ArticleAdvanced journal of emergency medicine2018
To Head CT Scan or Not: The Clinical Quandary in Suspected Subarachnoid Hemorrhage; a Validation Study on Ottawa Subarachnoid Hemorrhage Rule.
Article in Advanced journal of emergency medicine, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.
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Who cites it
3 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Management of patients presenting to the emergency department with sudden onset severe headache: systematic review of diagnostic accuracy studies.Emergency medicine journal : EMJ · 2022Pooled it
- High risk and low incidence diseases: Aneurysmal subarachnoid hemorrhage.The American journal of emergency medicine · 2025Review
- Subarachnoid haemorrhage rules in the decision for acute CT of the head: external validation in a UK cohort.Clinical medicine (London, England) · 2021Article
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Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionThe Ottawa Subarachnoid Hemorrhage rule (OSR) is a clinical decision tool identified for ruling out subarachnoid hemorrhage (SAH) in those patient above 15 years of age who present to the emergency department (ED) with acute onset atraumatic headache.
objectiveThe primary objective of this study was to externally validate the OSR in a single national health service (NHS) setting in the UK and secondly, to compare it with our current practice without using a decision rule.
methodA retrospective review of computerized medical records was done for all patients registered with headaches from January to December 2016. The data were manually charted on a data sheet from individual patient records. Patients fulfilling the preset inclusion and exclusion criteria as per the OSR were enrolled in the analysis. According to the OSR, if patient had any of the 6 criteria enlisted (age > 40 years, neck stiffness/pain, witnessed loss of consciousness, onset during exertion, thunderclap headache, limited neck flexion on examination), further diagnostic decision was required. All patients were followed up for 6 months on the computer system as it gets highlighted if the patient is represented again to the ED or is deceased.
resultsA total of 737 ED visits with acute headache were reviewed for potential eligibility. Out of these, 649 were estimated to be eligible. On excluding 485 patients that could not meet the predetermined inclusion criteria and 19 patients as per the exclusion criteria, 145 (19.7%) patients were included in the analysis. There were 5 cases of SAH, yielding an incidence of 3.4 % (95% CI 1.3 % - 8.3 %). The sensitivity for SAH was 100% (95% CI, 46.3 % - 100 %); specificity of 44.2 % (95% CI, 36 % - 53 %); positive predictive value of 6.02 % (95% CI 2.2 % - 14.1 %); and negative predictive value of 100% (95% CI, 92.7 % - 100%).
conclusionAlthough being poorly specific, the OSR is a highly sensitive, simple tool for ruling out SAH in alert patients with a headache in ED settings.
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