Association of the Patient Protection and Affordable Care Act With Ambulatory Quality, Patient Experience, Utilization, and Cost, 2014-2016.

IMPORTANCE

The Patient Protection and Affordable Care Act (ACA) expanded Medicaid eligibility at the discretion of states to US individuals earning up to 138% of the federal poverty level (FPL) and made private insurance subsidies available to most individuals earning up to 400% of the FPL. Its national impact remains debated.

OBJECTIVE

To determine the association of the ACA with ambulatory quality, patient experience, utilization, and cost.

DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used difference-in-differences (DiD) analyses comparing outcomes before (2011-2013) and after (2014-2016) ACA implementation for US adults aged 18 to 64 years with income below and greater than or equal to 400% of the FPL. Participants were respondents to the Medical Expenditure Panel Survey, a nationally representative annual survey. Data analysis was performed from January 2021 to March 2022.

EXPOSURES

ACA implementation.

MAIN OUTCOMES AND MEASURES

For quality and experience, this study examined previously published composites based on individual measures, including high-value care composites (eg, preventive testing) and low-value care composites (eg, inappropriate imaging), an overall patient experience rating, a physician communication composite, and an access-to-care composite. For utilization, outpatient, emergency, and inpatient encounters and prescribed medicines were examined. Overall and out-of-pocket expenditures were analyzed for cost.

RESULTS

The total sample included 123 171 individuals (mean [SD] age, 39.9 [13.4] years; 65 034 women [52.8%]). After ACA implementation, adults with income less than 400% of the FPL received increased high-value care (diagnostic and preventive testing) compared with adults with income 400% or higher of the FPL (change from 70% to 72% vs change from 84% to 84%; adjusted DiD, 1.20%; 95% CI, 0.18% to 2.21%; P = .02) with no difference in any other quality composites. Individuals with income less than 400% of the FPL had larger improvements in experience, communication, and access composites compared with those with income greater than or equal to 400% of the FPL (global rating of health, change from 69% to 73% vs change from 79% to 81%; adjusted DiD, 2.12%; 95% CI, 0.18% to 4.05%; P = .03). There were no differences in utilization or cost, except that receipt of primary care increased for those with lower income vs those with higher income (change from 65% to 66% vs change from 80% to 77%; adjusted DiD, 2.97%; 95% CI, 1.18% to 4.77%; P = .001) and total out-of-pocket expenditures decreased for those with lower income vs those with higher income (change from $504 to $439 vs from $757 to $769; adjusted DiD, -$105.50; 95% CI, -$167.80 to -$43.20; P = .001).

CONCLUSIONS AND RELEVANCE

In this cross-sectional national study, the ACA was associated with improved patient experience, communication, and access and decreased out-of-pocket expenditures, but little or no change in quality, utilization, and total cost.