Contribution of smoking and air pollution exposure in urban areas to social differences in respiratory health

BMC Public Health

Table 1 Distribution of SES (educational level) in the study group and the prevalence of women with impaired respiratory health by SES

	SES: all grades		<10 years		= 10 years of school education		>10 years
	N	%	N	%	N	%	N	%
SES	1251	100	318	25.4	637	50.9	296	23.7
Indicators of impaired respiratory health									p-value ¹ of linear trend effect of SES
Frequent cough	1247	26.3	316	30.1	636	26.7	295	21.4	0.0152
Frequent cough with phlegm production	1240	12.9	312	16.0	633	12.3	295	10.9	0.0561
Chronic bronchitis diagnosed by a physician	1245	11.2	317	10.1	635	12.9	293	8.5	0.5785
Bronchial asthma	1238	3.6	312	4.8	632	3.6	294	2.0	0.0683
COPD	1207	4.1	303	5.3	614	4.9	290	1.4	0.0193
FEV ₁ <80% predicted	1251	20.5	318	24.5	637	20.9	296	15.2	0.0045
FVC <80% predicted	1251	26.8	318	33.3	637	26.2	296	21.0	0.0005

^!Cochran-Mantel-Haenszel test
Abbreviations:
FEV₁: Forced expiratory volume in 1 second; FVC: Forced vital capacity; COPD: Chronic obstructive pulmonary disease

ISSN: 1471-2458