Should eligibility for medication therapy management be based on drug adherence?

BACKGROUND: Medicare Part D prescription drug plans must offer medication therapy management (MTM) services to qualified enrollees. Eligibility criteria used by plan sponsors are restrictive, and fewer than 10% of Part D enrollees receive MTM services. The extent to which plan criteria identify beneficiaries most at risk for suboptimal medication use is unknown.
OBJECTIVES: To (a) evaluate potential underuse of and poor adherence to evidence-based medications used in the treatment of Medicare beneficiaries with diabetes, heart failure, and chronic obstructive pulmonary disease (COPD) over 3 years; (b) determine whether MTM eligibility criteria used by the modal Part D plan in 2011 (drug spending ≥ $3,000, ≥ 3 chronic conditions, ≥ 8 Part D medications) identified Part D enrollees at greatest risk for underuse of and poor adherence to these drugs; and (c) demonstrate how sensitive MTM eligibility is to variations in criteria levels.
METHODS: Study subjects were selected from a 5% random sample of Part D enrollees with 1 or more of these diseases in 2006 and followed through 2008 or death. Longitudinal patterns of exposure and adherence to angiotensin-converting-enzyme inhibitor/angiotensin receptor blockers, beta-blockers, and COPD controller drugs were tracked comparing patterns for enrollees meeting/not meeting the modal 2011 MTM eligibility criteria.
RESULTS: Use of evidence-based medication was consistently suboptimal for every disease cohort studied. Higher rates of exposure and adherence were observed among those with high drug spending taking multiple Part D drugs. Current MTM criteria were found to target beneficiaries with above average utilization of evidence-based medication and to exclude those with more problematic utilization patterns. We estimate that lowering the maximum required drug count from 8 to 2 would increase the percentage of beneficiaries eligible for MTM by two thirds.
CONCLUSIONS: Our findings suggest that MTM eligibility criteria are not optimally targeted to capture underuse of and poor adherence to evidence-based medications. Policymakers should weigh the pros and cons of loosening restrictive MTM eligibility criteria to target patients with potentially greater needs.