Table 1 Characteristics of patients with suspected infection
|  | Fit (CFS 1–3) | Vulnerable (CFS 4) | Frail (CFS 5–9) |  |
|---|---|---|---|---|
n = 337 (51.8) | n = 109 (16.8) | n = 204 (31.4) | p-value | |
Age at admission (years old) | 67 (54–78) | 73 (64–81) | 77 (69–84) | < 0.01 |
Sex, male | 199 (59.1) | 68 (62.4) | 102 (50.0) | 0.05 |
BMI (kg/m2) | 22.4 (20.0–25.0) | 22.5 (19.6–24.9) | 20.8 (17.8–23.6) | < 0.01 |
Coexisting conditions | ||||
 Myocardial infarction | 11 (3.3) | 7 (6.4) | 7 (3.4) | 0.33 |
 Congestive heart failure | 20 (5.9) | 11 (10.1) | 28 (13.7) | < 0.01 |
 Peripheral vascular disease | 9 (2.7) | 7 (6.4) | 7 (3.4) | 0.17 |
 Cerebrovascular disease | 20 (5.9) | 9 (8.3) | 30 (14.7) | < 0.01 |
 Dementia | 12 (3.6) | 15 (13.8) | 48 (23.5) | < 0.01 |
 COPD | 12 (3.6) | 13 (11.9) | 30 (14.7) | < 0.01 |
 Connective tissue disease | 14 (4.2) | 13 (11.9) | 19 (9.3) | < 0.01 |
 Peptic ulcer disease | 13 (3.9) | 1 (0.9) | 10 (4.9) | 0.19 |
 Diabetes mellitus without organ damage | 47 (13.9) | 22 (20.2) | 42 (20.6) | 0.09 |
 Diabetes mellitus with organ damage | 28 (8.3) | 19 (17.4) | 14 (6.9) | < 0.01 |
 Chronic kidney disease | 19 (5.6) | 20 (18.3) | 16 (7.8) | < 0.01 |
 Hemiplegia | 3 (0.9) | 3 (2.8) | 25 (12.3) | < 0.01 |
 Malignancy (solid) | 30 (8.9) | 19 (17.4) | 28 (13.7) | 0.03 |
 Malignancy (blood) | 6 (1.8) | 0 | 1 (0.5) | 0.18 |
 Metastatic tumor | 6 (1.8) | 4 (3.7) | 5 (2.5) | 0.46 |
 Mild liver disease | 8 (2.4) | 11 (10.1) | 9 (4.4) | < 0.01 |
 Moderate to severe liver disease | 13 (3.9) | 1 (0.9) | 9 (4.4) | 0.26 |
 AIDS | 0 | 0 | 0 |  |
CCI | 1 (0–2) | 2 (1–4) | 2 (1–3) | < 0.01 |
SOFA score | 7 (4–10) | 8 (5–11) | 7 (5–10) | 0.59 |
APACHE II score | 18 (12–25) | 22 (17–28) | 21 (15–27) | < 0.01 |
Septic shock | 60 (17.8) | 23 (21.1) | 28 (13.7) | 0.22 |
Mechanical ventilation | 132 (39.3) | 46 (43.4) | 74 (36.5) | 0.49 |
Vital signs | ||||
 Glasgow coma scale | 13 (8–15) | 11 (8–15) | 12 (7–14) | < 0.01 |
 Systolic blood pressure (mmHg) | 107 (87–128) | 105 (80–137) | 109 (86–128) | 0.97 |
 Heat rate (/min) | 105 (88–125) | 108 (90–120) | 103 (86–118) | 0.18 |
 Respiratory rate (/min) | 24 (19–29) | 22 (18–27) | 23 (19–30) | 0.42 |
 Body temperature (°C) | 37.5 (36.5–38.5) | 37.5 (36.4–38.6) | 37.0 (36.3–38.1) | 0.03 |
Laboratory data | ||||
 White blood cells (/μL) | 11,000 (5780–15,580) | 10,520 (6700–16,000) | 11,780 (7450–17,200) | 0.32 |
 Hematocrit (%) | 35.4 (29.3–40.8) | 33.1 (26.8–39.1) | 34.4 (29.4–39.9) | 0.07 |
 Platelet (/μL) | 16.3 (9.8–24.4) | 18.0 (11.2–24.3) | 18.1 (12.9–25.5) | 0.16 |
 PT-INR | 1.2 (1.1–1.4) | 1.2 (1.1–1.4) | 1.2 (1.1–1.4) | 0.83 |
 Lactate (mmol/L) | 2.6 (1.4–4.4) | 2.7 (1.6–5.7) | 2.5 (1.4–4.4) | 0.27 |
 Glucose (mg/dL) | 142 (112–205) | 150 (109–210) | 138 (103–194) | 0.39 |
 Sodium (mEq/L) | 138 (134–141) | 138 (135–141) | 138 (134–141) | 0.94 |
 Potassium (mEq/L) | 4.0 (3.6–4.5) | 4.0 (3.4–4.7) | 4.1 (3.6–4.6) | 0.40 |
 Creatinine (mg/dL) | 1.5 (0.8–2.6) | 1.6 (0.9–2.9) | 1.2 (0.7–2.1) | 0.02 |
 Total bilirubin (mg/dL) | 0.8 (0.5–1.5) | 0.8 (0.5–1.5) | 0.7 (0.5–1.1) | 0.02 |
 C-reactive protein (mg/dL) | 13.6 (4.6–24.5) | 12.1 (3.9–24.9) | 10.5 (3.0–21.0) | 0.04 |
Positive blood cultures | 141 (44.2) | 49 (47.6) | 85 (44.5) | 0.84 |
Site of infection at final diagnosis | ||||
 Lung | 103 (30.6) | 39 (35.8) | 81 (39.7) | < 0.01 |
 Abdomen | 74 (22.0) | 21 (19.3) | 35 (17.2) | |
 Urinary tract | 49 (14.5) | 13 (11.9) | 44 (21.6) | |
 Soft Tissue | 43 (12.8) | 18 (16.5) | 20 (9.8) | |
 Others | 35 (10.4) | 9 (8.3) | 7 (3.4) | |