TABLE 1.
Baseline Characteristics of Patients in Unmatched and 1:1 Propensity Score-Matched Groups
| Characteristics | Unmatched Groups | Matched Groups | ||||
|---|---|---|---|---|---|---|
| Nonenhanced CT | Enhanced CT | SMD | Nonenhanced CT | Enhanced CT | SMD | |
| Patient number | 95,092 | 49,057 | 43,367 | 43,367 | ||
| Age, yr | 73.29 (16.65) | 65.62 (18.07) | 0.441 | 66.41 (18.84) | 66.91 (17.33) | 0.028 |
| Sex, female | 44,867 (47.2) | 21,951 (44.7) | 0.049 | 19,377 (44.7) | 19,510 (45.0) | 0.006 |
| Hospital volume | 0.201 | 0.033 | ||||
| 199 beds | 4,233 (4.5) | 1,179 (2.4) | 1,124 (2.6) | 987 (2.3) | ||
| 200–499 beds | 66,081 (69.5) | 31,087 (63.4) | 27,716 (63.9) | 28,340 (65.3) | ||
| 500 beds | 24,778 (26.1) | 16,791 (34.2) | 14,527 (33.5) | 14,040 (32.4) | ||
| Comorbidities | ||||||
| Congestive heart failure | 17,664 (18.6) | 4663 (9.5) | 0.263 | 3,661 (8.4) | 4,080 (9.4) | 0.034 |
| Chronic kidney disease | 5,210 (5.5) | 639 (1.3) | 0.232 | 512 (1.2) | 590 (1.4) | 0.016 |
| Hypertension | 37,444 (39.4) | 17,033 (34.7) | 0.097 | 14,488 (33.4) | 14,844 (34.2) | 0.017 |
| Diabetic nephropathy | 1,394 (1.5) | 249 (0.5) | 0.097 | 191 (0.4) | 242 (0.6) | 0.017 |
| Myocardial infarction | 5,118 (5.4) | 1,949 (4.0) | 0.067 | 1,765 (4.1) | 1,799 (4.1) | 0.004 |
| Laboratory test results at admission | ||||||
| Glomerular filtration rate, mL/min/1.73 m2 | 60.98 (34.19) | 73.99 (27.39) | 0.420 | 73.20 (38.95) | 72.18 (24.96) | 0.031 |
| Creatinine, mg/dL | 1.20 (1.26) | 0.84 (0.55) | 0.370 | 0.96 (0.91) | 0.85 (0.57) | 0.138 |
| Hemoglobin < 11 g/dL | 25,096 (26.4) | 9,840 (20.1) | 0.150 | 8,664 (20.0) | 8,936 (20.6) | 0.016 |
| Charlson Comorbidity Index | 2.40 (2.49) | 2.36 (2.68) | 0.014 | 2.11 (2.41) | 2.43 (2.73) | 0.124 |
| Nephrotoxic medication | ||||||
| Nonsteroidal anti-inflammatory drugs | 23,616 (24.8) | 16,317 (33.3) | 0.186 | 12,906 (29.8) | 13,180 (30.4) | 0.014 |
| Catecholamine | 1,756 (1.8) | 1,404 (2.9) | 0.067 | 981 (2.3) | 1,046 (2.4) | 0.010 |
| Diuretic medication | 14,607 (15.4) | 4,840 (9.9) | 0.166 | 3,561 (8.2) | 3,996 (9.2) | 0.036 |
| Antibiotic (aminoglycoside) | 31,639 (33.3) | 12,027 (24.5) | 0.039 | 422 (1.0) | 634 (1.5) | 0.045 |
| Antibiotic (anti-methicillin-resistant Staphylococcus aureus drug) | 889 (0.9) | 661 (1.3) | 0.014 | 567 (1.3) | 498 (1.1) | 0.014 |
| Diagnosis at admission | ||||||
| Trauma | 12,561 (13.2) | 3,155 (6.4) | 0.229 | 3,110 (7.2) | 3,127 (7.2) | 0.002 |
| Sepsis | 9,084 (9.6) | 2,845 (5.8) | 0.141 | 2,584 (6.0) | 2,741 (6.3) | 0.015 |
| Cerebrovascular disease | 9,659 (10.2) | 4,326 (8.8) | 0.046 | 3,742 (8.6) | 4,017 (9.3) | 0.022 |
| Macrovascular disease | 441 (0.5) | 2,772 (5.7) | 0.305 | 437 (1.0) | 673 (1.6) | 0.048 |
| Organ dysfunction | 31,639 (33.3) | 12,027 (24.5) | 0.194 | 12,280 (28.3) | 10,757 (24.8) | 0.080 |
| ICU admission | 5,133 (5.4) | 4,734 (9.6) | 0.162 | 3,002 (6.9) | 3,230 (7.4) | 0.020 |
| Emergency operation | 7,453 (7.8) | 9,573 (19.5) | 0.345 | 5,794 (13.4) | 6,662 (15.4) | 0.057 |
SMD = standardized mean difference.
Continuous variables are presented as means with sd, and categorical variables are presented as numbers with percentages.