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

NCT05222750 | Completed

• 1 other identifier: D8111R00011
• Study Type: observational
• Target: 41,200,246
• Locations: 1 country
• Sites: 1

Brief 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 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. 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

Outcome Measures

Primary Outcomes (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

  9 months

Study Arms (3)

Pre-COVID-19

Other: Pre-COVID-19

COVID-19

Other: COVID-19

COVID-19 vaccination roll - out

Other: COVID-19 vaccination roll-out

Interventions

Pre-COVID-19 OTHER

Pre-COVID-19

Pre-COVID-19

COVID-19 OTHER

COVID-19

COVID-19

COVID-19 vaccination roll-out OTHER

COVID-19 vaccination roll-out

COVID-19 vaccination roll - out

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

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.

You may qualify if:

• 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.

You may not qualify if:

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

Sponsors & Collaborators

• AstraZeneca: lead

Study Sites (1)

Research Site

Oxford, OX12JD, United Kingdom

Location

Related Links

• CSR Synopsis \_Redacted (002).pdf

MeSH Terms

Conditions

COVID-19

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 24, 2022
• First Posted: February 3, 2022
• Study Start: March 1, 2022
• Primary Completion: May 25, 2023
• Study Completion: May 25, 2023
• Last Updated: December 11, 2023

Record last verified: 2023-11

Data Sharing

• IPD Sharing: Will share
• Time Frame: AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.
• Access Criteria: When a request has been approved AstraZeneca will provide access to the deidentified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

Locations

GB (1)