Correlation between indoor air pollution and adult respiratory health in Zunyi City in Southwest China: situation in two different seasons

Table 4 Comparison of the median kitchen risk score and sleeping-area risk score among subjects with asthma-like symptoms and asthma and those without such symptoms in winter and summer

Asthma-like symptoms and asthma	Winter (n = 1207)		Summer (n = 610)
Asthma-like symptoms and asthma	Median score for kitchen risk factor (25th, 75th percentiles)	Median score for sleeping- area risk factor (25th, 75th percentiles)	Median score for kitchen risk factors (25th,75th percentiles)	Median score for sleeping area risk factors (25th,75th percentiles)
Subjects with asthma-like symptoms and asthma	6.0 (5.0–8.0)	3.0 (1.0–5.0)	3.5 (2.0–7.0)	2.0 (0.75–4.25)
Subjects without asthma-like symptoms and asthma (n = 1049)	6.0 (4.0–7.0)	2.0 (1.0–4.0)	2.0 (1.0–5.0)	2.0 (1.0–3.0)
Z value	−4.481^a	−4.007^a	−3.06^a	−1.46^a
p value	< 0.001***	< 0.001***	0.002**	0.144

^aNonparametric test (Mann–Whitney U test), α = 0.05; *significant at p < 0.05, **significant at p < 0.01, *** significant at p < 0.001