Project #185:
Investigating events following COVID-19

COVID-19 is associated with different symptoms. These symptoms usually go away within four weeks however, for some people, symptoms continue and new symptoms may develop. This is called post-COVID syndrome (or long COVID). Research to understand post-COVID syndrome is ongoing. Research has also shown that people with COVID-19 remain at elevated risk of health outcomes, such as heart attacks, up to a year after COVID-19. However, this research has mostly focused on cardiovascular disease, looked at a short time period after COVID-19, or has not considered whether people were vaccinated when they got COVID-19.

This project aims to address these gaps. We will investigate the rates of a broader range of outcomes in those with a COVID-19 diagnosis compared to those before or without a COVID-19 diagnosis in three cohorts. Specifically, we will study the association between COVID-19 and gastrointestinal, autoimmune, respiratory, renal and neurodegenerative outcomes. Our cohorts will differ by their vaccination status and the variant that people were likely exposed to - they are: the ‘pre-vaccination cohort’ (likely unvaccinated and likely exposed to wildtype or Alpha variants), the ‘vaccinated cohort’ (vaccinated and likely exposed to the Delta variant) and the ‘unvaccinated cohort’ (unvaccinated and likely exposed to the Delta variant).

We previously had an approved OpenSAFELY project for this purpose (Project 12), which resulted in peer-reviewed papers on COVID-19 and cardiovascular disease, diabetes, and mental illnesses. We are re-applying for access to expand our research to more disease areas. This will provide a more complete picture of what happens to people post COVID-19. In addition, we plan to extend our previous work on cardiovascular outcomes to understand whether rates remain elevated beyond a year. All analyses will be conducted in the three cohorts described above so we can understand whether being vaccinated when you have COVID-19 changes the rates of outcomes post-COVID-19. In addition, we will explore how we best account for differences between people who were and were not diagnosed with COVID-19 to support future COVID-19 research. Overall, our work to identify the physical and mental health consequences of COVID-19 may help us to identify the future healthcare needs of people and better understand post-COVID syndrome; while our work to explore how we best account for differences between people may improve research methods.