SynthesisTransfusion2025
Risk factors for vasovagal reactions in blood donors: A systematic review and meta-analysis.
Synthesis in Transfusion, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
8 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Risk factors for vasovagal reactions in blood donors: A systematic review and meta-analysis.Transfusion · 2025Pooled it
- Effects of pre-donation salt-loading on the occurrence of delayed vasovagal reactions.Vox sanguinis · 2026Trial
- Blood donor safety and selection criteria for individuals self-identifying as trans or non-binary.Vox sanguinis · 2026Review
- Preventing overfilling of blood bags to reduce clot formation and improve donor safety.Vox sanguinis · 2026Article
- Role of pain and anxiety in mediating relationships between donation history and vasovagal reaction symptoms in blood donors in England.Transfusion · 2026Article
- Engaging Youth in Blood Donation: A Call for Ethical Public Health Strategies.The Malaysian journal of medical sciences : MJMS · 2025Article
- Onsite vasovagal reactions with and without loss of consciousness are distinct outcomes with different risk factors.Vox sanguinis · 2025Article
- Artificial Intelligence in transfusion medicine: a paradigm shift on the horizon.Blood transfusion = Trasfusione del sangueArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
backgroundWhile blood donation is generally safe, some donors experience vasovagal reactions (VVRs) that may lead to injury and reduce likelihood of future donation. Several risk factors for VVRs have been identified, but the consistency, magnitude, and validity of their associations have not been systematically evaluated. Therefore, this systematic review and meta-analysis synthesized evidence for VVR risk factors.
methodsDatabase searches identified English-language studies published before February 2024 describing VVR risk factors in voluntary whole blood donors. Study characteristics, VVR and risk factor assessment methods, and effect sizes were extracted. Random-effects models pooled estimates across all studies and subgroups of geographical context, study quality, donation experience, and outcome severity. Inconsistently and infrequently reported risk factors were narratively synthesized.
resultsTotally 71 studies reporting a total of 19 million total donations were included. Female sex, new donor status, younger age, smaller blood volume, and lower blood pressure were positively associated with higher VVR risk. Donation-related fear, anxiety, and disgust were associated with higher VVR risk in narrative syntheses. Substantial between-study heterogeneity (I
conclusionThis systematic review and meta-analysis provides a comprehensive synthesis of risk factors for VVRs across wide-ranging blood service contexts and symptom severities, reinforcing evidence for previously identified factors. The heterogeneous associations of several risk factors motivate large-scale studies that enable comprehensive multivariable adjustment to evidence donor selection criteria and preventative intervention allocation.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.