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

Reconciling estimates of global spread and infection fatality rates of COVID-19: An overview of systematic evaluations

BACKGROUND

Estimates of community spread and infection fatality rate (IFR) of COVID-19 have varied across studies. Efforts to synthesize the evidence reach seemingly discrepant conclusions.

METHODS

Systematic evaluations of seroprevalence studies that had no restrictions based on country and which estimated either total number of people infected and/or aggregate IFRs were identified. Information was extracted and compared on eligibility criteria, searches, amount of evidence included, corrections/adjustments of seroprevalence and death counts, quantitative syntheses and handling of heterogeneity, main estimates and global representativeness.

RESULTS

Six systematic evaluations were eligible. Each combined data from 10 to 338 studies (9-50 countries), because of different eligibility criteria. Two evaluations had some overt flaws in data, violations of stated eligibility criteria and biased eligibility criteria (eg excluding studies with few deaths) that consistently inflated IFR estimates. Perusal of quantitative synthesis methods also exhibited several challenges and biases. Global representativeness was low with 78%-100% of the evidence coming from Europe or the Americas; the two most problematic evaluations considered only one study from other continents. Allowing for these caveats, four evaluations largely agreed in their main final estimates for global spread of the pandemic and the other two evaluations would also agree after correcting overt flaws and biases.

CONCLUSIONS

All systematic evaluations of seroprevalence data converge that SARS-CoV-2 infection is widely spread globally. Acknowledging residual uncertainties, the available evidence suggests average global IFR of ~0.15% and ~1.5-2.0 billion infections by February 2021 with substantial differences in IFR and in infection spread across continents, countries and locations.

Exposure to passive smoking during adolescence is associated with an increased risk of developing multiple sclerosis

BACKGROUND

Environmental factors are associated with acquiring multiple sclerosis (MS) particularly in adolescence.

OBJECTIVE

To test for association between MS and exposure to passive smoking at the age of 10-19.

METHODS

A total of 919 patients from the Danish MS Registry and Biobank and 3419 healthy blood donors who had not smoked before the age of 19 were targeted. We analyzed separately for each sex and for those never-smokers (cohort 1) and active smokers above the age of 19 (cohort 2). All participants completed standardized questionnaires about smoking and lifestyle. We matched cases and controls in the ratio of 1:2 by propensity scores discarding unmatchable individuals and used logistic regression adjusted for all covariates and interactions.

RESULTS

After matching, we included 110/213 male cases/controls and 232/377 female case/controls in cohort 1. In cohort 2, the numbers were 160/320 and 417/760, respectively. Among women in cohort 1, the odds ratio (OR) for MS by passive smoking at the age of 10-19 was 1.432 (p = 0.037) but in men it was 1.232 (p = 0.39). Among men in cohort 2, OR was 1.593 (p = 0.022) but among women it was only 1.102 (p = 0.44).

CONCLUSION

Among never smokers, female MS cases were more often than female controls reported with passive smoking between the age of 10 and 19, and among smokers above the age of 19, male MS patients were more often than male controls reported with passive smoking.

Blood donation and donors: insights from a large German teaching hospital (2008-2017)

BACKGROUND AND OBJECTIVES

The availability of blood and blood products is crucial for the provision of high-quality hospital services. We analyse changes in whole blood donations, donors and their behaviour over 9 years at a large German teaching hospital.

MATERIALS AND METHODS

A descriptive analysis using data from over 34 000 donors and 265 000 donations from a large university hospital's blood centre was conducted using data from July 2008 to December 2017. The analysis focussed on (a) whole blood donations and (b) donor characteristics and how they changed over time. We categorized donors into four categories according to their donation activity (First-Time, Highly Active, Active and Reactivated).

RESULTS

We observed falling donations over time and that donors donated less frequently. Consequently, we show a downward trend in the number of Highly Active donors, whilst First-Time donors remained stable. We also provide evidence that donors donated well below their capacity and that the blood type of donors appeared to be in line with the wider German donor population. Lastly, we show a sharp drop in the return rates of First-Time donors over time.

CONCLUSION

We recommend that Highly Active donors and former Highly Active donors are more carefully considered when planning donor engagement strategies and effort made in (at the very least) maintaining their donation activity. Our results in the context of the literature highlight the need for further research into the changing attitudes towards blood donation and prosocial activities.

Alcohol consumption in adolescence is associated with a lower risk of multiple sclerosis in a Danish cohort

BACKGROUND AND OBJECTIVE

Due to the possible existence of a vulnerable period of multiple sclerosis (MS) susceptibility in adolescence and because Danish teenagers have a high alcohol consumption, we investigated the association between alcohol consumption at ages 15-19 and the risk of developing MS.

METHODS

A total of 1717 patients with MS and 4685 healthy blood donors filled in a comprehensive environmental and lifestyle questionnaire. Data were analysed by logistic regression models and adjusted for selected confounders.

RESULTS

We found an inverse association between alcohol consumption in adolescence and risk of developing MS in both women (p < 0.001) and men (p = 0.012). Women with low alcohol consumption had an odds ratio (OR) of 0.56 (95% confidence interval (CI): 0.47-0.66) compared with non-drinking women. The ORs were similar for women with moderate (OR = 0.49, 95% CI: 0.38-0.62) and high consumption (OR = 0.57, 95% CI: 0.38-0.84). Men with low alcohol consumption had an OR of 0.69 (95% CI: 0.53-0.89) compared with non-drinking men but no decreased risk was found for men with moderate and high consumption.

CONCLUSION

Alcohol consumption in adolescence was associated with lower risk of developing MS among both sexes.

Who donates? Cross-country and periodical variation in blood donor demographics in Europe between 1994 and 2014

BACKGROUND

Ageing European populations put pressure on national blood supplies, increasing the need for blood and donor base rejuvenation. Therefore, we investigate how European countries' blood donor populations differ and how they have evolved over the last 2 decades. Previous comparative research, based on 1994 Eurobarometer data, indicate that the typical donor is an educated, middle-aged, white, married male. Other sociodemographic and socioeconomic correlates, such as employment status and type of community, are less clear.

STUDY DESIGN AND METHODS

Multilevel analyses are performed on repeated cross-level data from the Eurobarometer (waves 1994, 2002, 2009, and 2014) to compare information on "ever having donated" across sociodemographic categories, countries, and periods.

RESULTS

There are consistent but moderate country and period differences. The donor population rose to become largest in most countries by 2009, and stabilized thereafter. Over the studied period, donors were more likely to be higher educated, married men. Nevertheless, changes across time in donor profiles within countries did occur. Women were less likely to donate blood, especially in Southern and Eastern Europe, but this gender gap has declined. Furthermore, educational attainment seems more relevant for women, although, more recently, to a lesser extent.

CONCLUSION

Although there is a promising trend in which women, young people, and students are increasingly likely to donate, more attention is needed to reach the unemployed and the low to medium educated. Because the unemployed may lack structural opportunities to donate, and the low to medium educated may lack relevant knowledge on blood donation necessity, we recommend providing practical opportunities and information on the necessity of blood donation.

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.

Too Many Blood Donors - Response Bias in the Swiss Health Survey 2012

BACKGROUND

Data on blood donor status obtained from general surveys and health interview surveys have been widely used. However, the integrity of data on self-reported blood donor status from surveys may be threatened by sampling and non-sampling error. Our study aimed to compare self-reported blood donors (including one-time as well as regular donors) from the Swiss Health Survey 2012 (SHS) with register-based blood donors recorded by blood establishments and evaluate the direction and magnitude of bias in the SHS.

METHODS

We compared population-weighted SHS point estimates of the number of blood donors with their corresponding 95% confidence intervals to the respective figures from blood donor registries (birth cohorts 1978-1993) and estimates of donors based on period donor tables derived from blood donor registries (birth cohorts 1920-1993).

RESULTS

In the birth cohorts 1978-1993, the SHS-predicted number of donors was 1.8 times higher than the respective number of donors based on registry data. Adjusting for foreign and naturalized Swiss nationals that immigrated after their 18th birthday, the SHS overall predicted number of donors was 1.6 times higher. Similarly, SHS estimates for the 1920-1993 birth cohorts were 2.4 and 2.1 times higher as compared to register-based estimates. Generally, the differences between SHS and register-based donors were more pronounced in men than in women.

CONCLUSION

Self-reported blood donor status in the SHS is biased. Estimates of blood donors are substantially higher than respective estimates based on blood donor registries.

Giving blood and enrolling on the stem cell donor registry: ranking of obstacles and motives in Switzerland

BACKGROUND

To obtain a better understanding of factors affecting blood and blood stem cell donation behavior in Switzerland, a series of studies has been performed. In the recent study of this series, which is described here, motivators and barriers in the field of blood and blood stem cell donation were identified.

METHODS

Web-based survey data from a non-random sample of the Swiss population 2012/2013 (n = 3,153) were used to describe and compare the ranking of motives and obstacles to donate blood and to enroll on the Swiss blood stem cell registry. Wilcoxon rank-sum test and Spearman's rank correlations were used to assess differences and associations between ranks and groups.

RESULTS

The prospect of saving lives and solidarity were the top two motives to donate blood or to enroll on the blood stem cell registry. The top two obstacles to enroll on the blood stem cell registry were lack of general information on blood stem cell donation and on its risks, whereas the top two obstacles to donate blood were the lack of information where and when to donate and deferral of or exclusion from blood donation.

CONCLUSION

Classical altruistic motives are top drivers for giving blood as well as registering for blood stem cell donation. Recruitment campaigns should focus on these motivators. Similarities in motivational factors as well as in obstacles regarding blood and blood stem cell donation can be found.