Meteorological elements associated with vasovagal reactions in blood donors: Influence of collection setting and...

Vasovagal reactions (VVRs) are common adverse events associated with blood donation. While previous research has focused on intrinsic donor-related risk factors, we previously identified an association between specific meteorological elements and VVR incidence. This study aims to build on our earlier findings by investigating the potential modifying effects of collection setting and donation type.

This study analysed VVR incidence data from blood donations collected in northern Nara Prefecture, Japan, over a 3-year period (April 2020-March 2023). Daily VVR incidence rates were calculated and analysed in relation to meteorological elements, including temperature, humidity, atmospheric pressure and other related factors. Comparisons across quartiles of meteorological values were performed using Kruskal-Wallis and Jonckheere-Terpstra tests. Subgroup analyses were conducted by collection setting and donation type.

In mobile collections (whole blood only), significant associations were found only with the 7-day weighted moving average (7d WMA) of temperature and precipitation. In fixed-site collections, several temperature-related elements were significantly associated with VVR incidence in both same-day and 7d WMA analyses. Further stratification showed that whole blood donations at fixed sites showed limited associations with meteorological elements, whereas apheresis donations showed significant relationships with multiple temperature-related parameters in both same-day and 7d WMA analyses.

Meteorological elements affecting VVR incidence vary by the collection setting and donation type. Apheresis donations appear to be susceptible to environmental influences, especially ambient temperature. These findings highlight the importance of incorporating meteorological considerations into donor safety measures and operational planning, particularly for apheresis collections.