Background
Methods
Patients
Data collection
Follow‑up and study outcome
Statistical analyses
Results
Patient characteristics
Characteristics | Lost to follow-up | All | P* value | Patients survived | Patients died | P# value | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
No. of patients | N = 43 | N = 675 | N = 517 | N = 158 | |||||||
Age, years | 58 ± 11 | 54 ± 12 | 0.07 | 52.7 ± 12.1 | 59.1 ± 12.0 | < 0.001 | |||||
Male, n (%) | 10 (23.3) | 160 (23.7) | 1 | 112 (21.7) | 48 (30.4) | 0.032 | |||||
Farmer, n (%) | 25 (58.1) | 360 (53.3) | 0.649 | 261 (50.5) | 99 (62.7) | 0.010 | |||||
Ever smoker, n (%) | 2 (4.7) | 75 (11.1) | 0.283 | 48 (9.3) | 27 (17.1) | 0.010 | |||||
CTD types, n (%) | |||||||||||
PM/DM | 5 (11.6) | 201 (29.8) | 0.017 | 162 (31.3) | 39 (24.7) | 0.133 | |||||
SS | 8 (18.6) | 97 (14.4) | 0.590 | 77 (14.9) | 20 (12.7) | 0.568 | |||||
SSc | 7 (16.3) | 90 (13.3) | 0.751 | 71 (13.7) | 19 (12.0) | 0.675 | |||||
SLE | 5 (11.6) | 56 (8.3) | 0.633 | 40 (7.7) | 16 (10.1) | 0.431 | |||||
RA | 6 (14.0) | 50 (7.4) | < 0.001 | 25 (4.8) | 25 (15.8) | < 0.001 | |||||
AS | 0 (0) | 1 (0.1) | 1 | 1 (0.2) | 0 (0) | 1 | |||||
MCTD | 0 (0) | 40 (5.9) | 0.194 | 31 (6.0) | 9 (5.7) | 1 | |||||
UCTD | 11 (25.6) | 103 (15.3) | 0.114 | 81 (15.7) | 22 (13.9) | 0.684 | |||||
OCTD | 1 (2.3) | 37 (5.5) | 0.586 | 29 (5.6) | 8 (5.1) | 1 | |||||
Other complications, n (%) | |||||||||||
Hypertension | 11 (25.6) | 146 (21.6) | 0.676 | 110 (21.5) | 36 (22.8) | 0.770 | |||||
Diabetes | 2 (4.7) | 58 (8.6) | 0.534 | 46 (8.9) | 12 (7.6) | 0.727 | |||||
Days of symptoms, months | 6 (2–24) | 9 (2–36) | 0.054 | 6 (2–24) | 9 (2–36) | 0.054 | |||||
Baseline lung function | |||||||||||
FVC, %Predicted | 78.3 ± 15.9 | 80.2 ± 20.6 | 0.363 | 80.5 ± 20.1 | 79.3 ± 22.0 | 0.553 | |||||
FEV1, %Predicted | 80.0 ± 14.3 | 79.8 ± 21.5 | 0.940 | 80.0 ± 21.1 | 78.8 ± 22.9 | 0.556 | |||||
FEV1/FVC, % | 85.2 ± 8.4 | 82.4 ± 10.3 | 0.196 | 82.6 ± 9.4 | 81.7 ± 12.8 | 0.384 | |||||
DLco, %Predicted | 60.7 ± 13.6 | 52.6 ± 20.8 | 0.076 | 54.7 ± 20.2 | 45.9 ± 21.5 | < 0.001 | |||||
Echocardiography | |||||||||||
RAA, cm2 | 12.9 ± 1.8 | 13.2 ± 3.4 | 0.398 | 12.6 ± 2.1 | 15.1 ± 5.4 | < 0.001 | |||||
LVEF, % | 63.4 ± 2.9 | 63.0 ± 4.0 | 0.366 | 63.3 ± 3.5 | 61.8 ± 5.3 | 0.001 | |||||
PASP, mmHg | 28.6 ± 15.9 | 27.6 ± 11.5 | 0.781 | 26.1 ± 7.7 | 32.4 ± 18.5 | < 0.001 | |||||
Image charatern, n (%) | |||||||||||
Honeycombing | 3 (7.0) | 53 (7.9) | 1 | 30 (6.8) | 23 (14.6) | 0.001 | |||||
Fine reticular opacities | 14 (32.6) | 223 (33.0) | 1 | 160 (30.9) | 63 (39.9) | 0.046 | |||||
Diffuse bilateral ground-glass opacities | 39 (90.7) | 623 (92.3) | 0.932 | 477 (92.3) | 146 (92.4) | 1 | |||||
Local Pleural thickening | 24 (55.8) | 369 (54.7) | 0.748 | 268 (51.8) | 101 (63.9) | 0.010 | |||||
Pulmonary bullous | 9 (20.9) | 108 (16.0) | 0.525 | 74 (14.3) | 34 (21.5) | 0.042 | |||||
Hydrothorax | 3 (7.0) | 75 (11.1) | 0.554 | 47 (9.1) | 28 (17.7) | 0.004 | |||||
Hydropericardium | 3 (7.0) | 82 (12.1) | 0.439 | 52 (10.1) | 30 (19.0) | 0.004 | |||||
Small pulmonary nodules | 5 (11.6) | 137 (20.3) | 0.289 | 111 (21.5) | 26 (16.5) | 0.208 | |||||
Treatment, n (%) | |||||||||||
Immunosuppressive agents | 20 (46.5) | 364 (53.9) | 0.431 | 303 (58.6) | 61 (38.6) | < 0.001 | |||||
Glucocorticoids | 41 (95.3) | 608 (90.1) | 0.384 | 464 (89.7) | 144 (91.1) | 0.719 | |||||
Pirfenidone | 0 (0.0) | 61 (9.0) | 0.075 | 48 (9.3) | 13 (8.2) | 0.805 | |||||
Follow-up time, months | 50 (38–65) | 56 (44–69) | 20.5 (4–38) | < 0.001 |
Model derivation
Variables | Unadjusted hazard ratio | Multivariable analysis | ||
---|---|---|---|---|
Hazard ratio (95% CI) | P-value | Hazard ratio (95% CI) | P-value | |
Age, years | 1.041 (1.027–1.055) | < 0.001 | 1.035 (1.020–1.050) | < 0.001 |
Subtypes of CTD | ||||
RA | 2.292 (1.539–3.413) | < 0.001 | 1.788 (1.162–2.750) | 0.008 |
Baseline lung function | ||||
DLco, %Predicted | 0.982 (0.975–0.990) | < 0.001 | 0.984 (0.977–0.992) | < 0.001 |
Echocardiography | ||||
RVD, mm | 1.027 (1.017–1.038) | < 0.001 | 1.026 (1.012–1.039) | < 0.001 |
RAA, cm2 | 1.122 (1.093–1.151) | < 0.001 | 1.058 (1.015–1.102) | 0.007 |
PASP, mmHg | 1.025 (1.017–1.034) | < 0.001 | 1.008 (0.994–1.023) | 0.275 |
LVEF, % | 0.949 (0.926–0.973) | < 0.001 | 0.971 (0.943–1.001) | 0.054 |
Image charatern | ||||
Honeycombing | 2.167 (1.392–3.373) | 0.001 | 1.847 (1.158–2.947) | 0.010 |
Treatment | ||||
Immunosuppressive agents | 0.506 (0.367–0.697) | < 0.001 | 0.631 (0.450–0.885) | 0.008 |
Serologic test | ||||
CRP, mg/l | 1.005 (1.002–1.008) | < 0.001 | 1.002 (0.998–1.006) | 0.231 |
BNP, pg/ml | 1.000 (1.000–1.000) | < 0.001 | 1.000 (1.000–1.000) | 0.792 |
AST, U/l | 1.003 (1.002–1.005) | < 0.001 | 1.003 (1.002–1.005) | < 0.001 |
GGT, U/l | 1.002 (1.001–1.003) | < 0.001 | 1.001 (1.000–1.002) | 0.129 |
ALB, g/l | 0.936 (0.914–0.959) | < 0.001 | 0.959 (0.932–0.987) | 0.004 |
ILD-GAP model | 1.413 (1.285–1.554) | < 0.001 |
Model validation
Nomogram | ILD-GAP model | Nomogram + ILD-GAPmodel | |
---|---|---|---|
Likelihood ratio | 156.78 | 48.39 | 157.34 |
P-value | 0.455* | < 0.001# |
IDI (95% CI) | P-value | NRI-continuous (95% CI) | P-value | |
---|---|---|---|---|
3-year mortality | 0.137 (0.092–0.184) | < 0.001 | 0.294 (0.174–0.417) | < 0.001 |
5-year mortality | 0.136 (0.091–0.182) | < 0.001 | 0.325 (0.201–0.431) | < 0.001 |