Table 2 Demographics of study population

Age, mean ± SD

79.82 ± 10.32

80.63 ± 9.59

79.72 ± 10.26

< 0.001

Age stratification, in years old, n (%)

 18–39

150 (0.3)

190 (0.1)

102 (0.3)

< 0.001

 40–49

548 (1.0)

947 (0.6)

314 (1.0)

 50–59

2514 (4.5)

5510 (3.5)

1454 (4.4)

 60–69

6352 (11.3)

15,684 (9.9)

3500 (10.7)

 70–79

15,126 (26.8)

42,440 (26.8)

9019 (27.6)

 80–89

26,712 (47.4)

79,358 (50.1)

15,603 (47.7)

 >  = 90

5006 (8.9)

14,125 (8.9)

2723 (8.3)

Gender, n (%)

 Female

41,817 (74.1)

114,900 (72.6)

21,410 (65.4)

< 0.001

 Male

14,577 (25.8)

43,318 (27.4)

11,303 (34.5)

 Missing

14 (0.0)

36 (0.0)

2 (0.0)

Race, n (%)

 White

44,039 (78.1)

124,825 (78.9)

24,694 (75.5)

< 0.001

 Non-white

4843 (8.6)

16,248 (10.3)

4929 (15.1)

 Missing

7526 (13.3)

17,181 (10.9)

3092 (9.5)

Insurance, n (%)

 Medicare

48,223 (85.5)

138,236 (87.4)

28,463 (87.0)

< 0.001

 Medicaid

889 (1.6)

2739 (1.7)

984 (3.0)

 Private

5727 (10.2)

13,287 (8.4)

2429 (7.4)

 Self-pay

521 (0.9)

1361 (0.9)

330 (1.0)

 No charge

42 (0.1)

154 (0.1)

41 (0.1)

 Other

910 (1.6)

2262 (1.4)

423 (1.3)

 Missing

96 (0.2)

215 (0.1)

45 (0.1)

Charlson Comorbidity Score, n (%)

 0

21,955 (38.9)

54,812 (34.6)

7933 (24.2)

 < 0.001

 1

17,997 (31.9)

50,084 (31.6)

9901 (30.3)

 2

7139 (12.7)

21,939 (13.9)

5649 (17.3)

 >  = 3

8905 (15.8)

29,889 (18.9)

8922 (27.3)

 Missing

412 (0.7)

1530 (1.0)

310 (0.9)

 Mean ± SD

1.24 ± 1.55

1.41 ± 1.64

1.87 ± 1.86

< 0.001

Weekend admission, n (%)

 No

42,942 (76.1)

115,921 (73.2)

23,551 (72.0)

< 0.001

 Yes

13,466 (23.9)

42,333 (26.8)

9164 (28.0)

Elective admission, n (%)

 No

50,082 (88.8)

150,211 (94.9)

31,015 (94.8)

< 0.001

 Yes

6209 (11.0)

7774 (4.9)

1639 (5.0)

 Missing

117 (0.2)

269 (0.2)

61 (0.2)