Table 3

Effect modifications on the association between SHS exposure and respiratory symptoms among 1,562 non-current smoking workers a
Exposure metric Stratification factors Chronic cough Chronic phlegm Any wheeze
n OR 95% CI n OR 95% CI n OR 95% CI
Current Exposure Former smoking
  No 870 1.62 0.97 - 2.69 870 1.48 0.92 - 2.38 840 1.78 1.32 - 2.39
  Yes 692 1.31 0.73 - 2.33 692 1.69 0.98 - 2.93 662 1.73 1.21 - 2.45
Obesity (BMI ≥30 kg/m2)
  No 1033 1.68 1.04 - 2.73 1033 1.27 0.81 - 1.98 995 1.72 1.31 - 2.26
  Yes 522 1.19 0.64 - 2.22 522 2.06 1.11 - 3.83 500 1.99 1.33 - 2.99
Currently in urban area
  No 528 2.39 1.14 - 4.99 528 2.97 1.46 - 6.01 506 2.07 1.40 - 3.05
  Yes 1034 1.24 0.78 - 1.95 1034 1.19 0.78 - 1.83 996 1.67 1.26 - 2.22
Childhood SHS exposure
  No 459 2.31 1.06 - 5.02 459 2.42 1.06 - 5.53 437 1.41 0.94 - 2.13
  Yes 1077 1.24 0.80 - 1.93 1077 1.38 0.92 - 2.06 1040 1.97 1.50 - 2.60
Childhood Exposure Former smoking
  No 870 1.18 0.71 - 1.95 870 1.95 1.15 - 3.31 840 1.06 0.78 - 1.45
  Yes 692 1.16 0.60 - 2.23 692 1.57 0.85 - 2.92 662 1.24 0.84 - 1.83
Obesity (BMI ≥30 kg/m2)
  No 1033 0.86 0.54 - 1.39 1033 1.57 0.96 - 2.59 995 0.92 0.69 - 1.23
  Yes 522 2.63 1.21 - 5.75 522 2.63 1.31 - 5.29 500 1.93 1.25 - 2.95
Currently in urban area
  No 528 0.86 0.43 - 1.71 528 1.15 0.60 - 2.19 506 1.08 0.71 - 1.62
  Yes 1034 1.50 0.90 - 2.51 1034 2.47 1.43 - 4.25 996 1.24 0.92 - 1.68
Current SHS exposure
  No 572 1.80 0.83 - 3.93 572 2.71 1.18 - 6.20 550 0.89 0.60 - 1.33
  Yes 990 1.04 0.65 - 1.66 990 1.63 1.02 - 2.60 952 1.29 0.95 - 1.75

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, and also adjusted for either current exposure to SHS or childhood SHS exposure among never smokers or former smokers who quit at least 10 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