Table 4 Adjusted odds ratios (ORs) and population attributable fractions (PAFs) of exposure to environmental tobacco smoke (ETS) for hospital admissions with pneumonia among children aged <5 years

	Unadjusted OR		Adjusted OR*		PAF (%)
	(95% CI)	p Value	(95% CI)	p Value	(95% CI)
ETS exposure
Yes	1.81 (1.48 to 2.21)	<0.001	1.55 (1.25 to 1.92)	<0.001	28.7 (15.2 to 40.0)
No	1		1
Number of smokers in household
⩾2	1.64 (1.27 to 2.11)	<0.001	1.43 (1.08 to 1.89)	0.012	15.2 (2.8 to 26.0)
1	1.87 (1.52 to 2.30)	<0.001	1.59 (1.27 to 1.98)	<0.001	28.2 (17.5 to 37.5)
0	1		1
Type of smoker
Parental smoking	1.88 (1.53 to 2.31)	<0.001	1.53 (1.21 to 1.93)	<0.001	26.5 (12.6 to 38.1)
Other than parental smoking	1.61 (1.25 to 2.07)	<0.001	1.58 (1.21 to 2.08)	0.001	18.5 (7.0 to 28.6)
No	1		1

*Adjusted for sex, age (months), have siblings, wealth level, water source, father’s educational level and area, which was selected by backward stepwise selection.