Table 2 Risk factors for a low score on 15D (total score ≤0.65) based on univariate and backwards stepwise multivariate regression analysis

Gender

  Male

470

9.6

1.00

  Female

261

11.1

1.18

0.72-1.93

NS

Age at recruitment

  <60 years

214

9.8

1.00

  61–68 years

269

10.4

1.97

0.59-1.94

NS

  >69 years

248

10.1

1.03

0.56-1.90

NS

FEV₁ baseline % of predicted

  >80

94

8.2

1.00

1.00

  65–80

184

7.5

0.91

0.33-1.39

NS

1.02

0.35-3.01

NS

  40–64

318

9.8

1.21

0.53-1.88

NS

1.41

0.52-3.80

NS

  <40

135

16.5

2.21

0.86-5.71

0.100

3.08

1.10-8.63

0.03

Smoking cessation succeed

  Yes

355

7.9

1.00

  No

278

12.6

1.68

1.00-2.84

0.05

BMI units

  <19

32

9.3

0.65

0.15-2.91

NS

  19–25

248

6.2

1.00

  >25-30

272

9.2

0.99

0.55-1.79

NS

  >30

172

14.0

1.59

0.86-2.92

NS

Diabetes

  No

620

8.4

1.00

1.00

  Yes

111

19.8

2.70

1.56-4.66

<0.001

2.12

1.07-4.22

0.03

Cardiovascular Disease¹

  No

526

9.1

1.00

1.00

  Yes

205

12.7

1.45

0.87-2.40

NS

1.69

0.93-3.07

0.09

Hypertension

  No

434

9.4

1.00

  Yes

297

11.1

1.20

0.74-1.94

NS

Atrial Fibrillation

  No

468

11.1

1.00

-²

  Yes

30

23.3

2.44

1.00-5.95

0.05

Diffusing capacity

  Normal

220

10.0

1.00

  Mild/Moderately decrease

87

13.8

1.44

0.68-3.05

NS

  Severe decrease

102

11.8

1.20

0.57-2.53

NS

Cancer

  No

687

10.0

1.00

  Yes

44

11.4

1.15

0.44-3.01

NS

Psychiatric conditions

  No

488

5.9

1.00

1.00

  Yes

237

18.1

3.51

2.13-5.78

<0.001

4.65

2.57-8.40

<0.001

Alcohol abuse

  No

621

8.4

1.00

1.00

  Yes

110

20.0

2.74

1.58-4.73

<0.001

2.33

1.21-4.49

0.007