Table 4– Association of frequency of incense burning at home on subcategories of asthma and wheeze by GSTT1 genotype
GSTT1 presentGSTT1 null
Subjects n19371801
Frequency of incense burning#
 Asthma
  Lifetime asthma
   Never1.001.00
   Less than daily0.74 (0.45–1.21)0.74 (0.45–1.22)
   Daily1.04 (0.66–1.63)1.42 (0.94–2.13)
   p-value for trend0.870.09
  Current asthma
   Never1.001.00
   Less than daily1.22 (0.60–2.50)1.05 (0.54–2.05)
   Daily1.37 (0.69–2.75)1.78 (1.01–3.16)
   p-value for trend0.370.04
  Medication use
   Never1.001.00
   Less than daily1.22 (0.51–2.92)1.35 (0.60–3.00)
   Daily1.37 (0.59–3.18)2.26 (1.11–4.57)
   p-value for trend0.470.02
 Wheeze
  Lifetime wheeze
   Never1.001.00
   Less than daily0.96 (0.65–1.41)0.85 (0.57–1.26)
   Daily1.02 (0.70–1.49)1.40 (1.00–1.98)
   p-value for trend0.910.04
  Current wheeze
   Never1.001.00
   Less than daily0.78 (0.40–1.50)1.15 (0.62–2.14)
   Daily1.01 (0.55–1.87)1.17 (0.65–2.11)
   p-value for trend0.970.60
  Nocturnal wheeze
   Never1.001.00
   Less than daily0.86 (0.38–1.96)1.20 (0.45–3.23)
   Daily0.85 (0.37–1.95)3.21 (1.41–7.30)
   p-value for trend0.690.003
  Exercise wheeze
   Never1.001.00
   Less than daily2.03 (1.16–3.54)1.28 (0.71–2.31)
   Daily1.86 (1.06–3.28)1.99 (1.18–3.35)
   p-value for trend0.040.01
  • Data are presented as odds ratios with 95% confidence intervals, unless otherwise stated. Models are adjusted for age, sex, parental education, parental asthma, parental atopy, gestational age, city, maternal smoking during pregnancy and environmental tobacco smoke at home. #: average days of incense burning at home per month; : calculated by stratification with GSTT1 genotype.