Association of ambient air pollution and meteorological factors with primary care visits at night due to asthma attack

Table 4 Associations between air pollutants and primary care visits at night due to asthma attack by seasonal subgroups (multi pollutant model)

Meteorological elements/air pollutants	Unit increment	April–June			July–August			September–November			December–March
Meteorological elements/air pollutants	Unit increment	OR	95 % CI		OR	95 % CI		OR	95 % CI		OR	95 % CI
Atmospheric pressure	1 hPa	1.020	0.985	1.058	1.025	0.985	1.067	1.004	0.972	1.037	1.013	0.969	1.058
Relative humidity	10 %	1.239	0.981	1.564	1.319	0.800	2.172	0.787	0.608	1.018	1.183	0.847	1.652
Temperature	1 °C	1.029	0.96	1.103	1.306	1.092	1.561	0.980	0.938	1.023	1.043	0.970	1.121
Wind speed	1 m/s	1.001	0.801	1.252	1.019	0.796	1.304	0.878	0.713	1.082	0.965	0.710	1.312
Hours of daylight	1 h	1.015	0.959	1.073	0.963	0.888	1.044	0.939	0.895	0.986	1.046	0.974	1.123
NO₂	10 ppb	0.953	0.606	1.497	1.158	0.494	2.713	1.274	0.718	2.263	0.466	0.202	1.072
Ozone	10 ppb	1.012	0.853	1.201	1.128	0.933	1.365	1.043	0.807	1.346	0.495	0.284	0.862
SPM	10 μg/m³	0.948	0.817	1.101	0.951	0.726	1.246	0.948	0.782	1.151	0.724	0.524	0.999

Associations are shown as ORs and their 95 % CIs per unit increment of each indices

ISSN: 1347-4715