Table 6 Sub-analysis of patients who all received a pulmonary HRCT. Baseline characteristics and sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−), and area under the curve (AUC) for different diagnostic procedures in the detection of lung involvement in IRD patients with ILD
Variable | ILD group, number (%) | Non-ILD group, number (%) | Difference | AUC |
|---|---|---|---|---|
Number | 38 (50.0%) | 38 (50.0%) | ||
Age | 59.7 ± 15.0 years | 53.2 ± 14.7 years | t(74) = 1.91,P = 0.060 | |
PFT | 37 (97.4%) | 37 (97.4%) | χ2(1) = 0.000,P = 1.000 | |
Median ± SD | ||||
DLCO | 57.8 ± 19.3% | 76.0 ± 19.7% | t(71) = 3.99,P < 0.001 | 0.745 (0.633–0.857; P < 0.001) |
DLCO < 80%: sensitivity = 86.5%, specificity = 36.1%, LR+ = 1.35, LR− = 0.37 | ||||
TLC | 82.7 ± 20.8% | 97.4 ± 12.9% | t(51.1) = 3.49,P = 0.001 | 0.724 (0.598–0.849; P = 0.002) |
TLC < 80%: sensitivity = 39.4%, specificity = 94.1%, LR+ = 6.70, LR− = 0.64 | ||||
FVC | 78.9 ± 22.2% | 91.3 ± 16.4% | t(64.5) = 2.70,P = 0.009 | 0.667 (0.539–0.794; P = 0.014) |
FVC < 80%: sensitivity = 55.6%, specificity = 78.5%, LR+ = 2.57, LR− = 0.57 | ||||
FEV1 | 80.5 ± 23.5% | 91.1 ± 14.3% | t(55.5) = 2.30,P = 0.025 | 0.649 (0.517–0.782; P = 0.029) |
FEV1 < 80%: sensitivity = 54.3%, specificity = 78.4%, LR+ = 2.51, LR− = 0.58 | ||||
TLCO | 74.6 ± 18.5% | 82.8 ± 17.4% | t(97) = 1.93,P = 0.058 | 0.615 (0.485–0.746; P = 0.095) |
TLCO < 80%: sensitivity = 60.0%, specificity = 55.6%, LR+ = 1.35, LR− = 0.72 | ||||
Chest X-ray | 29 (76.3%) | 29 (76.3%) | χ2(1) = 0.000,P = 1.000 | |
Sensitivity = 72.4%, specificity = 58.6%, LR+ = 1.75, LR− = 0.47 | ||||
HRCT | 38 (100.0%) | 38 (100.0%) | χ2(1) = 0.000,P = 1.000 | |
Sensitivity = 100.0%, specificity = 52.6%, LR+ = 2.11, LR− = < 0.01 | ||||
Combination of chest X-ray and/or | ||||
DLCO < 80% | Sensitivity = 89.5%, specificity = 26.3%, LR+ = 1.21, LR− = 0.40 | |||
DLCO < 70% | Sensitivity = 84.2%, specificity = 50.0%, LR+ = 1.68, LR− = 0.32 | |||
FVC < 80% | Sensitivity = 78.9%, specificity = 57.9%, LR+ = 1.88, LR− = 0.36 | |||
FVC < 70% | Sensitivity = 71.1%, specificity = 65.8%, LR+ = 2.08, LR− = 0.44 | |||
Combination of the following: 1. DLCO < 80% and/or chest X-ray and 2. HRCT | Sensitivity = 89.5%, specificity = 65.8%, LR+ = 2.62, LR− = 0.16 | |||