Patterns and Predictors of Pre- and Post-donation Deferral in Brazil: a Multicenter Study of Eight Million Presentations (2007 to 2024)
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Clinical and laboratory screening are critical for maintaining donor safety and ensuring the quality of blood components. In Brazil, while legislation establishes eligibility criteria, screening implementation differs among blood centers. Objectives This study aims to evaluate the patterns and predictors of clinical pre-donation deferral and post-donation laboratory deferral at five major Brazilian blood centers between 2007 and 2024. Material and methods We analyzed adult (≥18 years) donor presentations from five REDS Brazil blood centers: Fundação Pró-Sangue (FPS), Hemominas, Hemope, Hemorio, and Hemoam. Two stages were evaluated: pre-donation deferral (ineligible during clinical/behavioral screening) and post-donation deferral (collected units deferred for reactive syphilis, HBV, HCV, HIV, HTLV, or Chagas disease). Center-specific codes were mapped to 15 harmonized categories: low hemoglobin/hematocrit, blood pressure or pulse, weight, feeling unwell or signs of infection, malaria-related deferral, donor withdrawal, medical diagnoses and conditions, medications and vaccinations, higher-risk behaviors or exposures, needle exposure/tattooing/piercings, vCJD or European travel, medical or dental procedures, pregnancy/childbirth/lactation, infectious disease–related deferral, and other reasons. Predictors of deferral were estimated using modified Poisson regression adjusted for sex, age, race, education, donor type, and blood center. Results Among 8,138,751 presentations, 1,739,731 (21.4%) resulted in pre-donation deferral, while 195,610 (3.06%) of the 6,399,020 collected donations were deferred post-donation. Over the study period, pre-donation deferral decreased from 22.4% to 20.2% and post-donation deferral from 3.30% to 2.78%, increasing the proportion of presentations yielding transfusable blood products (from 75.1% to 77.6%). Low hemoglobin/hematocrit accounted for 19.1% of classified pre-donation deferrals, followed by higher-risk behaviors or exposures. Syphilis-related deferrals increased from 36.5% to 47.3%, whereas HBV-related deferrals decreased from 47.6% to 33.0%. Pre-donation deferral was more likely among female donors (adjusted prevalence ratio (aPR) 1.49, 95% CI 1.48–1.50). Post-donation deferral was more likely among first-time donors (aPR 4.55, 95% CI 4.46–4.64), donors with lower educational attainment (aPR 2.28, 95% CI 2.22–2.34), and older donors (aPR 2.09, 95% CI 2.04–2.15). Center-specific differences were observed; Hemoam had the highest pre-donation deferral rate (24.0%), while Hemorio had the highest post-donation deferral rate (4.68%). Discussion Pre-donation deferral was more common among women, with low hemoglobin representing the leading cause of ineligibility. The increasing contribution of syphilis to post-donation deferrals is consistent with the resurgence of syphilis in Brazil. The higher odds of post-donation deferral among first-time donors is expected. The results reinforce the importance of retaining repeat donors to maximize blood component availability while maintaining blood safety. Conclusion Distinct predictors of pre- and post-donation deferral provide insights into potential tailored donor subgroup interventions to promote donor health, reduce unnecessary deferrals, and maximize the availability of blood components for transfusion.
Language: English
Subfield: Hematology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7223124346