Just 0.7% of Major League Baseball employees tested positive for antibodies to COVID-19, the illness caused by the new coronavirus.
Results were based about about 5,600 completed records from employees of 26 clubs. Samples were obtained on April 14 and 15.
"It allows us to get a peek of the nation-wide prevalence," said Dr. Jay Bhattacharya at Stanford, one the study's leaders, said Sunday.
Sixty people tested positive in the raw data, and adjustments were made for false positives and false negatives. Bhattacharya said the survey had a 0.5% false positive rate.
Data for players was not broken out.