The Massachusetts study concludes that medical "consultant availability in the emergency department decreased for many specialties, including general surgery, orthopedics, plastic surgery, obstetrics/gynecology, and psychiatry. … At least in one state, it has become more difficult for patients to obtain the emergency specialty care they need."

The Illinois report says the trend was because of "a large post-ACA increase in Medicaid visits and a modest increase in privately insured visits [which] outpaced a large reduction in ED visits by uninsured patients. These changes are larger than can be explained by population changes alone and are significantly different from trends in ED use before ACA implementation."

Taken together, the conclusions of the studies indicate that emergency departments are under greater strain since the act's passage.

"During the studied period, the burden of increasing patient volume was clear," says Jason Sanders, MD, PhD, of the Department of Emergency Medicine at Massachusetts General Hospital in Boston. "The proportion of emergency departments reporting any patients primarily cared for in the hallway climbed from 70 percent to 89 percent. That is obviously far from ideal and is indicative of an increasingly taxed emergency medical care system."

However, neither research team is prepared to predict how the trend will move going forward.

"Emergency departments continue to be squeezed by pressures inside and outside the hospital," says Scott Dresden, MD, MS, of Northwestern University Feinberg School of Medicine in Chicago, the lead author of the Illinois paper. But, he adds, "We still don't know if these results represent longer-term changes in health services use or a temporary spike in emergency department use due to pent up demand."