Study identification

EU PAS number

EUPAS103927

Study ID

106282

Official title and acronym

Epidemiology of thrombotic thrombocytopenia syndrome in integrated health-care database in England Secondary data analysis using a cohort design (Epidemiology of TTS)

DARWIN EU® study

No

Study countries

United Kingdom

Study description

Objectives and Hypotheses: The overall objective is to estimate event rates and describe characteristics of patients with a record for Thrombotic thrombocytopenia syndrome (TTS), thromboembolism (TE), or thrombocytopenia (TCP), in the general population of England. Data Source(s): This is a retrospective cohort study using linked secondary databases in England accessed through the Oxford Royal College of General Practitioners Clinical Informatics Digital Hub (ORCHID), linked to nationwide data containing COVID data including diagnosis, polymerase chain reaction tests and vaccinations. ORCHID has contemporary data from > 17 million with good historic data from 40% of practices. Study Population: All patients, who are present in the integrated health records of ORCHID database at the start of each study period (Pre-COVID cohort: 01 January 2011 to 31 December 2019, COVID cohort: 01 July 2020 to 31 December 2020 and COVID vaccination cohort 01 January 2021 until 4 July 2022). Variables: The study outcome TTS is defined as a TE with TCP with an interval of 7 days before or after the TE diagnosis. Covariates include: Demographics, socioeconomics, medical history and risk factors for thrombosis and/or thrombocytopenia. Statistical Analysis: Unadjusted incidence rates of TCP, TE, and TTS will be calculated with associated Poisson exact 95% confidence intervals (CI) by dividing the number of incident events by the person-time at risk (presented per 100,000 person years). Logistic regression analysis will be used to assess the association between covariates and TTS, by calculating odds ratios (OR) with 95% CI.

Study status

Finalised
Research institutions and networks

Institutions

Nuffield department of Primary Care Health Sciences,University Of Oxford

Contact details

Simon de Lusignan

Primary lead investigator

Study timelines

Date when funding contract was signed

Actual:

Study start date

Actual:

Data analysis start date

Actual:

Date of final study report

Planned:
Actual:
Sources of funding
Pharmaceutical company and other private sector 

More details on funding

AstraZeneca
Regulatory

Was the study required by a regulatory body?

Yes

Is the study required by a Risk Management Plan (RMP)?

Non-EU RMP only