Table 1

Analyses of covariance showing effect of (1) the Disability Discrimination Act (DDA); (2) being defined as “disabled”; and (3) the interaction between disability and the DDA on employment rate (overall and by social class)

Variable	Regression coefficient	t value*	Significance	95% CI
*All parameters have 1 degree of freedom.
†Interaction term combining disability status with implementation of the DDA.
Model 1: For all employment rates adjusted for social class and year
DDA (1998–2003)	5.51	2.08	0.041	0.23 to 10.79
Disability	−21.13	−15.28	<0.001	−23.87 to −18.38
Disability × DDA†	−6.78	−3.17	0.002	−11.04 to −2.53

Model 2: For employment rates social classes I and II adjusted for year
DDA (1998–2003)	6.07	1.75	0.096	−1.18 to 13.31
Disability	−14.85	−8.28	<0.001	−18.63 to −11.08
Disability×DDA†	−2.86	−1.02	0.319	−8.70 to 2.99

Model 3: For employment rates social class IIIN adjusted for year
DDA (1998–2003)	2.95	0.995	0.332	−3.26 to 9.16
Disability	−18.22	−11.79	<0.001	−21.45 to −14.98
Disability×DDA†	−5.22	−2.18	0.042	−10.23 to −0.21

Model 4: For employment rates social class IIIM adjusted for year
DDA (1998–2003)	6.10	3.31	1.85	−0.82 to 13.02
Disability	−25.19	−14.64	<0.001	−28.79 to −21.59
Disability×DDA†	−8.36	−3.13	0.005	−13.94 to −2.78

Model 5: For employment rates social classes IV and V adjusted for year
DDA (1998–2003)	6.92	2.58	0.019	1.30 to 12.55
Disability	−26.25	−18.75	<0.001	−29.18 to −23.32
Disability×DDA†	−10.7	−4.94	<0.001	−15.24 to −6.16