Medicaid Expansion
Conditions
Keywords
High-value care, Low-value care
Brief summary
Quasi-experimental pre-post analysis of the rate of high-value and low-value care services between states that expanded Medicaid and states that did not expand Medicaid January 1, 2014, for adult ambulatory visits, using visit-level survey data from the National Ambulatory Medical Care Survey January 1, 2012 - December 31, 2015.
Detailed description
Data Source: Visit level data obtained from the National Ambulatory Medical Care Survey (NAMCS) between January 1, 2012-December 31, 2015. Identification of Observations (Visits) for Primary Analysis: Adult visits in states that did expand Medicaid January 1, 2014 (experimental group) and states that did not expand Medicaid January 1, 2014 (control group). Eight Medicaid expansion states (experimental group): Arizona, California, Illinois, Massachusetts, New Jersey, Ohio, Washington Five states that did not expand Medicaid (control group): Florida, Georgia, North Carolina, Texas, Virginia. Visits will be included only if they could receive a low value service (visits for back pain, headache, general medical exam, URI) or high value service (visits with patients who have CAD, DM, CVD, Depression, CHF, Osteoporosis and no exclusion to receive the indicated high value service) when evaluating low value service counts and high value service counts respectively as opposed to all adult visits regardless of the opportunity to receive a high value or low value care service (e.g. visit for hand pain and none of the high or low value areas above.) Identification of Observations (Visits) for Secondary Analyses: Medicaid patient subpopulation will be defined as those visits for primary analysis that are coded with Medicaid as a pay type for the visit. New Medicaid patient subpopulation will be defined as those visits for primary analysis that are coded with Medicaid as a pay type, have not seen before, to a provider who is accepting new patients and accepts Medicaid for new patients. Create Indicator Variables for Primary and Secondary Outcome Analyses: Develop a set of low value and high value services with distinct inclusion and exclusion criteria for each service. Create indicator variable for each high value and low value service. Low value care measures (Imaging for Low Back Pain, Opioid for Low Back Pain, Opioid for Headache, Imaging for Headache, Antibiotic for Upper Respiratory Infection, General Medical Examination with ECG ordered, General Medical Examination with Urinalysis ordered.) High value care measures (Antiplatelet for CAD, Beta Blocker for CAD, Statin for CAD, Anticoagulation for Atrial Fibrillation, Statin for DM, Antiplatelet CVD, Treatment for Depression, Beta Blocker for CHF, ACE/ARB/ARNI for CHF, Treatment for Osteoporosis) Analysis: Evaluate for pre-intervention (Medicaid Expansion) parallel trends (This has already been established). Then perform pre-post difference-in-differences analyses of primary and secondary outcomes between the experimental group (states that expanded Medicaid) and control group (states that did not expand Medicaid). Regression analysis will be performed to adjust for respondent age, sex, race/ethnicity, number of chronic illnesses, and clinic rural/urban location. Stratified models based on payer type will allow for analyses of the Medicaid population. Perform sensitivity analyses of primary and secondary outcomes.
Interventions
OTHERMedicaid Expansion
Expansion of Medicaid, 01/01/2014
Sponsors
University of Michigan
University of California, Los Angeles
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* ≥18 years old * Visits between 01/01/2012 and 12/31/2015
Exclusion criteria
* \<18 years old * Visits before 01/01/2012 * Visits after 12/31/2015
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Rate of low-value and high-value services for adult ambulatory visits. | pre (01/01/2012 - 12/31/2013) and post (01/01/2014 - 12/31/2015) Medicaid expansion | Ex. Numerator = count of high value services provided for adult visits in Medicaid expansion states in 2012/ Denominator = Count of adult visits in Medicaid expansion state in 2012 that had the potential to receive a high value service. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Adult ambulatory visit volume changes | pre (01/01/2012 - 12/31/2013) and post (01/01/2014 - 12/31/2015) Medicaid expansion | All adults, Medicaid adults, New Medicaid adults |
| Rate of low-value and high-value services for Medicaid adult ambulatory visits | pre (01/01/2012 - 12/31/2013) and post (01/01/2014 - 12/31/2015) Medicaid expansion | Ex. Numerator = count of high value services provided for Medicaid adult visits in Medicaid expansion states in 2012/ Denominator = Count of Medicaid adult visits in Medicaid expansion state in 2012 that had the potential to receive a high value service |
| Rate of low-value and high-value services for New Medicaid adult ambulatory visits. | pre (01/01/2012 - 12/31/2013) and post (01/01/2014 - 12/31/2015) Medicaid expansion | Ex. Numerator = count of high value services provided for New Medicaid adult visits in Medicaid expansion states in 2012/ Denominator = Count of New Medicaid adult visits in Medicaid expansion state in 2012 that had the potential to receive a high value service. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Sensitivity analysis: repeat primary and secondary analysis with all adult visits, Medicaid visits, and New Medicaid visits | pre (01/01/2012 - 12/31/2013) and post (01/01/2014 - 12/31/2015) Medicaid expansion | 1\. Repeat primary and secondary analysis with all adult visits, Medicaid visits and New Medicaid visits with a denominator of all visits (not the denominator of visits with potential to receive low or high value service as described for the primary analyses) |
Countries
United States
Outcome results
None listed