Comparing self-reported utilization of physician services among Medicare beneficiaries: How do the 'dually eligible' stack up?

Background: Per capita spending among the nearly 9 million older adults with both Medicare and Medicaid coverage—the vulnerable “dually eligible” population—is five times greater compared to those with supplemental coverage (“Medicare and Other”) and basic coverage (“Medicare Only”). However, it is unclear whether duals' high utilization levels are due to lower cost-sharing (Medicaid subsidizes Medicare premiums and copayments for certain low-income duals) that reduces cost barriers to care or to fragmentation of care among duals, which leads to overutilization of services.

Objectives: To assess whether duals' utilization of care is greater relative to other Medicare beneficiaries and whether cost-sharing is associated with duals' utilization levels.

Methods: We examined 28,405 adults 65+ from the 2007 and 2009 California Health Interview Surveys to estimate self-reported annual physician visits using survey-weighted two-part models accounting for health, socioeconomic, and social support confounders. We examined 4,328 duals at three income levels to assess the cost-sharing and utilization relationship.

Results: The mean number of annual visits was 5.9. Duals had a greater risk (RR: 1.1; p<.05) of any visit compared to Medicare Only beneficiaries and reported 1.3 more (~22%) adjusted visits (p<.05) compared to other beneficiaries. Duals with 0-99% and 100-199% FPL had fewer adjusted annual visits (-0.4 and -0.7, respectively; p<.05) compared to those at 200%+ FPL.

Conclusions: The duals population experienced higher utilization compared to other Medicare beneficiaries, but high duals' utilization was not explained by cost-sharing. Additional work is needed to address whether care fragmentation is driving duals' high utilization levels.