Table 1 Baseline characteristics of the study population by admission status

n

13,431

10,251

3180

Male sex

5884 (43.8)

4433 (43.2)

1451 (45.6)

0.05

Age in years

72.0 [65.0, 81.0]

71.0 [65.0, 80.0]

74.0 [67.0, 83.0]

0.28

Race and Ethnicity

0.09

 Non-Hispanic White

9607 (71.5)

7275 (71.0)

2332 (73.3)

 Non-Hispanic Black

2136 (15.9)

1692 (16.5)

444 (14.0)

 Hispanic

1110 (8.3)

866 (8.4)

244 (7.7)

 Non-Hispanic Other

578 (4.3)

418 (4.1)

160 (5.0)

Nursing home resident

720 (5.4)

442 (4.3)

278 (8.7)

0.18

Initial Emergency Department visit

804 (6.0)

607 (5.9)

197 (6.2)

0.01

Arrived by Ambulance

3943 (29.4)

2432 (23.7)

1511 (47.5)

0.51

Weekend Admission

3550 (26.4)

2773 (27.1)

777 (24.4)

0.06

Time of Emergency Department visit

0.04

 7:00 AM-7:00 PM

10,293 (76.6)

7865 (76.7)

2428 (76.4)

 8:00 PM- 1:00 AM

2186 (16.3)

1681 (16.4)

505 (15.9)

 2:00 AM-6:00 AM

952 (7.1)

705 (6.9)

247 (7.8)

Season

0.05

 Winter

3355 (25.0)

2585 (25.2)

770 (24.2)

 Spring

3629 (27.0)

2735 (26.7)

894 (28.1)

 Summer

3125 (23.3)

2356 (23.0)

769 (24.2)

 Autumn

3322 (24.7)

2575 (25.1)

747 (23.5)

Insurance Type

 Medicare insurance

9094 (67.7)

6738 (65.7)

2356 (74.1)

0.18

 Private insurance

5318 (39.6)

4052 (39.5)

1266 (39.8)

0.01

 Medicaid insurance

2453 (18.3)

1922 (18.7)

531 (16.7)

0.05

Emergency Department Residency Program present

3644 (27.1)

2730 (26.6)

914 (28.7)

0.05

Emergency Department bed Coordinator present

10,188 (75.9)

7588 (74.0)

2600 (81.8)

0.19

Admitted patients ever boarded > 2 h.

10,432 (77.7)

7785 (75.9)

2647 (83.2)

0.18

Wait time in Emergency Department

18.0 [6.0, 35.2]

18.0 [7.0, 35.2]

16.0 [6.0, 35.2]

0.01

Wait time before first provider ≥ 1 h

1780 (13.3)

1375 (13.4)

405 (12.7)

0.02

Chronic conditions

 History of Pulmonary Embolism

517 (3.8)

338 (3.3)

179 (5.6)

0.11

 History of Heart disease

3659 (27.2)

2382 (23.2)

1277 (40.2)

0.37

 History of Alzheimer’s disease/Dementia

788 (5.9)

506 (4.9)

282 (8.9)

0.16

 History of Asthma

1116 (8.3)

829 (8.1)

287 (9.0)

0.03

 History of Cancer

1612 (12.0)

1076 (10.5)

536 (16.9)

0.19

 History of Stroke or Transient Ischemic Attack

1371 (10.2)

871 (8.5)

500 (15.7)

0.22

 History of Chronic Kidney Disease

1246 (9.3)

717 (7.0)

529 (16.6)

0.30

 History of Chronic Obstructive Pulmonary Disease

2114 (15.7)

1391 (13.6)

723 (22.7)

0.24

 History of Depression

1785 (13.3)

1312 (12.8)

473 (14.9)

0.06

 History of End stage renal disease

288 (2.1)

178 (1.7)

110 (3.5)

0.11

 Obesity ( Body Mass Index > 30)

944 (7.0)

622 (6.1)

322 (10.1)

0.15

 History of Obstructive Sleep Apnea

750 (5.6)

528 (5.2)

222 (7.0)

0.08

 Substance abuse or dependence

517 (3.8)

382 (3.7)

135 (4.2)

0.03

 Alcohol misuse, abuse, or dependence

418 (3.1)

300 (2.9)

118 (3.7)

0.04

 History of Diabetes Mellitus

3778 (28.1)

2725 (26.6)

1053 (33.1)

0.14

 Number of chronic conditions

2.0 [1.0, 4.0]

2.0 [1.0, 3.0]

3.0 [2.0, 5.0]

0.50

Presenting condition

 Fracture or dislocation

36 (0.3)

26 (0.3)

10 (0.3)

0.01

 Motor Vehicle Accident

66 (0.5)

63 (0.6)

3 (0.1)

0.09

 Accident including falls

440 (3.3)

363 (3.5)

77 (2.4)

0.07

 Back pain

1329 (9.9)

1196 (11.7)

133 (4.2)

0.28

 Chest pain, pressure or discomfort

895 (6.7)

601 (5.9)

294 (9.2)

0.13

 Shortness of breath

964 (7.2)

500 (4.9)

464 (14.6)

0.33

 Neurological symptoms

218 (1.6)

122 (1.2)

96 (3.0)

0.13

 Gastrointestinal bleeding

66 (0.5)

35 (0.3)

31 (1.0)

0.08

Abnormal Vitals

Temp < 96.8 or > 100.4 °F

619 (4.6)

352 (3.4)

267 (8.4)

0.21

SBP < 100 or ≥ 180 or DBP < 60 or ≥ 110 mmHg

3357 (25.0)

2383 (23.2)

974 (30.6)

0.17

HR < 60 or > 90 beats/min

4527 (33.7)

3149 (30.7)

1378 (43.3)

0.26

Respiratory rate < 11 or > 20 breaths/min

1406 (10.5)

797 (7.8)

609 (19.2)

0.34

Hypoxia (O₂sat < 90%)

361 (2.7)

180 (1.8)

181 (5.7)

0.21

Pain scale > 7

2447 (18.2)

2003 (19.5)

444 (14.0)

0.15