To avoid on-site deferrals wherever possible is crucial, as these lead to a negative donation experience and reduce intentions to return. Switzerland provides digital tools such as vaccine, travel and eligibility checks, prior to donation to donors to reduce on-site deferral. Travel- and vaccine-check also offer information on deferral length. Reported national on-site deferral rates from 2014 to 2023 were analyzed by category.

From 2014 – 2023 national deferral rates due to travel history, low hemoglobin (Hb) and other medical reasons were reported. Blood donation included whole blood and apheresis donations. The number of donations decreased in the last few years (Table 1) therefore we compared deferrals as relative to the number of collections. The regional blood centers collected and provided the data.

Table 1: Absolute numbers of total donations (whole blood and apheresis) and deferrals per category and year.

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The number of deferrals has remained stable between 10 and 15% since 2016 (Figure 1). A clear Covid influence is visible in 2020 and 2021. On the one hand, this is reflected in a decline in deferrals of the second category, as travel options were severely restricted during the pandemic. The category other medical criteria also declined in that particular period, which could be attributed to decrease in contact and infection transmission. On the other hand, deferrals due to low Hb values remained stable during the Covid period.

Figure 1: Relative deferrals per total donations in % by category and year.

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Despite the tools available, many on-site deferrals (Table 1) are still observed. Differentiation of other medical reasons for deferral would help to further analyze and indicate new reduction approaches such as new adapted tools and appropriate measures. International Benchmarking of certain deferral rates could also be helpful.

There is no conflict of interest.