Effect of Medicare Advantage on health care use and care dissatisfaction in mental illness

Objective: To examine the effects of Medicare Advantage (MA) enrollment on health care use and dissatisfaction with care received among Medicare beneficiaries with mental illness. Data Sources: I identified traditional Medicare (TM) and MA beneficiaries with mental illness using the Medicare Current Beneficiary Survey for 2012–2016. Study Design: I included two types of outcomes: four measures of health care use and 10 measures of care dissatisfaction. My primary independent variable was enrollment in TM versus MA. To address selective enrollment into MA, I used an instrumental variable (IV) approach. Following prior research, I decomposed the MA benchmark into exogenous and endogenous components and then used the exogenous component as my instrument. Data Collection/Extraction Methods: Not Applicable. Principal Findings: IV analyses showed that compared with TM enrollment, MA enrollment significantly decreased outpatient hospital visits and medical provider visits by 6.73 (95% CI: −12.10 to −1.36) and 36.48 (95% CI: −52.67 to −20.28). However, there were no significant changes in inpatient hospital admissions and prescription drug purchases. Compared with TM enrollment, MA enrollment significantly increased dissatisfaction with out-of-pocket expenses by 25.51 percentage points (95% CI: 0.43 to 50.60). However, there were no significant changes in other measures of care dissatisfaction in terms of access to care, quality of care, and prescription medication. Conclusions: These findings suggest that MA enrollment may lead to low health care use among those with mental illness, indicating efficient care delivery. Also, MA enrollment may not preclude those with mental illness from accessing needed care. However, high dissatisfaction with out-of-pocket expenses among MA beneficiaries may imply the use of out-of-network providers. Further research is warranted to investigate whether high dissatisfaction with out-of-pocket expenses may be attributable to MA's narrow networks for mental services.