Medicaid Expansion Linked With Reduction in Uninsurance and Improved Blood Pressure, Glucose Control Measures

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Results of a representative study of patients at federally qualified health centers found Medicaid expansion was associated with reduced rates of uninsurance, improved blood pressure and diabetes control measures, and progress in closing racial care disparities over 5 years.

Results of a nationally representative cohort study revealed Medicaid expansion was associated with better 5-year health performance outcomes for federally qualified health centers (FQHCs). In particular, data showed FQHCs in Medicaid-expanded states experienced improved blood pressure and glucose control measures over 5 years for Black and Hispanic patients when compared with data from FQHCs in nonexpansion states. Findings were published in JAMA Health Forum.

FQHCs provide primary care services to almost 30 million low-income Americans without concern for ability to pay, and typically serve 1 in 5 Medicaid enrollees, 1 in 5 rural residents, and 1 in 3 individuals with an income lower than the federal poverty level (FPL), authors explained.

“In 2013, before implementation of Medicaid expansion under the US Affordable Care Act (ACA), 44% of adults who were utilizing FQHCs did not have insurance, 92% had incomes less than 200% of the FPL, and 65% were members of racial and ethnic minority groups,” they added.

Although previous research has showed Medicaid expansion was associated with improved quality of care and increased service capacity at FQHCs in the short term, limited evidence exists regarding longer-term associations of expansion with FQHCs across the country.

To address this knowledge gap, investigators examined 5-year changes in uninsurance, blood pressure, and glucose control following Medicaid expansion using a representative sample of all FQHCs.

As uninsured and underinsured individuals with hypertension and diabetes often forgo effective treatment that can improve outcomes, and because these 2 conditions disproportionately affect some racial and ethnic minority groups, researchers focused their analyses of FQHC-level performance on blood pressure and glucose control data.

Publicly available information was gleaned from the Health Resources and Services Administration 2012-2018 Uniform Data System. To measure 5-year outcomes, only FQHCs in states that had expanded Medicaid by the end of 2014 were included in analyses.

“A total of 578 FQHCs (61.1%) were in Medicaid expansion states, representing 13 million patients per year at baseline, and 368 FQHCs (38.9%) were in nonexpansion states, representing 6 million patients per year at baseline,” researchers wrote.

Using difference-in-differences analyses, investigators assessed data in expansion and nonexpansion states before (2012-2013) vs after (2014-2018) expansion. Of the patients served at all 946 FQHCs, 64.4% were aged between 18 and 64 years, 57.4% were women, 18.9% were non-Hispanic Black, and 27.3% were Hispanic.


Overall, researchers found:

  • Following expansion, FQHCs in Medicaid expansion states experienced a 9.24 percentage point (PP) (95% CI, 7.94-10.54) decline in rates of uninsurance over the 5-year period compared with non–expansion-state FQHCs.
  • Over 5 years, expansion was associated with a 1.61-PP (95% CI, 0.58-2.64) comparative improvement in hypertension control and a 1.84-PP (95% CI, 0.71-2.98) comparative improvement in glucose control.
  • Stratified results suggest that improvements were consistently observed in Black and Hispanic populations.
  • Magnitude of change tended to increase with implementation time, as by year 5, expansion was associated with a 3.38-PP (95% CI, 0.80-5.96) comparative improvement in hypertension control and a 3.88-PP (95% CI, 0.86-6.90) comparative improvement in glucose control among Black populations.
  • A 2-PP increase in hypertension control across all FQHCs equates to nearly 100,000 additional patients with hypertension at FQHCs with blood pressure control.

“We observed larger associations between expansion and health outcome measures in the long vs short term following expansion, suggesting that intermediate outcomes, such as blood pressure and glucose control, may take time to improve following coverage expansions,” authors noted.

In addition, as expansion may also improve the financial revenue of FQHCs, these centers may be able to expand capacity or invest in quality improvement interventions.

Because previous research also showed that racial disparities in blood pressure control and hypertension among FQHCs patients persist, researchers stressed insurance alone will not eliminate these disparities. “Black, Hispanic, and American Indian/Alaskan Native patients face systemic inequities and structural racism that make it especially difficult to control blood pressure and glucose levels,” they said.

Authors were unable to adjust for individual-level factors, meaning they were unable to distinguish how gains in insurance coverage for patients vs gains in patient revenue for FQHCs were associated with outcomes, marking a limitation to the study.

“These findings suggest that over the long term, expanding Medicaid in all states may improve chronic disease health outcome measures at FQHCs, which provide care to millions of underserved patients,” they concluded.


Cole MB, Kim J, Levengood TW, and Trivedi AN. Association of Medicaid expansion with 5-year changes in hypertension and diabetes outcomes at federally qualified health centers. JAMA Health Forum. Published online September 10, 2021. doi:10.1001/jamahealthforum.2021.2375