Condition category
Circulatory System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
The SHED study aims to understand how acute headaches are dealt with by the Emergency Department (ED). It wants to understand how accurate the investigations for identifying and ruling out a bleed on the brain, called a subarachnoid haemorrhage are.

Who can participate?
Any adult with an acute severe headache that reached maximal intensity within one hour presenting to UK Emergency Departments (ED) between February and June 2020.

What does the study involve?
This study doesn’t involve any additional treatments or tests, and no extra questions other than those that the participant's doctor will ask you routinely. The study team are not seeking written consent for this study because it involves no change in patient clinical assessment or care. However, if participants do not want to take part it is easy to opt-out as described at

What are the possible benefits and risks of participating?
There will be no direct benefit to participants from taking part. However, this research may change the way that headaches are managed in the future and therefore impact future treatment for those who re-attend. It could also positively impact other patients who come to the hospital with the same problem.

As part of routine care participant's doctor may decide you need a CT Brain and/or CT angiography as part of your routine care. Those who take part in this study will not undergo any additional x-ray imaging. These procedures use ionising radiation to form images of your body and provide the doctor with other clinical information. Ionising radiation can cause cell damage that may, after many years or decades, turn cancerous. The chances of this happening to participants are the same whether they take part in this study or not. There is also a risk within the study of data storage. The study team have minimised this risk through use of a specialist medical database service which conforms to all current international standards. This project will be treated like any serious research study, with strict oversight and regular review.

Where is the study run from?
The Northern Care Alliance (UK) with data collected from over 100 UK emergency departments.

When is the study starting and how long is it expected to run for?
From February 2021 to August 2021

Who is funding the study?
The Royal College of Emergency Medicine (UK)

Who is the main contact?
Dr Robert Hirst

Trial website

Contact information



Primary contact

Dr Tom Roberts


Contact details

12 Hamilton Road
United Kingdom
+44 (0)7894234121



Additional contact

Dr Robert Hirst


Contact details

Emergency Department
Musgrove Park Hospital
Parkfield Drive
United Kingdom
+44 (0)7506 385159

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

Nil known

Study information

Scientific title

Subarachnoid Haemorrhage in the Emergency Department (SHED)



Study hypothesis

To understand the sensitivity of CT brain and the Ottawa subarachnoid clinical decision rule for patients presenting with acute severe headache (with maximal intensity within 1 h) to UK Emergency Departments.

Ethics approval

Approved 11/02/2020, South West Frenchay Research Ethics Committee (Level 3, Block B Whitefriars Lewins Mead, Bristol BS1 2NT;; +44 (0)207 104 8290), ref: 19/SW/0243

Study design

Prospective observational cohort study

Primary study design


Secondary study design

Cohort study

Trial setting


Trial type


Patient information sheet

Available from


Subarachnoid haemorrhage and acute severe headache


As an observational study, there will be no change to clinical practice. Headache features will be prospectively collected. Relevant investigations of CT brain, lumbar puncture, and CT-angiogram will be collected. 28-day follow-up data for subarachnoid haemorrhage and mortality will be collected.

Subarachnoid haemorrhage will be identified from the data collected as any of the following:
1. Subarachnoid Blood present on unenhanced CT reported by a trained radiologist. Site CT characteristics will be collected to include minimum criteria applied for inclusion in the final analysis, as follows:
1.1. A 3rd generation multi-slice scanner (4 to 320 slices/rotation)
1.2. 5-7.5 mm cuts for brain
1.3. 2.5 – 5mm cuts for the posterior fossa
2. Subarachnoid Blood present on CT-Angiogram or MR-Angiogram reported by a trained radiologist
3. CSF findings consistent with SAH according to the 2008 National Biochemist reporting guideline. The vast majority of UK laboratories processing CSF samples adhere to the 2008 clinical biochemistry guidelines. However, for those sites identified as using xanthochromia or red blood cells in lieu of 2008 criteria, the study team will adopt criteria stipulated in the original paper by Perry et al.
4. Visible xanthochromia. Red blood cells (>5×106/L) in the final tube of cerebrospinal fluid collected and an aneurysm identified on cerebral angiography (digital subtraction, computed tomography, or magnetic resonance angiography)

All cases of subarachnoid haemorrhage within the cohort will be captured, by performing follow up at 28 days from presentation. Clinical notes and primary care contact will be scrutinised, to determine reference standard diagnosis, clinical outcomes and mortality. HES data will be pursued using the 4 digit diagnostic codes for subarachnoid haemorrhage following database lock.

Intervention type



Drug names

Primary outcome measure

1. External validation the proposed 6 h CT brain rule out strategy for alert patients (defined as awake and fully orientated or GCS 15/15) presenting with acute non-traumatic headache, suggestive of subarachnoid haemorrhage using prospectively collected data

Secondary outcome measures

1. Change in sensitivity of CT brain imaging in patients presenting with acute severe headache over hourly intervals from 6 to 24 h after onset of headache using prospectively collected CT brain data
2. Validation of the Ottawa subarachnoid haemorrhage clinical decision rule in patients presenting with acute non-traumatic headache using prospectively collected clinical notes, primary care contact data, and HES data

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged ≥18 years
2. Presenting with a non-traumatic acute headache that reaches maximal intensity within one hour to UK Emergency Departments (ED) or equivalent acute secondary care environment

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Direct head trauma in the previous 7 days
2. Returning for reassessment of the same headache within the recruitment period
3. Established diagnosis of subarachnoid haemorrhage, brain neoplasm, ventricular shunt or hydrocephalus prior to attendance at the emergency department.
4. Focal neurological deficit
5. Headache with onset >14 days prior to attendance
6. Recurrent headaches defined as ≥3 headaches of similar character and intensity as presenting headache
7. Transfer from another hospital with confirmed subarachnoid haemorrhage
8. Prisoner presenting to ED/secondary care
9. Patient currently under detained Mental health act, presenting to ED/secondary care

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

North Bristol NHS Trust
BS10 5NB
United Kingdom

Sponsor information


Northern Care Alliance

Sponsor details

Salford Royal NHS Foundation Trust
Summerfield House
544 Eccles New Road
M5 5AP
United Kingdom
+44 (0)161 206 5235

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Royal College of Emergency Medicine

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

Universities (academic only)


United Kingdom

Results and Publications

Publication and dissemination plan

The results from this study will be submitted for publication in leading journals and to national conferences for presentation. The Trainee Emergency Research Network (TERN) aims to be a promoting force for research opportunity in emergency medicine and will be providing regular input to the national academic conference agenda for emergency medicine, to highlight recent projects, ongoing work and opportunity for submission of ideas. 29

In addition, this project offers the opportunity for TERN to develop a national strategy with regards to project output and knowledge translation. Recent collaborations with online learning resources ensure that this project will be regularly appraised and updated throughout delivery, through a dedicated TERN section on this college website.

TERN will also aim to develop a local dissemination strategy using trainees to highlight findings and implement change where relevant within local departments. Free Open Access Medical Education channels will be used to highlight and appraise the project results. Blogs, podcasts and discussions will be planned to highlight lessons learned about trainee networks research and cloud-based data collection.

IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

28/10/2020: Trial’s existence confirmed by the Health Research Authority (HRA) and Health and Care Research Wales (HCRW).