Massachusetts became the first and only state to ban ambulance diversions in 2009, and other locations have moved to stop the potentially harmful practice of temporarily closing a facility to incoming ambulances, but it still occurs in most of the nation's largest cities, a review by the Milwaukee Journal Sentinel found.
Seven things to know:
1. Two-thirds of the nation's largest 25 cities allow ambulance diversion or practices like it, including nine of the top 10. These cities include New York, Los Angeles, Phoenix and San Diego.
2. Ambulance diversion started in the 1980s in response to overcrowded emergency rooms, where patients could wait hours or even days to be admitted.
Several studies have found diversion fails to solve ER overcrowding and puts patients at risk by delaying care, according to the Journal Sentinel. But some healthcare officials have argued ending diversions would lead to catastrophic, dangerous crowding.
3. However, after Massachusetts banned the practice in 2009, an August 2014 federal study of the state's experience found that didn't happen.
"Despite fears that the ban would lead to increased emergency room crowding and ambulance delays, the steps hospitals took to improve patient flow in the wake of the ban prevented such problems," said the report from the Agency for Healthcare Research and Quality.
4. In April 2016, Milwaukee County implemented a no-diversion policy. The hospitals removed diversions by making their whole operations more efficient, not just the emergency departments.
5. The county was heading toward ending diversion in 2014 when 37-year-old Milwaukee resident Tiffany Tate had a stroke during her shift at the Medical College of Wisconsin cafeteria.
She was only about 350 yards from Froedtert Hospital and its top-ranked stroke center but was not taken there because its ER was on diversion. It took almost four hours for Ms. Tate to get the care she would have gotten at Froedtert. She later died.
6. In Los Angeles County, hospitals still divert ambulances regularly. Each hospital in the county is on ambulance diversion about two hours each day on average, a 2017 report cited by the Journal Sentinel found. That number is down from about six hours per hospital per day in 2005.
7. Cathy Chidester, MSN, RN, director of the Los Angeles County Emergency Medical Services Agency, said surrounding counties have "banned" diversion but their operations are the same. Hospitals have talked about improving practices, but nothing concrete has happened, and it may have been different if there had been a case such as Tiffany Tate's in Milwaukee, Ms. Chidester said.
"Efficiency is talked about all the time here," she said. "But without something horrifying happening, like what you had up there, it just reverts to the way it was."