Table 1.

Differential changes in antidepressant use and adherence for ACOs compared with control group¹ among beneficiaries with depression

	Pre-contract period2			Differential change from pre-contract period to post period, ACOs vs. control group
	Unadjusted mean (in 2011)	Difference between ACOs and control group	Difference in trend between ACOs and control group	Post year 2012	Post year 2013
Pioneer ACOs3
Total days supplied	223.7	.5	1.1	4.2**	2.2
Any antidepressant use, %	83.0	.2	.2	.3	−.4
Among antidepressant users, proportion of days covered by days supplied, %	78.1	.2	−.1	.8**	.9*
MSSP ACOs4
Total days supplied	223.7	3.4***	−.4	N/A	−.5
Any antidepressant use, %	83.0	.1***	−.1	N/A	−.5*
Among antidepressant users, proportion of days covered by days supplied, %	78.1	.3	−.1	N/A	.4*

^*p<.05

^**p<.01

^***p<.001

¹Control group consists of beneficiaries attributed to providers that did not enter into an ACO contract (either Pioneer or MSSP) with Medicare by 2013.

²The pre-contract period took place between 2009–2011 for the Pioneer and 2012 MSSP ACOs and between 2009–2012 for the 2013 MSSP ACOs.

³Pioneer ACO sample size: pre-contract period N=19,502 person-years, post-year 2012 N=7,577; post-year 2013 N=7,963. Control group pre-contract period N=446,508 person-years; post year 2012 N= 172,487 person-years, 2013 N= 186,701 person-years.

⁴MSSP ACO sample size: 2012 entry MSSP pre-contract period N=38,062 person-years; 2013 entry MSSP pre-contract period N=43,008 person-years; 2012 entry MSSP post-year 2013 N=16,112; 2013 entry MSSP post-year 2013 N=14,246. 2012 entry MSSP pre-contract period control group N=446,508 person-years, 2013 entry MSSP pre-contract period control group N=619,355 person-years; 2012/2013 entry MSSP post-contract period control group N=186,701 person-years.