Table 1.
Characteristics of cases in the full cohort. Outcome categories 1, 2, and 3 refer to cases that were alive without readmission to the hospital within 30 days post discharge, alive with readmission within 30 days post discharge and dead inpatient or within 30 days post discharge, respectively
| Overall (n = 445,989) | Outcome category 1 (alive, no readmission; n = 359,961) | Outcome category 2 (alive, with readmission; n = 55,552) | Outcome category 3 (death; n = 30,476) | |
|---|---|---|---|---|
| Patient demographics | ||||
| Age (years; mean (SD)) | 61.66 (18.24) | 60.16 (18.55) | 66.38 (15.86) | 70.84 (13.83) |
| Male (%) | 222,644 (49.9) | 177,267 (49.2) | 28,753 (51.8) | 16,624 (54.5) |
| Race (%) | ||||
| Chinese | 27,471 (6.2) | 24,615 (6.8) | 1958 (3.5) | 898 (2.9) |
| Indian | 316,474 (71.0) | 250,930 (69.7) | 41,022 (73.8) | 24,522 (80.5) |
| Malay | 47,508 (10.7) | 39,606 (11.0) | 5973 (10.8) | 1929 (6.3) |
| Others | 54,536 (12.2) | 44,810 (12.4) | 6599 (11.9) | 3127 (10.3) |
| Comorbidity (%) | ||||
| Myocardial infarction | 26,594 (6.0) | 15,653 (4.3) | 6242 (11.2) | 4699 (15.4) |
| Congestive heart failure | 49,575 (11.1) | 32,360 (9.0) | 11,809 (21.3) | 5406 (17.7) |
| Peripheral vascular disease | 25,878 (5.8) | 16,701 (4.6) | 6258 (11.3) | 2919 (9.6) |
| Stroke | 57,730 (12.9) | 41,674 (11.6) | 10,463 (18.8) | 5593 (18.4) |
| Dementia | 12,385 (2.8) | 8129 (2.3) | 2625 (4.7) | 1631 (5.4) |
| Pulmonary | 42,770 (9.6) | 30,385 (8.4) | 8868 (16.0) | 3517 (11.5) |
| Rheumatic | 6180 (1.4) | 4645 (1.3) | 1147 (2.1) | 388 (1.3) |
| Peptic ulcer disease | 17,193 (3.9) | 11,834 (3.3) | 3478 (6.3) | 1881 (6.2) |
| Mild liver disease | 20,483 (4.6) | 14,318 (4.0) | 4216 (7.6) | 1949 (6.4) |
| Severe liver disease | 7119 (1.6) | 3863 (1.1) | 1906 (3.4) | 1350 (4.4) |
| Diabetes (without complications) | 55,699 (12.5) | 42,529 (11.8) | 8756 (15.8) | 4414 (14.5) |
| Diabetes with complications | 104,682 (23.5) | 76,553 (21.3) | 19,987 (36.0) | 8142 (26.7) |
| Paralysis | 24,903 (5.6) | 17,683 (4.9) | 4692 (8.4) | 2528 (8.3) |
| Renal | 91,213 (20.5) | 62,033 (17.2) | 20,290 (36.5) | 8890 (29.2) |
| Cancer (non-metastatic) | 39,571 (8.9) | 27,627 (7.7) | 6778 (12.2) | 5166 (17.0) |
| Metastatic cancer | 35,225 (7.9) | 18,469 (5.1) | 5683 (10.2) | 11,073 (36.3) |
| ED Admission | ||||
| ED LOS (hours; mean (SD)) | 2.86 (1.70) | 2.84 (1.72) | 2.58 (1.62) | 2.12 (1.42) |
| ED Triage code (%) | ||||
| P1 | 83,221 (18.7) | 59,513 (16.5) | 11,696 (21.1) | 12,012 (39.4) |
| P2 | 250,382 (56.1) | 199,708 (55.5) | 33,906 (61.0) | 16,768 (55.0) |
| P3 and P4 | 112,386 (25.2) | 100,740 (28.0) | 9950 (17.9) | 1696 (5.6) |
| ED Boarding Time (hours; mean (SD)) | 4.78 (3.81) | 4.80 (3.79) | 4.79 (3.94) | 4.48 (3.89) |
| Consultation Waiting Time (hours; mean (SD)) | 0.77 (0.80) | 0.80 (0.82) | 0.71 (0.72) | 0.53 (0.60) |
| Inpatient admission | ||||
| Day of Week (%) | ||||
| Friday | 62,453 (14.0) | 50,314 (14.0) | 7801 (14.0) | 4338 (14.2) |
| Monday | 74,192 (16.6) | 60,142 (16.7) | 9091 (16.4) | 4959 (16.3) |
| Weekend | 115,418 (25.9) | 92,387 (25.7) | 14,604 (26.3) | 8427 (27.7) |
| Midweek | 193,926 (43.5) | 157,118 (43.6) | 24,056 (43.3) | 12,752 (41.8) |
| Admission Type (%) | ||||
| A1 | 16,814 (3.8) | 14,795 (4.1) | 1195 (2.2) | 824 (2.7) |
| B1 | 37,345 (8.4) | 32,938 (9.2) | 2658 (4.8) | 1749 (5.7) |
| B2 | 212,261 (47.6) | 174,752 (48.5) | 23,238 (41.8) | 14,271 (46.8) |
| C | 179,569 (40.3) | 137,476 (38.2) | 28,461 (51.2) | 13,632 (44.7) |
| Previous LOS (days; mean (SD)) | 3.57 (8.55) | 3.04 (7.90) | 5.34 (10.00) | 6.50 (11.55) |
| Healthcare utilisation in the previous year | ||||
| No. inpatient visits (mean (SD)) | 0.93 (2.21) | 0.62 (1.42) | 2.66 (4.46) | 1.44 (2.17) |
| No. surgery (mean (SD)) | 0.20 (0.74) | 0.15 (0.63) | 0.42 (1.10) | 0.37 (0.99) |
| No. ICU stays (mean (SD)) | 0.02 (0.25) | 0.02 (0.22) | 0.05 (0.35) | 0.05 (0.36) |
| No. HD stays (mean (SD)) | 0.09 (0.47) | 0.07 (0.40) | 0.17 (0.68) | 0.17 (0.69) |
| Vital sign and clinical tests | ||||
| Ventilation (%) | 89 (0.0) | 47 (0.0) | 7 (0.0) | 35 (0.1) |
| Resuscitation (%) | 9083 (2.0) | 6211 (1.7) | 1045 (1.9) | 1827 (6.0) |
| Pulse, beat/minute (mean (SD))a | 82.85 (17.23) | 81.99 (16.73) | 83.35 (17.00) | 92.05 (20.51) |
| Respiration, breath/minute (mean (SD))a | 17.84 (1.77) | 17.76 (1.60) | 17.98 (1.81) | 18.59 (2.98) |
| SpO2, % (mean (SD))a | 97.98 (3.25) | 98.05 (3.05) | 97.93 (3.12) | 97.34 (5.22) |
| DBP, mmHg (mean (SD))a | 71.33 (13.55) | 71.67 (13.36) | 71.14 (13.70) | 67.62 (14.93) |
| SBP, mmHg (mean (SD))a | 133.68 (25.53) | 134.05 (25.19) | 135.98 (26.22) | 125.13 (26.63) |
| Bicarbonate, mmol/L (mean (SD))a | 22.78 (3.78) | 22.91 (3.55) | 22.55 (3.97) | 21.67 (5.39) |
| Creatinine, μmol/L (mean (SD))a | 154.70 (208.52) | 142.72 (196.69) | 213.21 (259.28) | 185.61 (215.82) |
| Potassium, mmol/L (mean (SD))a | 4.16 (0.72) | 4.14 (0.69) | 4.23 (0.76) | 4.36 (0.91) |
| Sodium, mmol/L (mean (SD))a | 135.02 (5.17) | 135.30 (4.84) | 134.56 (5.39) | 132.76 (7.30) |
Outcome categories were compared using Kruskal-Wallis and Chi-square test for continuous and categorical variables, respectively. All tests had p-value< 0.001
DBP diastolic blood pressure, ED emergency department, HD high dependency ward, ICU intensive care unit, LOS length of stay, SBP systolic blood pressure, SD standard deviation, SpO2 blood oxygen saturation
aExcluding 9365 missing entries for pulse, 10,772 missing entries for respiration, 10,704 missing entries for SpO2, 5348 missing entries for SBP and DBP, 56857 missing entries for bicarbonate, 56,742 missing entries for creatinine, 58,747 missing entries for potassium, and 56,678 missing entries for sodium