The investigators found that 55% of the population would not meet criteria to donate, mostly because of preventable health conditions (19% hypertension, 15% obesity, 11.6% excessive alcohol intake, 12% diabetes). Sixty percent of individuals with an adjusted income of $35,000 per year could not donate due to medical conditions vs. 49% of individuals making >$100,000 per year. If one includes non-US citizenship as criteria for not being able to donate, 68.5% of the US population would not be able to donate.