Table 5

OLS regression model results for female age-height standardised FEV₁ by social class of head of household, ambient air quality index quintile and both adjusting for potential confounders

Women aged 16–79: n = 14849	(a) Social class model			(b) Ambient air quality model			(c) Reciprocally adjusted model
*β coefficient of −0.01 shows FEV₁ 1% lower than expected given age and height.
Model α/constant:	0.992			0.989			1.005
Explanatory variables	β*	95% CI	p	β	95% CI	p	β	95% CI	p
Ambient air quality index: Good	Ref group
Poor				−0.019	−0.026, −0.013	<0.001	−0.018	−0.025, −0.012	<0.001
Social class of head of household: I–II	Ref group
III–V	−0.027	−0.033, −0.021	<0.001				−0.026	−0.033, −0.020	<0.001
HSE survey year: 1995	Ref group
1996	0.012	0.005, 0.018	<0.001	0.012	0.006, 0.019	<0.001	0.012	0.005, 0.018	<0.001
1997	0.019	0.011, 0.026	<0.001	0.019	0.011, 0.026	<0.001	0.019	0.011, 0.026	<0.001
Smoking status: Never	Ref group
Former	0.002	−0.005, 0.009	0.550	0.002	−0.004, 0.009	0.485	0.002	−0.005, 0.009	0.586
Current	−0.052	−0.059, −0.045	<0.001	−0.056	−0.063, −0.048	<0.001	−0.052	−0.059, −0.044	<0.001
Passive smoke exposure: No	Ref group
Yes	−0.015	−0.025, −0.006	0.001	−0.018	−0.028, −0.009	<0.001	−0.015	−0.024, −0.005	0.002
Urban-rural category: Urban	Ref group
Rural	0.020	0.012, 0.029	<0.001	0.012	0.003, 0.021	0.009	0.009	0.000, 0.018	0.062
Body mass index: <20	Ref group
>20 to 25	0.046	0.034, 0.059	<0.001	0.048	0.035, 0.060	<0.001	0.046	0.034, 0.059	<0.001
<25 to 30	0.033	0.020, 0.045	<0.001	0.032	0.019, 0.045	<0.001	0.032	0.019, 0.045	<0.001
>30	0.009	−0.005, 0.023	0.192	0.007	−0.007, 0.020	0.336	0.009	−0.004, 0.023	0.183
Ever diagnosed with asthma: No	Ref group
Yes	−0.060	−0.070, −0.050	<0.001	−0.060	−0.070, −0.050	<0.001	−0.060	−0.070, −0.050	<0.001
Used inhaler in previous 24 hours: No	Ref group
Yes	−0.131	−0.145, −0.118	<0.001	−0.133	−0.146, −0.119	<0.001	−0.132	−0.145, −0.118	<0.001