CHICAGO – The 2006 Massachusetts health care reform law that expanded insurance coverage to unprecedented levels resulted in modest increases in emergency department and hospital utilization among adults, according to preliminary results from a large observational study.
For adults under age 65, ED visits increased from 1,970,976 in 2005 to 2,279,492 in 2009, while hospitalizations increased from 457,298 to 490,458.
Adults older than 65 years had 450,933 ED visits before reform and 470,109 ED visits after reform, while hospitalizations in this group totaled 223,229 before and 300,596 after reform.
The rate of uninsured patients decreased over the same period, from 6.2% to 3.7% among ED patients and from 1.3% to 0.6% among hospitalized patients, Dr. Peter Smulowitz, an instructor in medicine at Harvard Medical School in Boston, said at the annual meeting of the Society for Academic Emergency Medicine.
In regression modeling that controlled for secular trends and other confounders, the increased insurance rates had a positive but nonsignificant effect on ED visits among those under age 65 (P = .09) and a significant, positive impact on those over 65 (P = .01).
Increasing insurance predicted increasing hospitalizations for the under-65 population (P = .03), while there was a negative effect for increasing insurance on hospitalizations for the over-65 population (P = .003).
The modest, nonsignificant uptick in ED use among younger adults may represent barriers in access to primary care, Dr. Smulowitz suggested. "The results are mostly consistent with our hypothesis that limitations and access to care will make it so that patients who are newly insured will not necessarily have another place to gain care, and so emergency department visits will remain constant, if not slightly increase, and hospitalizations might increase as well," he said.
The 2006 Massachusetts law has been used as a model for the Affordable Care Act and is being closely watched. Many physicians thought insurance would increase ED use because of continued barriers in access to care, while many policy makers thought reform efforts would result in a dramatic decrease in ED visits, Dr. Smulowitz observed.
Earlier research showed a null effect of the 2006 law on ED use in Massachusetts compared with neighboring Vermont and New Hampshire (N. Engl. J. Med. 2011;365:e25).
The current analysis compared geographic differences, at the zip code level, in the percentage of uninsured during a 1-year period before health care reform and an identical period after reform using administrative data from 2005 to 2009 in the Massachusetts Division of Health Care Finance and Policy Acute Hospital Case Mix database. Overall, there were 2,421,909 ED visits and 680,527 hospitalizations before reform and 2,580,088 ED visits and 791,054 hospitalizations after reform.
Session moderator Dr. Katherine Heilpern, chair of emergency medicine at Emory University in Atlanta, said the findings of a modest increase in ED and hospital utilization fly in the face of dire headlines about the Massachusetts experience, and asked whether the issue is just a matter of granularity.
Dr. Smulowitz responded that the ability to delve into the data over several years and to control for secular trends provides a very different take than just looking at raw numbers. He said additional models are warranted to further clarify the findings, particularly in terms of comparing differences in ED and hospitalization rates between the under- and over-65 populations.
He also stressed that the data are preliminary, and acknowledged that the study was limited by assumptions that the population within a zip code remains stable over time and that the changing insurance rate mirrors the overall population.
Dr. Smulowitz reported funding from the Charles A. King Trust Postdoctoral Research Fellow program and the Eleanor and Miles Shore Fellowship Program for Scholars in Medicine.