New study challenges cytokine storm as cause of death in COVID-19 patients.

A study by scientists at Northwestern University Feinberg School of Medicine found that secondary bacterial pneumonia that does not resolve was a key driver of death in patients with COVID-19, and may even exceed death rates from the viral infection itself. The study also found evidence that COVID-19 does not cause a "cytokine storm," so often believed to cause death. The scientists developed a new machine learning approach called CarpeDiem, which groups similar ICU patient-days into clinical states based on electronic health record data.