Evaluation of federated learning variations for COVID-19 diagnosis using chest radiographs from 42 US and European hospitals. - Le Peng; Gaoxiang Luo; Andrew Walker; Zachary Zaiman; Emma K. Jones; Hemant Gupta; Kristopher Kersten; John L. Burns; Christopher A. Harle; Tanja Magoc; Benjamin Shickel; Scott D. Steenburg; et al. (J. Am. Medical Informatics Assoc., 2022)