NEJM: Healthcare reform sees little change in ED utilization
Does an expansion of health insurance increase or decrease use of the emergency department (ED)? Both possibilities can be justified, according to a perspective published in the New England Journal of Medicine Sept. 7. On the one hand, research on patient cost sharing predicts that reducing the out-of-pocket costs of an ED visit and expanding insurance coverage, especially in the face of physician shortages, could result in increased ED utilization.

Some have cited Massachusetts healthcare reform, claiming that if anything, universal coverage brought higher rates of emergency room visits due to difficulty in obtaining appointments with outpatient physicians. Others predict that expanded coverage will reduce ED use, since previously uninsured patients would now have access to preventive care.

A survey of emergency physicians conducted in April 2010 revealed that more than 70 percent of the physician respondents said they expected emergency visits to increase after passage of the Patient Protection and Affordable Care Act (PPACA).

To explore the importance of these effects, Christopher Chen, BA, from Washington University School of Medicine in St. Louis, and colleagues examined Massachusetts’ healthcare reform experience. The findings were published in the Sept. 22 edition of The New England Journal of Medicine.

The state's 2006 healthcare reform was a model for the PPACA and reduced the proportion of Massachusetts adults under age 65 who were uninsured by 7.7 percentage points between 2006 and 2009. To determine whether any changes in ED utilization in Massachusetts reflected the effects of reform or were representative of broader regional trends in ED utilization, researchers used New Hampshire and Vermont as control states.

Chen and colleagues examined quarterly ED visits before and after implementation of two waves of Massachusetts healthcare reform law. In the first wave, Commonwealth Care, a new state-subsidized private insurance plan, opened enrollment in October 2006 (initially to people with incomes below 100 percent of the federal poverty level and later including those with incomes up to 300 percent of the federal poverty level). Within one year, employers with 11 or more full-time employees were required to make a “fair and reasonable” contribution toward an employee healthcare plan or pay a per-employee assessment. In the second wave, adults in Massachusetts were required to have health insurance or face financial penalties beginning in January 2008.

The data on combined inpatient and outpatient ED use suggest that Massachusetts healthcare reform did not change ED utilization relative to the states where no such reform was enacted. The continuous upward trend in ED utilization throughout three separate test periods is consistent from state to state. Researchers said if they didn't know which state had implemented reform they could not guess on the basis of the data.

Although the majority of ED visits are outpatient, inpatient visits to the ED account for a large fraction of the ED costs (approximately 65 percent). On the basis of their findings, Chen and colleagues concluded that Massachusetts' healthcare reform law “neither increased nor decreased ED utilization relative to that in other states.”

The findings underscore the problem with evaluating policies by looking only at single trends and not examining simultaneous countervailing trends or comparable trends that cannot be attributed to policies, the researchers offered. “The opportunities to repeat this mistake will be even greater when it comes to evaluating the PPACA, since it will be difficult to find appropriate controls, and rigorous evaluations will rely on variation in reform related to differences in timing or state-level variations in their implementation,” Chen and Scheffler wrote. “This may seem obvious, but its validity was ignored by those who concluded that Massachusetts reform caused an increase in ED use simply because ED use was higher after reform.”