The number of people who present to emergency departments with dizziness is increasing, as is the percentage of emergency department visits resulting from dizziness, according to research presented at the 2013 Annual Meeting of the American Neurological Association. Benign positional vertigo is one of the major causes of dizziness, yet clinicians are administering a proven cure, the Epley maneuver, less often, said Kevin Kerber, MD.
At the same time, an increasing proportion of patients who present with dizziness are receiving CAT scans, which may have little value in this context and may entail more harm than benefit for these patients, in terms of radiation exposure, cost, length of stay in the emergency department, and misdiagnoses, said Dr. Kerber, Associate Professor of Neurology at the University of Michigan in Ann Arbor. The system used to document emergency department visits may be contributing to the high rate of CAT scans, he added.
CNS Diagnoses Have Remained Stable
After anecdotally observing that neurologists rarely administered the Epley maneuver to patients with dizziness, Dr. Kerber and colleagues examined a nationally representative data set of emergency department rotations to assess the efficiency of care for these persons. The researchers found dizziness and vertigo presentations to be among the most common reasons that patients present to the emergency department.
The performance of diagnostic studies, particularly CAT scans, in this population has been increasing for nearly 20 years. In 1995, approximately 10% of patients presenting in the emergency department with dizziness underwent a CAT scan. The rate of patients with dizziness who received a CAT scan was 25% in 2004 and has continued to increase. Yet the number of CNS diagnoses remained unchanged during the same period, said Dr. Kerber.
For patients with dizziness, having a CAT scan was associated with an increased length of stay (ie, from 40 to 77 minutes) in the emergency department. The effect is modified by the number of other tests performed. A CAT scan, therefore, may decrease treatment efficiency, said Dr. Kerber.
Could Documentation Systems Influence Care?
To investigate the topic further, Dr. Kerber and colleagues designed a prospective population-based study of patients presenting with benign positional vertigo. Although all of the emergency departments included in the study used the same templates to document care, the researchers noticed variations between templates.
A patient with dizziness who visited an emergency department and whose care was documented using a template with a CAT scan item in its diagnostic testing section had an approximately 30% chance of getting a CAT scan. In contrast, a patient who visited an emergency department and whose care was documented using a template without a CAT scan item had a 12% chance of getting the scan. The study adjusted the results for various demographic and clinical factors. Although the study is observational, “it makes us wonder whether the systems that document care might be somehow impacting care,” said Dr. Kerber.
An analysis of nystagmus assessments yielded similar findings. In the majority of cases, neurologists were not able to make meaningful clinical inferences based on the way the nystagmus assessments were documented. “Oftentimes, [the assessment] would just say, ‘positive nystagmus,’ which, in this setting, tells you nothing,” said Dr. Kerber.
In addition, more than 80% of patients diagnosed with peripheral vestibular dysfunction had a documented description of nystagmus that conflicted with this diagnosis. The documentation often stated that no nystagmus had been observed, even though nystagmus is a hallmark of these peripheral vestibular diagnoses, said Dr. Kerber.
Appropriate Testing and Treatment Have Declined
An examination of documentation of care for patients with benign positional vertigo revealed that the Dix–Hallpike test is rarely performed and that the canalith repositioning maneuver, also known as the Epley maneuver, are performed even less frequently.
About 80% of documents relating to patients who received a diagnosis of benign positional vertigo from an emergency department doctor had no mention of the Dix–Hallpike test. More than 95% of these documents had no mention of the Epley maneuver or the canalith repositioning maneuver. In contrast, 30% of the documents noted that patients received a CAT scan.
During a three-year period, each month was associated with a 3% decrease in the likelihood of having a Dix–Hallpike test documented. Approximately 50% of the variance in whether a patient receives a Dix–Hallpike test was explained at the provider level. The results are “a marker of uncertainty in care that’s not standardized,” said Dr. Kerber.
Improving Treatment of Benign Positional Vertigo
In August 2013, Dr. Kerber and colleagues began developing a multifaceted intervention to increase the testing and treatment of benign positional vertigo. The investigators plan to implement the intervention in a community emergency department and test it in a clinical trial. The trial will examine various secondary outcomes, including cost of care, primary-level variability, neuroimaging use, and length of emergency department stay.
The intervention and trial will result from a collaboration between neurologists, otolaryngologists, community physicians, academic emergency physicians, behavioral psychologists, implementation scientists, and media experts. “Trying to get people to change behavior is not easy,” said Dr. Kerber. “We need input from multiple people so we get it right.”