Table 2 Discharged patient characteristics and clinical outcomes by the supervision group

Age, mean (SD), year

50.2 (21.7)

48.9 (22.8)

50.8 (20.8)

53.9 (19.9)

56.5 (19.4)

44.9 (21.4)

 < .001

Male, n (%)

94,000 (46.1)

40,986 (48.4)

37,470 (44.7)

9,238 (43.0)

2,356 (44.3)

3,950 (46.5)

 < .001

Vital sign

 Body temperature, mean (SD), °C

36.9 (1.0)

36.9 (1.0)

36.9 (1.1)

36.9 (1.0)

36.8 (1.2)

36.7 (1.2)

 < .001

 Heart rate, mean (SD), beats per min

89.0 (18.7)

89.8 (19.6)

88.5 (18.1)

88.6 (17.9)

87.3 (17.5)

86.5 (18.1)

 < .001

 Respiratory rate, mean (SD), breaths per min

19.2 (2.1)

19.3 (2.3)

19.1 (1.9)

19.1 (1.9)

18.9 (1.9)

18.3 (2.2)

 < .001

 Oxygen saturation, median (IQR), %

98.0 (3.0)

98.0 (3.0)

98.0 (3.0)

98.0 (3.0)

98.0 (3.0)

98.0 (3.0)

 < .001

 Systolic blood pressure, mean (SD), mmHg

135.6 (27.1)

134.0 (27.0)

136.3 (26.9)

137.6 (27.4)

138.5 (28.4)

137.7 (27.0)

 < .001

 Diastolic blood pressure, mean (SD), mmHg

77.7 (14.8)

77.0 (15.1)

78.1 (14.6)

78.3 (14.7)

78.4 (15.0)

78.5 (15.0)

 < .001

 GCS-E, n (%)

 < .001

  1

60 (0.0)

37 (0.0)

18 (0.0)

1 (0.0)

3 (0.1)

1 (0.0)

  2

184 (0.1)

127 (0.1)

43 (0.1)

8 (0.0)

4 (0.1)

2 (0.0)

  3

547 (0.3)

369 (0.4)

147 (0.2)

16 (0.1)

11 (0.2)

4 (0.0)

  4

203,073 (99.6)

84,176 (99.4)

83,653 (99.8)

21,458 (99.9)

5,304 (99.7)

8,482 (99.9)

 GCS-V, n (%)

 < .001

  1

604 (0.3)

392 (0.5)

164 (0.2)

29 (0.1)

14 (0.3)

5 (0.1)

  2

707 (0.3)

433 (0.5)

219 (0.3)

33 (0.2)

14 (0.3)

8 (0.1)

  3

384 (0.2)

229 (0.3)

125 (0.1)

22 (0.1)

7 (0.1)

1 (0.0)

  4

973 (0.5)

594 (0.7)

270 (0.3)

71 (0.3)

22 (0.4)

16 (0.2)

  5

201,196 (98.7)

83,061 (98.1)

83,083 (99.1)

21,328 (99.3)

5,265 (98.9)

8,459 (99.6)

 GCS-M, n (%)

 < .001

  1

36 (0.0)

20 (0.0)

11 (0.0)

3 (0.0)

2 (0.0)

0 (0.0)

  2

24 (0.0)

15 (0.0)

4 (0.0)

2 (0.0)

2 (0.0)

1 (0.0)

  3

108 (0.1)

67 (0.1)

35 (0.0)

4 (0.0)

2 (0.0)

0 (0.0)

  4

463 (0.2)

323 (0.4)

117 (0.1)

15 (0.1)

3 (0.1)

5 (0.1)

  5

1,418 (0.7)

886 (1.0)

407 (0.5)

76 (0.4)

27 (0.5)

22 (0.3)

  6

201,815 (99.0)

83,398 (98.5)

83,287 (99.3)

21,383 (99.5)

5,286 (99.3)

8,461 (99.7)

 Body weight, mean (SD), kg

58.7 (19.7)

57.2 (21.3)

59.6 (18.8)

60.4 (17.2)

60.6 (17.9)

58.9 (19.0)

 < .001

 Comorbidity

55,189 (27.1)

22,959 (27.1)

22,181 (26.4)

6,763 (31.5)

1,839 (34.6)

1,447 (17.0)

 < .001

 Coronary artery disease

9,432 (4.6)

3,953 (4.7)

3,687 (4.4)

1,148 (5.3)

424 (8.0)

220 (2.6)

 < .001

 Malignancy

23,951 (11.7)

9,979 (11.8)

9,576 (11.4)

3,021 (14.1)

742 (13.9)

633 (7.5)

 < .001

 Heart failure

5,261 (2.6)

2,411 (2.8)

1,984 (2.4)

563 (2.6)

200 (3.8)

103 (1.2)

 < .001

 COPD

2,284 (1.1)

1,116 (1.3)

805 (1.0)

248 (1.2)

61 (1.1)

54 (0.6)

 < .001

 Stroke

13,177 (6.5)

5,849 (6.9)

5,064 (6.0)

1,583 (7.4)

403 (7.6)

278 (3.3)

 < .001

 Dementia

1,913 (0.9)

983 (1.2)

635 (0.8)

207 (1.0)

52 (1.0)

36 (0.4)

 < .001

 Diabetes mellitus

15,125 (7.4)

6,653 (7.9)

5,841 (7.0)

1,789 (8.3)

514 (9.7)

328 (3.9)

 < .001

 End-stage renal disease

3,922 (1.9)

1,730 (2.0)

1,570 (1.9)

402 (1.9)

136 (2.6)

84 (1.0)

 < .001

 Hypertension

41,707 (20.5)

17,343 (20.5)

16,750 (20.0)

5,174 (24.1)

1,409 (26.5)

1,031 (12.1)

 < .001

 Liver cirrhosis

3,722 (1.8)

1,476 (1.7)

1,561 (1.9)

466 (2.2)

125 (2.3)

94 (1.1)

 < .001

 Peptic ulcer disease

1,634 (0.8)

708 (0.8)

605 (0.7)

211 (1.0)

70 (1.3)

40 (0.5)

 < .001

 Peripheral vascular disease

1,103 (0.5)

516 (0.6)

412 (0.5)

118 (0.5)

40 (0.8)

17 (0.2)

 < .001

 Rheumatic disease

4,232 (2.1)

1,792 (2.1)

1,743 (2.1)

485 (2.3)

128 (2.4)

84 (1.0)

 < .001

Time of presentation

 Month, n (%)

 < .001

  1

18,614 (9.1)

7,375 (8.7)

7,904 (9.4)

1,908 (8.9)

470 (8.8)

957 (11.3)

  2

19,132 (9.4)

7,963 (9.4)

8,303 (9.9)

2,269 (10.6)

595 (11.2)

2 (0.0)

  3

18,656 (9.2)

7,216 (8.5)

8,461 (10.1)

2,349 (10.9)

630 (11.8)

0 (0.0)

  4

17,672 (8.7)

7,089 (8.4)

8,120 (9.7)

1,979 (9.2)

484 (9.1)

0 (0.0)

  5

17,854 (8.8)

7,387 (8.7)

7,983 (9.5)

1,997 (9.3)

487 (9.2)

0 (0.0)

  6

17,586 (8.6)

7,055 (8.3)

7,909 (9.4)

2,101 (9.8)

521 (9.8)

0 (0.0)

  7

17,398 (8.5)

7,128 (8.4)

7,809 (9.3)

2,012 (9.4)

448 (8.4)

1 (0.0)

  8

14,912 (7.3)

6,795 (8.0)

4,764 (5.7)

1,349 (6.3)

363 (6.8)

1,641 (19.3)

  9

14,306 (7.0)

6,603 (7.8)

4,731 (5.6)

1,245 (5.8)

276 (5.2)

1,451 (17.1)

  10

15,299 (7.5)

6,828 (8.1)

5,558 (6.6)

1,427 (6.6)

335 (6.3)

1,151 (13.6)

  11

15,634 (7.7)

6,675 (7.9)

5,861 (7.0)

1,329 (6.2)

323 (6.1)

1,446 (17.0)

  12

16,801 (8.2)

6,595 (7.8)

6,458 (7.7)

1,518 (7.1)

390 (7.3)

1,840 (21.7)

 Day of the week, n (%)

 < .001

  Sunday

35,195 (17.3)

14,986 (17.7)

14,571 (17.4)

3,288 (15.3)

706 (13.3)

1,644 (19.4)

  Monday

29,509 (14.5)

11,724 (13.8)

12,061 (14.4)

3,540 (16.5)

993 (18.7)

1,191 (14.0)

  Tuesday

28,080 (13.8)

11,170 (13.2)

11,835 (14.1)

3,152 (14.7)

791 (14.9)

1,132 (13.3)

  Wednesday

25,177 (12.3)

10,588 (12.5)

10,268 (12.2)

2,640 (12.3)

645 (12.1)

1,036 (12.2)

  Thursday

26,275 (12.9)

10,864 (12.8)

10,793 (12.9)

2,856 (13.3)

753 (14.1)

1,009 (11.9)

  Friday

27,665 (13.6)

11,584 (13.7)

11,333 (13.5)

2,951 (13.7)

741 (13.9)

1,056 (12.4)

  Saturday

31,963 (15.7)

13,793 (16.3)

13,000 (15.5)

3,056 (14.2)

693 (13.0)

1,421 (16.7)

 Time of the day, n (%)

 < .001

  00:00–04:00

22,736 (11.2)

9,342 (11.0)

9,937 (11.8)

1,829 (8.5)

497 (9.3)

1,131 (13.3)

  04:00–08:00

17,765 (8.7)

7,284 (8.6)

7,980 (9.5)

1,621 (7.5)

270 (5.1)

610 (7.2)

  08:00–12:00

36,784 (18.0)

15,042 (17.8)

13,798 (16.5)

4,766 (22.2)

1,790 (33.6)

1,388 (16.4)

  12:00–16:00

39,866 (19.6)

16,757 (19.8)

15,804 (18.8)

4,495 (20.9)

1,146 (21.5)

1,664 (19.6)

  16:00–20:00

43,244 (21.2)

18,247 (21.5)

17,559 (20.9)

4,700 (21.9)

932 (17.5)

1,806 (21.3)

  20:00–24:00

43,469 (21.3)

18,037 (21.3)

18,783 (22.4)

4,072 (19.0)

687 (12.9)

1,890 (22.3)

 Triage level, n (%)

 < .001

  1

114 (0.1)

82 (0.1)

23 (0.0)

7 (0.0)

2 (0.0)

0 (0.0)

  2

29,090 (14.3)

10,840 (12.8)

11,728 (14.0)

3,882 (18.1)

1,304 (24.5)

1,336 (15.7)

  3

156,049 (76.5)

62,829 (74.2)

66,409 (79.2)

16,754 (78.0)

3,855 (72.4)

6,202 (73.1)

  4

16,075 (7.9)

9,257 (10.9)

5,132 (6.1)

750 (3.5)

146 (2.7)

790 (9.3)

  5

2,536 (1.2)

1,701 (2.0)

569 (0.7)

90 (0.4)

15 (0.3)

161 (1.9)

Waiting time, median (IQR), minute

6.4 (10.6)

5.8 (9.7)

6.3 (10.2)

8.2 (13.1)

8.0 (13.0)

10.4 (16.2)

 < .001

Hospital

 < .001

 Academic, n (%)

197,337 (96.8)

80,419 (94.9)

81,875 (97.6)

21,309 (99.2)

5,245 (98.6)

8,489 (100.0)

 Community, n (%)

6,527 (3.2)

4,290 (5.1)

1,986 (2.4)

174 (0.8)

77 (1.4)

0 (0.0)

Complaint

 < .001

 Non-trauma, n (%)

170,571 (83.7)

66,546 (78.6)

72,140 (86.0)

20,023 (93.2)

5,051 (94.9)

6,811 (80.2)

 Trauma, n (%)

33,293 (16.3)

18,163 (21.4)

11,721 (14.0)

1,460 (6.8)

271 (5.1)

1,678 (19.8)

Outcomes

 Revisit within 72 h of the last discharge, n (%)

6,669 (3.3)

2,712 (3.2)

2,707 (3.2)

794 (3.7)

229 (4.3)

227 (2.7)

 < .001

 Mortality within 7 days after the ED visit, n (%)

102 (0.1)

49 (0.1)

34 (0.0)

12 (0.1)

3 (0.1)

4 (0.0)

0.601

 LOS, median (IQR), minutes

128.4 (165.6)

93.2 (235.9)

120.0 (83.6)

200.5 (81.4)

319.8 (146.4)

90.7 (88.6)

 < .001

 Medical expenses, median (IQR), dollar

2,304.0 (2,558.0)

1,979.0 (3,082.0)

2,336.0 (2,036.0)

2,972.0 (2,495.0)

3,988.5 (4,473.5)

1,497.0 (1,037.0)

 < .001