Practice Variation in the Diagnosis of Aneurysmal Subarachnoid Hemorrhage: A Survey of US and Canadian Emergency Medicine Physicians.

BACKGROUND AND AIMS: Spontaneous subarachnoid hemorrhage (SAH) from a brain aneurysm, if untreated in the acute phase, leads to loss of functional independence in about 30% of patients and death in 27-44%. To evaluate for SAH, the American College of Emergency Physicians (ACEP) Clinical Policy recommends obtaining a non-contrast brain computed tomography (CT) scan followed by a lumbar puncture (LP) if the CT is negative. On the other hand, current evidence from prospectively collected data suggests that CT alone may be sufficient to rule out SAH in patients who present within 6 h of symptom onset while anecdotal evidence suggests that CT angiogram (CTA) may be used to detect aneurysms, which are the probable cause of SAH. Since many different options are available to emergency physicians, we examined their practice pattern variation by observing their diagnostic approaches and their adherence to the ACEP Clinical Policy.

METHODS: We developed, validated, and distributed a survey to emergency physicians at three practice sites: (1) Stanford Healthcare, California, (2) Intermountain Healthcare (five emergency departments), Utah, and (3) Ottawa General Hospital, Toronto. The survey questions examined physician knowledge on CT and LP's test performance and used case-based scenarios to assess diagnostic approaches, variation in practice, and adherence to guidelines. Results were presented as proportions with 95% CIs.

RESULTS: Of the 216 physicians surveyed, we received 168 responses (77.8%). The responses by site were: (1) (n = 38, 23.2%), (2) (n = 70, 42.7%), (3) (n = 56, 34.1%). To the CT and LP test performance question, most physicians indicated that CT alone detects > 90% of SAH in those with a confirmed SAH [n = 150 (89.3%, 95% CI 83.6-93.5]. To the case-based questions, most physicians indicated that they would perform a CTA along with a CT [n = 110 (65.5%, 95% CI 57.8-72.6)], some indicated a LP along with a CT [n = 57, 33.9% 95% CI 26.8-41.6)], and a few indicated both a CTA and a LP [n = 16, 9.5%, 95% CI 5.5-15.0]. We also observed practice site variation in the proportion of physicians who indicated that they would use CTA: (1) (n = 25, 65.8%), (2) (n = 54, 77.1%), and (3) (n = 28, 50.0%) (p = 0.006).

CONCLUSIONS: Survey responses indicate that physicians use some or all of the imaging tests, with or without LP to diagnose SAH. We observed variation in the use of CTA by site and academic setting and divergence from ACEP Clinical Policy.