Table 3.

Estimates for the interaction between gas cooking and GSTM1 null genotype on bronchial responsiveness in the European Community Respiratory Health Survey II, restricting the analysis according to cooking characteristics

Cooking characteristics	N	β (95% CI)	p Value
Gas hobs (without gas oven) vs electricity	1565	−0.53 (−1.06 to −0.001)	0.050
Gas hobs (with gas oven) vs electricity	1393	−0.85 (−1.43 to −0.27)	0.004
Bottled gas vs electricity	814	−1.59 (−2.98 to −0.20)	0.025
Gas mains vs electricity	1934	−0.60 (−1.04 to −0.15)	0.009
Cooked every day in the last four weeks	1578	−0.72 (−1.32 to −0.12)	0.018
Cooked every day in the last four weeks (ventilated kitchen)	1205	−0.50 (−1.04 to 0.04)	0.071
Cooked every day in the last four weeks (unventilated kitchen)	373	−1.47 (−2.54 to −0.40)	0.007