title: A single-centre study of vasovagal reaction in blood donors: Influence of age, sex, donation status, weight, total blood volume and volume of blood collected.
abstract: BACKGROUND
  Vasovagal reactions (VVRs) in blood donors.
  
  
  OBJECTIVE
  To find an association of age, sex, donation status, weight, total blood volume and volume of blood collected with occurrence of immediate VVR.
  
  
  METHODS
  Retrospective single-centre study.
  
  
  METHODS
  The study was conducted from March 2000 to November 2010 at a tertiary care blood transfusion centre. All VVRs with or without syncope occurring during or at the end of donation were noted.
  
  
  METHODS
  For qualitative association, c (2)-test was used. Unpaired 't' test was used for assessing difference between two groups with respect to VVR status. Simultaneous impact of all risk factors was assessed using multivariate logistic regression analysis. The data entry software SPSS (version 17.0) was used for statistical analysis. A P-value <0.05 was considered statistically significant.
  
  
  RESULTS
  Overall 1085 VVRs were reported in relation to 88,201 donations, resulting in an overall VVR rate of 1.23%, that is, an incidence of 1 in every 81 donations. Donors with low blood volume, first-time donors, with low weight and female donors had higher absolute donation VVR rates than other donors.
  
  
  CONCLUSIONS
  Donation-related vasovagal syncopal reactions are a multifactorial process determined largely by weight, age, first-time donor status and total blood volume. Our study reinforces the fact that blood donation is a very safe procedure, which could be made even more event-free by following certain friendly, reassuring practices and by ensuring strict pre-donation screening procedures.
authors.affiliation: Department of Transfusion Medicine, Armed Forces Medical College, Pune, India.
authors.forename: Joseph
authors.initials: J
authors.lastname: Philip
authors.affiliation: Department of Transfusion Medicine, Armed Forces Medical College, Pune, India.
authors.forename: R S
authors.initials: RS
authors.lastname: Sarkar
authors.affiliation: Department of Transfusion Medicine, Armed Forces Medical College, Pune, India.
authors.forename: Neelesh
authors.initials: N
authors.lastname: Jain
keywords: Blood donor; first-time donors; total blood volume; vasovagal reaction; volume of blood collected