Table 1.
Comparisons of Characteristics of Participants in the Training Set and Testing Set
| Variables | Total (n=1922) | Testing (n=576) | Training (n=1346) | Statistics | P |
|---|---|---|---|---|---|
| Gender, n (%) | χ2=3.813 | 0.051 | |||
| Female | 979 (50.94) | 313 (54.34) | 666 (49.48) | ||
| Male | 943 (49.06) | 263 (45.66) | 680 (50.52) | ||
| Age, Year, Mean ± SD | 71.16 ± 10.87 | 70.95 ± 11.07 | 71.26 ± 10.79 | t=−0.57 | 0.569 |
| Ventilation, n (%) | χ2=0.220 | 0.639 | |||
| No | 339 (17.64) | 98 (17.01) | 241 (17.90) | ||
| Yes | 1583 (82.36) | 478 (82.99) | 1105 (82.10) | ||
| Congestive heart failure, n (%) | χ2=2.985 | 0.084 | |||
| No | 870 (45.27) | 278 (48.26) | 592 (43.98) | ||
| Yes | 1052 (54.73) | 298 (51.74) | 754 (56.02) | ||
| Atrial fibrillation, n (%) | χ2=0.453 | 0.501 | |||
| No | 1270 (66.08) | 387 (67.19) | 883 (65.60) | ||
| Yes | 652 (33.92) | 189 (32.81) | 463 (34.40) | ||
| Renal failure, n (%) | χ2=2.241 | 0.134 | |||
| No | 1629 (84.76) | 499 (86.63) | 1130 (83.95) | ||
| Yes | 293 (15.24) | 77 (13.37) | 216 (16.05) | ||
| Malignant cancer, n (%) | χ2=0.169 | 0.681 | |||
| No | 1648 (85.74) | 491 (85.24) | 1157 (85.96) | ||
| Yes | 274 (14.26) | 85 (14.76) | 189 (14.04) | ||
| Heart rate, beat/min, Mean ± SD | 93.95 ± 19.41 | 94.14 ± 18.71 | 93.87 ± 19.71 | t=0.27 | 0.783 |
| SBP, mmHg, Mean ± SD | 126.35 ± 24.76 | 126.85 ± 24.56 | 126.13 ± 24.85 | t=0.58 | 0.562 |
| DBP, mmHg, Mean ± SD | 68.09 ± 18.28 | 68.65 ± 18.26 | 67.85 ± 18.29 | t=0.88 | 0.380 |
| Temperature, °C, Mean ± SD | 36.67 ± 0.73 | 36.68 ± 0.75 | 36.67 ± 0.72 | t=0.07 | 0.947 |
| SPO2, %, Mean ± SD | 95.59 ± 4.88 | 95.57 ± 4.58 | 95.60 ± 5.01 | t=−0.10 | 0.920 |
| Respiratory rate, beat/min, Mean ± SD | 21.48 ± 6.20 | 21.63 ± 6.20 | 21.41 ± 6.21 | t=0.72 | 0.469 |
| SOFA score, M (Q1, Q3) | 4.00 (2.00, 7.00) | 4.00 (2.00, 7.00) | 4.00 (2.00, 7.00) | Z=−1.559 | 0.119 |
| GCS score, n (%) | χ2=0.003 | 0.959 | |||
| <13 | 469 (24.40) | 141 (24.48) | 328 (24.37) | ||
| ≥13 | 1453 (75.60) | 435 (75.52) | 1018 (75.63) | ||
| CURB-65, M (Q1, Q3) | 3.00 (2.00, 3.00) | 2.00 (2.00, 3.00) | 3.00 (2.00, 3.00) | Z=−0.538 | 0.590 |
| WBC, K/uL, M (Q1, Q3) | 10.60 (7.60, 14.90) | 10.55 (7.40, 14.60) | 10.60 (7.60, 15.00) | Z=−0.918 | 0.359 |
| Platelet, K/uL, M (Q1, Q3) | 219.00 (163.00, 285.00) | 214.00 (159.00, 287.00) | 220.00 (163.00, 282.00) | Z=−0.640 | 0.522 |
| Hemoglobin, g/dL, Mean ± SD | 10.97 ± 2.13 | 11.04 ± 2.08 | 10.95 ± 2.15 | t=0.87 | 0.383 |
| RDW, %, Mean ± SD | 15.33 ± 2.09 | 15.32 ± 2.09 | 15.34 ± 2.10 | t=−0.23 | 0.816 |
| Creatinine, mg/dL, M (Q1, Q3) | 1.00 (0.70, 1.50) | 1.00 (0.70, 1.50) | 1.00 (0.70, 1.50) | Z=−1.541 | 0.123 |
| BUN, mg/dL, M (Q1, Q3) | 24.00 (17.00, 37.00) | 23.00 (17.00, 35.00) | 24.00 (17.00, 37.00) | Z=−0.444 | 0.657 |
| Glucose, mg/dL, M (Q1, Q3) | 142.00 (114.00, 180.00) | 142.50 (114.00, 176.50) | 141.00 (115.00, 180.00) | Z=−0.003 | 0.997 |
| Anion gap, Mean ± SD | 216.97 ± 13.64 | 216.76 ± 13.43 | 217.05 ± 13.74 | t=−0.43 | 0.670 |
| Steroid therapy, n (%) | χ2=0.269 | 0.604 | |||
| No | 1463 (76.12) | 434 (75.35) | 1029 (76.45) | ||
| Yes | 459 (23.88) | 142 (24.65) | 317 (23.55) | ||
| Infectious diseases, n (%) | χ2=0.868 | 0.351 | |||
| No | 1482 (77.11) | 452 (78.47) | 1030 (76.52) | ||
| Yes | 440 (22.89) | 124 (21.53) | 316 (23.48) | ||
| RPR, M (Q1, Q3) | 0.07 (0.05, 0.09) | 0.07 (0.05, 0.10) | 0.07 (0.05, 0.09) | Z=0.745 | 0.457 |
| Log (RPR×1000), Mean ± SD | 4.29 ± 0.53 | 4.29 ± 0.51 | 4.28 ± 0.55 | t=0.27 | 0.787 |
| LOS, day, M (Q1, Q3) | 3.14 (1.87, 6.25) | 3.23 (1.95, 6.18) | 3.13 (1.82, 6.31) | Z=0.711 | 0.477 |
| Outcome, n (%) | χ2=0.049 | 0.826 | |||
| Alive | 1660 (86.37) | 499 (86.63) | 1161 (86.26) | ||
| Dead | 262 (13.63) | 77 (13.37) | 185 (13.74) |
Abbreviations: SD, standard deviation; M, median; Q1, 1st Quartile; Q3, 3st Quartile; SBP, systolic blood pressure; DBP, diastolic blood pressure; SPO2, oxygen saturation; SOFA, the sequential organ failure assessment; CURB-65, the Confusion; Urea; Respiratory Rate; Blood Pressure and Age; GCS, Glasgow Coma Scale; WBC, white blood cell; RDW, red blood cell distribution width; BUN, blood urea nitrogen; RPR, RDW to platelet ratio; LOS, length of stay.