CI) | LR− (95% CI) | |
| Chest X-ray | ||||||||
| ILO profusion category 0 | 246 | 36 | 67.3 (57.7 to 75.9) | 86.0 (81.4 to 89.8) | 87.2 (82.8 to 90.9) | 64.9 (55.4 to 73.6) | 4.81 (3.51 to 6.59) | 0.38 (0.29 to 0.50) |
| ILO profusion category ≥1 | 40 | 74 | ||||||
| Respiratory function parameter | ||||||||
| FEV1 | ||||||||
| ≥ LLN | 228 | 78 | 18.8 (11.5 to 28.0) | 93.4 (89.6 to 96.2) | 74.5 (69.2 to 79.3) | 52.9 (35.1 to 70.2) | 2.86 (1.52 to 5.37) | 0.87 (0.79 to 0.96) |
| <LLN | 16 | 18 | ||||||
| FVC | ||||||||
| ≥ LLN | 232 | 82 | 14.6 (8.2 to 23.3) | 95.1 (91.6 to 97.4) | 73.9 (68.7 to 78.7) | 53.8 (33.4 to 73.4) | 2.97 (1.42 to 6.18) | 0.90 (0.82 to 0.98) |
| <LLN | 12 | 14 | ||||||
| FEV1/FVC | ||||||||
| ≥ LLN | 216 | 76 | 20.8 (13.2 to 30.3) | 88.5 (83.8 to 92.2) | 74.0 (68.5 to 78.9) | 41.7 (27.6 to 56.8) | 1.82 (1.08 to 3.06) | 0.89 (0.80 to 1.00) |
| <LLN | 28 | 20 | ||||||
| DLco | ||||||||
| ≥ LLN | 229 | 83 | 13.5 (7.4 to 22.0) | 93.9 (90.1 to 96.5) | 73.4 (68.1 to 78.2) | 46.4 (27.5 to 66.1) | 2.20 (1.09 to 4.45) | 0.92 (0.85 to 1.00) |
| <LLN | 15 | 13 | ||||||
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; HRCT, high-resolution CT; ILO, International Labour Office; LLN, lower limit of normal; LR, likelihood ratio; NPV, negative predictive value; PPV, positive predictive value.