Exploration of the Healthy Donor Effect Among 0.6 Million Blood Donors in China: Longitudinal Study

BACKGROUND

The World Health Organization emphasizes the importance of completely voluntary blood donation to maintain safe and sustainable blood supplies. However, the benefits of blood donation for donors, such as reducing the risk of disease, remain a topic of debate due to the existence of the healthy donor effect (HDE). This effect arises because of inherent health differences between blood donors and the general population, and it is also considered a methodological issue.

OBJECTIVE

This study aims to generate a more detailed health profile of blood donors from a donor cohort study to mitigate and quantify the HDE and properly interpret the association between blood donation and disease outcomes among blood donors.

METHODS

A retrospective cohort study was conducted between January 2012 and December 2018 among donors before their first donation. One-to-one propensity score matching was conducted through a random selection of individuals without any history of blood donation, as reported from their electronic health records. We conducted a Poisson regression between blood donors and non-blood donors before the first donation to estimate the adjusted incidence rate ratio (AIRR) of selected blood donation-related diseases, as defined by 13 categories of International Classification of Diseases, Tenth Revision (ICD-10) codes.

RESULTS

Of the 0.6 million blood donors, 15,115 had an inpatient record before their first donation, whereas 17,356 non-blood donors had an inpatient record. For the comparison between blood donors and the matched non-blood donors, the HDE (the disease incidence rate ratio between non-blood donors and blood donors) was an AIRR of 1.152 (95% CI 1.127-1.178; P<.001). Among disease categories not recommended for blood donation in China, the strongest HDE was observed in the ICD-10 D50-D89 codes, which pertain to diseases of the blood and blood-forming organs as well as certain disorders involving the immune mechanism (AIRR 3.225, 95% CI 2.402-4.330; P<.001). After age stratification, we found that people who had their first blood donation between 46-55 years old had the strongest HDE (AIRR 1.816, 95% CI 1.707-1.932; P<.001). Both male and female donors had significant HDE (AIRR 1.082, 95% CI 1.05-1.116; P=.003; and AIRR 1.236, 95% CI 1.196-1.277; P<.001, respectively) compared with matched non-blood donors.

CONCLUSIONS

: Our research findings suggest that the HDE is present among blood donors, particularly among female donors and those who first donated blood between the ages of 46 and 55 years.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200055983; https://www.chictr.org.cn/showproj.html?proj=51760.

A donor safety evidence literature review of the short- and long-term effects of plasmapheresis

Many blood establishments are expanding plasmapheresis collection capacity to achieve increasing plasma for fractionation volume targets, driven by immunoglobulin product demand. Some adverse events occur in both apheresis and whole blood collection, such as venepuncture-related trauma and vasovagal reactions. Others are specifically related to the apheresis procedure, such as citrate reactions, haemolysis, infiltration and air embolism. Whilst plasmapheresis procedures are generally well tolerated, theoretical longer term donor health considerations, such as the effects on donor plasma protein levels, bone mineral density, iron deficiency and malignancy also require consideration. An evidence-based framework that supports a safe and sustainable increase in the collection of plasma is essential. Our review demonstrates a lack of high-quality evidence on risks and outcomes specifically in plasmapheresis. Whilst conservative procedural controls and donor harm minimization policies will mitigate risk, high-quality evidence is needed to facilitate practice change that is safe and sustainable and maximizes the potential of individual donor differences.

Substance use disorder and alcohol consumption patterns among Dutch physicians: a nationwide register-based study

PURPOSE

Problematic substance use and Substance Use Disorders (SUD) are common in all layers of the population. Several studies suggest higher prevalence rates of problematic substance use among physicians compared to the general population, which is harmful for themselves and potentially impairs quality of care. However, nationwide comparison with a highly educated reference group is lacking. Using nationwide register data, this study compared the prevalence of clinical SUD diagnoses and alcohol consumption patterns between physicians and a highly educated reference population.

METHODS

A retrospective study was performed using registry data from 2011 up to and including 2019, provided by Statistics Netherlands. From the data, a highly educated reference group was selected and those with an active medical doctor registration were identified as "physicians". Clinical SUD diagnoses were identified by DSM-IV codes in mental healthcare registries. Benchmark analyses were performed, without statistical testing, to compare the prevalence of SUD diagnoses and alcohol consumption patterns between physicians and the reference population.

RESULTS

Clinical SUD diagnoses were found among 0.3% of the physicians and 0.5% of the reference population, with higher proportions of sedative use disorder among physician patients. Among drinkers, the prevalence rates of heavy and excessive drinking were respectively 4.0% and 4.3% for physicians and 7.7% and 6.4% for the reference population.

CONCLUSION

Prevalence rates of SUD diagnoses were fairly comparable between physicians and the highly educated reference population, but physicians displayed more favorable alcohol consumption patterns. The use of sedatives by physicians might deserve attention, given the relatively higher prevalence of sedative use disorder among physicians. Overall, we observed relatively low prevalence rates of SUD diagnoses and problematic alcohol use, which may reflect a treatment gap and social desirable answers.

Health Behavior and Lifestyle Trends among Platelet Donors: Results from a Questionnaire-Based Survey in Norway

Background

Blood donors are on average healthier than the general population, a phenomenon known as the “healthy donor effect.” Earlier studies have also pointed to healthier behaviors among whole blood donors than the general population. This study is aimed at assessing the prevalence of four healthy behaviors (sufficient physical activity, avoiding cigarette smoking, low to moderate alcohol use, and maintaining a healthy weight) among platelet donors and to compare the results with those in the general population of similar ages.

Methods

Eighty-six platelet donors were asked to complete a questionnaire designed to assess physical activity, smoking, and alcohol use. Sociodemographic information including gender, age, and education was also collected from all participants. Chi-square statistics and logistic regression were used in statistical analysis.

Results

The mean age of the study donors was 51 years, 56% were female. Most were employed (90%), and 48% hold a bachelor's or higher degree. The prevalence of healthy behaviors differed by education gradients but not by gender and age. About 49% of the donors met the weekly physical activity recommendations, less than 5% were daily smokers, and~26% were classified as more frequent drinkers (≥1 to ≤5 times per week). The corresponding percentages for the general population were, respectively, 33%, 13%, and 35%. The prevalence of overweight and obesity, as assessed by body mass index (BMI), among donors were 50% and 29%, respectively, much higher than the current prevalence of overweight and obesity of 37% and 19%, respectively, among adults in the general population.

Conclusions

The individual health behaviors of the majority of the study population could be characterized by a relatively high level of physical activity, low prevalence of daily smoking, and moderate alcohol drinking. The above-average overweight/obesity prevalence among platelet donors in this cohort is of concern because of the potential serious health consequences and it warrants further reflection.

Daily mobility patterns in patients with bipolar disorder and healthy individuals

BACKGROUND

Alterations in energy and activity in bipolar disorder (BD) differ between affective states and compared with healthy control individuals (HC). Measurements of activity could discriminate between BD and HC and in the monitoring of affective states within BD. The aims were to investigate differences in 1) passively collected smartphone-based location data (location data) between BD and HC, and 2) location data in BD between affective states.

METHODS

Daily, patients with BD and HC completed smartphone-based self-assessments of mood for up to nine months. Location data reflecting mobility patterns, routine and location entropy was collected daily. A total of 46 patients with BD and 31 HC providing daily data was included.

RESULTS

A total of 4,859 observations of smartphone-based self-assessments of mood and mobility patterns were available from patients with BD and 1,747 observations from HC. Patients with BD had lower location entropy compared with HC (B= -0.14, 95% CI= -0.24; -0.034, p=0.009). Patients with BD during a depressive state were less mobile compared with a euthymic state. Patients with BD during an affective state had lower location entropy compared with a euthymic state (p<0.0001). The AUC of combined location data was rather high in classifying patients with BD compared with HC (AUC: 0.83).

LIMITATIONS

Individuals willing to use smartphones for daily self-monitoring may represent a more motivated group.

CONCLUSION

Alterations in location data reflecting mobility patterns may be a promising measure of illness and illness activity in patients with BD and may be used to monitor the effects of treatments.

Demographical Pattern of Blood Donors and Pre-Donation Deferral Causes in Dhahran, Saudi Arabia

Background

Understanding the demographic features of blood donors is important for identifying the donor structure and guiding the recruitment and retention strategies of donors. This study was aimed to determine the demographic characteristics of blood donors, the types of donation drives, and the frequency and reasons for pre-donation deferral in our population.

Methods

This cross-sectional study included data analysis of all prospective blood donors presenting themselves for donation at the Blood Bank of the King Fahad Military Medical Complex, Dhahran, Saudi Arabia between January 2010 and December 2018. Eligibility of blood donation was assessed using a standardized history questionnaire, physical examination, hemoglobin estimation, pulse rate, blood pressure, and temperature. The questionnaire included the demographic features of the donor such as age, gender, and the reason for donation and other specific risk factors that potentially affect the safety of the donor or the recipient. Data analyzed using the analysis of SPSS version 20 (SPSS Inc., Chicago, IL, USA) were used to calculate the unadjusted odds ratios (OR) and the respective 95% confidence interval for the association between the various demographic parameters.

Results

A total of 28,189 potential donations were recorded during the study period; of these, 77.4% were family replacements with females accounting for only 1.8% of all donations. Most of the donors were Saudi nationals (92.1%) of whom donors between 18 and 34 years old constituted 87.9%, while those over 40 years old represented only 7.9% of the donations. Pre-donation temporary deferral occurred in 3300 (11.7%) of all potential donation attempts. The most common causes being the recent intake of medication (24.4%) followed by low hemoglobin (14.8%), low or high blood pressure (14.6%), low or high pulse rate (13.6%), and low weight (11.6%).

Conclusion

A profile of blood donors consisting mainly of young male citizens who mostly donated for family replacement was detected. Deferral rate was found to be average when compared to other countries; the causes being similar to those detected in other developed countries. Simple descriptive statistics has shown no marked difference was noted over the 9 years of the study in neither the profile of blood donors nor the cause for temporary deferral of prospective blood donors.

Mood instability in patients with newly diagnosed bipolar disorder, unaffected relatives, and healthy control individuals measured daily using smartphones

OBJECTIVES

To investigate whether mood instability (MI) qualify as a trait marker for bipolar disorder (BD) we investigated: 1) differences in smartphone-based self-reported MI between three groups: patients with newly diagnosed BD, unaffected first-degree relatives (UR), and healthy control individuals (HC); 2) the correlation between MI and functioning, stress, and duration of illness, respectively; and 3) the validity of smartphone-based self-evaluated mood ratings as compared to observer-based ratings of depressed and manic mood.

METHODS

203 patients with newly diagnosed BD, 54 UR and 109 HC were included as part of the longitudinal Bipolar Illness Onset study. Participants completed daily smartphone-based mood ratings for a period of up to two years and were clinically assessed with ratings of depression, mania and functioning.

RESULTS

Mood instability scores were statistically significantly higher in patients with BD compared with HC (mean=1.18, 95%CI: 1.12;1.24 vs 1.05, 95%CI: 0.98;1.13, p = 0.007) and did not differ between patients with BD and UR (mean=1.17, 95%CI: 1.07;1.28, p = 0.91). For patients, increased MI scores correlated positively with impaired functioning (p<0.001), increased stress level (p<0.001) and increasing number of prior mood episodes (p<0.001). Smartphone-based mood ratings correlated with ratings of mood according to sub-item 1 on the Hamilton Depression Rating Scale 17-items and the Young Mania Rating Scale, respectively (p´s<0.001).

LIMITATION

The study had a smaller number of UR than planned.

CONCLUSION

Mood instability is increased in patients with newly diagnosed BD and unaffected relatives and associated with decreased functioning. The findings highlight MI as a potential trait marker for BD.

Lifestyle behaviours, ethnicity and menstruation have little added value in prediction models for low haemoglobin deferral in whole blood donors

OBJECTIVE

To investigate the added value of questionnaire-based predictors to existing prediction models for low haemoglobin (Hb) deferral in whole blood donors.

BACKGROUND

Prediction models for Hb deferral risk can be applied in the invitation process of donors for a blood donation. Existing prediction models are based on routinely collected data. The model performance might be improved by the addition of predictive factors.

METHODS

The added value of food consumption, smoking, physical activity, ethnicity and menstruation in the prediction of Hb deferral was assessed by comparing the existing models with extended models using the following measures: model X² , concordance (c)-statistic and net reclassification improvement (NRI).

RESULTS

Addition of one candidate predictor to the models did not substantially improve the model performance. Addition of multiple new candidate predictors significantly increased the model X² (from 137 to 159 for men, and from 157 to 199 for women) and resulted in a non-significant increase of the c-statistic (from 0.85 to 0.87 for men, and from 0.78 to 0.81 for women). The NRI for men was 11.4% and for women 1.5% after addition of multiple predictors.

CONCLUSION

Addition of lifestyle behaviours, ethnicity or menstruation to prediction models for low Hb deferral in whole blood donors improved the model performance, but not substantially. For easy use in practice, we do not recommend addition of the investigated predictors to the prediction models.

Do deferred donors continue their donations? A large-scale register study on whole blood donor return in the Netherlands

BACKGROUND

Temporary deferral of whole blood donors is essential for a safe blood supply, yet deferral may impact donor return. Different deferral reasons may differently affect return, and donor experience may interfere with this. Therefore, we studied the joint effect of deferral reason and donor experience on return.

STUDY DESIGN AND METHODS

We used a large‐scale retrospective cohort design including all Dutch donors with a whole blood donation attempt in 2013 to 2015 (n = 343,825). We established details of the target donation (including deferral reason if applicable), details of attendances in the 2 years after the target donation, donor characteristics (blood type, sex, age), and donor experience (first‐time, novice, experienced, reactivated). Descriptive statistics as well as time‐to‐events methods were used.

RESULTS

Experienced donors were most likely to return, even after deferral (nondeferred 96% vs. deferred 92%). First‐time and reactivated donors were less likely to return after deferral (69 and 61%, respectively) compared to their nondeferred counterparts (82 and 76%, respectively). First‐time hemoglobin (Hb)‐deferred donors were less likely to return and slower to return than other donors. Similar results were found for reactivated donors deferred for short‐term medical reasons.

CONCLUSION

Deferral reason and donor experience individually as well as jointly impacted donor return. Particularly first‐time and reactivated donors were at risk of nonreturn, especially when deferred for Hb or short‐term medical reasons, respectively. Blood banks designing and implementing donor retention strategies should thus not only take successful but also unsuccessful donation experiences and different experience levels into account.

Blood donation from 2006 to 2015 in Zhejiang Province, China: annual consecutive cross-sectional studies

OBJECTIVES

To describe the basic demographical characteristics of whole blood donors in Zhejiang Province, China, from 2006 to 2015 and to examine the trends in individual characteristics associated with blood donation and the relationship between weight and donation.

DESIGN

Cross-sectional study comparing characteristics of blood donors and annual donations for the period 2006 to 2015.

SETTING

Urban and rural communities in Zhejiang, China (11 cities, 89 districts or counties and 1379 townships).

PARTICIPANTS

3 226 571 volunteer blood donors.

OUTCOME MEASURES

Volume of each whole blood donation and donation frequency. All data were collected by trained staff and entered into a standardised electronic information system.

RESULTS

The number of blood donations generally trended up in Zhejiang Province from 2006 to 2015. Donors were predominately males aged 18 to 25 years, but this major donor age group shifted to the 26 to 45 year range by 2015. The rate of repeated blood donation was 30.8 per cent. The blood volume per donation concentrated in 200 mL and 400 mL categories has been gradually shifted to 300 mL and 400 mL. Approximately one-third of donors had a college education. The average weight of donors increased over time for both men and women. Both the blood volume of each donation and donation frequency were proportional to weight.

CONCLUSIONS

The trend of voluntary non-remunerated blood donation in Zhejiang province is positive. However, given the expected growth in demand for whole blood, more research is needed to increase both the donor pool and the rate of repeated donation. The relationship between body weight and blood donation warrants further study because while improving nutritional status is associated with higher average donation volume and more frequent donations, overnutrition may lead to poorer quality of donated blood. Blood donation may present a unique opportunity for health education and body weight management to monitor and improve population health.

Effect of communicating phenotypic and genetic risk of coronary heart disease alongside web-based lifestyle advice: the INFORM Randomised Controlled Trial

Objective

To determine whether provision of web-based lifestyle advice and coronary heart disease risk information either based on phenotypic characteristics or phenotypic plus genetic characteristics affects changes in objectively measured health behaviours.

Methods

A parallel-group, open randomised trial including 956 male and female blood donors with no history of cardiovascular disease (mean [SD] age=56.7 [8.8] years) randomised to four study groups: control group (no information provided); web-based lifestyle advice only (lifestyle group); lifestyle advice plus information on estimated 10-year coronary heart disease risk based on phenotypic characteristics (phenotypic risk estimate) (phenotypic group) and lifestyle advice plus information on estimated 10-year coronary heart disease risk based on phenotypic (phenotypic risk estimate) and genetic characteristics (genetic risk estimate) (genetic group). The primary outcome was change in physical activity from baseline to 12 weeks assessed by wrist-worn accelerometer.

Results

928 (97.1%) participants completed the trial. There was no evidence of intervention effects on physical activity (difference in adjusted mean change from baseline): lifestyle group vs control group 0.09 milligravity (mg) (95% CI −1.15 to 1.33); genetic group vs phenotypic group −0.33 mg (95% CI −1.55 to 0.90); phenotypic group and genetic group vs control group −0.52 mg (95% CI −1.59 to 0.55) and vs lifestyle group −0.61 mg (95% CI −1.67 to 0.46). There was no evidence of intervention effects on secondary biological, emotional and health-related behavioural outcomes except self-reported fruit and vegetable intake.

Conclusions

Provision of risk information, whether based on phenotypic or genotypic characteristics, alongside web-based lifestyle advice did not importantly affect objectively measured levels of physical activity, other health-related behaviours, biological risk factors or emotional well-being.

Trial registration number

ISRCTN17721237; Pre-results.

Determinants of blood donation willingness in the European Union: a cross-country perspective on perceived transfusion safety, concerns, and incentives

BACKGROUND

Willingness to donate blood depends on personal characteristics, beliefs, and motivations, but also on the cultural context. The aim of this study was to examine whether willingness to donate blood is associated with attitudes toward blood transfusion, personal motivators, and incentives and whether these factors vary across countries in the European Union (EU).

STUDY DESIGN AND METHODS

The sample consisted of 27,868 participants, from 28 EU member states, who were interviewed about blood donation and transfusion-related issues for the 2014 round of the Eurobarometer, a country-comparative survey, collected on behalf of the European Commission. Participants were asked whether they would be willing to donate blood and for which reasons (motivators) and which incentives are appropriate to receive in return for a blood donation.

RESULTS

Willingness to donate varied significantly across countries and was positively associated with perceived blood transfusion safety. Furthermore, helping family or people in need were the most powerful motivators for blood donation willingness in almost all countries. In contrast, the number of participants who were willing to donate to alleviate shortages or to contribute to research varied widely across countries. The wish to receive certain incentives, however, did not seem to be related to willingness to donate.

CONCLUSION

Perceived blood transfusion safety and personal motivations may be stronger determinants of willingness to donate than receiving certain incentives. EU-wide strategies and guidelines for donor recruitment and retention should take both overall and country-specific patterns into account. For example, education on the importance of donation could be considered.

Donor InSight: characteristics and representativeness of a Dutch cohort study on blood and plasma donors

Background and Objectives

More insight into donor health and behaviour may contribute to more efficient and focused strategies regarding donor care and management. Donor InSight (DIS) is a Dutch cohort study of blood and plasma donors. We aimed to outline the objectives and methods of DIS, describe the cohort, and compare it to the active Dutch donor population.

Materials and Methods

In 2007‐2009 (DIS‐I, n = 31 338) and 2012‐2013 (DIS‐II, 34 826, of whom 22 132 also participated in DIS‐I) questionnaire data on demographics, donation, lifestyle, family composition, health and disease were collected. A second follow‐up (DIS‐III, n = 3046), including donors with differing haemoglobin trajectories, was completed in 2015‐2016. DIS‐III includes data on genetic determinants, iron and red cell indices. Representativeness of the DIS‐I sample for the entire Dutch donor population was assessed by comparing characteristics of both.

Results

Donor InSight was initially set up because of a need for more detailed information and evidence as a basis for decision‐making in blood banks. DIS‐I sample is comparable to the total Dutch donor population in terms of age, body mass index, haemoglobin level, blood pressure, blood type and donation behaviour.

Conclusion

Donor InSight is a cohort study representative of the Dutch donor population. It provides evidence to support evidence‐based decision making.

Cross-species molecular dissection across alcohol behavioral domains

This review summarizes the proceedings of a symposium presented at the "Alcoholism and Stress: A Framework for Future Treatment Strategies" conference held in Volterra, Italy on May 9-12, 2017. Psychiatric diseases, including alcohol-use disorders (AUDs), are influenced through complex interactions of genes, neurobiological pathways, and environmental influences. A better understanding of the common neurobiological mechanisms underlying an AUD necessitates an integrative approach, involving a systematic assessment of diverse species and phenotype measures. As part of the World Congress on Stress and Alcoholism, this symposium provided a detailed account of current strategies to identify mechanisms underlying the development and progression of AUDs. Dr. Sean Farris discussed the integration and organization of transcriptome and postmortem human brain data to identify brain regional- and cell type-specific differences related to excessive alcohol consumption that are conserved across species. Dr. Brien Riley presented the results of a genome-wide association study of DSM-IV alcohol dependence; although replication of genetic associations with alcohol phenotypes in humans remains challenging, model organism studies show that COL6A3, KLF12, and RYR3 affect behavioral responses to ethanol, and provide substantial evidence for their role in human alcohol-related traits. Dr. Rob Williams expanded upon the systematic characterization of extensive genetic-genomic resources for quantifying and clarifying phenotypes across species that are relevant to precision medicine in human disease. The symposium concluded with Dr. Robert Hitzemann's description of transcriptome studies in a mouse model selectively bred for high alcohol ("binge-like") consumption and a non-human primate model of long-term alcohol consumption. Together, the different components of this session provided an overview of systems-based approaches that are pioneering the experimental prioritization and validation of novel genes and gene networks linked with a range of behavioral phenotypes associated with stress and AUDs.

Smoking fewer than 20 cigarettes per day and remaining abstinent for more than 12 hours reduces carboxyhemoglobin levels in packed red blood cells for transfusion

Background

The prevalence of smokers among blood donors and the effect of smoking on the quality of donated blood have not been extensively explored. In the present study, we determined the prevalence of smoker donors in a large blood bank in Southern Brazil and evaluated the quality of packed red blood cells (RBCs) from these donors through recommended quality control tests and measurement of carboxyhemoglobin (COHb) levels. We then assessed the influence of smoking habits and abstinence before donation on these parameters.

Material and methods

An observational study was conducted to determine the prevalence of smoking donors, while a prospective cohort study compared conventional hematological and serological parameters and COHb levels at 0, 15, and 30 days after donation in RBCs donated by smokers (N = 31) and nonsmokers (N = 31) and their association with smoking habits and abstinence before donation.

Results

Of 14,428 blood donations received in 1 year, 5.9% were provided by smokers. Storage over time slightly altered some quality parameters, such as hematocrit, hemoglobin, hemolysis, and COHb levels, in RBC packs. COHb levels were higher in RBC packs from smokers (8%) than from non-smokers (2%), and increased as a function of the number of cigarettes smoked daily and time elapsed since the last cigarette smoked before donation. Lower levels were found in RBC packs from donors who smoked fewer than 20 cigarettes per day or remained abstinent for more than 12h before giving blood.

Conclusion

Although cigarette smoke had no significant effect on blood quality parameters such as hematocrit, hemoglobin, or hemolysis, it quadrupled COHb levels in packed RBCs. Abstinence from smoking for more than 12h or smoking fewer than 20 cigarettes daily helped decrease COHb levels.

Implications

Given the increasing prevalence of tobacco use worldwide, we suggest blood banks recommend 12h of tobacco abstinence before donation and analyze COHb levels in donated blood as an approach to reduce risk for high-risk recipients.

The association between psychosocial factors and change in lifestyle behaviour following lifestyle advice and information about cardiovascular disease risk

Background

Physical activity (PA) and fruit and vegetable intake (FVI) are two key modifiable risk factors for cardiovascular disease (CVD). Achieving change in these behaviours is challenging and affected by many variables including psychosocial factors. We aimed to investigate the association between social support, stress and mood, and change in PA and FVI following provision of CVD risk information and web-based lifestyle advice.

Methods

Seven hundred sixteen blood donors (56% male; mean age 57 years) from the intervention arms of the Information and Risk Modification (INFORM) trial, a randomised controlled trial to assess the impact of providing CVD risk and web-based lifestyle information, were analysed as a prospective cohort. We used linear and logistic regression analyses to quantify the association between social support, stress and mood at baseline and behaviour change following the intervention. We modelled objective (average acceleration measured by Axivity AX3 wrist-worn accelerometers and plasma carotenoid levels) and subjective (self-reported recreational PA and FVI) outcomes as change between baseline and 12 weeks follow-up.

Results

There was no clear association between social support and change in objective or subjective PA. Higher levels of stress and, to a lesser extent, depression symptoms were associated with smaller improvement in self-reported PA (β -1.53 h/week vigorous PA, 95% confidence interval (CI) -2.30 to -0.75, p < 0.001 for stress; β -1.64 h/week, 95% CI -3.50 to 0.21, p = 0.082 for little interest). Higher social support was associated with greater odds and higher stress was associated with lower odds of increasing self-reported FVI to five portions per day (odds ratio (OR) 1.33, 95% CI 1.05 to 1.69, p = 0.020 for social support; OR 0.57, 95% CI 0.43 to 0.76, p < 0.001 for stress). The associations between psychosocial factors and objective FVI were not statistically significant.

Conclusions

High stress and low mood may reduce the likelihood and extent of reported change in PA and FVI following CVD risk information and advice. Greater social support may be associated with increased FVI. The role of psychosocial factors should be considered when developing, tailoring and evaluating future interventions.

Trial registration

Current Controlled Trials ISRCTN17721237. Registered 12 January 2015.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5655-7) contains supplementary material, which is available to authorized users.

Associations of health status with subsequent blood donor behavior-An alternative perspective on the Healthy Donor Effect from Donor InSight

INTRODUCTION

In donor health research, the 'Healthy Donor Effect' (HDE) often biases study results and hampers their interpretation. This refers to the fact that donors are a selected 'healthier' subset of a population due to both donor selection procedures and self-selection. Donors with long versus short donor careers, or with high versus low donation intensities are often compared to avoid this HDE, but underlying health differences might also cause these differences in behaviour. Our aim was to estimate to what extent a donor´s perceived health status associates with donation cessation and intensity.

METHODS

All active whole blood donors participating in Donor InSight (2007-2009; 11,107 male; 12,616 female) were included in this prospective cohort study. We performed Cox survival and Poisson regression analyses to assess whether self-reported health status, medication use, disease diagnosed by a physician and recently having consulted a general practitioner (GP) or specialist were associated with (time to) donation cessation and donation intensity.

RESULTS

At the end of 2013, 44% of the donors in this study had stopped donating. Donors in self-rated good health had a 15% lower risk to stop donating compared to donors in perceived poorer health. Medication use, disease diagnoses and consulting a GP were associated with a 20-40% increased risk to stop donating and a lower donation intensity, when adjusting for age, number of donations and new donor status. Both men and women reporting good health made on average 10% more donations.

CONCLUSION

Donors with a "good" health status were less likely to stop donating blood and tended to donate blood more often than donors with perceived poorer health status. This implies that the HDE is an important source of selection bias in studies on donor health and this includes studies where comparisons within donors are made. This HDE should be adjusted for appropriately when assessing health effects of donation and donors' health status may provide estimates of future donation behavior.

Blood donor show behaviour after an invitation to donate: The influence of collection site factors

BACKGROUND AND OBJECTIVES

Show behaviour after invitation to donate varies considerably across donors. More insight into this variation is important for blood banks in achieving stable stocks. This study examined individual factors determining intended show behaviour. Most importantly, however, this study is the first study to account for variation in donor behaviour across different collection sites.

MATERIALS AND METHODS

We applied a multilevel approach to data from Donor InSight, including 11 889 donors from 257 fixed and mobile collection sites in the Netherlands. The aim of the multilevel models was to account for variance at two levels, that is donors and collection sites. We estimated the likelihood of showing after invitation based on individual predictors, including demographics, donation history and attitude. At the collection site level, we included satisfaction with the blood bank aggregated from individual responses by donors who donate at this site, opening hours and collection site type, that is fixed/mobile.

RESULTS

Most importantly, show behaviour varied considerably across collection sites and depended on characteristics of these sites. Moreover, women, older and more experienced donors had higher odds of showing after invitation than men, younger and less experienced donors. Donors higher on warm glow, self-efficacy and donor identity more likely showed after an invitation. Higher aggregate satisfaction and donating at fixed collection sites increased the odds of show.

CONCLUSION

In addition to individual factors, collection site characteristics are important in explaining variation in donor show behaviour, thus presenting clues for blood bank policies and interventions to improve donor show.

Organ Donation Registration and Decision-Making Among Current Blood Donors in the Netherlands

INTRODUCTION

In the Netherlands, there is a constant shortage in donor organs, resulting in long waiting lists. The decision to register as organ donor is associated with several demographic, cultural, and personal factors. Previous research on attitudes and motivations toward blood and organ donations provided similar results.

RESEARCH QUESTION

The current study investigated demographic, cultural, and personal determinants of organ donation registration among current Dutch blood donors.

DESIGN

We used data from Donor InSight (2012; N = 20 063), a cohort study among Dutch blood donors, to test whether age, gender, religious and political preferences, donor attitude, and altruism predicted organ donor registration among current blood donors.

RESULTS

Organ donors were more often represented in the blood donor population compared to the general Dutch population. Women showed a higher propensity to be registered as organ donor. Higher education as well as higher prosocial value orientation, prosocial behavior, that is, doing volunteer work, and awareness of need significantly associated with being registered as organ donor. Religious denomination negatively predicted organ donation registration across all faiths.

DISCUSSION

Results are discussed in light of cultural context, and possible implications for improving information provision and recruitment are mentioned.

Individual, contextual and network characteristics of blood donors and non-donors: a systematic review of recent literature

BACKGROUND

The ageing population and recent migration flows may negatively affect the blood supply in the long term, increasing the importance of targeted recruitment and retention strategies to address donors. This review sought to identify individual, network and contextual characteristics related to blood donor status and behaviour, to systematically discuss differences between study results, and to identify possible factors to target in recruitment and retention efforts.

METHODS

The systematic review was conducted in accordance with a predefined PROSPERO protocol (CRD42016039591). After quality assessments by multiple independent raters, a final set of 66 peer-reviewed papers, published between October 2009 and January 2017, were included for review.

RESULTS

Individual and contextual characteristics of blood donor status and behaviour were categorised into five main lines of research: donor demographics, motivations and barriers, adverse reactions and deferral, contextual factors, and blood centre factors. Results on donor demographics, motivations and barriers, and contextual factors were inconclusive, differing between studies, countries, and sample characteristics. Adverse reactions and deferral were negatively related to blood donor behaviour. Blood centre factors play an important role in donor management, e.g., providing information, reminders, and (non-)monetary rewards. No studies were found on network characteristics of (non-)donors.

DISCUSSION

Although individual and contextual characteristics strongly relate to blood donor status and behaviour, mechanisms underlying these relations have not been studied sufficiently. We want to stress the importance of longitudinal studies in donor behaviour, exploring the role of life events and network characteristics within blood donor careers. Increased understanding of donor behaviour will assist policy makers of blood collection agencies, with the ultimate goal of safeguarding a sufficient and matching blood supply.

Genomewide Association Study of Alcohol Dependence Identifies Risk Loci Altering Ethanol-Response Behaviors in Model Organisms

BACKGROUND

Alcohol dependence (AD) shows evidence for genetic liability, but genes influencing risk remain largely unidentified.

METHODS

We conducted a genomewide association study in 706 related AD cases and 1,748 unscreened population controls from Ireland. We sought replication in 15,496 samples of European descent. We used model organisms (MOs) to assess the role of orthologous genes in ethanol (EtOH)-response behaviors. We tested 1 primate-specific gene for expression differences in case/control postmortem brain tissue.

RESULTS

We detected significant association in COL6A3 and suggestive association in 2 previously implicated loci, KLF12 and RYR3. None of these signals are significant in replication. A suggestive signal in the long noncoding RNA LOC339975 is significant in case:control meta-analysis, but not in a population sample. Knockdown of a COL6A3 ortholog in Caenorhabditis elegans reduced EtOH sensitivity. Col6a3 expression correlated with handling-induced convulsions in mice. Loss of function of the KLF12 ortholog in C. elegans impaired development of acute functional tolerance (AFT). Klf12 expression correlated with locomotor activation following EtOH injection in mice. Loss of function of the RYR3 ortholog reduced EtOH sensitivity in C. elegans and rapid tolerance in Drosophila. The ryanodine receptor antagonist dantrolene reduced motivation to self-administer EtOH in rats. Expression of LOC339975 does not differ between cases and controls but is reduced in carriers of the associated rs11726136 allele in nucleus accumbens (NAc).

CONCLUSIONS

We detect association between AD and COL6A3, KLF12, RYR3, and LOC339975. Despite nonreplication of COL6A3, KLF12, and RYR3 signals, orthologs of these genes influence behavioral response to EtOH in MOs, suggesting potential involvement in human EtOH response and AD liability. The associated LOC339975 allele may influence gene expression in human NAc. Although the functions of long noncoding RNAs are poorly understood, there is mounting evidence implicating these genes in multiple brain functions and disorders.

Meat consumption is a major risk factor for hepatitis E virus infection

Background

The incidence of autochthonous hepatitis E virus genotype 3 (HEV gt3) infections in Western Europe is high. Although pigs are a major reservoir of the virus, the exact sources and transmission route(s) of HEV gt3 to humans remain unclear.

Methods

To determine the role of meat consumption at a population level, the seroprevalence of anti-HEV IgG antibodies was compared between Dutch blood donors with a vegetarian lifestyle and donors who consume meat on a daily basis.

Results

The age-weighted anti-HEV IgG seroprevalence among donors not eating meat was significantly lower than among meat-eating donors (12.4% vs 20.5%, p = 0.002). For both groups the prevalence strongly increased with age and the difference in prevalence was apparent for all age groups.

Conclusions

Compared with meat-eating donors, the incidence of HEV infection is significantly lower among donors not eating meat, indicating that meat consumption is a major risk factor for HEV infection.

Socio-demographic characteristics of Danish blood donors

Background

Blood transfusion is an essential component of a modern healthcare system. Because knowledge about blood donor demography may inform the design of strategies for donor recruitment and retention, we used nationwide registers to characterize the entire population of blood donors in Denmark in 2010.

Methods

The study population comprised all Danes in the age range eligible for blood donation (N = 3,236,753) at the end of 2010. From the Scandinavian Donations and Transfusions (SCANDAT) register, we identified 174,523 persons who donated blood in Danish blood banks at least once in 2010. The association between sociodemographic characteristics and blood donor prevalence was examined using regression models.

Results

The overall prevalence of blood donation was 5.4% among both women and men. The age-specific prevalence of blood donation peaked at 25 years of age (6.8%) for women and 30 years of age (5.7%) for men. Children of any age were associated with lower prevalence of blood donation among women, while the opposite was seen for men. Middle to high income groups, but not the highest income group, had fourfold higher donor prevalence than the lowest income group (6.7% compared to 1.7%). The prevalence of blood donation was considerably lower among men living with their parents (2.9%) or alone (3.9%) than among men cohabitating with a woman (6.2%).

Summary

Social marginalization, as indicated by low income and being a male living without a woman, was associated with lower prevalence of blood donation. However, individuals with very high incomes and women with children were underrepresented in the Danish blood donor population.

Whole Blood Donation Affects the Interpretation of Hemoglobin A1c

Introduction

Several factors, including changed dynamics of erythrocyte formation and degradation, can influence the degree of hemoglobin A_1c (HbA_1c) formation thereby affecting its use in monitoring diabetes. This study determines the influence of whole blood donation on HbA_1c in both non-diabetic blood donors and blood donors with type 2 diabetes.

Methods

In this observational study, 23 non-diabetic blood donors and 21 blood donors with type 2 diabetes donated 475 mL whole blood and were followed prospectively for nine weeks. Each week blood samples were collected and analyzed for changes in HbA_1c using three secondary reference measurement procedures.

Results

Twelve non-diabetic blood donors (52.2%) and 10 (58.8%) blood donors with type 2 diabetes had a significant reduction in HbA_1c following blood donation (reduction >-4.28%, P < 0.05). All non-diabetic blood donors with a normal ferritin concentration predonation had a significant reduction in HbA_1c. In the non-diabetic group the maximum reduction was -11.9%, in the type 2 diabetes group -12.0%. When eligible to donate again, 52.2% of the non-diabetic blood donors and 41.2% of the blood donors with type 2 diabetes had HbA_1c concentrations significantly lower compared to their predonation concentration (reduction >-4.28%, P < 0.05).

Conclusion

Patients with type 2 diabetes contributing to whole blood donation programs can be at risk of falsely lowered HbA_1c. This could lead to a wrong interpretation of their glycemic control by their general practitioner or internist.

Comparison of Criteria for Choosing the Number of Classes in Bayesian Finite Mixture Models

Identifying the number of classes in Bayesian finite mixture models is a challenging problem. Several criteria have been proposed, such as adaptations of the deviance information criterion, marginal likelihoods, Bayes factors, and reversible jump MCMC techniques. It was recently shown that in overfitted mixture models, the overfitted latent classes will asymptotically become empty under specific conditions for the prior of the class proportions. This result may be used to construct a criterion for finding the true number of latent classes, based on the removal of latent classes that have negligible proportions. Unlike some alternative criteria, this criterion can easily be implemented in complex statistical models such as latent class mixed-effects models and multivariate mixture models using standard Bayesian software. We performed an extensive simulation study to develop practical guidelines to determine the appropriate number of latent classes based on the posterior distribution of the class proportions, and to compare this criterion with alternative criteria. The performance of the proposed criterion is illustrated using a data set of repeatedly measured hemoglobin values of blood donors.

Blood donors' physical characteristics are associated with pre- and post-donation symptoms - Donor InSight

BACKGROUND

Observational data suggest that some donors might benefit from donating while others may be harmed. The aim of this study was to investigate the prevalence and potential, routinely measured, determinants of pre- and post-donation symptoms.

MATERIALS AND METHODS

In Donor InSight, questionnaire data from 23,064 whole blood donors (53% female) were linked to routinely measured data on donors' physical characteristics (haemoglobin, blood pressure, body mass index and estimated blood volume) from the Dutch donor database. Absolute and relative associations between donors' physical donor and the presence of pre- and post-donation symptoms were studied using multivariable logistic regression.

RESULTS

Pre-donation symptoms (lack of energy, headaches) were reported by 3% of men and 3% of women. Five percent of men and 4% of women reported positive post-donation symptoms (feeling fit, fewer headaches). Negative symptoms (fatigue, dizziness) were more common, occurring in 8% of men and 19% of women. All the studied donors' physical characteristics were positively associated with pre- and positive post-donation symptoms and negatively associated with negative symptoms. Body mass index was most consistently and independently associated with symptoms.

DISCUSSION

Donors' physical characteristics, in particular body mass index, were consistently associated with pre- and post-donation symptoms. This indicates that subgroups of donors more and less tolerant to donation might be identifiable using routinely measured data. Further research is warranted to study underlying mechanisms and potential strategies to predict and prevent donor reactions.

Prediction of hemoglobin in blood donors using a latent class mixed-effects transition model

Blood donors experience a temporary reduction in their hemoglobin (Hb) value after donation. At each visit, the Hb value is measured, and a too low Hb value leads to a deferral for donation. Because of the recovery process after each donation as well as state dependence and unobserved heterogeneity, longitudinal data of Hb values of blood donors provide unique statistical challenges. To estimate the shape and duration of the recovery process and to predict future Hb values, we employed three models for the Hb value: (i) a mixed-effects models; (ii) a latent-class mixed-effects model; and (iii) a latent-class mixed-effects transition model. In each model, a flexible function was used to model the recovery process after donation. The latent classes identify groups of donors with fast or slow recovery times and donors whose recovery time increases with the number of donations. The transition effect accounts for possible state dependence in the observed data. All models were estimated in a Bayesian way, using data of new entrant donors from the Donor InSight study. Informative priors were used for parameters of the recovery process that were not identified using the observed data, based on results from the clinical literature. The results show that the latent-class mixed-effects transition model fits the data best, which illustrates the importance of modeling state dependence, unobserved heterogeneity, and the recovery process after donation. The estimated recovery time is much longer than the current minimum interval between donations, suggesting that an increase of this interval may be warranted.

Blood donation and blood donor mortality after adjustment for a healthy donor effect

BACKGROUND

Studies have repeatedly demonstrated that blood donors experience lower mortality than the general population. While this may suggest a beneficial effect of blood donation, it may also reflect the selection of healthy persons into the donor population. To overcome this bias, we investigated the relation between blood donation frequency and mortality within a large cohort of blood donors. In addition, our analyses also took into consideration the effects of presumed health differences linked to donation behavior.

STUDY DESIGN AND METHODS

Using the Scandinavian Donation and Transfusion database (SCANDAT), we assessed the association between annual number of donations in 5-year windows and donor mortality by means of Poisson regression analysis. The analyses included adjustment for demographic characteristics and for an internal healthy donor effect, estimated among elderly donors exempted from continued donation because of age criteria.

RESULTS

Statistical analyses included 1,182,495 donors of whom 15,401 died during 9,526,627 person-years of follow-up. Analyses adjusted only for demographic characteristics showed a 18.6% reduction in mortality per additional annual donation (95% confidence interval [CI], 16.8%-20.4%). After additional adjustment for the internal healthy donor effect, each additional annual donation was associated with a 7.5% decreased mortality risk 7.5% (95% CI, 5.7%-9.4%).

CONCLUSION

We observed an inverse relationship between donation frequency and mortality. The magnitude of the association was reduced after adjustment for an estimate of self-selection in the donor population. Our observations indicate that repeated blood donation is not associated with premature death, but cannot be interpreted as conclusive evidence of a beneficial health effect.

Higher outdoor temperatures are progressively associated with lower blood pressure: a longitudinal study in 100,000 healthy individuals

This study investigated the shape of associations between climate parameters (mean daily temperature and humidity) and systolic and diastolic blood pressure in a large longitudinal cohort of healthy individuals. The study population comprised 101,377 Dutch whole blood and plasma donors (50% men), who made 691,107 visits to the blood bank between 2007 and 2009. Climate parameters were acquired from the Royal Netherlands Meteorological Institute. Associations with blood pressure, measured prior to each blood donation, were studied using (piecewise) linear regression analyses within Generalized Estimating Equation models. On average, systolic blood pressure was 0.18 mm Hg, and diastolic blood pressure was 0.11 mm Hg lower per one degree Celsius higher mean daily temperature. Higher daily temperatures were associated with lower blood pressure, independent of humidity and potentially confounding factors. These associations were stronger at older age and higher temperatures. Seasonality should therefore be taken into account when monitoring blood pressure, particularly in older individuals.

The effect of hyperglycaemia on in vitro cytokine production and macrophage infection with Mycobacterium tuberculosis

Type 2 diabetes mellitus is an established risk factor for tuberculosis but the underlying mechanisms are largely unknown. We examined the effects of hyperglycaemia, a hallmark of diabetes, on the cytokine response to and macrophage infection with Mycobacterium tuberculosis. Increasing in vitro glucose concentrations from 5 to 25 mmol/L had marginal effects on cytokine production following stimulation of peripheral blood mononuclear cells (PBMCs) with M. tuberculosis lysate, LPS or Candida albicans, while 40 mmol/L glucose increased production of TNF-α, IL-1β, IL-6 and IL-10, but not of IFN-γ, IL-17A and IL-22. Macrophage differentiation under hyperglycaemic conditions of 25 mmol/L glucose was also associated with increased cytokine production upon stimulation with M. tuberculosis lysate and LPS but in infection experiments no differences in M. tuberculosis killing or outgrowth was observed. The phagocytic capacity of these hyperglycaemic macrophages also remained unaltered. The fact that only very high glucose concentrations were able to significantly influence cytokine production by macrophages suggests that hyperglycaemia alone cannot fully explain the increased susceptibility of diabetes mellitus patients to tuberculosis.

Travel behavior and deferral of Dutch blood donors: consequences for donor availability

BACKGROUND

Donors returning from areas with outbreaks of infectious diseases may donate infectious blood back home. Geographic donor deferral is an effective measure to ensure the blood safety, but donor deferral may pose a threat for the blood supply especially after holiday seasons. Insight into the travel behavior of blood donors is a first step to define appropriate deferral strategies. This study describes the travel behavior of Dutch donors, the actual deferral, and the consequences of deferral strategies on donor availability.

STUDY DESIGN AND METHODS

A questionnaire designed to assess travel behavior (destination, frequency, and duration of travels) was sent to 2000 Dutch donors. The impact of travel deferral policies on donor availability was calculated, expressed as proportionate decrease in donor availability. The deferral policies considered were 1) deferral based on entire countries instead of affected regions where an infection is prevalent and 2) deferral after any travel outside Europe ("universal deferral").

RESULTS

Of the 1340 respondents, 790 (58.9%) donors traveled within Europe only, 61 (4.6%) outside Europe only, and 250 (18.7%) within and outside Europe. The deferral for entire countries and universal deferral would lead to 11.1 and 11.4% decrease in donor availability, respectively.

CONCLUSION

Most Dutch donors traveled outside the Netherlands, while 23.2% traveled outside Europe. Universal deferral resulted in an additional decrease in donor availability of 0.3% compared with deferral for entire countries instead of affected regions where an infection is prevalent. Thus, the universal deferral could be considered as a simpler and safer measure.

The need to label red blood cell units with their haemoglobin content: a single centre study on haemoglobin variations due to donor-related factors

BACKGROUND

Red blood cell (RBC) transfusions are given as "number of units" without considering the haemoglobin (Hb) content of these units. Donor factors influencing Hb level in whole blood donors and, ultimately, in RBC units have not been studied.

MATERIALS AND METHODS

Donor data for a period of 1.5 years were retrospectively analysed and the effects of age, gender and weight on the Hb level of the donors were determined. The correlation between donor's Hb concentration with total Hb in the RBC unit was analysed. Additionally, actual Hb content of 125 RBC units was determined. The total Hb content of these RBC units was also mathematically calculated based on the blood donors' Hb. The ability of this mathematically calculated Hb to predict actual Hb content per RBC unit was then analysed.

RESULTS

The mean Hb level in female donors was 1.79 g/dL lower than in the male donors (p<0.001). Increasing age was associated with a lower mean Hb in the donors (p<0.01), while a higher body weight correlated weakly (r=0.06) but significantly with increased mean Hb (p<0.01). Logistic regression analysis showed that in blood donors, female gender had a stronger influence on lowering the mean Hb than either older age or lower weight. A variation of nearly 100% (42.3-80.8 g Hb per unit) was seen in the total Hb content of the RBC units tested. Mathematically calculated Hb content correlated well (r=0.6; p<0.01) with the actual Hb content of the RBC units.

DISCUSSION

We demonstrated the effect of gender, age and weight on Hb levels in whole blood donors. Dissimilarities in the donor Hb caused nearly 100% variations in the Hb content of the RBC units. It would, therefore, be prudent to label RBC units with their total Hb content. This total Hb content can be predicted fairly accurately from the donor's pre-donation Hb level.

Combined oral contraception and obesity are strong predictors of low-grade inflammation in healthy individuals: results from the Danish Blood Donor Study (DBDS)

BACKGROUND

C-reactive protein (CRP) is a well-established marker of inflammation. The level of CRP is affected by several lifestyle factors. A slightly increased CRP level, also known as low-grade inflammation (LGI), is associated with increased risk of several diseases, especially cardiovascular disease. The aim of this study was to identify predictors of increased CRP levels in healthy individuals. We therefore assessed CRP in a large cohort of blood donors.

METHODS

We measured plasma CRP levels in 15,684 participants from the Danish Blood Donor Study. CRP was measured by a commercial assay. Furthermore, all participants completed a standard questionnaire on smoking status, alcohol consumption, physical activity, diet, and various body measurements. Female participants also reported the use of contraception, childbirth, and menopausal status. The relationship between LGI (defined here as a plasma CRP level between 3 mg/L and 10 mg/L) and predictors was explored by multivariable logistic regression analysis. Results were presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

We found LGI in a total of 1,561 (10.0%) participants. LGI was more frequent in women using combined oral contraception (OC) (29.9%) than in men (6.1%) and women not using OC (7.9%). Among premenopausal women, OC was the strongest predictor of LGI (odds ratio = 8.98, p<0.001). Additionally, body mass index (BMI) and waist circumference were positively associated with LGI.

CONCLUSION

High BMI and abdominal obesity strongly predicted LGI among healthy individuals. However, the most striking finding was the high prevalence of LGI among premenopausal women who used combined oral contraception. Although the significance of CRP as a marker of inflammation is well known, the role of CRP in pathogenesis is still uncertain. The impact of oral contraception on CRP levels should nevertheless be considered when CRP is used in risk assessment.

Risk factors for complications in donors at first and repeat whole blood donation: a cohort study with assessment of the impact on donor return

BACKGROUND

First-time donation is among recognised risk factors for vasovagal reactions to blood donation and reactions are known to reduce donor return. We assessed associations between potential risk factors and vasovagal reactions and needle-related complications in first-time whole blood donation in comparison to repeat donation and analysed the impact of complications on donor return.

MATERIALS AND METHODS

We performed a cohort study on whole blood donations in The Netherlands from 1/1/2010 to 31/12/2010 using data extracted from the blood service information system. Donation data up to 31/12/2011 were used to ascertain donor return.

RESULTS

In 2010 28,786 donors made first whole blood donations and there were 522,958 repeat donations. Vasovagal reactions occurred in 3.9% of first donations by males and 3.5% of first donations by females compared to in 0.2% and 0.6%, respectively, of repeat donations. Associations of vasovagal reactions with other factors including age, body weight, systolic and diastolic blood pressure were similar in first-time and repeat donors. Needle-related complications occurred in 0.2% of male and 0.5% of female first-time donations and in 0.1% and 0.3%, respectively, of repeat donations. Among first-time donors, the return rate within 1 year was 82% following an uncomplicated first donation, but 55% and 61% following vasovagal reactions and needle-related complications, respectively; the corresponding percentages among repeat donors were 86%, 58% and 82%.

DISCUSSION

Among first-time donors, females suffered less than males from vasovagal reactions. Other risk factors had similar associations among first-time and repeat donors. Vasovagal reactions and needle-related complications in both first-time and repeat donors are followed by reduced donor return.

Individual Characteristics Associated with Blood Donation: A Cross-National Comparison of the German and Swiss Population between 1994 and 2010

OBJECTIVE

The aim of this study is to compare individual characteristics associated with blood donation in the German and Swiss population between 1994 and 2010.

METHODS

Population-based survey data from the Eurobarometer 1994 and 2009, the Swiss Health Survey 1997, and the Swiss Blood Donation Survey 2010 were used to compare age-adjusted percentages of German and Swiss adults ever having donated blood (n = 8,746). A multivariate logistic regression was applied to the pooled data to estimate odds ratios (OR).

RESULTS

Donor rates between 1994 and 2010 increased by 8.6% in Germany (p = 0.0045) and remained stable in Switzerland. The likelihood to report donating increased with age. Gender differences (OR = 2.85; p = 0.0000) and differences between education levels were more pronounced in Switzerland as compared to Germany (OR = 2.56; p = 0.0000 and OR = 2.73; p = 0.0010). Furthermore education differences were more marked in men in both countries (OR = 1.99; p = 0.0000 and OR = 1.68; p = 0.0140).

CONCLUSION

The blood establishments should intensify their efforts to motivate women and lower educated people to give blood. Our data suggest that population-based surveys could be a helpful tool to describe donor rates in different countries and to guide future recruitment strategies.