Table 3

Adjusted ORs (95% CI) of symptom occurrence usage by heater type

	Wheeze		Cough		Dyspnoea
	Same day	Lag 1	Same day	Lag 1	Same day	Lag 1
UFGH versus other heater used (n=1713 vs 2421 days)	1.21 (0.99 to 1.48)	1.22 (1.00 to 1.50)^*	0.77 (0.53 to 1.11)	0.79 (0.54 to 1.15)	0.78 (0.56 to 1.09)	0.79 (0.56 to 1.12)
UFGH used versus no heating (n=1713 vs 1388 days)	1.25 (1.05 to 1.50)^*	1.22 (1.01 to 1.48)^*	1.38 (0.91 to 2.09)	1.55 (1.00 to 2.40)^*	1.87 (1.30 to 2.70)^*	2.05 (1.41 to 2.99)^*
Other heater used versus no heating (n=2421 vs 1388 days)	1.01 (0.88 to 1.17)	1.03 (0.89 to 1.20)	1.15 (0.83 to 1.59)	1.21 (0.85 to 1.71)	1.40 (0.99 to 2.00)	1.56 (1.07 to 2.28)^*

Adjusted for age, gender, exposure to tobacco smoke, exposure to cooking gas, ambient temperature, humidity and external NO₂ levels.
↵* Significant finding (p<0.05).
UFGH, unflued gas heater.