Table 4. Coefficients and 95% confidence intervals for the adjusted effect of asthma severity (BTS step) and other predictor variables on standardised attainment, from two separate multiple regression models (active asthma: 882 children, inactive asthma: 462 children).

	asthma	β	95% CI for β		P-value
BTS Step 2,3,4 or 5 vs. 1	inactive	−0.098	−0.259	0.062	0.23
	active	−0.003	−0.097	0.091	0.95
Bronchodilator use (last 12 months)	inactive	NA	NA	NA	NA
	active	0.000	−0.017	0.017	0.98
Bangladeshi vs. White	inactive	−0.110	−0.291	0.071	0.23
	active	0.044	−0.082	0.169	0.49
Other ethnicity vs. White	inactive	0.022	−0.125	0.169	0.76
	active	0.125	−0.019	0.269	0.09
standardised age	inactive	0.095	0.019	0.171	0.01
	active	0.079	0.022	0.136	0.007
girls vs. boys	inactive	0.057	−0.081	0.194	0.42
	active	−0.086	−0.177	0.006	0.07
smoking household (Yes vs. No)	inactive	−0.127	−0.253	−0.001	0.05
	active	−0.020	−0.136	0.095	0.73
Council Tax band (A–C vs. D–H)	inactive	0.038	−0.091	0.168	0.56
	active	0.052	−0.101	0.205	0.50
living in social housing (Yes vs. No)	inactive	−0.029	−0.206	0.149	0.75
	active	−0.045	−0.195	0.105	0.55
in receipt of benefits	inactive	−0.003	−0.172	0.165	0.97
	active	−0.097	−0.245	0.051	0.20
free school meals (Yes vs. No)	inactive	−0.190	−0.330	−0.049	0.009
	active	−0.076	−0.185	0.043	0.207
special educational needs (Yes v No)	inactive	−0.880	−1.067	−0.689	<0.001
	active	−1.024	−1.210	−0.838	<0.001
allergic rhinitis diagnosis (Yes vs. No)	inactive	−0.038	−0.185	0.108	0.60
	active	−0.004	−0.130	0.122	0.95
eczema diagnosis (Yes vs. No)	inactive	−0.076	−0.228	0.075	0.32
	active	0.063	−0.042	0.168	0.24
mental health problems (Yes vs. No)	inactive	−0.143	−0.562	0.276	0.50
	active	0.197	−0.036	0.429	0.10
constant term	inactive	0.593	0.239	0.947	0.001
	active	0.572	0.337	0.806	<0.001