Collaborative Cohort of Cohorts for COVID-19 Research (C4R) Study: Study Design

Area of Science:

• Epidemiology
• Public Health
• Longitudinal Studies

Background:

• The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study.
• It comprises 14 established US prospective cohort studies with data dating back to 1971.
• These cohorts collected data on diseases, risk factors, behavior, cognition, biomarkers, and social determinants of health.

Purpose of the Study:

• To link pre-pandemic health data with SARS-CoV-2 infection and COVID-19 illness.
• To evaluate risk and resilience factors for COVID-19 severity and outcomes, including postacute sequelae.
• To assess the social and behavioral impact of the pandemic on long-term health trajectories.

Main Methods:

• C4R links pre-COVID-19 phenotyping with SARS-CoV-2 infection and COVID-19 illness data.
• Standardized questionnaires, hospitalization/death ascertainment, and SARS-CoV-2 serosurveys are used.
• Master protocols utilize existing cohort retention and surveillance for data collection.

Main Results:

• Extensive pre-pandemic data minimize bias, enabling robust analysis.
• Harmonized, research-quality phenotyping is available for pooling and sharing.
• The study captures diverse US population demographics (age 18-108, racial, ethnic, socioeconomic, geographic).

Conclusions:

• C4R provides a unique resource for understanding COVID-19.
• It facilitates the evaluation of factors influencing COVID-19 severity and long-term health.
• The study supports collaborative research to expedite scientific findings on the pandemic's impact.