Table 3.

Estimated Impacts of the 2011 Coding Change on Payments and Utilization

Parameter	Estimate	% Change	SE	p
Payments
CT of the abdomen or of the pelvis (the reference group)
Intercept	6.0418	–	0.0087	<.0001***
Slope	0.0013	+0.13	0.0004	.0017**
Change in intercept in 2011	−0.0055	−0.55	0.0097	.5735
Change in slope in 2011	0.0033	+0.33	0.0013	.0089**
CT of the abdomen and pelvis (w.r.t. the reference group)
Intercept	0.5665	+76.21	0.0057	<.0001***
Slope	−0.0000	−0.00	0.0004	.9919
Change in intercept in 2011	−0.2740	−23.97	0.0104	<.0001***
Change in slope in 2011	−0.0036	−0.36	0.0014	.0083**
Other covariates
Health plan type	–	–	–	<.0001***
State	–	–	–	<.0001***
Utilization
CT of the abdomen or of the pelvis (the reference group)
Intercept	−10.8499	–	0.0105	<.0001***
Slope	−0.0012	−0.12	0.0005	.0171*
Change in intercept in 2011	−0.0511	−4.98	0.0120	<.0001***
Change in slope in 2011	0.0044	+0.44	0.0016	.0045**
CT of the abdomen and pelvis (w.r.t. the reference group)
Intercept	1.6169	+403.74	0.0074	<.0001***
Slope	0.0018	+0.18	0.0006	.0010***
Change in intercept in 2011	0.0663	+6.85	0.0131	<.0001***
Change in slope in 2011	0.0036	+0.36	0.0017	.0338*
Other covariates
Health plan type	–	–	–	<.0001***
State	–	–	–	<.0001***
Weekend indicator	−0.8456	−57.07	0.0032	<.0001***
Dispersion	0.0726	–	0.0007	–

Estimates of effects for individual health plan types and states are not reported due to limited space. Full table with all estimated coefficients is available in the appendix.

*p ≤ .05; **p ≤ .01; ***p ≤ .001.