Medicare Shared Savings Program Fails to Improve Diabetes Adherence

The Medicare Shared Savings Program failed to improve medication use or increase adherence among patients with cardiovascular disease or diabetes, according to a recent study in JAMA Cardiology. 

“Accountable care organizations (ACOs) in the Medicare Shared Savings Program are eligible for shared savings bonuses if spending for their patient population falls below a financial benchmark,” J Michael McWilliams, MD, PhD, of the department of health care policy at Harvard Medical School, and colleagues, wrote. “Improving medication use and adherence may be additionally attractive to ACOs as a strategy to achieve savings because the Medicare Shared Savings Program does not include Part D prescription drug spending in an ACO’s spending or benchmark. Thus, increasing patients’ use of prescription drugs to improve performance on quality measures or to lessen the need for nondrug services may support greater shared-savings bonuses than other quality improvement efforts or substitutions that require increases in certain nondrug services.”

In order to determine if ACO participation in the Medicare Shared Savings Program had any impact on outcomes or adherence, the researchers studied fee-for-service Medicare claims for use of antihypertensive, lipid-lowering, and hypoglycemic medications. They gathered claims data from 2009 to 2014 and conducted difference in difference comparisons of changes for patients in ACOs from the time before ACO-attribution to the time after. Drug classes included in the study were statins, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, beta-blockers, thiazide diuretics, calcium channel blockers, and metformin.

Study results showed that, when comparing pre-ACO participation to post-ACO participation, there were no significant changes in medication use among the drug classes studied, aside from a slight differential increase in the use of thiazides among beneficiaries with hypertension. They found that the proportion of days covered by 1 prescription fill did not change significantly after ACO participation initiated, except in the case of beta-blockers for one year of the study. —David Costill