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respectively. First-time status showed a higher risk compared to repeat donor status (OR 4Æ3, 2Æ1–8Æ8). Gender and low EBV were not risk factors in this period. For Period 2, the final logistic model included donation site, age group, gender, race ⁄ ethnicity, first time ⁄repeat status, EBV, systolic blood pressure, collection status and blood centre as covariates. Donation at fixed sites and on bus mobiles had significantly lower risk of LOC compared to donation at mobile set-ups: 0Æ5 (0Æ4–0Æ7) and 0Æ8 (0Æ6– 0Æ9), respectively. There was a significantly increasing risk with younger age: 17–18, OR 2Æ1 (1Æ7–2Æ6); 19–22, OR 2Æ0 Fainting risks during stages of donation 3 2011 The Author(s) Vox Sanguinis 2011 International Society of Blood Transfusion, Vox Sanguinis (2011) Table 1 Characteristics of the blood donor population and their donations: fainting cases across time course of donation Donor and donation characteristics Registrations by category Period 1 N = 956 766 Whole blood donations by category Period 2 N = 554 534 Period 3A N = 553 941 Period 3B N = 553 169 Number Number Rate ⁄ 1000 Number Number Rate ⁄ 1000 Number Rate ⁄ 1000 Number Rate ⁄ 1000 Overall 956 766 43 0Æ04 554 534 593 1Æ1 772 1Æ4 155 0Æ3 Reaction location On-site 43 593 772 – Off-site – – – 155 Donation International Society of Blood Transfusion, Vox Sanguinis (2011) EBV groups: 30 min not shown, maximum fainting onset time: on-site = 160 min and off-site = 265 min. Panel b includes all fainting records, n = 1520, with missing onset time classified accordingly based on location of reaction and other record information. Table 2 Comparing predictors of fainting across time course of blood donation, 2007 data Onset time of event Period 1 Registration Period 2 Phlebotomy Period 3A Post-phlebotomy and on-site Period 3B Post-phlebotomy and off-site Donation activity Registration and medical health screening During phlebotomy up to 4 min from tube clamping ⁄ needle removal >4 min from tube clamping ⁄ needle removal, on-site >4 min from tube clamping ⁄ needle removal, off-site Most likely position Ambulatory Recumbent ⁄ Semi-recumbent Ambulatory Ambulatory Approach in multivariable analysis (MVA) Predictor selection Step-wise Step-wise Predictor selection Variables used in final MVA Age Sex Donor Status (EBV not included in final model because it was not significant) Donation Site Age Sex Race ⁄ Ethnicity Donor Status EBV Systolic BP Collection Status Centre Donation Site Age Race ⁄ Ethnicity Donor Status EBV Pulse Collection Status Centre Donation Site Age Sex Donor Status EBV Fainting 43 593 772 155 Registrations ⁄ Donations 956 766 554 534 553 941 553 169 EBV, estimated blood volume. 6 M. Bravo et al. 2011 10 11 12 13 14 15 Fixed MobileBus Mobile Setup 17-18 19-22 23-24 25-65 >65 Male Female Black, non-Hisp Hispanic Other/mixed, non-Hisp Asian or Pac Isl, non-Hisp Caucasian, non-Hisp Missing First Ɵme Repeat (1)5000 90 140 Incomplete Complete Donor and DonaƟon CharacterisƟcs Fixed Mobile Bus Mobile Set-up 17-18 19-22 23-24 25-65 >65 Male Female Black, non-Hisp Hispanic Other/mixed, non-Hisp Asian/Pac Isl, non-Hisp Caucasian, non-Hisp Missing First-Ɵme Repeat 5000 90 140 Incomplete Complete Dona Ɵon Site Age (years) Sex Race/ Ethnicity Dona Ɵon Status Es Ɵmated Blood Volume (ml) Pulse SystolicBP (mmHg) Collec Ɵon Status Donor and DonaƟon CharacterisƟcs Odds RaƟos and Confidence Intervals Period 3A: Post -phlebotomy, On-site Period 2: Phlebotomy Period 3B: Post -phlebotomy, Off -site Period 1: RegistraƟon and Eligibility Assessment Fig. 2 Multivariable analyses of factors associated with fainting – before, during and after whole blood donation. Fainting risks during stages of donation 7 2011 The Author(s) Vox Sanguinis 2011 International Society of Blood Transfusion, Vox Sanguinis (2011) donors were injured and 163 (31 men and 132 women) required OMC. The rate of injury for men and women combined in Period 1 is extremely low (2 per million donor registration). The injury rate was low in male and female donors in recumbent ⁄semi recumbent position, Period 2 (0Æ01 and 0Æ02 per 1000 donations respectively). The highest injury rate is seen in Period 3A (0Æ07 and 0Æ09 ⁄ 1000 donations for male and female donors, respectively). When considering only those donations in which LOC occurred, the total rate of injury per fainting reaction was lowest during Period 2, increased in Period 1 and 3A and peaked in Period 3B. Discussion Blood donors are subjected to psychological and haemodynamic challenges during the blood donation process. During the study period, 94% of injuries observed ⁄reported, in association with vasovagal reactions, occurred in donors who experienced LOC. Our data show variation in factors associated with fainting across different periods and suggest variation

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