Table 1 Baseline patient characteristics in unmatched and propensity-matched groups
Variables | Unmatched group | Matched group | ||||
|---|---|---|---|---|---|---|
H2RA group | PPI group | SMD | H2RA group | PPI group | SMD | |
n = 1227 | n = 1879 | Â | n = 1088 | n = 1088 | Â | |
Age, mean (SD) | 74.5 (13.1) | 73.7 (13.0) | 0.06 | 74.2 (13.2) | 74.4 (12.9) | 0.02 |
Age category | Â | Â | 0.09 | Â | Â | 0.06 |
 10–19 | 1 (0.1) | 0 (0.0) |  | 1 (0.1) | 0 (0.0) |  |
 20–29 | 7 (0.7) | 6 (0.5) |  | 5 (0.5) | 4 (0.4) |  |
 30–39 | 19 (1.8) | 23 (2.0) |  | 19 (1.7) | 19 (1.7) |  |
 40–49 | 30 (2.8) | 39 (3.4) |  | 31 (2.8) | 27 (2.5) |  |
 50–59 | 91 (8.6) | 96 (8.5) |  | 82 (7.5) | 88 (8.1) |  |
 60–69 | 198 (18.7) | 207 (18.3) |  | 196 (18.0) | 196 (18.0) |  |
 70–79 | 324 (30.6) | 342 (30.2) |  | 308 (28.3) | 301 (27.7) |  |
 80–89 | 326 (30.8) | 365 (32.3) |  | 364 (33.5) | 366 (33.6) |  |
 90–99 | 62 (5.9) | 52 (4.6) |  | 80 (7.4) | 85 (7.8) |  |
 100– | 0 (0.0) | 1 (0.1) |  | 2 (0.2) | 2 (0.2) |  |
Sex (female), n (%) | 615 (50.1) | 891 (47.4) | 0.05 | 545 (50.1) | 542 (49.8) | 0.01 |
ICU admission, n (%) | 449 (36.6) | 867 (46.1) | 0.20 | 414 (38.1) | 434 (39.9) | 0.04 |
HCU admission, n (%) | 52 (4.2) | 99 (5.3) | 0.05 | 50 (4.6) | 50 (4.6) | < 0.001 |
Hospital type (academic center), n (%) | 240 (19.6) | 606 (32.3) | 0.29 | 239 (22.0) | 206 (18.9) | 0.08 |
Hospital volume, case/year mean (SD) | 5.5 (4.9) | 7.2 (7.4) | 0.27 | 5.7 (5.1) | 5.7 (5.2) | 0.01 |
Comorbidity,n(%) | ||||||
 Myocardial infarction | 16 (1.3) | 17 (0.9) | 0.04 | 11 (1.0) | 9 (0.8) | 0.02 |
 Congestive heart failure | 70 (5.7) | 130 (6.9) | 0.05 | 65 (6.0) | 58 (5.3) | 0.03 |
 Peripheral vascular disease | 16 (1.3) | 26 (1.4) | 0.01 | 14 (1.3) | 13 (1.2) | 0.01 |
 Cerebrovascular disease | 58 (4.7) | 72 (3.8) | 0.04 | 47 (4.3) | 46 (4.2) | 0.01 |
 Dementia | 34 (2.8) | 48 (2.6) | 0.01 | 28 (2.6) | 27 (2.5) | 0.01 |
 Chronic pulmonary disease | 41 (3.3) | 52 (2.8) | 0.03 | 30 (2.8) | 36 (3.3) | 0.03 |
 Mild liver disease | 37 (3.0) | 70 (3.7) | 0.04 | 33 (3.0) | 32 (2.9) | 0.01 |
 Severe liver disease | 1 (0.1) | 7 (0.4) | 0.06 | 1 (0.1) | 0 (0.0) | 0.04 |
 Rheumatologic disease | 30 (2.4) | 42 (2.2) | 0.01 | 25 (2.3) | 24 (2.2) | 0.006 |
 Hemiplegia or paraplegia | 2 (0.2) | 3 (0.2) | 0.001 | 2 (0.2) | 1 (0.1) | 0.03 |
 Diabetes without chronic complications | 120 (9.8) | 182 (9.7) | 0.003 | 104 (9.6) | 95 (8.7) | 0.03 |
 Diabetes with chronic complications | 23 (1.9) | 43 (2.3) | 0.03 | 20 (1.8) | 21 (1.9) | 0.007 |
 Renal disease | 71 (5.8) | 183 (9.7) | 0.15 | 69 (6.3) | 69 (6.3) | < 0.001 |
 Any malignancy, including leukemia and lymphoma | 207 (16.9) | 300 (16.0) | 0.02 | 188 (17.3) | 184 (16.9) | 0.01 |
 Metastatic solid tumor | 66 (5.4) | 96 (5.1) | 0.01 | 61 (5.6) | 58 (5.3) | 0.01 |
Consciousness level, n (%) | ||||||
 Alert | 925 (75.4) | 1308 (69.6) | 0.13 | 808 (74.3) | 813 (74.7) | 0.01 |
 Delirium | 178 (14.5) | 324 (17.2) | 0.08 | 167 (15.3) | 166 (15.3) | 0.003 |
 Somnolence | 50 (4.1) | 100 (5.3) | 0.06 | 43 (4.0) | 48 (4.4) | 0.02 |
 Coma | 55 (4.5) | 115 (6.1) | 0.07 | 53 (4.9) | 48 (4.4) | 0.02 |
Intervention, n (%) | ||||||
 Mechanical ventilation | 667 (54.4) | 1258 (67.0) | 0.26 | 625 (57.4) | 638 (58.6) | 0.02 |
 Intermittent renal replacement therapy | 176 (14.3) | 364 (19.4) | 0.14 | 170 (15.6) | 177 (16.3) | 0.02 |
 Continuous renal replacement therapy | 23 (1.9) | 64 (3.4) | 0.10 | 21 (1.9) | 21 (1.9) | < 0.001 |
 Polymyxin B hemoperfusion | 306 (24.9) | 552 (29.4) | 0.10 | 284 (26.1) | 284 (26.1) | < 0.001 |
 Central venous insertion | 350 (28.5) | 783 (41.7) | 0.28 | 335 (30.8) | 345 (31.7) | 0.02 |
Catecholamine, n (%) | ||||||
 Dopamine | 948 (77.3) | 1213 (64.6) | 0.28 | 809 (74.4) | 820 (75.4) | 0.02 |
 Noradrenaline | 660 (53.8) | 1324 (70.5) | 0.35 | 641 (58.9) | 631 (58.0) | 0.02 |
 Vasopressin | 47 (3.8) | 143 (7.6) | 0.16 | 47 (4.3) | 47 (4.3) | < 0.001 |
 Adrenaline | 69 (5.6) | 122 (6.5) | 0.04 | 65 (6.0) | 68 (6.2) | 0.01 |
Transfusion,n(%) | ||||||
 Red cell transfusion | 379 (30.9) | 733 (39.0) | 0.17 | 361 (33.2) | 369 (33.9) | 0.02 |
 Platelets transfusion | 54 (4.4) | 142 (7.6) | 0.13 | 52 (4.8) | 58 (5.3) | 0.03 |
 Fresh frozen plasma transfusion | 327 (26.7) | 471 (25.1) | 0.04 | 288 (26.5) | 292 (26.8) | 0.01 |
 Antithrombin, n (%) | 245 (20.0) | 463 (24.6) | 0.11 | 234 (21.5) | 232 (21.3) | 0.004 |
 Recombinant human soluble thrombomodulin, n (%) | 198 (16.1) | 383 (20.4) | 0.11 | 190 (17.5) | 192 (17.6) | 0.005 |
 Immunoglobulin, n (%) | 457 (37.2) | 735 (39.1) | 0.04 | 428 (39.3) | 393 (36.1) | 0.07 |
 Albumin, n (%) | 823 (67.1) | 1369 (72.9) | 0.13 | 738 (67.8) | 753 (69.2) | 0.03 |
Danaparoid, n (%) | 6 (0.5) | 22 (1.2) | 0.08 | 6 (0.6) | 10 (0.9) | 0.04 |
Low-molecular-weight heparin, n (%) | 11 (0.9) | 27 (1.4) | 0.05 | 11 (1.0) | 14 (1.3) | 0.03 |
Hydrocortisone, n (%) | 155 (12.6) | 340 (18.1) | 0.15 | 145 (13.3) | 145 (13.3) | < 0.001 |
Initial antibiotics use, n (%) | ||||||
Initial use of two or more | 342 (27.9) | 568 (30.2) | 0.05 | 320 (29.4) | 329 (30.2) | 0.02 |
Penicillin | 0 (0.0) | 2 (0.1) | 0.05 | 0 (0.0) | 0 (0.0) | < 0.001 |
Ampicillin | 0 (0.0) | 2 (0.1) | 0.05 | 0 (0.0) | 0 (0.0) | < 0.001 |
Ampicillin/sulbactam | 27 (2.2) | 46 (2.4) | 0.02 | 25 (2.3) | 27 (2.5) | 0.01 |
Piperacillin/tazobactam | 88 (7.2) | 217 (11.5) | 0.15 | 86 (7.9) | 97 (8.9) | 0.04 |
First-generation cephalosporin | 47 (3.8) | 66 (3.5) | 0.02 | 42 (3.9) | 45 (4.1) | 0.01 |
Second-generation cephalosporin | 499 (40.7) | 573 (30.5) | 0.21 | 418 (38.4) | 419 (38.5) | 0.002 |
Third-generation cephalosporin without effect for Pseudomonas aeruginosa | 43 (3.5) | 53 (2.8) | 0.04 | 40 (3.7) | 41 (3.8) | 0.01 |
Third-generation cephalosporin with effect for Pseudomonas aeruginosa | 3 (0.2) | 8 (0.4) | 0.03 | 3 (0.3) | 3 (0.3) | <0.001 |
Fourth-generation cephalosporin | 30 (2.4) | 44 (2.3) | 0.01 | 29 (2.7) | 27 (2.5) | 0.01 |
Carbapenem | 753 (61.4) | 1306 (69.5) | 0.17 | 703 (64.6) | 690 (63.4) | 0.03 |
Fluoroquinolone | 7 (0.6) | 11 (0.6) | 0.002 | 6 (0.6) | 5 (0.5) | 0.01 |
Aminoglycoside | 18 (1.5) | 18 (1.0) | 0.05 | 16 (1.5) | 13 (1.2) | 0.02 |
Clindamycin | 50 (4.7) | 40 (3.5) | 0.06 | 41 (3.8) | 45 (4.1) | 0.02 |
Tetracycline | 1 (0.1) | 5 (0.3) | 0.04 | 1 (0.1) | 2 (0.2) | 0.03 |
Macrolide | 0 (0.0) | 7 (0.4) | 0.09 | 0 (0.0) | 0 (0.0) | < 0.001 |
Anti-MRSA drug | 20 (1.6) | 62 (3.3) | 0.11 | 20 (1.8) | 20 (1.8) | < 0.001 |
Antifungal drug | 4 (0.3) | 14 (0.7) | 0.06 | 4 (0.4) | 5 (0.5) | 0.02 |