Effects of Medicare Advantage on preventive care use and health behavior

To examine the effects of Medicare Advantage (MA) enrollment on preventive care use and health behavior.

The Medicare Current Beneficiary Survey, the Area Health Resources File, the Geographic Variation Public Use File, and the Centers for Medicare and Medicaid Services annual risk and ratebook files for 2012-2016.

Outcomes included 11 measures of preventive care use and six measures of health behavior. My primary independent variable was MA enrollment. For each outcome, I first conducted linear regression analysis while adjusting for individual-level and county-level characteristics. Then, I conducted the following alternative analyses to account for differences in observed and/or unobserved characteristics between MA and traditional Medicare (TM) enrollees: propensity score (PS) matching analysis and instrumental variable (IV) analysis.

I extracted 9399 MA enrollees and 15,543 TM enrollees.

Linear regression and PS matching analyses showed that MA enrollment was statistically significantly associated with higher likelihood of having blood pressure measurement, cholesterol measurement, and influenza vaccine, lower likelihood of receiving an HbA1C test, and higher likelihood of currently smoking. However, the magnitude of the associations was small. There were no statistically significant associations in other measures. IV analyses also found no or limited evidence that MA enrollment led to statistically significant changes in preventive care use and health behavior. Specifically, MA enrollment led to statistically significant improvements in the likelihood of doing any physical activities (1.29 [95% CI: 0.51-2.07]) or doing muscle-strengthening activities (0.72 [95% CI: 0.03-1.41]). No statistically significant changes were observed in other measures.

MA plans may not necessarily increase the use of preventive services and improve health behaviors. As improvements in preventive services and health behavior may have the potential to achieve better outcomes while lowering costs, policy makers should consider developing targeted interventions for MA to achieve those improvements.