Disparity implications of utilization-based eligibility criteria for medication therapy management services

Background: Since January 1, 2006, the Centers for Medicare and Medicaid Services have required prescription drug plans to offer medication therapy management services (MTMS) for Medicare Part D beneficiaries meeting three criteria: having multiple chronic conditions, using multiple covered drugs, and/or being likely to incur over $4,000 (in 2006 dollars) in annual drug costs. Racial and ethnic minorities may be less likely to qualify for MTMS according to these utilization-based criteria since minorities tend to use fewer drugs than their majority counterparts.

Methods: Using the Medical Expenditure Panel Survey (2004-2005) and logistic regression, we examined whether there would be disparities in eligibility fulfillment for any possible combinations of the three MTMS criteria among Medicare beneficiaries. Racial and ethnic disparities were examined by comparing non-Hispanic blacks with non-Hispanic whites, and comparing Hispanic whites with non-Hispanic whites, respectively. Multivariate logistic regression was used to adjust for possible differences in sociodemographic characteristics between groups. The eligibility thresholds used were $4,000 in 2006 dollars, 3 medical conditions and/or 6 drugs. Sensitivity analyses were conducted using variations of these thresholds.

Results: Among Medicare beneficiaries, the odds ratios for meeting the eligibility criteria for non-Hispanic blacks, compared to non-Hispanic whites, ranged from 0.191 to 0.813. Odds ratios for Hispanic whites ranged from 0.054 to 0.775. Most odds ratios were statistically significant (p<0.05).

Conclusion: Non-Hispanic blacks and Hispanic whites would be less likely to qualify for MTMS than non-Hispanic whites. Decision-makers need to be cautions when determining eligibility criteria.