Table 1.
Baseline characteristics before and after propensity score matching
| Before propensity score matching | After propensity score matching | |||||
| ICU | HDU | ICU | HDU | |||
| Characteristics | (n = 7,528) | (n = 7,331) | ASD | (n = 4,982) | (n = 4,982) | ASD |
| Age, years, mean (SD) | 74 (15) | 77 (13) | 23 | 75 (14) | 75 (14) | 1 |
| Male, n (%) | 5,081 (67) | 4,688 (64) | 8 | 3,270 (66) | 3,298 (66) | 1 |
| Smoking history, n (%) | ||||||
| Nonsmoker | 3,621 (48) | 3,719 (51) | 5 | 2,483 (50) | 2,463 (49) | 1 |
| Current/past smoker | 2,404 (32) | 2,352 (32) | 0 | 1,619 (32) | 1,613 (32) | 0 |
| Unknown | 1,503 (20) | 1,260 (17) | 7 | 880 (18) | 906 (18) | 1 |
| Body mass index at admission, kg/m2, n (%) | ||||||
| < 18.5 | 1,975 (26) | 2,085 (28) | 5 | 1,356 (27) | 1,335 (27) | 1 |
| 18.5–24.9 | 3,385 (45) | 3,034 (41) | 7 | 2,130 (43) | 2,166 (43) | 2 |
| 25.0–29.9 | 861 (11) | 792 (11) | 2 | 564 (11) | 559 (11) | 0 |
| ≥ 30.0 | 332 (4) | 278 (4) | 3 | 214 (4) | 217 (4) | 0 |
| Missing | 975 (13) | 1,142 (16) | 8 | 718 (14) | 705 (14) | 1 |
| Charlson comorbidity index, mean (SD) | 1.4 (1.4) | 1.4 (1.4) | 1 | 1.4 (1.4) | 1.4 (1.4) | 2 |
| Comorbidities, n (%) | ||||||
| Congestive heart failure | 2,330 (31) | 2,463 (34) | 6 | 1,663 (33) | 1,661 (33) | 0 |
| Malignancy | 520 (7) | 531 (7) | 1 | 339 (7) | 344 (7) | 0 |
| Metastatic solid tumor | 67 (1) | 51 (1) | 2 | 31 (1) | 40 (1) | 2 |
| Physical function at admission, n (%) | ||||||
| Total/severe dependence (Barthel Index 0–60) | 5,449 (72) | 5,514 (75) | 6 | 3,697 (74) | 3,712 (75) | 1 |
| Slight/moderate dependence (Barthel Index 61–99) | 122 (2) | 174 (2) | 5 | 92 (2) | 87 (2) | 1 |
| Independent (Barthel Index 100) | 573 (8) | 565 (8) | 0 | 362 (7) | 357 (7) | 0 |
| Missing | 1,384 (18) | 1,078 (15) | 10 | 831 (17) | 826 (17) | 0 |
| Cognitive function before admission, n (%) | ||||||
| No dementia | 5,472 (73) | 4,939 (67) | 12 | 3,485 (70) | 3,517 (71) | 1 |
| Mild dementia | 1,120 (15) | 1,290 (18) | 7 | 811 (16) | 768 (15) | 2 |
| Moderate/severe dementia | 936 (12) | 1,102 (15) | 8 | 686 (14) | 697 (14) | 1 |
| Home medical care before admission, n (%) | 733 (10) | 949 (13) | 10 | 559 (11) | 549 (11) | 1 |
| Ambulance use, n (%) | 6,250 (83) | 5,856 (80) | 8 | 4,034 (81) | 4,056 (81) | 1 |
| Admission on a weekend, n (%) | 1,992 (26) | 1,902 (26) | 1 | 1,321 (27) | 1,334 (27) | 1 |
| Location before hospitalization, n (%) | ||||||
| Home | 5,872 (78) | 5,706 (78) | 0 | 3,906 (78) | 3,924 (79) | 1 |
| Other hospitals | 1,084 (14) | 754 (10) | 13 | 607 (12) | 610 (12) | 0 |
| Nursing home | 572 (8) | 871 (12) | 15 | 469 (9) | 448 (9) | 1 |
| Cause of pneumonia, n (%) | ||||||
| Typical bacteria | 3,770 (50) | 3,542 (48) | 4 | 2,506 (50) | 2,527 (51) | 1 |
| Atypical bacteria | 128 (2) | 77 (1) | 6 | 57 (1) | 65 (1) | 1 |
| Viruses | 127 (2) | 94 (1) | 3 | 73 (1) | 71 (1) | 0 |
| Fungus, parasite, and others | 142 (2) | 105 (1) | 4 | 82 (2) | 93 (2) | 2 |
| Pathogen-nonconfirmed | 3,361 (45) | 3,513 (48) | 7 | 2,264 (45) | 2,226 (45) | 2 |
| Community-acquired pneumonia, n (%) | 6,735 (89) | 6,663 (91) | 1 | 4,481 (90) | 4,514 (91) | 2 |
| Severity of pneumonia, n (%) | ||||||
| Blood urea nitrogen >21 mg/dl or dehydration | 5,137 (68) | 4,634 (63) | 11 | 3,246 (65) | 3,291 (66) | 2 |
| Oxygenation | ||||||
| SpO2 > 90% in room air | 1,133 (15) | 992 (14) | 4 | 745 (15) | 743 (15) | 0 |
| SpO2 > 90% in FiO2 < 35% | 1,541 (20) | 1,978 (27) | 15 | 1,189 (24) | 1,137 (23) | 3 |
| SpO2 > 90% in FiO2 ≥ 35% | 4,854 (64) | 4,361 (59) | 10 | 3,048 (61) | 3,102 (62) | 2 |
| Impaired consciousness | 4,402 (58) | 3,897 (53) | 11 | 2,732 (55) | 2,753 (55) | 1 |
| Systolic blood pressure < 90 mmHg | 2,328 (31) | 1,833 (25) | 13 | 1,276 (26) | 1,332 (27) | 3 |
| A-DROP score, mean (SD) | 1,417 (19) | 1,160 (16) | 8 | 812 (16) | 831 (17) | 1 |
| Immunocompromised, n (%) | 3,819 (51) | 3,086 (42) | 17 | 2,245 (45) | 2,348 (47) | 4 |
| CRP ≥ 20mg/dl or lung infiltration, n (%) | 3.1 (1.3) | 3.0 (1.2) | 5 | 3.0 (1.2) | 3.0 (1.3) | 2 |
| Organ support therapies on the day of admission, n (%) | ||||||
| Dopamine | 930 (12) | 600 (8) | 14 | 504 (10) | 514 (10) | 1 |
| Dobutamine | 434 (6) | 185 (3) | 16 | 160 (3) | 171 (3) | 1 |
| Noradrenaline | 2,463 (33) | 1,007 (14) | 46 | 919 (18) | 991 (20) | 4 |
| Adrenaline | 785 (10) | 699 (10) | 3 | 454 (9) | 464 (9) | 1 |
| Vasopressin | 323 (4) | 86 (1) | 19 | 71 (1) | 84 (2) | 2 |
| Cardiac massage | 550 (7) | 650 (9) | 6 | 388 (8) | 382 (8) | 0 |
| Defibrillation | 110 (1) | 72 (1) | 4 | 57 (1) | 58 (1) | 0 |
| Red blood cell transfusion | 369 (5) | 161 (2) | 15 | 124 (2) | 146 (3) | 2 |
| Fresh frozen plasma transfusion | 142 (2) | 35 (0) | 13 | 30 (1) | 35 (1) | 1 |
| Platelet transfusion | 59 (1) | 18 (0) | 8 | 14 (0) | 15 (0) | 0 |
| Albumin | 509 (7) | 159 (2) | 22 | 131 (3) | 151 (3) | 2 |
| Renal replacement therapy | 357 (5) | 153 (2) | 15 | 132 (3) | 134 (3) | 0 |
| Extracorporeal membrane oxygenation | 48 (1) | 7 (0) | 9 | 4 (0) | 7 (0) | 1 |
| Hospital characteristics, n (%) | ||||||
| Teaching hospital | 7,059 (94) | 6,742 (92) | 7 | 4,618 (93) | 4,613 (93) | 0 |
| Tertiary emergency hospital | 4,381 (58) | 4,898 (67) | 18 | 2,973 (60) | 2,920 (59) | 2 |
| Academic hospital | 1,595 (21) | 564 (8) | 39 | 512 (10) | 562 (11) | 3 |
| Total number of hospital beds | ||||||
| Low (24–381 beds) | 1,750 (23) | 2,025 (28) | 10 | 1,430 (29) | 1,438 (29) | 0 |
| Medium low (382–522 beds) | 1,703 (23) | 1,966 (27) | 10 | 1,279 (26) | 1,248 (25) | 1 |
| Medium high (523–680 beds) | 1,868 (25) | 1,836 (25) | 1 | 1,222 (25) | 1,208 (24) | 1 |
| High (681–1,334 beds) | 2,207 (29) | 1,504 (21) | 21 | 1,051 (21) | 1,088 (22) | 2 |
ICU, intensive care unit; HDU, high-dependency care unit; ASD, absolute standardized mean difference; SD, standard deviation; A-DROP, age, dehydration, respiration, disorientation, and blood pressure; CRP, C-reactive protein