Table 1. Study characteristics of ED visits within the past 12 months.

ED, emergency department; MSA, metropolitan statistical area

Characteristic

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

P-value

Total, 18 years and over, age-adjusted

17.2 ± 0.3

20.2 ± 0.3

19.7 ± 0.3

20.5 ± 0.3

20 ± 0.3

20.7 ± 0.3

20.5 ± 0.3

20.5 ± 0.3

20.2 ± 0.3

20.7 ± 0.4

21.4 ± 0.3

21.4 ± 0.3

20.4 ± 0.3

19.5 ± 0.3

18.8 ± 0.3

18.6 ± 0.3

18.8 ± 0.3

19.4 ± 0.3

18.6 ± 0.3

21.3 ± 0.3

21.7 ± 0.3

-

Sex (one or more ED visits percentage (SE))

Male

16.1 ± 0.4

18.7 ± 0.4

18.8 ± 0.4

19.6 ± 0.4

18.2 ± 0.4

19.3 ± 0.4

18.6 ± 0.4

19 ± 0.5

18.4 ± 0.5

19.3 ± 0.5

19.9 ± 0.5

18.5 ± 0.4

18 ± 0.4

17 ± 0.4

16.5 ± 0.4

16.9 ± 0.4

16.9 ± 0.4

17 ± 0.4

16.3 ± 0.4

18.9 ± 0.5

19.4 ± 0.5

P < 0.05

Female

18.2 ± 0.4

21.6 ± 0.4

20.5 ± 0.4

21.5 ± 0.4

21.8 ± 0.4

22.1 ± 0.4

22.3 ± 0.4

22.1 ± 0.4

21.9 ± 0.4

22.1 ± 0.5

22.9 ± 0.5

24.3 ± 0.5

22.7 ± 0.4

22 ± 0.4

21 ± 0.4

20.3 ± 0.4

20.6 ± 0.4

21.7 ± 0.5

20.9 ± 0.5

23.6 ± 0.5

24 ± 0.4

Age group (one or more ED visits percentage (SE))

18–24 years

21.7 ± 0.9

25.7 ± 0.9

23.8 ± 0.9

24.7 ± 0.9

23.9 ± 0.9

24.4 ± 1

25.3 ± 1

24.9 ± 1.1

23.3 ± 1.1

24.1 ± 1.1

24.6 ± 1.1

25.4 ± 1

23.8 ± 1

22.3 ± 0.9

20.8 ± 0.9

20.9 ± 1.1

20.5 ± 1.1

20.6 ± 1

19.2 ± 1.1

21 ± 1.1

21.2 ± 1.1

P < 0.05

25–44 years

16.5 ± 0.4

18.8 ± 0.4

18.3 ± 0.4

19.4 ± 0.4

18.6 ± 0.4

19.7 ± 0.4

19.2 ± 0.4

18.9 ± 0.5

19.3 ± 0.5

20.6 ± 0.6

21.1 ± 0.6

20.7 ± 0.5

19.5 ± 0.5

18.4 ± 0.5

17.7 ± 0.4

17.5 ± 0.5

17.9 ± 0.5

18.1 ± 0.5

17.4 ± 0.5

20.5 ± 0.6

21 ± 0.5

45–54 years

14.3 ± 0.6

17.9 ± 0.6

17.7 ± 0.6

18.1 ± 0.6

17.8 ± 0.6

17.9 ± 0.6

17.6 ± 0.6

17.9 ± 0.7

18 ± 0.7

17.1 ± 0.7

18 ± 0.7

18.6 ± 0.7

18 ± 0.6

18 ± 0.6

17.2 ± 0.6

16.2 ± 0.6

16.4 ± 0.6

18.4 ± 0.7

17.1 ± 0.7

18.7 ± 0.8

20.1 ± 0.7

55–64 years

15.1 ± 0.6

17 ± 0.7

18.5 ± 0.7

18.4 ± 0.7

19.3 ± 0.7

18.4 ± 0.7

19 ± 0.7

18.9 ± 0.8

18.7 ± 0.8

18.2 ± 0.8

18.9 ± 0.7

19.8 ± 0.7

18.5 ± 0.7

18 ± 0.7

18.1 ± 0.7

18.9 ± 0.7

18.4 ± 0.7

17.8 ± 0.7

18.4 ± 0.7

19 ± 0.7

20.3 ± 0.6

65–74 years

17.3 ± 0.8

21.6 ± 0.8

19.7 ± 0.8

21.2 ± 0.8

19.7 ± 0.8

20.8 ± 0.9

20.8 ± 0.8

20.6 ± 1

20.2 ± 1

20.7 ± 1

21.6 ± 1

20.7 ± 0.9

20.4 ± 0.8

19.9 ± 0.8

18.4 ± 0.8

18.9 ± 0.8

18.3 ± 0.7

20.5 ± 0.8

18.5 ± 0.7

23 ± 0.8

22.6 ± 0.7

75 years and over

23.1 ± 0.9

26.2 ± 0.9

25.4 ± 0.9

27.1 ± 1

26.6 ± 1

28.7 ± 1

27.1 ± 0.9

28.9 ± 1.3

26.5 ± 1.1

26.4 ± 1.2

28.8 ± 1.2

27.4 ± 1.1

27 ± 0.9

25.3 ± 1

25.3 ± 1

24.4 ± 0.9

26.7 ± 1

27.4 ± 1

27.6 ± 1

32.5 ± 1.1

30.9 ± 0.9

Race (one or more ED visits percentage (SE))

White only

16.6 ± 0.3

19.4 ± 0.3

19 ± 0.3

19.6 ± 0.3

19.2 ± 0.3

20 ± 0.3

19.8 ± 0.3

20.1 ± 0.4

19.6 ± 0.4

20.4 ± 0.4

20.4 ± 0.4

20.7 ± 0.4

19.8 ± 0.3

18.8 ± 0.3

18.1 ± 0.3

17.7 ± 0.3

18 ± 0.4

18.9 ± 0.4

17.9 ± 0.4

20.6 ± 0.4

20.6 ± 0.4

P < 0.05

Black or African American only

22.2 ± 0.8

26.5 ± 0.8

25.2 ± 0.8

27.8 ± 0.8

27.8 ± 0.8

27 ± 0.9

26.3 ± 0.8

25.6 ± 0.8

26.3 ± 0.9

25.1 ± 0.9

31.1 ± 0.9

28.6 ± 0.9

28 ± 0.8

26.4 ± 0.8

25.4 ± 0.8

26.3 ± 0.8

26.6 ± 0.9

25.6 ± 0.9

25.3 ± 1.1

26.9 ± 1

29.3 ± 1

American Indian or Alaska Native only

29.2 ± 4

30.3 ± 3.4

33.8 ± 4.7

25.3 ± 4.1

22.5 ± 3.7

27.8 ± 3.8

31 ± 4.6

21.1 ± 3.7

26.7 ± 3.3

30.2 ± 3

23.5 ± 3.1

22.6 ± 3

27.3 ± 3.1

22.1 ± 3

26.7 ± 3.1

31.1 ± 3.4

28.3 ± 3.3

26.7 ± 2.9

27.2 ± 2.9

31.7 ± 3

33.6 ± 3.7

Asian only

9.7 ± 1.2

13.6 ± 1.3

12.7 ± 1.4

13.6 ± 1.4

12.9 ± 1.4

12.2 ± 1.2

15.4 ± 1.4

13.6 ± 1.1

11.9 ± 1.1

11.5 ± 1.1

13.2 ± 1.1

13.3 ± 1

9.9 ± 0.7

10.9 ± 0.9

10.1 ± 0.8

11 ± 1

9.4 ± 0.8

11.5 ± 1.1

11.7 ± 1

14.7 ± 1.3

13.2 ± 1.1

Percent of poverty level (one or more ED visits percentage (SE))

Below 100%

26 ± 0.9

29 ± 0.9

26.5 ± 0.9

28.6 ± 0.9

26.3 ± 0.8

29.3 ± 0.9

29.8 ± 0.9

28.2 ± 1

29.9 ± 1

30 ± 1.1

31.5 ± 1

30.6 ± 0.9

30.5 ± 0.8

29.6 ± 0.8

30 ± 0.8

28.6 ± 0.8

29.5 ± 0.9

29.8 ± 1

28.6 ± 1

33.8 ± 1.1

34.1 ± 1.1

P < 0.05

100–199%

20.7 ± 0.7

23.9 ± 0.7

24.4 ± 0.7

24.7 ± 0.7

23.2 ± 0.7

23.6 ± 0.7

23.2 ± 0.7

24 ± 0.9

23.6 ± 0.8

24.3 ± 0.9

26.6 ± 0.8

25.6 ± 0.7

24.1 ± 0.7

23.9 ± 0.7

22.9 ± 0.7

23.4 ± 0.8

24.1 ± 0.8

25.5 ± 0.9

25.2 ± 0.9

26.1 ± 0.9

27.9 ± 0.9

200–399%

16.9 ± 0.5

19.8 ± 0.5

19.2 ± 0.5

20.2 ± 0.5

20 ± 0.5

20.4 ± 0.6

20.2 ± 0.5

19.9 ± 0.6

20 ± 0.7

19.8 ± 0.6

20.8 ± 0.6

20.4 ± 0.6

18.8 ± 0.5

18.6 ± 0.5

17.7 ± 0.5

17.2 ± 0.6

17.1 ± 0.6

19.2 ± 0.6

18.3 ± 0.6

21.2 ± 0.6

20.8 ± 0.6

400% or more

13.6 ± 0.4

16.8 ± 0.5

16.4 ± 0.4

16.6 ± 0.5

16.8 ± 0.5

17.5 ± 0.5

16.9 ± 0.5

16.9 ± 0.6

16.1 ± 0.5

16.9 ± 0.5

16.3 ± 0.5

17 ± 0.5

16.1 ± 0.5

14.1 ± 0.5

13.4 ± 0.5

13.5 ± 0.5

14.3 ± 0.5

13.9 ± 0.5

13.6 ± 0.5

16 ± 0.5

16 ± 0.4

Health insurance status at the time of interview (18–64 years) (one or more ED visits percentage (SE))

Insured

16.1 ± 0.3

19.5 ± 0.3

19.2 ± 0.3

19.6 ± 0.3

19.7 ± 0.4

20.1 ± 0.4

20 ± 0.3

19.9 ± 0.4

19.4 ± 0.4

20.3 ± 0.4

20.5 ± 0.4

20.8 ± 0.4

19.4 ± 0.4

19.1 ± 0.4

18.1 ± 0.4

18.2 ± 0.4

18 ± 0.4

18.7 ± 0.4

17.6 ± 0.4

19.9 ± 0.4

20.5 ± 0.4

P < 0.05

Private

14.5 ± 0.3

17.6 ± 0.3

17.2 ± 0.3

17.4 ± 0.3

17.4 ± 0.4

18 ± 0.4

17.3 ± 0.4

17.2 ± 0.4

16.9 ± 0.4

17 ± 0.4

16.7 ± 0.4

17.4 ± 0.4

15.7 ± 0.4

15 ± 0.4

14.1 ± 0.4

14.5 ± 0.4

14.1 ± 0.4

14.5 ± 0.4

14.1 ± 0.4

16.2 ± 0.4

16.5 ± 0.4

Medicaid

35.4 ± 1.4

42.2 ± 1.5

39.6 ± 1.3

40.4 ± 1.4

39.7 ± 1.3

36.8 ± 1.3

40.1 ± 1.3

39 ± 1.4

37.9 ± 1.4

39.7 ± 1.6

41.5 ± 1.4

40.2 ± 1.2

37.6 ± 1.2

39.7 ± 1.1

38 ± 1.1

34.9 ± 1.1

34.9 ± 1.1

35.4 ± 1.2

32.6 ± 1.2

37 ± 1.2

37.7 ± 1.1

Uninsured

18.3 ± 0.7

19.3 ± 0.7

18.6 ± 0.7

20.4 ± 0.7

18.1 ± 0.7

19 ± 0.7

19.5 ± 0.7

18.9 ± 0.8

20.3 ± 0.8

19.1 ± 0.8

21.2 ± 0.8

21.3 ± 0.7

21 ± 0.7

18.8 ± 0.7

18.5 ± 0.7

16.5 ± 0.7

18 ± 0.9

17.6 ± 1

19.1 ± 1

20.6 ± 1.1

22.1 ± 1

Location of residence

Within MSA

16.6 ± 0.3

19.6 ± 0.3

19.3 ± 0.3

19.8 ± 0.3

19.5 ± 0.3

20.3 ± 0.3

20.1 ± 0.3

20.1 ± 0.4

19.7 ± 0.4

20.1 ± 0.4

20.9 ± 0.4

20.8 ± 0.3

20 ± 0.3

18.9 ± 0.3

18.3 ± 0.3

18.1 ± 0.3

18.2 ± 0.3

18.9 ± 0.3

18.2 ± 0.4

20.8 ± 0.4

21.3 ± 0.3

P < 0.05

Outside MSA

19.5 ± 0.7

22.5 ± 0.6

21.3 ± 0.7

23.4 ± 0.7

22.3 ± 0.8

22.6 ± 0.8

22.3 ± 0.7

22.6 ± 0.9

22.9 ± 0.8

23.9 ± 1

24 ± 0.7

25.5 ± 0.9

23 ± 0.8

22.9 ± 0.9

22.2 ± 0.9

22 ± 0.8

22.8 ± 0.9

23.4 ± 1

21.5 ± 0.9

25 ± 1

24.8 ± 1