USE OF CLINICAL PATHWAYS RESULTED IN LOWER IMAGING RATES FOR A MEDICARE POPULATION

Purpose: As Medicare imaging expenditures quadrupled in 1995-2005, reports of inappropriate use and potential harm from additional testing and diagnostic errors also emerged.  To address both cost and quality concerns, CMS reduced imaging Fee-for-Service (FFS) payments in 2006, 2007, and 2010. In addition to similar payment changes, WellPoint Medicare Advantage (MA) plans initiated a radiology utilization management (UM) program in 2005. This study examined the impact of this program on 2008-2011 imaging use.

Method: We obtained Medicare FFS data from a nationally representative 5% sample of Medicare beneficiaries and MA data from HealthCore’s Integrated Research Database (HIRD) including WellPoint affiliated BCBS plans. We compared imaging rates between Medicare FFS, where providers were subject to imaging payment reductions only, and MA, where providers were subject to both payment changes and radiology UM. The primary outcome was change in use of outpatient imaging in Ohio, Indiana, and Kentucky between the years 2008-2011. We also analyzed emergency room (ER) imaging use to examine possible substitution effect. We used propensity score weighting to reduce imbalances in observed covariates and applied regression analysis (including interaction of group and year effect) to compare changes in utilization between the cohorts.

Result: CT scans, MRIs and resting echocardiograms were the most common imaging tests in all years. After weighting, the rate of outpatient imaging declined from 700 per 1000 member-years in 2008 to 654 in 2011 in FFS, compared to a decline from 705 in 2008 to 603 in 2011 in MA, representing declines of 7% and 15%, respectively.  Regression results showed that the UM program reduced utilization by 56 per 1000 enrollees (95% confidence interval, 38 to 74) in the MA group, relative to the FFS group. The ER imaging use increased for both cohorts; however the rate of change for each group was similar (p>0.05).

Conclusion: The presence of a UM program for imaging was associated with a significant reduction in outpatient imaging rates in MA enrollees as compared to FFS Medicare. This result was observed without increased imaging use in the ER setting relative to FFS.  The program we evaluated is an example of how UM initiatives can complement national efforts such as Choosing Wisely and have greater impact as compared to efforts focused solely on payment reduction.