ED Death Rates Fall by Nearly 50% From 1997 to 2011

Between 1997 and 2011 there was a nearly 50% drop in emergency department (ED) mortality rates for US adults, most likely because of advances in palliative, prehospital, and emergency care, according to a new study published in the July 2016 issue of Health Affairs.

The study found that ED mortality rates decreased from 1.48 per thousand in 1997 to 0.77 per thousand US adults in 2011, a 48% reduction. There was no significant change in inpatient hospital mortality from 2005 to 2011, even though the rate peaked in 2009.

Hemal K. Kanzaria, MD, MS, assistant professor in the Department of Emergency Medicine at the University of California, San Francisco, and colleagues evaluated US mortality rates in the ED by analyzing ED visit data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 1997 to 2011, the most recent year for which data are available. The NHAMCS is an annual national probability sample survey of ED visits in nonfederal, general, and short-stay hospitals that is conducted by the National Center for Health Statistics. The survey, which included all ED visits by adults ages 18 and older throughout the 15-year span of the study, also includes data on patients’ demographic characteristics, reasons for the visits, and mortality. Data were stratified by age, sex, race/ethnicity, insurance status, triage category, urbanicity, geographic region, and whether there had been a recent ED visit or hospitalization.

The patients who died in the ED and those who were dead on arrival were grouped together for 1997 to 2006 but were coded separately from 2007 to 2011. However, both deaths in the ED and deaths on arrival were included in the figures on ED deaths.

A total of 367,618 observations were made, representing 1.3 billion ED visits across the nation. Compared with patients who survived to ED discharge/hospital admission, those who suffered ED death were on average older, more likely to be male and white, and had more severe triage acuity scores. The proportion of patients visiting rural EDs, or EDs in the South, was higher in patients who died compared with those who survived.

For 62.7% of ED visits in which patients died, patients were unconscious, dead on arrival, or in cardiopulmonary arrest. For the remaining patients, shortness of breath (8.3% of visits) was the most common reason for an ED visit, followed by injury (5.1%) and chest pains (3.9%).

Visits by non-Hispanic black patients and Medicaid recipients accounted for the greatest increase in ED visits from 1997 to 2011; a lower proportion of ED visits were triaged as requiring immediate or emergent care in 2011 (13.2%) than in 1997 (22.7%). The ED visit rate per thousand enrollees in Medicare or Medicaid also increased substantially between 1997 and 2011, from 405.1 to 534.6 for Medicare enrollees and from 646.2 to 863.4 for those covered by Medicaid.

The researchers believe there are several possible explanations for the substantial downward trend in ED mortality:

• Patients may be surviving only until admitted as inpatients.
• Palliative care is playing an increasing role in dying patients’ lives, with more patients dying in hospice settings outside acute care hospitals and the ED.
• Witholding or terminating resuscitation efforts in the prehospital setting could also contribute to the reduction in ED mortality. A drop in ED mortality could be the result of patients with cardiac arrest no longer being transported to the hospital.
• ED visit rates increased substantially for both Medicaid and Medicare beneficiaries.
• Improvements in emergency medicine and public health could also help explain the drop in ED mortality.
• Continued public health achievements, including smoking cessation and motor vehicle safety, may have played a role in the trend.

Further research is needed to separate out the underlying causative factors in order to improve our understanding of the impact that recent advances in palliative, prehospital, and emergency critical care has had on where people die in the United States.