Official US COVID-19 Death Toll Is a 'Substantial Undercount,' Yale Study Finds Conducted by researchers at Yale University, the study was published on Wednesday in 'JAMA Internal Medicine.' Using data from the National Center for Health Statistics Data, the study compared excess deaths in the U.S. between March 1 and May 30 with deaths from COVID-19 during the same time. The total deaths of 781,000 during this time was 122,300 higher than expected. 95,235 of these deaths were attributed to coronavirus. According to researchers, most of the remaining excess deaths were likely caused by the coronavirus as well. Dan Weinberger, Yale, via CNBC Because COVID-19 affects almost every system of the body, the uptick in strokes and heart attacks was also indirectly caused by the coronavirus. Some states, including TX and AZ, show more than a 50 percent discrepancy between COVID-19 deaths and excess deaths.