Initially Missed or Delayed Diagnosis of Subarachnoid Hemorrhage: A Nationwide Survey of Contributing Factors and Outcomes in Japan

Background: Subarachnoid hemorrhage (SAH) remains a significant cause of mortality in Japan. The Japan Stroke Society set out to conduct a nationwide survey to identify contributing factors and outcomes of SAH misdiagnosis. Methods: We initially surveyed 737 training institutes and 1259 departments in Japan between April 2012 and March 2014 for the presence of misdiagnosed SAH. Clinical information was then sought from respondents with a positive misdiagnosis. Information on 579 misdiagnosed cases was collected. Results: Most initial misdiagnoses occurred in nonteaching hospitals (72%). Of those presenting with headache, 55% did not undergo a computed tomography (CT) scan. In addition, SAH was missed in the patients who underwent CT scans. The clinically diagnosed rerupture rate was 27%. Mortality among all cases was 11%. Institutes achieving a final diagnosis were staffed by neurologists or neurosurgeons. Multivariate logistic regression analysis indicated that age (>= 65), consciousness level (Japan Coma Scale score at correct diagnosis), rerupture of an aneurysm, and no treatment by clipping or coiling were significantly associated with poor clinical outcome. Conclusions: The prognosis of misdiagnosis of SAH is severe. Neuroradiological assessment and correct diagnosis can prevent SAH misdiagnosis. When there is a possible diagnosis of SAH, consultation with a specialist is important.