Table 1 Characteristics study participants and distributions of cases and prevalence ratios (PR) for ever asthma and current asthma in the Mountain Air Project study (2016–2017)

All participants

972

100

218

…

157

…

County of Residence (n = 972)

 Harlan

589

60.6

120

Ref

––-

81

Ref

––-

 Letcher

383

39.4

98

1.24

0.98–1.57

76

1.43

1.07–1.90

Season of Interview (n = 972)

 Winter

192

19.8

49

1.32

0.90–1.92

35

1.66

1.00–2.74

 Spring

396

40.7

92

1.20

0.86–1.69

71

1.64

1.04–2.58

 Summer

195

20.1

40

1.05

0.71–1.57

30

1.39

0.83–2.34

 Fall

189

19.4

37

Ref

––-

21

Ref

––-

Age group (n = 972)

 18–34

140

14.3

45

2.69

1.77–4.11

27

2.06

1.22–3.47

 35–64

594

60.9

145

2.04

1.40–2.97

108

1.94

1.26–2.99

 65 + 

238

24.8

28

Ref

––-

22

Ref

––-

Gender (n = 972)

 Female

571

58.7

142

1.32

1.03–1.69

105

1.42

1.05–1.93

 Male

401

41.3

76

Ref

––-

52

Ref

––-

Educational attainment (n = 971)

  < High School

254

26.1

58

1.07

0.82–1.40

48

1.33

0.96–1.83

 High school or some college

599

61.6

129

Ref

––-

86

Ref

––-

 College

118

12.1

30

1.17

0.83–1.65

22

1.29

0.84–1.97

 Missing

1

0.1

1

1

Annual household income (n = 735)

  < $25 K

451

46.4

111

1.21

0.85–1.73

82

1.22

0.79–1.88

 $25-$50 K

138

14.2

32

1.15

0.74–1.78

20

0.98

0.56–1.71

 $50 K + 

146

15.0

30

Ref

––-

22

Ref

––-

 Missing

237

24.4

45

0.93

0.62–1.41

33

0.93

0.57–1.53

Type of dwelling (n = 972)

 Single family house

634

65.2

134

Ref

––-

96

Ref

––-

 Mobile home

288

29.6

64

1.06

0.81–1.38

43

0.99

0.71–1.38

 Multi-unit housing

50

5.1

20

1.92

1.33–2.78

18

2.41

1.60–3.64

Body mass index (BMI) (kg/m²) (n = 925)

 Underweight (< 18.5)

19

2.0

5

1.35

0.61–2.96

4

1.53

0.61–3.84

 Normal (18.5–24.9)

217

22.3

45

1.07

0.75–1.52

32

1.08

0.70–1.67

 Overweight (25.0–29.9)

276

28.4

54

Ref

––-

38

Ref

––-

 Obese (30.0 +)

413

42.5

102

1.28

0.96–1.72

75

1.34

0.93–1.92

 Missing

47

4.8

12

8

Season allergies (n = 969)

 Yes

546

56.2

155

1.91

1.47–2.49

113

2.00

1.44–2.76

 No

423

43.5

63

Ref

––-

44

Ref

––-

 Missing

3

0.3

0

0

Smoking status (n = 969)

 Current

320

32.9

73

1.02

0.78–1.34

55

1.12

0.80–1.56

 Former

230

23.7

49

0.98

0.72–1.32

36

1.02

0.70–1.49

 Never

419

43.1

91

Ref

––-

64

Ref

––-

 Missing

3

0.3

2

2

Lives with current smoker (n = 972)

 Yes

626

64.4

145

1.09

0.85–1.40

106

1.14

0.84–1.56

 No

346

35.6

73

Ref

––-

51

Ref

––-

Current employment (n = 972)

 Homemaker

194

20.0

51

2.05

1.35–3.11

39

1.91

1.18–3.08

 Full-time

215

22.1

51

1.84

1.21–2.80

34

1.49

0.91–2.45

 Part-time / Full-time student / Unemployed

159

16.4

33

1.62

1.02–2.57

20

1.20

0.68–2.10

 Retired

219

22.5

28

Ref

––-

23

Ref

––-

 Disabled

185

19.0

55

2.31

1.53–3.48

41

2.09

1.31–3.35

Ever had dusty job, including mining (n = 952)

 Yes

350

36.0

64

Ref

––-

46

Ref

––-

 No

622

64.0

154

1.36

1.04–1.76

111

1.36

0.99–1.87