Table 1 Patient characteristics and univariate regression model for patients with and without unplanned hospital admission

Gender, n (%)

0.3035¹

 Female

32,319 (60.8)

26 (53.1)

32,345 (60.8)

 Male

20,815 (39.2)

23 (46.9)

20,838 (39.2)

 X

2 (0.0)

0 (0.0)

2 (0.0)

Anesthesia type, n (%)

0.0030¹

 General

26,195 (49.3)

37 (75.5)

26,232 (49.3)

 Local

1262 (2.4)

1 (2.0)

1263 (2.4)

 MAC

25,679 (48.3)

11 (22.4)

25,690 (48.3)

Age

0.2007²

 Median

57.0

52.0

57.0

 IQR

43.0, 69.0

42.0, 65.0

43.0, 69.0

Age categorical, n (%)

0.3411¹

 18–64

35,641 (67.1)

36 (73.5)

35,677 (67.1)

  ≥ 65

17,495 (32.9)

13 (26.5)

17,508 (32.9)

Surgical duration (mins)

 < .0001²

 Median

29.0

64.0

29.0

 IQR

18.0, 58.0

29.0, 119.0

18.0, 58.0

Surgical complexity, n (%)

 < .0001¹

 Low (< 60 min)

40,344 (75.9)

22 (44.9)

40,366 (75.9)

 Moderate (60 to 179 min)

12,115 (22.8)

18 (36.7)

12,133 (22.8)

 High (≥ 180 min)

677 (1.3)

9 (18.4)

686 (1.3)

BMI

0.3763²

 Median

28.1

28.4

28.1

 IQR

24.7, 32.3

25.4, 33.4

24.7, 32.3

BMI categorical, n (%)

0.4925¹

  < 30

33,257 (62.6)

28 (57.1)

33,285 (62.6)

 30, 35

11,820 (22.2)

11 (22.4)

11,831 (22.2)

 35, 40

5254 (9.9)

5 (10.2)

5259 (9.9)

  ≥ 40

2805 (5.3)

5 (10.2)

2810 (5.3)

Condensed surgical specialty, n (%)

0.0077¹

 Gen

10,150 (19.1)

18 (36.7)

10,168 (19.1)

 Gyn/Uro

11,088 (20.9)

13 (26.5)

11,101 (20.9)

 Opth

11,454 (21.6)

5 (10.2)

11,459 (21.5)

 Ortho

17,459 (32.9)

10 (20.4)

17,469 (32.8)

 Other

2985 (5.6)

3 (6.1)

2988 (5.6)

Surgical specialty, n (%)

0.0887¹

 Breast

2509 (4.7)

0 (0.0)

2509 (4.7)

 ColoRectal

785 (1.5)

1 (2.0)

786 (1.5)

 Dental

136 (0.3)

0 (0.0)

136 (0.3)

 ENT

434 (0.8)

1 (2.0)

435 (0.8)

 Endo

17 (0.0)

0 (0.0)

17 (0.0)

 Gen

2272 (4.3)

7 (14.3)

2279 (4.3)

 Gyn

6321 (11.9)

6 (12.2)

6327 (11.9)

 Neuro

2388 (4.5)

2 (4.1)

2390 (4.5)

 OB Service

22 (0.0)

0 (0.0)

22 (0.0)

 OMFS

2 (0.0)

0 (0.0)

2 (0.0)

 Opth

11,454 (21.6)

5 (10.2)

11,459 (21.5)

 Ortho

15,293 (28.8)

9 (18.4)

15,302 (28.8)

 Pain

2166 (4.1)

1 (2.0)

2167 (4.1)

 Plastic

3090 (5.8)

8 (16.3)

3098 (5.8)

 Special procedures

8 (0.0)

0 (0.0)

8 (0.0)

 SurgOnc

42 (0.1)

0 (0.0)

42 (0.1)

 Trauma

789 (1.5)

1 (2.0)

790 (1.5)

 Uro

4745 (8.9)

7 (14.3)

4752 (8.9)

 Vasc

663 (1.2)

1 (2.0)

664 (1.2)

ASA CLASS, n (%)

0.0602¹

 1

5564 (10.5)

3 (6.1)

5567 (10.5)

 2

29,819 (56.1)

23 (46.9)

29,842 (56.1)

 3

17,545 (33.0)

22 (44.9)

17,567 (33.0)

 4

208 (0.4)

1 (2.0)

209 (0.4)

PONV SCORE, n (%)

0.6067¹

 0

1187 (2.2)

1 (2.0)

1188 (2.2)

 1

8347 (15.7)

8 (16.3)

8355 (15.7)

 2

20,210 (38.0)

18 (36.7)

20,228 (38.0)

 3

16,756 (31.5)

14 (28.6)

16,770 (31.5)

 4

5204 (9.8)

8 (16.3)

5212 (9.8)

 5

1432 (2.7)

0 (0.0)

1432 (2.7)

Diabetes mellitus, n (%)

1.0000¹

 No

45,611 (85.8)

42 (85.7)

45,653 (85.8)

 Yes

7525 (14.2)

7 (14.3)

7532 (14.2)

Obstructive sleep apnea n (%)

0.1667¹

 No

45,021 (84.7)

38 (77.6)

45,059 (84.7)

 Yes

8115 (15.3)

11 (22.4)

8126 (15.3)

Hypertension, n (%)

0.3941¹

 No

42,695 (80.4)

37 (75.5)

42,732 (80.3)

 Yes

10,441 (19.6)

12 (24.5)

10,453 (19.7)

Asthma, n (%)

0.4737¹

 No

47,361 (89.1)

41 (83.7)

47,402 (89.1)

 Yes

5775 (10.9)

8 (16.3)

5783 (10.9)

Hyperlipidemia, n (%)

0.7445¹

 No

38,566 (72.6)

37 (75.5)

38,603 (72.6)

 Yes

14,570 (27.4)

12 (24.5)

14,582 (27.4)

Coronary artery disease, n (%)

0.0753¹

 No

51,406 (96.7)

45 (91.8)

51,451 (96.7)

 Yes

1730 (3.3)

4 (8.2)

1734 (3.3)

Peripheral vascular disease, n (%)

0.0090¹

 No

52,688 (99.2)

46 (93.9)

52,734 (99.2)

 Yes

448 (0.8)

3 (6.1)

451 (0.8)

Angina, n (%)

1.0000¹

 No

52,880 (99.5%)

49 (100.0%)

52,929 (99.5%)

 Yes

256 (0.5)

0 (0.0)

256 (0.5)

Myocardial infarction, n (%)

1.0000¹

 No

52,220 (98.3)

48 (98.0)

52,268 (98.3)

 Yes

916 (1.7)

1 (2.0)

917 (1.7)

Atrial fibrillation, n (%)

0.7243¹

 No

50,682 (95.4)

46 (93.9)

50,728 (95.4)

 Yes

2454 (4.6)

3 (6.1)

2457 (4.6)

Supraventricular Tachycardia, n (%)

1.0000¹

 No

52,724 (99.2)

49 (100.0)

52,773 (99.2)

 Yes

412 (0.8)

0 (0.0)

412 (0.8)

VHD, n (%)

0.6546¹

 No

51,593 (97.1)

47 (95.9)

51,640 (97.1)

 Yes

1543 (2.9)

2 (4.1)

1545 (2.9)

Congestive heart failure, n (%)

0.6270¹

 No

52,040 (97.9)

47 (95.9)

52,087 (97.9)

 Yes

1096 (2.1)

2 (4.1)

1098 (2.1)

Seizures, n (%)

1.0000¹

 No

52,382 (98.6)

48 (98.0)

52,430 (98.6)

 Yes

754 (1.4)

1 (2.0)

755 (1.4)

Cerebrovascular accident, n (%)

1.0000¹

 No

52,021 (97.9)

48 (98.0)

52,069 (97.9)

 Yes

1115 (2.1)

1 (2.0)

1116 (2.1)

Transient ischemic attack, n (%)

0.6842¹

 No

52,576 (98.9)

49 (100.0)

52,625 (98.9)

 Yes

560 (1.1)

0 (0.0)

560 (1.1)

Anemia, n (%)

0.0965¹

 No

49,141 (92.5)

42 (85.7)

49,183 (92.5)

 Yes

3995 (7.5)

7 (14.3)

4002 (7.5)

COPD, n (%)

0.1480¹

 No

52,401 (98.6)

47 (95.9)

52,448 (98.6)

 Yes

735 (1.4)

2 (4.1)

737 (1.4)

ESKD, n (%)

1.0000¹

 No

52,979 (99.7)

49 (100.0)

53,028 (99.7)

 Yes

157 (0.3)

0 (0.0)

157 (0.3)

CKD, n (%)

0.6512¹

 No

51,651 (97.2)

47 (95.9)

51,698 (97.2)

 Yes

1485 (2.8)

2 (4.1)

1487 (2.8)

Thyroid disease, n (%)

0.3162¹

 No

45,717 (86.0)

45 (91.8)

45,762 (86.0)

 Yes

7419 (14.0)

4 (8.2%)

7423 (14.0%)

DVT, n (%)

0.0442¹

 No

52,318 (98.5)

46 (93.9)

52,364 (98.5)

 Yes

818 (1.5%)

3 (6.1)

821 (1.5)

Smoking, n (%)

0.6938¹

 No

45,377 (85.4)

43 (87.8)

45,420 (85.4)

 Yes

7759 (14.6)

6 (12.2)

7765 (14.6)

Cancer, n (%)

0.3951¹

 No

49,448 (93.1)

44 (89.8)

49,492 (93.1)

 Yes

3688 (6.9)

5 (10.2)

3693 (6.9)