From UpToDate: In the general population without a personal history of VTE, a study involving 1690 unrelated individuals from Europe found a prevalence of FVL

From UpToDate: In the general population without a personal history of VTE, a study involving 1690 unrelated individuals from Europe found a prevalence of FVL of approximately 4 percent, and a study involving 356 individuals from Canada found an incidence of approximately 5 percent [47,48]. In a series of 4047 men and women participating in the Physicians' Health Study and the Women's Health Study (both in the United States), the following frequencies for FVL heterozygosity were found [49]: ●Caucasians – 5.3 percent ●Hispanic Americans – 2.2 percent ●Native Americans – 1.2 percent ●African Americans – 1.2 percent ●Asian Americans – 0.45 percent A higher prevalence of FVL (12 to 14 percent) has been reported in populations in parts of Greece, Sweden, and Lebanon Compared to a more likely cause for thrombophilia in the patient population, ie inflammatory response, endothelial damage, up regulation of clotting factors; I think focusing on factor V Leiden (and I’m speaking just as a clinician, not as someone who has had to work with covid patients, we’ve had relatively SFA here in Australia thankfully) is a footnote. And any patient who is admitted is going to be on anticoagulants anyway, nullifying most of any procoagulant effect of FVL in hospitalised patients. It might show up in the data, it might be a footnote, but treatment would be covered under normal VTE prophylaxis (and seems like many protocols are now stepping up fairly significantly the prophylaxis regime)