Table 1 General characteristics of the study population

 Yes

4,565

2.45

320

6.18

4,245

2.34

<0.0001

 No

181,926

97.55

4,859

93.82

177,067

97.66

 Male

83,801

44.94

2,819

54.43

80,982

44.66

<0.0001

 Female

102,690

55.06

2,360

45.57

100,330

55.34

 ≤19

80,859

43.36

62

1.20

80,797

44.56

<0.0001

 20–29

13,342

7.15

26

0.50

13,316

7.34

 30–39

21,861

11.72

89

1.72

21,772

12.01

 40–49

20,849

11.18

213

4.11

20,636

11.38

 50–59

18,911

10.14

449

8.67

18,462

10.18

 60–69

16,170

8.67

1,047

20.22

15,123

8.34

 ≥70

14,499

7.77

3,293

63.58

11,206

6.18

 ≤10 (low)

14,779

7.92

816

15.76

13,963

7.70

<0.0001

 11–20

10,388

5.57

330

6.37

10,058

5.55

 21–30

11,584

6.21

370

7.14

11,214

6.18

 31–40

13,884

7.44

405

7.82

13,479

7.43

 41–50

16,266

8.72

370

7.14

15,896

8.77

 51–60

19,443

10.43

421

8.13

19,022

10.49

 61–70

22,858

12.26

440

8.50

22,418

12.36

 71–80

26,097

13.99

542

10.47

25,555

14.09

 81–90

26,628

14.28

716

13.83

25,912

14.29

 ≥91 (high)

24,564

13.17

769

14.85

23,795

13.12

 Medical aid

3,934

2.11

269

5.19

3,665

2.02

<0.0001

 NHI, self-employed insured

63,816

34.22

2,044

39.47

61,772

34.07

 NHI, employee insured

118,741

63.67

2,866

55.34

115,875

63.91

 2004

23,728

12.72

1,116

21.55

22,612

12.47

<0.0001

 2005

23,724

12.72

920

17.76

22,804

12.58

 2006

21,994

11.79

709

13.69

21,285

11.74

 2007

19,922

10.68

656

12.67

19,266

10.63

 2008

19,109

10.25

597

11.53

18,512

10.21

 2009

18,064

9.69

455

8.79

17,609

9.71

 2010

16,369

8.78

267

5.16

16,102

8.88

 2011

16,521

8.86

268

5.17

16,253

8.96

 2012

14,947

8.01

149

2.88

14,798

8.16

 2013

12,113

6.50

42

0.81

12,071

6.66

 None

179,110

96.04

4,304

83.10

174,806

96.41

<0.0001

 Mild

5,874

3.15

581

11.22

5,293

2.92

 Severe

1,507

0.81

294

5.68

1,213

0.67

 ≤1

126,882

68.04

328

6.33

126,554

69.80

<0.0001

 2

24,752

13.27

405

7.82

24,347

13.43

 3

16,685

8.95

890

17.18

15,795

8.71

 ≥4

18,172

9.74

3,556

68.66

14,616

8.06

Average pharmaceutical expenditures for asthma in each year (KRW)

24,773.30

±63,689.71

51,765.29

±111,475.00

24,002.30

±61,611.30

<0.0001

Region

 Metropolitan

83,723

44.89

2,001

38.64

81,722

45.07

<0.0001

 Other

102,768

55.11

3,178

61.36

99,590

54.93

Number of medical centers per 1000 residents

9.17

±4.39

9.89

±5.11

9.15

±4.37

<0.0001

Population size

420,845.64

±259,860.18

351,277.38

±259,532.33

422,832.79

±259,596.53

<0.0001

Proportion of seniors (%)

12.09

±4.94

14.16

±6.42

12.03

±4.87

<0.0001

Financial independence rate of local government (%)

59.06

±21.79

53.6

±22.60

59.22

±21.74

<0.0001

Average follow-up (months)

62.17

±34.26

38.43

±28.57

62.85

±34.17

<0.0001