Measuring the cost implications of the Collaborative Accountable Care initiative in Texas

We analyzed changes in healthcare spending associated with the implementation of Cigna's Collaborative Accountable Care (CAC) initiative in a large multi-clinic physician practice. We compared claims from 2009, prior to the CAC initiative, against claims for 2010 to 2011, contrasting the patients covered by Cigna's CAC initiative with patients in other practices in the same geographic area covered by Cigna's medical plan. We used a propensity weighted difference-in-differences approach, adjusting for age, sex, health status, and secular trends to isolate the treatment effect of the CAC. The CAC initiative resulted in a 5.7% reduction in net spending per patient for 2010 to 2011, relative to what spending would have been without the initiative. This reduced spending was evident in multiple service categories: evaluation and management, procedures, imaging, tests, and durable medical equipment. Professional payments, inpatient facility, and outpatient facility payments for Medical Clinic of North Texas enrollees all experienced significant cost savings relative to the control group. About half of the savings resulted from using lower-priced sources. The CAC initiative, which includes an embedded care coordinator and a list of recommended providers, was associated with cost savings similar to those reported by other initiatives, such as global budgets and risk-based contracts.