The Collaborative Cohort of Cohorts for COVID-19 Research, or “C4R,” is a new nationwide study of more than 50,000 individuals to determine factors that predict the severity and long-term health impacts of COVID-19. This study will include participants from nearly every U.S. state, with an estimated 24% of the participants who are Black, 21% are Latinx, 5% are Native American, 2% are Asians, and 47% are White. It will include adults both with and without heart, lung, blood, and brain diseases.

Participants in the 14 cohorts included in C4R will be asked to complete two questionnaires to assess history of COVID infection as well as the impact of the COVID pandemic on health, sleep, behaviors, and more. We will also ask participants to provide a small sample of blood (dried blood spot) to determine whether they have antibodies to COVID. Those who have been hospitalized for COVID infection will be asked to share their medical records to determine the severity and characteristics of their COVID illness. This information will be used to determine the impact of the COVID pandemic on individuals in the community, and what the long-term effects may be of having COVID.

Taking part to this study is absolutely voluntary and will not affect the eligibility in other studies, but we are urging you to consider the importance of your participation. Please note that if you are not already participating in one of the 14 cohorts collaborating in C4R, you will not be able to enroll in C4R. 

If you have any questions, please contact your cohort or Contact C4R. 

Thank you for your participation!

C4R Population.