Table 4

Effect modification of the association between lifetime home SHS exposure and respiratory symptoms a
Stratification factors Life-time home exposure Chronic cough Chronic phlegm Any wheeze
Former smoking OR 95% CI p OR 95% CI p OR 95% CI p
Yes Less than 10 years ref ref ref
10-19 years 2.25 0.83 - 6.12 1.96 0.83 - 4.65 1.16 0.68 - 1.97
20-29 years 2.47 0.94 - 6.48 2.09 0.91 - 4.78 1.18 0.71 - 1.96
at least 30 years 1.81 0.68 - 4.82 2.18 0.97 - 4.93 1.26 0.77 - 2.07
No Less than 10 years ref ref ref
10-19 years 1.04 0.56 - 1.91 1.79 0.99 - 3.24 1.21 0.84 - 1.74
20-29 years 1.37 0.70 - 2.67 1.71 0.88 - 3.56 1.10 0.72 - 1.69
at least 30 years 1.17 0.58 - 2.35 1.54 0.77 - 3.10 1.33 0.86 - 1.69
Obesity (BMI ≥30 kg/m2)
Yes Less than 10 years ref ref ref *
10-19 years 3.42 1.18 - 9.90 2.45 1.07 - 5.59 1.55 0.91 - 2.63
20-29 years 5.99 1.99 - 18.02 2.32 0.95 - 5.56 1.88 1.04 - 3.40
at least 30 years 4.78 1.61 - 14.23 2.84 1.21 - 6.70 2.27 1.28 - 4.03
No Less than 10 years ref ref ref
10-19 years 1.03 0.56 - 1.89 1.61 0.87 - 2.99 1.11 0.77 - 1.59
20-29 years 1.12 0.60 - 2.10 1.78 0.96 - 3.33 1.00 0.68 - 1.46
at least 30 years 0.77 0.39 - 1.53 1.49 0.77 - 2.87 1.07 0.72 - 1.58
Currently in urban area
Yes Less than 10 years ref ref ref
10-19 years 1.65 0.87 - 3.11 2.25 1.19 - 4.22 1.47 1.01 - 2.15
20-29 years 1.81 0.94 - 3.48 2.31 1.21 - 4.42 1.19 0.80 - 1.78
at least 30 years 1.35 0.69 - 2.67 1.94 1.01 - 3.75 1.47 0.99 - 2.19
No Less than 10 years ref ref ref
10-19 years 0.88 0.35 - 2.22 1.26 0.57 - 2.79 0.90 0.55 - 1.49
20-29 years 1.78 0.72 - 4.42 1.37 0.58 - 3.22 1.16 0.67 - 2.01
at least 30 years 1.47 0.58 - 3.73 1.99 0.85 - 4.62 1.13 0.64 - 1.98
Current SHS exposure
Yes Less than 10 years ref ref ref
10-19 years 1.39 0.77 - 2.52 1.75 0.99 - 3.09 1.43 0.97 - 2.11
20-29 years 1.13 0.60 - 2.14 1.41 0.77 - 2.58 1.39 0.92 - 2.10
at least 30 years 1.02 0.55 - 1.89 1.32 0.74 - 2.37 1.19 0.81 - 1.76
No Less than 10 years ref ref ref
10-19 years 1.53 0.52 - 4.48 2.86 1.00 - 8.16 1.01 0.63 - 1.64
20-29 years 5.21 1.89 - 14.42 3.94 1.37 - 11.33 0.88 0.51 - 1.50
at least 30 years 2.84 0.87 - 9.24 5.38 1.69 - 17.15 1.31 0.71 - 2.40

a Logistic regression model adjusted for age, sex, race, job title, former smoking, pack-years, years since quitting, BMI, region of country, and urban residence except the stratification factor for each model among never smokers or former smokers who quit at least 10 years before completing the questionnaire.

* p for interaction < 0.05.

Laden et al.

Laden et al. BMC Public Health 2013 13:93   doi:10.1186/1471-2458-13-93

Open Data