The NCATS National COVID Cohort Collaborative (N3C), which includes DBMI faculty, powered two large studies that reinforced a potential link between metformin and less-severe COVID-19 outcomes. One study of EHRs from more than 6,600 adults found that those with type 2 diabetes who were taking metformin before developing COVID-19 were less likely to be hospitalized, need mechanical ventilation or die. A second study of people with either prediabetes or polycystic ovary syndrome (a condition commonly treated with metformin) showed that metformin use was linked to less severe COVID-19.