Post ACA Reform: Evaluation of Community Health Center Care of Diabetes
Condition: Diabetes Mellitus (DM)
MeSH terms: Diabetes Mellitus
Study type: Observational

Summary: 
      This innovative and timely study will measure the impact of Affordable Care Act (ACA)
      Medicaid expansions on diabetes mellitus (DM) prevention, treatment, expenditures and health
      outcomes. To assess this natural policy experiment, the investigators will use electronic
      health record data from the ADVANCE clinical data research network (CDRN) of the National
      Patient-Centered Clinical Research Network (PCORnet).
    

Detailed description: 
      Diabetes mellitus (DM) is one of the most prevalent chronic diseases, affecting over 29
      million people in the United States (US). The number of people with DM is expected to
      increase by 200% between 2005 and 2050, from 16 to 48 million. Health insurance and continued
      access to healthcare services are essential for optimal DM care and management; thus, it is
      hypothesized that Affordable Care Act (ACA) Medicaid expansions could substantially improve
      access to health insurance and essential healthcare services for patients with DM risk (aged
      ≥45 + overweight) and patients diagnosed with DM. Studies of single state Medicaid expansions
      showed increased utilization of healthcare services, access to providers, receipt of
      preventive care services, and improved health outcomes post-expansion; however, past studies
      did not have concurrent control states. In 2012, the US Supreme Court ruled that states were
      not legally required to implement ACA Medicaid expansion, creating a 'natural policy
      experiment' - a unique national opportunity to test the effect of ACA Medicaid expansion on
      healthcare access and services for patients at risk for DM or diagnosed with DM ('with DM
      risk or DM'). By January 1, 2015, 28 states and the District of Columbia had implemented the
      expansion; Medicaid enrollment increased by an estimated 12.9% in expansion states, compared
      to 2.6% in non-expansion states. The investigators propose to use this unprecedented natural
      policy experiment to study the effect of state-level Medicaid expansions on DM prevention,
      treatment, expenditures, and health outcomes. As many persons affected by both DM and the ACA
      Medicaid expansions receive primary care in safety net community health centers (CHCs), the
      proposed analyses will use electronic health record (EHR) data from the national ADVANCE
      clinical data research network (CDRN) of CHCs (ADVANCE is one of 11 CDRNs in the national
      PCORnet data network). The ADVANCE CDRN has patient-level data from 470 CHCs in 12 Medicaid
      expansion states (n=1,242,823 patients) and 248 CHCs in 9 non-expansion states (n=830,399
      patients). This nationally unique data resource will let the investigators measure pre-post
      DM-related utilization and receipt of preventive services in expansion versus non-expansion
      states, illuminating the impact of ACA Medicaid expansions on DM prevention and treatment Our
      proposed study, Post ACA Reform: EValuation of community hEalth ceNTer care of Diabetes
      (PREVENT-D) has the following specific aims:

      Aim 1. Compare pre-post insurance status, overall visits, and chronic disease management
      visits among patients with DM risk or DM, in expansion versus non-expansion states.

      Aim 2. Compare pre-post receipt of primary and secondary DM preventive services (e.g.,
      screening for obesity, lipid levels, glycosylated hemoglobin) among patients with DM risk or
      DM, in expansion versus non-expansion states.

      Aim 3. Compare pre-post changes in DM-related biomarkers (e.g., body mass index, blood
      pressure, lipid levels) in patients with DM risk or DM among newly insured (gained Medicaid
      in post-period), already insured (had coverage in pre- and post-period), and continuously
      uninsured (no coverage in pre- and post-period) patients in states that expanded Medicaid.

      Aim 4: Measure pre-post changes in Oregon Medicaid expenditures among newly insured compared
      to already insured patients with DM risk or DM.
    

Intervention name(s): Medicaid Expansion
Intervention type(s): Other
Intervention description(s): There will be no direct intervention, but rather an observation of change based on whether a state expanded Medicaid or not
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Study eligible patients within electronic health record data from the ADVANCE clinical data
        research network (CDRN) of PCORnet
      
Keywords: healthcare access; healthcare utilization; health expenditures; preventive services; biomarkers