Table 2 Patient features, resource use and occurrence of clinically relevant events in cases and controls

Age, mean (SD)

68.5 (17.2)

57.5 (18.4)

 < 0.001

Sex at birth, n (%)

0.095

 Female

850 (47.4%)

901 (50.2%)

 Male

944 (52.6%)

893 (49.8%)

Charlson Comorbidity Index, median [IQR]

2 [1–6]

1 [0–3]

 < 0.001

Modified Frailty Index, median [IQR]

2 [1–3]

1 [0–2]

 < 0.001

Previous hospitalization (last month), n (%)

471 (26.3%)

319 (17.8%)

 < 0.001

Pneumonia on past year, n (%)

175 (9.8%)

79 (4.4%)

 < 0.001

Episode of mental confusion on past year, n (%)

238 (13.3%)

116 (6.5%)

 < 0.001

Previously on hospice/long-term facility/homecare, n (%)

93 (5.2%)

39 (2.2%)

 < 0.001

Dependency for daily living activities, n (%)

620 (34.6%)

232 (12.9%)

 < 0.001

Known comorbidities at admission, n (%)

 Dementia

196 (10.9%)

58 (3.2%)

 < 0.001

 Transitory Ischemic Attack

18 (1.0%)

18 (1.0%)

1.00

 Stroke

174 (9.7%)

83 (4.6%)

 < 0.001

 Previous myocardial infarction

137 (7.6%)

110 (6.1%)

0.086

 Angina/coronary stent

137 (7.6%)

129 (7.2%)

0.656

 Heart failure

221 (12.3%)

144 (8.0%)

 < 0.001

 Hypertension

912 (50.8%)

767 (42.8%)

 < 0.001

 Diabetes, uncomplicated

473 (26.4%)

403 (22.5%)

0.007

 Diabetes, complicated

136 (7.6%)

119 (6.6%)

0.299

 Rheumatologic disease

66 (3.7%)

78 (4.3%)

0.349

 Acquired immunodeficiency syndrome

50 (2.8%)

43 (2.4%)

0.529

 Cirrhosis

65 (3.6%)

37 (2.1%)

0.006

 Cancer

726 (40.5%)

453 (25.3%)

 < 0.001

Hospital admission

 Admission type^a

  Medical

1524 (84.9%)

1524 (84.9%)

–

  Elective surgery

149 (8.3%)

149 (8.3%)

–

  Urgent surgery/trauma

121 (6.7%)

121 (6.7%)

–

 Relevant diagnosis at admission

  Infection

709 (39.5%)

538 (30.0%)

 < 0.001

  Respiratory diagnosis

   Asthma

11 (0.6%)

19 (1.1%)

0.199

   Chronic pulmonary obstructive disease

87 (4.8%)

53 (3.0%)

0.004

   Other chronic lung disease

19 (1.1%)

16 (0.9%)

0.735

  Cardiac diseases

   ST-elevation myocardial infarction

31 (1.7%)

38 (2.1%)

0.466

   Non-ST-elevation myocardial infarction

33 (1.8%)

28 (1.6%)

0.606

   Unstable angina

18 (1.0%)

31 (1.7%)

0.083

   Angina, unspecified

12 (0.7%)

9 (0.5%)

0.663

   Uncompensated heart failure

137 (7.6%)

87 (4.8%)

0.001

   Deep vein thrombosis

48 (2.7%)

32 (1.8%)

0.089

   Pulmonary thromboembolism

27 (1.5%)

27 (1.5%)

1.00

  Neurological diseases

   Ischemic stroke

83 (4.6%)

58 (3.2%)

0.039

   Hemorrhagic stroke

18 (1.0%)

10 (0.6%)

0.183

   Transient ischemic attack

3 (0.2%)

12 (0.7%)

0.035

   Subarachnoid hemorrhage

17 (0.9%)

8 (0.4%)

0.107

   Polyradiculopathy/myasthenia

3 (0.2%)

3 (0.2%)

1.00

  Renal diseases

   Acute, non-related to cirrhosis

91 (5.1%)

39 (2.2%)

 < 0.001

   Chronic, not on dialysis

75 (4.2%)

43 (2.4%)

0.004

   Chronic, needing dialysis

31 (1.7%)

40 (2.2%)

0.338

  Abdominal diseases

   Uncompensated cirrhosis

36 (2.0%)

20 (1.1%)

0.042

   Digestive bleeding

12 (0.7%)

7 (0.4%)

0.358

   Spontaneous bacterial peritonitis

2 (0.1%)

0 (0.0%)

0.500

   Hepatorenal syndrome

3 (0.2%)

0 (0.0%)

0.250

   Acute pancreatitis

24 (1.3%)

27 (1.5%)

0.778

  Uncompensated diabetes

70 (3.9%)

61 (3.4%)

0.477

  Admission for diagnostic procedures

535 (29.8%)

515 (28.7%)

0.463

  Other

648 (36.1%)

640 (35.7%)

0.808

Resource use

 Intensive care unit admission, n (%)

853 (47.5%)

340 (19%)

 < 0.001

 Hospital length-of-stay, median [IQR]

9 [5–19]

6 [4–11]

 < 0.001

 Antibiotic days of therapy, days per 1000 patients/day

603

437

 < 0.001

 Days using antibiotics, median [IQR]

5.5 [1.3–11]

1 [0–6]

 < 0.001

Events during hospitalization

 Sepsis (main definition)

525 (29.3%)

232 (12.9%)

  Up to 2 days from admission

383 (21.3%)

198 (11%)

 < 0.001

  After 2 days from admission

311 (17.3%)

77 (4.3%)

 < 0.001

 Stroke

65 (3.6%)

28 (1.6%)

 < 0.001

  Coronary syndrome^b,c

80 (4.5%)

42 (2.3%)

0.001

 Acute severe hypertensive episode

228 (12.7%)

133 (7.4%)

 < 0.001

 Fall

63 (3.5%)

20 (1.1%)

 < 0.001

 Seizure

93 (5.2%)

34 (1.9%)

 < 0.001

 Pulmonary thromboembolism

40 (2.2%)

11 (0.6%)

 < 0.001

 Bronchospasm

118 (6.6%)

27 (1.5%)

 < 0.001

 Digestive bleeding

122 (6.8%)

27 (1.5%)

 < 0.001

 Severe pain^d

138 (7.7%)

76 (4.2%)

 < 0.001