Background
Methods
Study design and patients
Measurements
Outcomes
Statistical analyses
Results
Baseline characteristics
Variables | CAD (n = 664) | No CAD (n = 3242) | P-value | Men | Women | ||||
---|---|---|---|---|---|---|---|---|---|
CAD (n = 500) | No CAD (n = 2564) | P-value | CAD (n = 164) | No CAD (n = 678) | P-value | ||||
Age (years) | 73.0 (13.0) | 68.0 (13.0) | < 0.001 | 73.0 (13.0) | 68.0 (13.0) | < 0.001 | 73.0 (13.0) | 69.0 (13.0) | < 0.001 |
Body-mass index (kg/m2) | 22.7 (5.2) | 21.8 (4.7) | < 0.001 | 22.7 (4.9) | 21.7 (4.7) | < 0.001 | 22.6 (6.3) | 22.2 (5.5) | 0.079 |
Smoking status | |||||||||
Non-smoker | 233 (35.1%) | 991 (30.6%) | < 0.001 | 108 (21.6%) | 462 (18.0%) | < 0.001 | 125 (76.2%) | 529 (78.0%) | 0.803 |
Ex-smoker | 296 (44.6%) | 1360 (41.9%) | 277 (55.4%) | 1281 (50.0%) | 19 (11.6%) | 79 (11.7%) | |||
Current smoker | 135 (20.3%) | 891 (27.5%) | 115 (23.0%) | 821 (32.0%) | 20 (12.2%) | 70 (10.3%) | |||
Hospital admissions in the previous year | |||||||||
< 2 | 492 (74.1%) | 2460 (75.9%) | 0.346 | 358 (71.6%) | 1907 (74.4%) | 0.201 | 134 (81.7%) | 553 (81.6%) | 1.000 |
≥ 2 | 172 (25.9%) | 782 (24.1%) | 142 (28.4%) | 657 (25.6%) | 30 (18.3%) | 125 (18.4%) | |||
Emergency visits in the previous year | |||||||||
< 2 | 529 (79.7%) | 2508 (77.4%) | 0.201 | 388 (77.6%) | 1953 (76.2%) | 0.527 | 141 (86.0%) | 555 (81.9%) | 0.250 |
≥ 2 | 135 (20.3%) | 734 (22.6%) | 112 (22.4%) | 611 (23.8%) | 23 (14.0%) | 123 (18.1%) | |||
Symptoms | |||||||||
Increased cough | 421 (63.4%) | 1916 (59.1%) | 0.041 | 318 (63.6%) | 1500 (58.5%) | 0.037 | 103 (62.8%) | 416 (61.4%) | 0.789 |
Increased sputum volume | 271 (40.8%) | 1297 (40.0%) | 0.728 | 209 (41.8%) | 1023 (39.9%) | 0.455 | 62 (37.8%) | 274 (40.4%) | 0.594 |
Wheezing | 574 (86.4%) | 2711 (83.6%) | 0.071 | 427 (85.4%) | 2133 (83.2%) | 0.236 | 147 (89.6%) | 578 (85.3%) | 0.167 |
mMRC | 3.0 (1.0) | 3.0 (1.0) | 0.020 | 3.0 (1.0) | 3.0 (1.0) | 0.071 | 3.0 (1.0) | 3.0 (1.0) | 0.107 |
CAT | 20.0 (10.0) | 19.0 (9.0) | 0.045 | 20.0 (11.0) | 19.0 (9.0) | 0.096 | 20.0 (8.0) | 19.0 (9.0) | 0.283 |
Post-bronchodilator FEV1% predicted | 43.2 (24.7) | 41.8 (26.9) | 0.368 | 41.4 (23.9) | 40.3 (25.6) | 0.202 | 45.8 (24.1) | 49.4 (27.8) | 0.233 |
Post-bronchodilator FEV1/FVC (%) | 52.0 (16.0) | 50.0 (17.0) | 0.002 | 50.0 (16.0) | 48.0 (16.0) | 0.023 | 56.0 (16.0) | 55.0 (16.0) | 0.147 |
Comorbidity | |||||||||
Respiratory disease | |||||||||
Asthma | 56 (8.4%) | 299 (9.2%) | 0.554 | 40 (8.0%) | 216 (8.4%) | 0.792 | 16 (9.8%) | 83 (12.2%) | 0.420 |
Bronchiectasis | 80 (12.0%) | 403 (12.4%) | 0.796 | 56 (11.2%) | 296 (11.5%) | 0.878 | 24 (14.6%) | 107 (15.8%) | 0.722 |
Lung cancer | 4 (0.6%) | 48 (1.5%) | 0.092 | 3 (0.6%) | 42 (1.6%) | 0.101 | 1 (0.6%) | 6 (0.9%) | 1.000 |
Pulmonary artery hypertension | 62 (9.3%) | 280 (8.6%) | 0.598 | 43 (8.6%) | 232 (9.0%) | 0.798 | 19 (11.6%) | 48 (7.1%) | 0.075 |
SAS | 7 (1.1%) | 39 (1.2%) | 0.846 | 7 (1.4%) | 34 (1.3%) | 1.000 | 0 (0.0%) | 5 (0.7%) | 0.589 |
Pneumonia | 201 (30.3%) | 1004 (31.0%) | 0.747 | 153 (30.6%) | 779 (30.4%) | 0.958 | 48 (29.3%) | 225 (33.2%) | 0.354 |
Cardiovascular disease | |||||||||
Hypertension | 316 (47.6%) | 993 (30.6%) | < 0.001 | 235 (47.0%) | 772 (30.1%) | < 0.001 | 81 (49.4%) | 221 (32.6%) | < 0.001 |
Heart failure | 72 (10.8%) | 118 (3.6%) | < 0.001 | 53 (10.6%) | 91 (3.5%) | < 0.001 | 19 (11.6%) | 27 (4.0%) | < 0.001 |
Arrhythmia | 88 (13.3%) | 152 (4.7%) | < 0.001 | 68 (13.6%) | 130 (5.1%) | < 0.001 | 20 (12.2%) | 22 (3.2%) | < 0.001 |
Digestive disease | |||||||||
Gastroesophageal reflux disease | 18 (2.7%) | 58 (1.8%) | 0.123 | 14 (2.8%) | 48 (1.9%) | 0.222 | 4 (2.4%) | 10 (1.5%) | 0.492 |
Peptic ulcer | 15 (2.3%) | 57 (1.8%) | 0.427 | 10 (2.0%) | 52 (2.0%) | 1.000 | 5 (3.0%) | 5 (0.7%) | 0.029 |
Chronic gastritis | 38 (5.7%) | 133 (4.1%) | 0.076 | 29 (5.8%) | 105 (4.1%) | 0.094 | 9 (5.5%) | 28 (4.1%) | 0.523 |
Cerebrovascular disease | 77 (11.6%) | 194 (6.0%) | < 0.001 | 64 (12.8%) | 154 (6.0%) | < 0.001 | 13 (7.9%) | 40 (5.9%) | 0.369 |
Endocrine and metabolic disease | |||||||||
Diabetes | 110 (16.6%) | 296 (9.1%) | < 0.001 | 86 (17.2%) | 237 (9.2%) | < 0.001 | 24 (14.6%) | 59 (8.7%) | 0.028 |
Osteoporosis | 6 (0.9%) | 36 (1.1%) | 0.690 | 6 (1.2%) | 24 (0.9%) | 0.617 | 0 (0.0%) | 12 (1.8%) | 0.137 |
Other malignant tumors | 12 (1.8%) | 54 (1.7%) | 0.869 | 10 (2.0%) | 47 (1.8%) | 0.856 | 2 (1.2%) | 7 (1.0%) | 0.690 |
Pre-admission non-drug therapy | |||||||||
Pulmonary rehabilitation | 70 (10.5%) | 312 (9.6%) | 0.473 | 53 (10.6%) | 247 (9.6%) | 0.511 | 17 (10.4%) | 65 (9.6%) | 0.769 |
Home oxygen therapy | 82 (12.3%) | 457 (14.1%) | 0.241 | 71 (14.2%) | 374 (14.6%) | 0.836 | 11 (6.7%) | 83 (12.2%) | 0.052 |
Noninvasive ventilation | 10 (1.5%) | 38 (1.2%) | 0.561 | 8 (1.6%) | 31 (1.2%) | 0.511 | 2 (1.2%) | 7 (1.0%) | 0.690 |
Pre-admission medication | |||||||||
LAMA | 227 (34.2%) | 1103 (34.0%) | 0.964 | 197 (39.4%) | 914 (35.6%) | 0.115 | 30 (18.3%) | 189 (27.9%) | 0.013 |
LABA | 211 (31.8%) | 1035 (31.9%) | 0.964 | 183 (36.6%) | 850 (33.2%) | 0.148 | 28 (17.1%) | 185 (27.3%) | 0.009 |
ICS | 229 (34.5%) | 1090 (33.6%) | 0.685 | 191 (38.2%) | 895 (34.9%) | 0.168 | 38 (23.2%) | 195 (28.8%) | 0.173 |
OCS | 9 (1.4%) | 102 (3.1%) | 0.014 | 9 (1.8%) | 84 (3.3%) | 0.087 | 0 (0.0%) | 18 (2.7%) | 0.032 |
Examinations and treatments during hospitalization
Variables, N (missing)a | CAD (n = 664) | No CAD (n = 3242) | P-value | Men | Women | ||||
---|---|---|---|---|---|---|---|---|---|
CAD (n = 500) | No CAD (n = 2564) | P-value | CAD (n = 164) | No CAD (n = 678) | P-value | ||||
Heart rate (beats per min), 4 | 84.0 (20.0) | 87.0 (19.0) | < 0.001 | 84.0 (22.0) | 87.0 (20.0) | < 0.001 | 85.0 (18.0) | 87.0 (18.0) | 0.131 |
Respiratory rate (breaths per min), 12 | 20.0 (2.0) | 20.0 (2.0) | 0.595 | 20.0 (2.0) | 20.0 (2.0) | 0.705 | 20.0 (2.0) | 20.0 (2.0) | 0.634 |
Blood gasb, 1983 | |||||||||
pH | 7.42 (0.05) | 7.41 (0.05) | 0.430 | 7.41 (0.05) | 7.41 (0.05) | 0.941 | 7.42 (0.04) | 7.42 (0.05) | 0.326 |
PaO2 (mmHg) | 71.0 (19.0) | 70.0 (19.0) | 0.428 | 70.9 (19.0) | 71.0 (19.0) | 0.511 | 71.0 (19.0) | 68.0 (18.0) | 0.445 |
PaCO2 (mmHg) | 41.2 (9.0) | 41.4 (10.0) | 0.426 | 41.0 (9.0) | 41.4 (10.0) | 0.290 | 42.0 (10.0) | 41.8 (9.0) | 0.929 |
Blood routine, 48 | |||||||||
WBCs (× 109/L) | 7.20 (3.83) | 7.21 (3.75) | 0.451 | 7.38 (3.82) | 7.26 (3.84) | 0.447 | 7.01 (3.90) | 7.12 (3.54) | 0.739 |
Neutrophils (%) | 70.0 (15.5) | 70.1 (17.6) | 0.737 | 71.3 (16.0) | 70.3 (17.8) | 0.554 | 68.6 (13.2) | 69.5 (16.8) | 0.823 |
Lymphocytes (%) | 19.0 (13.0) | 18.7 (14.6) | 0.698 | 18.1 (12.7) | 18.2 (14.7) | 0.500 | 21.2 (12.5) | 20.9 (14.0) | 0.983 |
NLR | 3.7 (3.7) | 3.7 (4.3) | 0.744 | 3.8 (4.1) | 3.9 (4.6) | 0.545 | 3.3 (2.8) | 3.3 (3.1) | 0.900 |
Eosinophils (%) | 1.6 (2.6) | 1.4 (2.8) | 0.030 | 1.6 (2.7) | 1.5 (2.9) | 0.037 | 1.4 (2.5) | 1.3 (2.5) | 0.404 |
Red blood cells (× 1012/L) | 4.48 (1.00) | 4.52 (1.00) | 0.063 | 4.51 (1.00) | 4.58 (1.00) | 0.033 | 4.42 (1.00) | 4.35 (1.00) | 0.538 |
Hemoglobins (g/L) | 136.0 (22.0) | 138.0 (24.0) | 0.056 | 137.0 (22.0) | 140.0 (24.0) | 0.028 | 131.0 (19.0) | 130.0 (21.0) | 0.257 |
Platelets (× 109/L) | 199.0 (80.0) | 208.0 (96.0) | 0.127 | 196.0 (80.5) | 204.0 (97.0) | 0.116 | 208.0 (92.5) | 219.5 (90.8) | 0.501 |
Blood biochemistry, 127 | |||||||||
ALT (U/L) | 16.0 (11.8) | 16.6 (12.0) | 0.160 | 17.0 (12.4) | 17.0 (12.9) | 0.298 | 15.0 (9.2) | 15.0 (11.0) | 0.653 |
AST (U/L) | 19.0 (9.0) | 19.5 (9.5) | 0.037 | 19.2 (9.7) | 19.7 (9.4) | 0.250 | 17.5 (8.7) | 19.0 (10.0) | 0.040 |
BUN (mmol/L) | 5.7 (2.9) | 5.4 (2.6) | < 0.001 | 5.8 (2.9) | 5.5 (2.6) | 0.001 | 5.1 (2.6) | 4.8 (2.4) | 0.029 |
Cr (μmol/L) | 72.0 (29.3) | 70.4 (23.1) | 0.002 | 76.5 (29.8) | 73.0 (21.3) | < 0.001 | 59.2 (23.0) | 58.7 (19.9) | 0.675 |
Blood glucose (mmol/L), 137 | 5.6 (1.9) | 5.5 (1.8) | 0.020 | 5.7 (2.0) | 5.5 (1.9) | 0.037 | 5.6 (1.8) | 5.4 (1.7) | 0.251 |
NT-proBNP (pg/ml), 2997 | 230.6 (584.0) | 113.0 (220.0) | < 0.001 | 236.0 (577.0) | 111.0 (219.0) | < 0.001 | 201.0 (558.0) | 119.0 (230.0) | 0.187 |
CRP (mg/L), 1610 | 5.0 (12.0) | 4.7 (15.0) | 0.793 | 5.0 (15.0) | 5.0 (16.0) | 0.950 | 4.3 (9.0) | 4.3 (11.0) | 0.731 |
PCT (ng/ml), 1693 | 0.06 (0.10) | 0.05 (0.08) | 0.610 | 0.06 (0.10) | 0.05 (0.08) | 0.727 | 0.05 (0.07) | 0.05 (0.07) | 0.660 |
SABD, 0 | 472 (71.1%) | 2447 (75.5%) | 0.019 | 357 (71.4%) | 1941 (75.7%) | 0.042 | 115 (70.1%) | 506 (74.6%) | 0.277 |
LAMA, 0 | 53 (8.0%) | 334 (10.3%) | 0.074 | 44 (8.8%) | 271 (10.6%) | 0.260 | 9 (5.5%) | 63 (9.3%) | 0.123 |
LABA, 0 | 50 (7.5%) | 387 (11.9%) | 0.001 | 41 (8.2%) | 309 (12.1%) | 0.014 | 9 (5.5%) | 78 (11.5%) | 0.031 |
ICS, 0 | 71 (10.7%) | 441 (13.6%) | 0.043 | 56 (11.2%) | 350 (13.7%) | 0.149 | 15 (9.1%) | 91 (13.4%) | 0.151 |
Nebulized corticosteroids, 0 | 438 (66.0%) | 2061 (63.6%) | 0.249 | 324 (64.8%) | 1613 (62.9%) | 0.447 | 114 (69.5%) | 448 (66.1%) | 0.408 |
Systemic corticosteroids, 0 | 180 (27.1%) | 1091 (33.7%) | 0.001 | 144 (28.8%) | 876 (34.2%) | 0.022 | 36 (22.0%) | 215 (31.7%) | 0.017 |
Antibiotics, 0 | 577 (86.9%) | 2807 (86.6%) | 0.851 | 426 (85.2%) | 2208 (86.1%) | 0.622 | 151 (92.1%) | 599 (88.3%) | 0.209 |
ICU admission, 0 | 13 (2.0%) | 29 (0.9%) | 0.022 | 12 (2.4%) | 25 (1.0%) | 0.013 | 1 (0.6%) | 4 (0.6%) | 1.000 |
Sex differences in the predictors of comorbid CAD
Variablesa | Coefficient B | Standard error | Wald | P-value | OR | 95% CI lower | 95% CI upper |
---|---|---|---|---|---|---|---|
Men | |||||||
Age (years) | 0.042 | 0.006 | 48.436 | < 0.001 | 1.043 | 1.030 | 1.055 |
Body-mass index (kg/m2) | 0.048 | 0.015 | 10.773 | 0.001 | 1.049 | 1.019 | 1.079 |
Hypertension | 0.430 | 0.106 | 16.289 | < 0.001 | 1.537 | 1.247 | 1.893 |
Heart failure | 0.889 | 0.193 | 21.252 | < 0.001 | 2.433 | 1.667 | 3.550 |
Arrhythmia | 0.659 | 0.170 | 14.954 | < 0.001 | 1.933 | 1.384 | 2.699 |
Cerebrovascular disease | 0.558 | 0.164 | 11.508 | 0.001 | 1.747 | 1.266 | 2.412 |
Diabetes | 0.497 | 0.145 | 11.718 | 0.001 | 1.643 | 1.236 | 2.183 |
Constant | -6.022 | 0.562 | 114.621 | < 0.001 | |||
Women | |||||||
Age (years) | 0.044 | 0.010 | 17.562 | < 0.001 | 1.045 | 1.024 | 1.066 |
Pre-admission home oxygen therapy | − 0.840 | 0.358 | 5.496 | 0.019 | 0.432 | 0.214 | 0.871 |
Pre-admission LABA | − 0.621 | 0.242 | 6.593 | 0.010 | 0.537 | 0.335 | 0.863 |
Hypertension | 0.668 | 0.187 | 12.759 | < 0.001 | 1.951 | 1.352 | 2.814 |
Heart failure | 1.024 | 0.344 | 8.837 | 0.003 | 2.784 | 1.417 | 5.468 |
Arrhythmia | 1.207 | 0.339 | 12.688 | < 0.001 | 3.343 | 1.721 | 6.496 |
Constant | − 4.731 | 0.747 | 40.084 | < 0.001 |
Clinical outcomes during hospitalization
Clinical outcomes | CAD (n = 664) | No CAD (n = 3242) | P-value | Men | Women | ||||
---|---|---|---|---|---|---|---|---|---|
CAD (n = 500) | No CAD (n = 2564) | P-value | CAD (n = 164) | No CAD (n = 678) | P-value | ||||
Length of hospital stay (days) | 10.0 (5.8) | 9.0 (4.0) | < 0.001 | 10.0 (5.0) | 9.0 (5.0) | < 0.001 | 9.0 (5.0) | 9.0 (4.0) | 0.122 |
Total cost during hospitalization (US$) | 1419.3 (952.4) | 1352.1 (862.1) | 0.002 | 1502.2 (987.3) | 1373.4 (886.6) | < 0.001 | 1197.0 (812.3) | 1289.4 (756.6) | 0.421 |
Change of CAT at discharge compared to admission | − 8.0 (9.0) | − 7.0 (9.0) | 0.003 | − 8.0 (9.0) | − 7.0 (9.0) | 0.006 | − 8.0 (8.0) | − 7.0 (9.0) | 0.235 |
CAT at day 30 | 11.0 (9.0) | 11.0 (8.0) | 0.020 | 12.0 (9.0) | 11.0 (8.0) | 0.046 | 11.0 (7.0) | 10.0 (9.0) | 0.194 |
mMRC at day 30 | 2.0 (1.0) | 1.0 (1.0) | < 0.001 | 2.0 (1.0) | 1.0 (1.0) | 0.003 | 2.0 (1.0) | 1.0 (1.0) | 0.007 |
St George’s Respiratory Questionnaire at day 30 | |||||||||
Symptoms | 52.4 (21.0) | 53.6 (18.0) | 0.225 | 52.6 (20.0) | 54.0 (18.0) | 0.659 | 49.3 (19.0) | 52.2 (18.0) | 0.108 |
Activities | 41.8 (31.0) | 42.6 (30.0) | 0.812 | 41.8 (37.0) | 47.2 (30.0) | 0.868 | 42.3 (37.0) | 41.8 (30.0) | 0.870 |
Impacts | 14.2 (25.0) | 14.1 (24.0) | 0.936 | 14.3 (25.0) | 14.1 (24.0) | 0.832 | 12.9 (23.0) | 14.3 (23.0) | 0.842 |
Total | 29.3 (23.0) | 30.0 (22.0) | 0.764 | 29.7 (23.0) | 30.3 (22.0) | 0.986 | 27.9 (21.0) | 29.6 (22.0) | 0.595 |
All-cause readmission or death within 30 days | 13 (3.1%) | 68 (3.4%) | 0.770 | 11 (3.4%) | 59 (3.7%) | 0.872 | 2 (2.0%) | 9 (2.2%) | 1.000 |
AECOPD readmission within 30 days | 11 (2.7%) | 47 (2.4%) | 0.861 | 9 (2.8%) | 40 (2.5%) | 0.846 | 2 (2.1%) | 7 (1.7%) | 0.686 |
Clinical outcomes within 30 days after discharge
Variables | Crude HR (95% CI) | P-value | Adjusted HR (95% CI)a | P-value |
---|---|---|---|---|
CAD | 0.91 (0.50–1.64) | 0.744 | – | – |
Sex and status of CAD | ||||
Men without CAD | 1.00 (reference) | – | – | – |
Men with CAD | 0.92 (0.48–1.75) | 0.793 | – | – |
Women without CAD | 0.59 (0.29–1.19) | 0.142 | – | – |
Women with CAD | 0.54 (0.13–2.23) | 0.398 | – | – |
Age (years) | 1.01 (0.99–1.03) | 0.381 | – | – |
Men | 1.69 (0.90–3.20) | 0.105 | – | 0.337 |
Body-mass index (kg/m2) | 0.95 (0.89–1.01) | 0.081 | – | 0.385 |
Smokerb | 1.00 (0.62–1.60) | 0.999 | – | – |
Hospital admissions ≥ 2 in the previous year | 2.32 (1.49–3.60) | < 0.001 | 1.94 (1.24–3.04) | 0.004 |
mMRC ≥ 2 | 1.65 (0.83–3.30) | 0.155 | – | – |
CAT ≥ 10 | 1.23 (0.54–2.83) | 0.623 | – | – |
Post-bronchodilator FEV1% predicted | 0.97 (0.96–0.99) | < 0.001 | 0.98 (0.96–0.99) | 0.001 |
Comorbidity | ||||
Respiratory diseases | 1.24 (0.80–1.93) | 0.334 | – | – |
Cardiovascular diseasesc | 1.39 (0.90–2.14) | 0.142 | – | – |
Digestive diseases | 1.35 (0.65–2.81) | 0.416 | – | – |
Cerebrovascular disease | 1.53 (0.77–3.07) | 0.226 | – | – |
Endocrine and metabolic diseases | 1.30 (0.70–2.39) | 0.406 | – | – |
Other malignant tumors | 1.50 (0.37–6.10) | 0.572 | – | – |
Laboratory data during hospitalization | ||||
PaO2 (mmHg) | 1.00 (0.99–1.01) | 0.540 | – | – |
PaCO2 (mmHg) | 1.02 (1.00–1.03) | 0.110 | – | – |
NLR | 1.01 (1.00–1.01) | < 0.001 | 1.01 (1.00–1.01) | < 0.001 |
Eosinophils (%) | 0.95 (0.87–1.03) | 0.210 | – | – |
NT-proBNP (pg/ml) | 1.00 (1.00–1.00) | 0.936 | – | – |
CRP (mg/L) | 0.99 (0.99–1.00) | 0.270 | – | – |
PCT (ng/ml) | 0.84 (0.47–1.51) | 0.563 | – | – |
Treatment during hospitalization | ||||
SABD | 0.89 (0.54–1.46) | 0.641 | – | – |
LAMA | 0.90 (0.41–1.94) | 0.780 | – | – |
LABA | 0.71 (0.33–1.53) | 0.378 | – | – |
ICS | 0.61 (0.28–1.32) | 0.212 | – | – |
Nebulized corticosteroids | 1.20 (0.76–1.92) | 0.434 | – | – |
Systemic corticosteroids | 2.33 (1.50–3.60) | < 0.001 | 2.01 (1.30–3.13) | 0.002 |
Antibiotics | 1.61 (0.74–3.48) | 0.232 | – | – |