Background
Methods
Patient selection
GAP model
Variables | GAP Points | No. of patients |
---|---|---|
Gender | ||
Female | 0 | 315 (25.7) |
Male | 1 | 913 (74.3) |
Age, yr | ||
≤60 | 0 | 263 (21.4) |
61–65 | 1 | 208 (16.9) |
>65 | 2 | 757 (61.6) |
Physiology | ||
FVC, % predicted | ||
>75 | 0 | 626 (50.9) |
50–75 | 1 | 540 (44.0) |
<50 | 2 | 62 (5.0) |
DLCO, % predicted | ||
>55 | 0 | 735 (59.9) |
36–55 | 1 | 399 (32.5) |
≤35 | 2 | 94 (7.6) |
Can not perform | 3 | - |
GAP stage | ||
Stage I | 0–3 | 760 (60.2) |
Stage II | 4–5 | 455 (36.1) |
Stage III | 6–8 | 47 (3.7) |
Statistical analysis
Results
Demographic characteristics
Variable | Total GAP score (n = 1,228) |
p-value | |||||
---|---|---|---|---|---|---|---|
1 (n = 150) | 2 (n = 208) | 3 (n = 376) | 4 (n = 317) | 5 (n = 138) | 6 (n = 39) | ||
Age, yr | 56.2 ± 5.7 | 62.5 ± 8.9 | 69.0 ± 7.8 | 71.7 ± 7.6 | 72.4 ± 7.5 | 71.8 ± 5.9 | <0.001a
|
Sex, male (%) | 91 (60.7) | 114 (54.8) | 281 (74.7) | 269 (84.9) | 123 (89.1) | 35 (89.7) | <0.001 |
Duration of symptoms at diagnosis (Month) | 15.9 ± 27.9 | 9.8 ± 15.0 | 10.7 ± 20.6 | 10.8 ± 21.8 | 9.5 ± 17.8 | 5.4 ± 12.8 | 0.133 |
Smoking | <0.001 | ||||||
Non-smoker | 57 (41.3) | 98 (49.5) | 106 (31.7) | 80 (28.3) | 33 (27.3) | 6 (16.7) | |
Former | 36 (26.1) | 49 (24.7) | 139 (41.6) | 126 (44.5) | 59 (48.8) | 19 (52.8) | |
Current | 45 (32.6) | 51 (25.8) | 89 (26.6) | 77 (27.2) | 29 (24.0) | 11 (30.6) | |
Smoking duration (yrs) | 29.1 ± 9.1 | 29.8 ± 11.0 | 37.6 ± 11.6 | 38.0 ± 13.0 | 37.4 ± 15.7 | 41.3 ± 9.0 | <0.001a
|
Smoking amounts (PYrs) | 32.1 ± 18.2 | 30.7 ± 19.5 | 37.0 ± 18.0 | 36.6 ± 20.1 | 38.6 ± 25.7 | 40.0 ± 17.9 | 0.024a
|
Diagnostic method (%) | <0.001 | ||||||
Clinical | 33 (22.0) | 86 (41.3) | 235 (62.5) | 244 (77.0) | 119 (86.2) | 34 (87.2) | |
Surgical | 117 (78.0) | 122 (58.7) | 141 (37.5) | 73 (23.0) | 19 (13.8) | 5 (12.8) | |
Outcome | <0.001 | ||||||
Alive | 92 (61.3) | 118 (56.7) | 167 (44.4) | 114 (36.0) | 36 (26.1) | 10 (25.6) | |
Dead | 24 (16.0) | 31 (14.9) | 82 (21.8) | 83 (26.2) | 35 (25.4) | 15 (38.5) | |
Loss | 34 (22.7) | 59 (28.4) | 127 (33.8) | 120 (37.9) | 67 (48.6) | 14 (35.9) | |
ANA positivity | 34 (33.7) | 31 (28.4) | 63 (37.3) | 38 (29.9) | 20 (35.1) | 4 (23.5) | 0.580 |
RF positivity | 21 (20.4) | 18 (16.5) | 42 (24.1) | 36 (28.3) | 14 (29.2) | 2 (11.1) | 0.177 |
CRP (mg/L) | 1.3 ± 3.4 | 2.2 ± 4.3 | 4.0 ± 11.5 | 5.9 ± 15.9 | 7.6 ± 22.1 | 14.2 ± 38.7 | <0.001a
|
CPI | 28.0 ± 10.8 | 34.9 ± 12.3 | 35.8 ± 14.9 | 42.8 ± 12.8 | 55.7 ± 8.0 | 62.9 ± 6.8 | <0.001a
|
Physiological and radiological parameters
Variable | Total GAP score (n = 1,228) |
p-value | |||||
---|---|---|---|---|---|---|---|
1 (n = 150) | 2 (n = 208) | 3 (n = 376) | 4 (n = 317) | 5 (n = 138) | 6 (n = 39) | ||
Pulmonary function test | |||||||
FVC (%) | 85.6 ± 13.4 | 81.9 ± 17.4 | 81.3 ± 17.2 | 71.4 ± 15.7 | 63.2 ± 15.1 | 55.5 ± 12.9 | <0.001a
|
FEV1 (%) | 93.1 ± 15.0 | 91.4 ± 21.2 | 92.5 ± 19.5 | 82.9 ± 16.8 | 74.4 ± 16.2 | 64.9 ± 14.9 | <0.001a
|
TLC (%) | 90.8 ± 19.7 | 84.8 ± 19.7 | 87.2 ± 18.5 | 80.2 ± 18.6 | 72.0 ± 15.6 | 67.1 ± 23.9 | <0.001a
|
DLCO (%) | 75.8 ± 15.8 | 67.4 ± 17.1 | 67.1 ± 21.3 | 59.2 ± 19.9 | 41.7 ± 13.6 | 31.9 ± 11.1 | <0.001a
|
Resting PaO2 mm Hg | 90.5 ± 21.2 | 85.8 ± 19.6 | 82.5 ± 22.3 | 78.6 ± 18.7 | 74.5 ± 21.5 | 69.5 ± 13.7 | <0.001a
|
Resting PaCO2 mm Hg | 39.3 ± 8.2 | 39.2 ± 6.5 | 37.4 ± 7.8 | 36.5 ± 6.2 | 35.1 ± 6.9 | 36.7 ± 6.4 | <0.001a
|
Radiologic finding | |||||||
Reticular pattern | 108 (75.5) | 144 (73.5) | 214 (60.5) | 185 (65.4) | 82 (65.6) | 22 (62.9) | 0.008 |
Honeycombing change | 105 (77.2) | 141 (71.9) | 282 (78.6) | 241 (81.4) | 110 (84.0) | 31 (81.6) | 0.101 |
Ground glass opacities | 98 (68.5) | 132 (68.4) | 206 (58.9) | 155 (58.5) | 67 (56.3) | 22 (68.8) | 0.052 |
Nodular lesions | 26 (20.3) | 37 (19.9) | 85 (25.5) | 58 (23.6) | 23 (21.9) | 8 (25.8) | 0.702 |
Comorbidities and initial respiratory symptoms
Survival analysis on the basis of GAP score
Variable | Univariate | Multivariate | ||||
---|---|---|---|---|---|---|
HR | 95 % CI |
p-value | HR | 95 % CI |
p-value | |
Age | 1.015 | 1.002–1.028 | 0.028 | 1.018 | 1.005–1.031 | 0.006 |
Sex (M/F) | 1.184 | 0.890–1.575 | 0.245 | 1.264 | 0.949–1.684 | 0.109 |
FVC (%) | 0.985 | 0.978–0.992 | <0.001 | 0.986 | 0.979–0.993 | <0.001 |
DLCO (%) | 0.987 | 0.981–0.993 | <0.001 | 0.989 | 0.983–0.995 | 0.001 |
Variable | Total GAP score | Total | |||||
---|---|---|---|---|---|---|---|
1 (n = 11) | 2 (n = 21) | 3 (n = 60) | 4 (n = 63) | 5 (n = 28) | 6 (n = 13) | ||
Respiratory failure | 8 (72.7) | 11 (52.4) | 21 (35.0) | 25 (39.7) | 12 (42.9) | 6 (46.2) | 83 |
Infection | 2 (18.2) | 6 (28.6) | 19 (31.7) | 26 (41.3) | 10 (35.7) | 4 (30.8) | 67 |
Heart failure | 6 (1.0) | 5 (7.9) | 2 (7.1) | 1 (7.7) | 14 | ||
Lung cancer | 1 (9.1) | 4 (19.0) | 9 (15.0) | 5 (7.9) | 2 (7.1) | 1 (7.7) | 22 |
Othersa
| 5 (8.3) | 2 (3.2) | 2 (7.1) | 1 (7.7) | 10 |
Sub-analysis by GAP score
Variable | GAP Points | Total GAP score (n = 1,228) |
p-value | |||||
---|---|---|---|---|---|---|---|---|
1 (n = 150) | 2 (n = 208) | 3 (n = 376) | 4 (n = 317) | 5 (n = 138) | 6 (n = 39) | |||
Gender | <0.001 | |||||||
Female | 0 | 59 (39.3) | 94 (45.2) | 95 (25.3) | 48 (15.1) | 15 (10.9) | 4 (10.3) | |
Male | 1 | 91 (60.3) | 114 (54.8) | 281 (74.7) | 269 (84.9) | 123 (89.1) | 35 (89.7) | |
Age, yr | <0.001 | |||||||
≤60 | 0 | 121 (80.7) | 76 (36.5) | 45 (12.0) | 15 (4.7) | 6 (4.3) | - | |
61–65 | 1 | 29 (19.3) | 76 (36.5) | 66 (17.6) | 24 (7.6) | 12 (8.7) | 1 (2.6) | |
>65 | 2 | - | 56 (26.9) | 265 (70.5) | 278 (87.7) | 120 (87.0) | 38 (97.4) | |
Physiology | ||||||||
FVC, % predicted | <0.001 | |||||||
>75 | 0 | 127 (84.7) | 134 (64.4) | 249 (66.2) | 94 (29.7) | 22 (15.9) | - | |
50-75 | 1 | 23 (15.3) | 71 (34.1) | 121 (32.2) | 211 (66.6) | 92 (66.7) | 22 (56.4) | |
<50 | 2 | - | 3 (1.4) | 6 (1.6) | 12 (3.8) | 24 (17.4) | 17 (43.6) | |
DLCO, % predicted | <0.001 | |||||||
>55 | 0 | 143 (95.3) | 172 (82.7) | 263 (69.9) | 147 (46.4) | 10 (7.2) | - | |
36–55 | 1 | 7 (4.7) | 35 (16.8) | 108 (28.7) | 156 (49.2) | 81 (58.7) | 12 (30.8) | |
≤35 | 2 | - | 1 (0.5) | 5 (1.3) | 14 (4.4) | 47 (34.1) | 27 (69.2) |