Table 1.
Characteristics for patients in the derivation and the validation cohorts
| Variable | Derivation cohort | Validation cohort |
|---|---|---|
| n | 2,230 | 788 |
| Mortality (death during hospitalization) | 30 (1.3) | 10 (1.3) |
| Amputation during index hospitalization | 463 (20.8) | 184 (23.3) |
| Median age (years [first through third quartiles]) | 60 (50–71) | 60 (50–71) |
| Male sex | 1,359 (60.9) | 493 (62.6) |
| Previous admission within ≤30 days | 214 (9.6) | 68 (8.6) |
| Transferred from an acute-care hospital | 19 (0.9) | 8 (1.0) |
| Transferred from a skilled nursing facility | 72 (3.2) | 32 (4.1) |
| Race/ethnicity | ||
| White | 1,574 (70.6) | 593 (75.3) |
| Black | 420 (18.8) | 115 (14.6) |
| Other | 236 (10.6) | 80 (10.2) |
| Comorbidities | ||
| Congestive heart failure | 522 (23.4) | 171 (21.7) |
| History of coronary disease | 532 (23.9) | 193 (24.5) |
| Immunosuppressive medication | 73 (3.3) | 33 (4.2) |
| Cancer | 46 (2.1) | 12 (1.5) |
| Peripheral vascular disease | 807 (36.2) | 287 (36.4) |
| Chronic liver disease | 31 (1.4) | 9 (1.1) |
| Chronic lung disease | 232 (10.4) | 97 (12.3) |
| Previous stroke | 234 (10.5) | 74 (9.4) |
| Chronic renal disease | 445 (20.0) | 153 (19.4) |
| History of amputation | 611 (27.4) | 203 (25.8) |
| Renal dialysis treatment | 53 (2.4) | 23 (2.9) |
| Type of skin and soft-tissue infection | ||
| Cellulitis | 1,788 (80.2) | 629 (79.8) |
| Infected ulcer | 360 (16.1) | 129 (16.4) |
| Surgical site | 82 (3.7) | 30 (3.8) |
| Severe infection clinical presentation | ||
| Systolic blood pressure <100 mmHg | 293 (13.1) | 110 (14.0) |
| Temperature <96°F or >100.5°F | 681 (30.5) | 238 (30.2) |
| Pulse <49 or >125 bpm | 128 (5.7) | 40 (5.1) |
| Respiration <10 or >29 breaths per minute | 86 (3.9) | 35 (4.4) |
| Altered mental status | 173 (7.8) | 66 (8.4) |
| Laboratory results | ||
| Albumin <2.8 g/dL | 237 (10.6) | 95 (12.1) |
| Blood urea nitrogen >40 mg/dL | 399 (17.9) | 121 (15.4) |
| Creatinine >3 mg/dL | 176 (7.9) | 65 (8.2) |
| Sodium >145 mEq/dL | 24 (1.1) | 11 (1.4) |
| Total bilirubin >0.8 mg/dL | 206 (9.2) | 89 (11.3) |
| pO2 <55 or >140 or O2 sat <90% | 37 (1.7) | 10 (1.3) |
| Prothrombin time international normalized ratio >1.2 or prothrombin time >14 s | 209 (9.4) | 68 (8.6) |
| Bands on leukocyte differential >13% | 80 (3.6) | 29 (3.7) |
| White blood cell count >11,000 per mm3 | 1,037 (46.5) | 397 (50.4) |
| Glucose on admission (mg/dL) | ||
| ≤70 | 100 (4.5) | 35 (4.4) |
| 71–135 | 331 (14.8) | 124 (15.7) |
| 136–240 | 717 (32.2) | 236 (29.9) |
| >240 | 1,082 (48.5) | 393 (49.9) |
Data are n (%), unless otherwise indicated. The P values for each variable is >0.05, indicating that the derivation and validation cohorts are similar.