Meteorological factors associated with the occurrence of the vasovagal reflex during blood donation

Abstract

BackgroundInternal factors such as young age, female sex, and first-time blood donation are implicated as risk factors for vasovagal reaction (VVR) associated with blood donation for blood donors. However, the involvement of external factors has not yet been clarified. This study explored the effects of meteorological conditions as external factors on the onset of blood donation-associated VVR. Methods: Meteorological conditions were compared between days when blood donation-associated VVR occurred and days when it did not. During the 3-year period from April 1, 2020, 1 092 days during which at least one of the fixed facilities or mobile blood drives was operational were examined for the VVR cases. For meteorological conditions, we used meteorological data published on the website of the Nara Local Meteorological Observatory, located in the northern part of Nara Prefecture. Occurrence and non-occurrence groups included the days when VVR occurred and did not occur among blood donors, respectively. Days of VVR occurrence only in the southern part of the prefecture, which is a mountainous area with different meteorological conditions, were excluded from the occurrence group. A multivariate logistic regression analysis was conducted to identify meteorological variables associated with VVR occurrence. Results: The occurrence and non-occurrence groups included data from 348 and 744 days, respectively. The regression analysis indicated that a large diurnal temperature range, low minimum temperature, and low wind speed were risk factors. Conclusions: The meteorological conditions may play a role in VVR onset.