Table 3 Univariate analysis of risk factors for increased SpCO (upper section) and symptoms / limitations (lower section) in participants without active smoking status in (N = 808 participants). * Only three participants cooked with electricity

Risk factors for increased SpCO values

 Age

18–29

155

7

4–12

0.59

30–39

121

7

4.5–12

40–49

221

8

4–14

50–59

142

7.5

4–13

60–69

98

9

4–15

70–79

60

6

2.25–13

 ≥ 80

11

5

1–11

 Sex

Male

349

7

4–12

0.76

Female

459

7

4–14

 Type of participant

Patient of outpatient department

315

7

4–13

0.84

Accompanying person or visitor

493

7

4–13

 Area of residence

Urban

230

10

5–14

 < 0.01

Rural

578

6

4–12

Passive exposure to cigarette smoking

No

387

6

4–13

0.06

Yes

421

8

4–13

 Place of cooking in household (no data n = 24)

Outside

321

9

4–14

 < 0.01: outside vs. inside – separate kitchen

 < 0.01: inside – living room vs. inside – separate kitchen

 < 0.01

Inside – living room

110

10.5

5–15

Inside – separate kitchen

353

6

4–12

 Cooking activity (no data n = 3)

Regular cooking

500

7

4–14

0.63

No regular cooking

305

7

4–12

 Cooking fuel / method of cooking (no data n = 23)

Wood on open fire

178

8

3.75–13

 < 0.01: wood in stove vs. gas/electricity

0.07: charcoal vs. gas/electricity

0.1

Wood in stove

14

11.5

7–13

Charcoal

511

7

4–14

Gas/electricity

63*

5

3–11

Other

19

9

5–16

 Biomass vs. non-biomass cooking fuel (no data n = 23)

Wood/charcoal

703

7

4–13

0.06: gas/electricity vs. other

0.06: wood/charcoal vs. gas/electricity

0.1

Gas/electricity

63*

5

3–11

Other

19

9

5–16

 Occupational exposure to dusts vs. fumes

No exposure

161

6

4–12

 < 0.01: dust exposure vs. Mixed exposure:

0.05: dust exposure vs. Fume exposure

 < 0.01

Dust exposure

257

5

4–12

Fume exposure

8

10

5.75–18.5

Mixed exposure

382

9

4–14

Symptoms and limitations according to SpCO values

 Severity of shortness of breath

0 (none)

499

6

4–12

0.02: severity 0 vs. severity 2

0.11

1 (light)

201

8

4–14

2 (moderate)

89

9

4–16

3 (severe)

19

7

3–15

 Limitations due to shortness of breath at home or at work

0 (none)

599

7

4–12

0.26

1 (light)

131

8

3–13

2 (moderate)

57

9

4–16

3 (severe)

21

11

4.5–15

 Refrained from taking a job due to shortness of breath

No

686

7

4–12

 < 0.01

Yes

122

10

4–15.25