The HINTS exam for evaluation of patients with acute vestibular syndrome (AVS) has been all the rage over the past decade. Originally described in 2009, it reported phenomenal accuracy at differentiating peripheral from central causes of vertigo. However, the performance of the test has mostly been validated by neurologists and otolaryngologist.
This retrospective chart review looked at how often a HINTS exam was appropriately performed and the sensitivity & specificity of the test at this single ED in Ontario. The authors point out that doctors did not get any specific training on the HINTS exam prior to this review.
A total of 2,309 patients presented with a primary complaint of vertigo or dizziness. Almost 20% got a HINTS exam! However almost all (96.9%) of them were performed inappropriately as it was not clinically indicated. In addition, many patients got both a Dix-Hallpike test and a HINTS exam… which should never happen as they are “intended in mutually exclusive patient populations.”
In the end, the sensitivity & specificity of the test as performed was terrible.
What are we to conclude?
At this single ED, the HINTS exam performed poorly in untrained doctors who did the exam on the wrong patients.
They conclude that “additional training of emergency physicians may be required.” This is quite an understatement.
Of course, this study is far from perfect, but it serves as a cautionary tale.
This is not the only study suggesting a problem. A systematic review and metanalysis in 2020 concluded that “the HINTS exam, when used in isolation by emergency physicians has not been shown to be sufficiently accurate to rule out a stroke in those presenting with AVS.”
I do not think the HINTS exam is overly simple. Nor did I believe there are enough cases of vestibular stroke for an average emergency physician to develop and maintain proficiency with the exam. But perhaps I’m wrong… there are some very clever doctors who disagree with me.
Until such time we get further evidence, we should not be giddy over the HINTS exam.
Dmitriew C, Regis A, Bodunde O, et al. Diagnostic Accuracy of the HINTS Exam in an Emergency Department: A Retrospective Chart Review. Acad Emerg Med 2021;28:387-393. [link to free full text]
Dr Brian Doyle is an emergency physician originally from the United States but now very much calls Tasmania his home. Unfortunately, it will now be a bit more difficult to deport him from the country as he passed his Australian citizenship test a few years ago. (He was able to answer that Phar Lap won the Melbourne rather than the Davis Cup). His main interests are mostly the clinical aspects of emergency medicine but also in education, ultrasound and critical appraisal of the literature. He spends much of his time annoying people to help out with conferences.