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COVID-19NCT05222750

Epidemiology of Thrombotic Thrombocytopenia Syndrome in Integrated Health-care Database in England

An observational study of COVID-19, run by AstraZeneca at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Background/Rationale: A rare syndrome of thrombosis associated with low platelets has been reported in a few cases of recent exposure to COVID-19 vaccine. Medicines \& Healthcare products Regulatory Agency (MHRA) had requested for all cases of thrombosis or thrombocytopenia occurring within 28 days of coronavirus… Read more about this study

Who is it for?
Any age
Conditions the study is for
COVID-19
What is being tested?
Pre-COVID-19, COVID-19 and COVID-19 vaccination roll-out
Type of treatment
Vaccines
How many people
41,200,246 participants
Where
1 siteUnited Kingdom
Study dates
1 Mar 2022to 25 May 2023
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Study population: All patients, with a primary focus from age 16 years old and older, in England who are present in the integrated database at the start of each study period.

Who may be able to join

  • All patients, with a primary focus from age 16 years old and older, in England who are present in the integrated database at the start of each study period.

Who cannot join

  • Less than 12 months of prior history at start of each respective study period.

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Research Site

    Oxford, OX12JD

Other trials in United Kingdom

About this study

Official title: Epidemiology of Thrombotic Thrombocytopenia Syndrome in Integrated Health-care Database in England.Secondary Data Analysis Using a Cohort Design

Background/Rationale: A rare syndrome of thrombosis associated with low platelets has been reported in a few cases of recent exposure to COVID-19 vaccine. Medicines \& Healthcare products Regulatory Agency (MHRA) had requested for all cases of thrombosis or thrombocytopenia occurring within 28 days of coronavirus vaccine to be reported via the online yellow card system. This syndrome seems to be affecting patients of all ages and both genders; at present there is no clear signal of risk factors. Up to and including 14 April 2021, the MHRA had received 168 United Kingdom (UK) reports of thrombo-embolic events with concurrent low levels of platelets following the use of the COVID-19 Vaccine AstraZeneca. The United Kingdom (UK) is uniquely placed to study this area because of its registration-based primary care system, and a unique identifier number links primary care to secondary care data. Additionally, vaccination is well advanced, maximising population wide vaccine exposure.

Objectives and Hypotheses: Estimate event rates and describe characteristics of patients with a record for thrombotic thrombocytopenia syndrome, thromboembolism or thrombocytopenia, in the general population of England.

Read more

Methods:

Study design: Secondary data analysis using a cohort design. Data Source(s): This is a retrospective cohort study using linked secondary databases in England accessed through the NHS Digital Trusted Research Environment (TRE). The primary care data will be linked with vaccination, primary care data, hospitalization, COVID-19 test results, mortality data at the national level for capture of key study variables. This integrated digital health system will also include other linkages such as the Oxford-Royal College of General Practitioners sentinel network; ORCHID.

Study Population: All patients, with our population of interest in England who are present in the integrated health records of NHS Digital TRE and/or the Oxford Royal College of General Practitioners Clinical Informatics Digital Hub (ORCHID) database at the start of each study period.

Variables: Demographic, socioeconomic, clinical descriptors and risk factors for thrombosis and/or thrombocytopenia; COVID-19 vaccines.

Statistical Analysis: The event rates with 95% CIs will be calculated by dividing the number of events with person-time at risk per 100,000 person-years. Further, event count and event rates will be evaluated in a relationship with COVID-19 vaccination date.

Conditions
COVID-19
Being tested
Pre-COVID-19, COVID-19, COVID-19 vaccination roll-out
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Pre-COVID-19Other

    Pre-COVID-19

  • COVID-19Other

    COVID-19

  • COVID-19 vaccination roll-outOther

    COVID-19 vaccination roll-out

Study groups in NCT05222750
Study groupRoleWhat they receive
Pre-COVID-19Not described
Receives: Other: Pre-COVID-19
COVID-19Not described
Receives: Other: COVID-19
COVID-19 vaccination roll - outNot described
Receives: Other: COVID-19 vaccination roll-out

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Estimate event rates and describe characteristics of patients with a record for thrombotic thrombocytopenia syndrome, thromboembolism or thrombocytopenia, in the general population of England.

    This is to complete studies in NHS Digital and ORCHID data

    Measured: 9 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Feb 2022
  2. Study start1 Mar 2022
  3. Primary completion25 May 2023
  4. Study completion25 May 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Other
Enrolment
41,200,246 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05222750
Sponsor's protocol ID
D8111R00011
Status last verified
Nov 2023
First submitted
24 Jan 2022
Last updated
11 Dec 2023
Results posted
No
Individual data sharing
Yes: Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.

Questions about this trial

What is this clinical trial studying?

An observational study of COVID-19, run by AstraZeneca at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 11 Dec 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Estimate event rates and describe characteristics of patients with a record for thrombotic thrombocytopenia syndrome, thromboembolism or thrombocytopenia, in the general population of England. (time frame: 9 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Dec 2023.

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