Mental Health Service Use Among Medicare Beneficiaries with Depression, Diabetes and Heart Disease After Cost-sharing Parity

• In Event: From Coverage to Care: Networks, Cost-Sharing, and Access

Abstract

Background
Depression is associated with adverse health outcomes and high healthcare spending among Medicare beneficiaries with comorbid diabetes and heart disease. Beneficiaries with multiple conditions who face financial constraints may forego depression treatment based on perceived need and cost. The Medicare Improvements for Patients and Providers Act of 2008 reduced cost-sharing for outpatient mental health services from 50% prior to 2010 to 20% in 2014, creating parity with outpatient medical care.  

Objective
Our objective was to evaluate changes in outpatient mental health service use and expenditures after parity among Medicare beneficiaries with depression and comorbid diabetes and/or heart disease. 

Data
We analyzed publicly available Medical Expenditure Panel Survey (MEPS) data using the MEPS person-level sample weights to derive nationally representative estimates. Given the wide and varied impact of federal and state policies enacted during the COVID-19 pandemic on mental health service use and delivery beginning in 2020, we restricted our time horizon to pre-pandemic years (2008-2019).  

Study Design
We employed a single-group interrupted time series design to examine changes after parity immediately (level change at parity) and over time (post-parity trend). We estimated Ordinary Least Squares regression models to examine mean and proportion of outpatient mental health service use. We specified two-part models to estimate use among users and out-of-pocket expenditures and reported the average marginal effects. We conducted stratified analysis to assess changes in outcomes after parity by comorbidity status. 

Population
The analytic sample included 2,701 Medicare beneficiaries aged ≥65 years with depression and comorbid diabetes and/or heart disease. This corresponded to a nationally representative sample of 33,466,007 beneficiaries with depression, among whom 34.1% had comorbid diabetes, 42.9% had comorbid heart disease, and 23.0% had both comorbidities.   

Principal Findings
The post-parity trend in mean use increased significantly from 0.186 visits per year (95% CI: 0.06, 0.31) among beneficiaries with depression and diabetes to 0.804 visits per year (95% CI: 0.69, 0.92) among beneficiaries with depression, diabetes, and heart disease. For the latter group, this translated into a relative difference of 3.965 more visits in 2019 compared to the projected counterfactual. Beneficiaries with depression, diabetes, and heart disease also experienced the largest post-parity trend increase in use among users of 0.911 visits per year (95% CI: 0.16, 1.66). Out-of-pocket expenditures did not increase significantly among any group. 

Conclusions
Parity was associated with increasing access to outpatient mental health services without increasing costs to Medicare beneficiaries with depression and comorbid diabetes and/or heart disease. The magnitude of service use increases varied by condition and number of comorbidities. Beneficiaries with depression, diabetes, and heart disease exhibited the greatest price sensitivity to the cost-sharing reductions and equivalence with medical care established by parity. This suggests that parity successfully addressed a key barrier to mental health care among beneficiaries with co-occurring depression and chronic diseases who often experience high medical costs. 

Implications
Policymakers should consider how beneficiaries with comorbidities experience cost barriers to mental health care differently and collaborate with providers to implement complementary policies and clinical practices that effectively address them.

Author

• Sonia M Tetlow, Georgia Budget & Policy Institute
  Presenting Author