Air pollution after acute bronchiolitis is a risk factor for preschool asthma: a nested case-control study

Table 3 Associations between subsequent exposure to ambient air pollutants and preschool asthma in acute bronchiolitis infants. (n=2637)

Major air pollutions (per IQR)	OR	95%CI	p-value	aOR^a	95%CI	p-value
0-3 months
SO₂ (ppb)	1.978	1.730-2.262	<.0001	1.977	1.728-2.261	<.0001
PM_2.5 (μg/m³)	2.512	2.149-2.936	<.0001	2.510	2.148-2.935	<.0001
PM₁₀ (μg/m³)	1.518	1.354-1.701	<.0001	1.517	1.354-1.700	<.0001
NO (ppb)	1.922	1.653-2.235	<.0001	1.919	1.651-2.232	<.0001
NO₂ (ppb)	1.625	1.405-1.880	<.0001	1.623	1.403-1.877	<.0001
NOx(ppb)	1.754	1.510-2.038	<.0001	1.752	1.508-2.035	<.0001
0-6 months
SO₂ (ppb)	1.971	1.725-2.253	<.0001	1.970	1.724-2.252	<.0001
PM_2.5 (μg/m³)	2.605	2.216-3.063	<.0001	2.603	2.214-3.061	<.0001
PM₁₀ (μg/m³)	1.535	1.368-1.723	<.0001	1.535	1.368-1.722	<.0001
NO (ppb)	1.918	1.649-2.230	<.0001	1.915	1.647-2.227	<.0001
NO₂ (ppb)	1.630	1.406-1.890	<.0001	1.628	1.404-1.887	<.0001
NOx(ppb)	1.740	1.500-2.020	<.0001	1.738	1.497-2.017	<.0001
0-12 months
SO₂ (ppb)	2.042	1.779-2.343	<.0001	2.040	1.777-2.342	<.0001
PM_2.5 (μg/m³)	2.538	2.172-2.966	<.0001	2.538	2.172-2.965	<.0001
PM₁₀ (μg/m³)	1.559	1.394-1.743	<.0001	1.559	1.394-1.744	<.0001
NO (ppb)	1.952	1.676-2.275	<.0001	1.950	1.673-2.272	<.0001
NO₂ (ppb)	1.645	1.422-1.903	<.0001	1.643	1.420-1.901	<.0001
NOx(ppb)	1.771	1.525-2.058	<.0001	1.769	1.523-2.056	<.0001

ORs (95% Cis) were estimated for per IQR increase in SO₂, PM_2.5, PM_10, NO, NO_2, and NO_X
Abbreviations: SO₂: sulphur dioxide; PM_2.5: particulate matters with diameters at 2.5 micrometers and smaller; PM₁₀: particulate matters with diameters at 10 micrometers and smaller; NO: nitrogen oxide; NO₂: nitrogen dioxide; NO_X: nitrogen oxides; OR: crude odds ratio; aOR: adjusted odds ratio
^aConditional logistic regressions were conducted controlling baseline demographic characteristics age, gender, allergic rhinitis, chronic sinusitis, and atopic dermatitis

ISSN: 1476-069X