Abstract
BACKGROUND: The initial ecology of medical care study was published in 1961, offering a framework by which to investigate individuals' contact with the medical system. We studied changes in the framework around the implementation of the Patient Protection and Affordable Care Act (ACA) within longer-term trends. METHODS: The 2002-2016 Medical Expenditure Panel Survey was used to determine rates of visit/contact per 1,000 individuals per month for physicians, primary care physicians, specialty physicians, emergency departments, inpatient hospitalizations, dental visits, and home health visits for the overall population and by age group, poverty category, health status, and race/ethnicity. Adjusted Wald tests were used to investigate differences between the pre-ACA (2012-2013) and post-ACA (2014-2015) periods. Multivariable linear regression was used to determine trends over the study period (2002-2016). RESULTS: The survey included 525,804 person-years. The uninsured rate decreased from 12.8% (95% CI, 12.0%-13.7%) in 2013 to 7.6% (95% CI, 7.0%-8.3%) in 2016. From 2002 to 2016, the numbers of individuals in a month who had contact with primary care physicians, dental care, and inpatient hospitalizations decreased. Primary care physician contact decreased most among the elderly and those reporting fair/poor health. After ACA implementation, few significant changes were identified in the overall population or by age, poverty category, race/ethnicity, or health status. CONCLUSIONS: The medical ecology framework was not notably altered 2 years after implementation of the ACA. The long-term decrease in primary care contact does not appear to have been interrupted after implementation of the ACA, was observed across income and age categories, and was most evident among the elderly and individuals reporting fair/poor health.