by Joyce Frieden
Most patients who visit the emergency department (ED) four or more times a year have health insurance and a primary care physician, a review of the literature found.
“The uninsured represent only 15% of frequent users and are no more likely to be frequent users than they are to be occasional ED users (<4 visits/year),” Eduardo LaCalle, MD, MPH and Elaine Rabin, MD, of the Mount Sinai School of Medicine in New York City, wrote online in Annals of Emergency Medicine.
Their review also showed that frequent ED users were more likely than occasional users to have visited primary care physicians in the previous year.
In fact, having five or more outpatient visits within the year was an independent risk factor for frequent ED use. “These findings underscore the important observation that most frequent users indeed have primary care physicians,” the researchers wrote.
“Widely held assumptions about the patient population who frequently visits EDs, and their reasons for visiting, have not been, for the most part, supported by research on the topic,” LaCalle and Rabin wrote.
To get a better idea of the characteristics of frequent ED users, the researchers used Medline to find studies of adult and pediatric patients presenting frequently to EDs in the U.S.
Prospective and retrospective studies published in peer-reviewed journals from 1990 or later were considered. Earlier studies were not included “because the evolution of use of the healthcare system in the U.S. has likely rendered them less relevant,” the authors noted.
Their search yielded 25 studies; 14 of those included data from single sites and 11 used multisite or population-level data. Most of the EDs studied were university hospital-based or affiliated public hospitals.
Women and blacks were disproportionately associated with frequent ED use, but the data showed that, in absolute numbers, the majority of frequent ED users — 60% — were white. The mean age was around 40.
LaCalle and Rabin noted that “many studies on frequent ED use have considered the influence of insurance status and have found this patient population to be predominantly covered.”
Much of that coverage, however, is provided through Medicare and Medicaid, and frequent ED users are more likely to be enrolled in those programs. “Among those patients who can be characterized as ‘occasional’ users, 36% are publicly insured,” the researchers found, “versus the 60% of frequent users who carry Medicare or Medicaid.”
One national survey cited by the researchers found that the odds ratio for patients with government insurance being frequent users was 2.1 (P<0.001).
Laws that expand public insurance coverage — such as the provision loosening Medicaid eligibility requirements included in the recently passed healthcare reform bill — may result in more patients making frequent use of EDs, the authors suggested.
“Because a frequent user is more likely to be covered by government insurance than to be uninsured, if having public insurance somehow increases ED visits, then [expanding public] insurance may actually increase the number of frequent ED users,” they wrote.
Frequent ED users also tended to be sicker than occasional users, according to the researchers, with one study estimating the admission rate for frequent users at 51% per year during a 5-year period.
These patients also were more likely to be transported by ambulance and had greater mortality associated with their ED visits.
Although frequent ED users reported subjectively poorer physical health, the researchers found “marked heterogeneity” in their presenting complaints.
“Some studies report a preponderance of exacerbations of chronic illness (e.g., renal failure, chronic obstructive pulmonary disease/asthma, sickle cell disease), whereas others describe many visits attributable to less specific symptomatology and pain,” they wrote.
The variation in presenting complaints observed by study site was also reflected in the differing degrees that mental health problems were associated with frequent use, LaCalle and Rabin noted.
For example, alcohol-related visits and psychiatric morbidity were significant predictors of frequent visits for populations studied in Boston and San Francisco but not in less urban areas.
The principal reasons given by patients for using the ED included anticipated expediency and ability to receive free care in the ED, although 69% of patients said they would continue to use the ED if copays were required.
“The data from these studies challenge the common assumption that frequent ED use is a problem of uninsured, ethnic minority patients inappropriately seeking basic primary care in the ED,” the authors concluded. “Most frequent users are either publicly or privately insured, and, perhaps surprising to some, frequent users also have concurrently high utilization of primary care and health care in general.”
Joyce Frieden is a MedPage Today News Editor.