Introduction

The COVID-19 pandemic has caused an unprecedented impact on blood transfusion and collection with large-scale disruption to both the supply and demand for blood. Early evidence suggests European countries and across the world have experienced initial drops in whole blood donations, despite centres implementing extra safety measures and public appeals across Europe to encourage continued donation [1-7]. Research from Hong Kong and China has suggested that anxiety and fear of contracting COVID-19 were deterrents to donating blood [7, 8], which is consistent with findings from studies on the SARS and avian flu outbreaks [9, 10]. Falling donations have been partly mitigated in the short term by the postponement of elective surgeries, but future demand remains unpredictable and is dependent on how the pandemic evolves [1, 11]. Therefore, maintaining blood supplies remains an important public health concern during the pandemic. In the past, donors have responded well to public appeals to donate in situations of perceived exceptional need, such as the September 11 attacks, mass shootings in the United States and bush fires in Australia where large influxes of donors in short periods of time were documented [11, 12]. Such reactionary spikes have already been observed in some settings across Europe and in Brazil in response to public calls to donate [3, 13-15]. However, motivations that drive such responses may wane over time and especially so if driven by first-time donors [12].

Large interruptions to donation activity may have stark consequences for healthcare systems and should be avoided by careful tracking of the supply and demand of blood during these uncertain times. It is therefore essential to gain an initial perspective on the impact of COVID-19 on blood donors and an understanding of the key aspects of their motivation to donate (or not donate) during this crisis. The aim of this paper was to provide early insight into blood donation activity across seven European countries and the motivation of blood donors to donate or not to donate during the first phase of the COVID-19 crisis. We do so to understand what is driving changes in donation behaviour and which policies might help to restore donation levels.

Methods

We asked approximately 7000 people about their blood donation activity and motivation to donate or not to donate within the second wave of the European Covid Survey (ECOS) in June 2020. ECOS is an online survey across seven European countries. Around 1000 people in Denmark, France, Germany, Italy, Portugal, the Netherlands and the UK, representative of their country, participated in the study. The survey was organized in a way to avoid self-selection, as respondents were not aware of the survey questions beforehand. Participants completed the survey during the period 9–22 June 2020 using online panels provided by the market research company Dynata. Diverse recruiting campaigns reaching out to around 120 000 people were administered online (open recruitment, loyalty programmes, affiliate networks and mobile apps). Survey respondents received payment, which varied depending on the platform they were recruited through. The survey was programmed in the Qualtrics research suite where quotas were implemented to ensure that the country samples matched national census shares, which were representative in terms of age, sex, region and education level. A declaration of compliance for the project was reviewed and approved before the start of the project by the Vice Dean for Research according to the terms of use and ethical standards of the Faculty of Business, Economics and Social Sciences at the University of Hamburg and the European Commission’s RESPECT Code of Practice [16].

Survey questions and scales

Firstly, we asked all participants whether they had donated blood during the previous 10 years before February 2020 (COVID-19 period), and for those that answered ‘yes’, we asked how many times they had donated in the 2 years prior to COVID-19. A timeframe of 10 years was used to capture donors that may have not been active for some time, but could have responded to the crisis by donating blood. Furthermore, we asked whether the entire sample had donated blood since the beginning of February 2020, as this marks the beginning of the COVID-19 pandemic in Europe. Overall, we were able to identify (a) blood donors, (b) those that donated during COVID-19 and (c) active donors with at least one donation in the 2 years prior to COVID-19.

To understand the impact of COVID-19, we asked donors directly whether they donated less than, more than or the same as they normally would (in the absence of COVID-19). To gain a better understanding of the motivations underlying the decision to donate, we asked those that stated that they did donate during COVID-19, about the extent to which they made a special effort to do so in order to help their healthcare system. Possible responses included ‘yes, somewhat’, ‘yes, definitely’, ‘no’ and ‘I don’t know’. The phrasing of the question aimed to identify whether donors saw COVID-19 as a ‘call to arms’ and responded by helping their healthcare system during the crisis by relieving blood shortages.

As a potential motivator to donate during the pandemic, and following suit from the World Health Organization, we asked all donors how worried they were about their healthcare system being overloaded [17]. Possible responses were on a 5-point scale from (1) do not worry at all, (2) slightly worry, (3) moderately worry, (4) worry quite a bit and (5) worry a lot. Responses 4 and 5 were combined to create a binary variable for analysis. We included the question as an indicator of how concerned donors were with how their healthcare system was handling the crisis and as a signal for the need for additional support. Despite blood donations not normally being needed directly to treat COVID-19 patients, blood donation supply concerns during the period were heavily reported in the media [11, 18-20].

Furthermore, all survey respondents were asked to assess their likelihood of being infected with the novel coronavirus whilst donating blood during the COVID-19 period (1 = no risk; 5 = very high risk), measuring infection risk as a potential barrier to donation, for example risk of travelling to the donation site, contact with staff and other donors. Lastly, we asked those who donated during the COVID-19 period if they were aware of being offered and receiving an antibody test, which we considered a potential incentive to donate. Responses included ‘yes, my blood was tested for COVID-19 antibodies’, ‘no, my blood was not tested for COVID-19 antibodies’ and ‘I don’t know if my blood was tested for COVID-19 antibodies’.

Statistical analysis

The analysis was conducted in two parts (1) a descriptive analysis of blood donors during COVID-19 and (2) a logistic regression of donation turnout during COVID-19 among all respondents and active donors.

To analyse the likelihood of donating during the COVID-19 period, we performed logistic regression analysis across the entire sample of individuals in order to understand which factors were driving the decision to donate during the pandemic. Our dependent variable was binary, indicating whether the sample donated during the COVID-19 period or not (0 or 1). The focal independent variables of interest were (a) having a perceived high or very high (4 or 5) risk of infection risk whilst donating blood (0 or 1), (b) being worried quite a bit or a lot about the healthcare system being overloaded (0 or 1), (c) whether individuals had a vulnerable person living in their household or not (elderly, disabled or with chronic conditions) (0 or 1) and (d) whether they quite strongly or fully adhered to COVID-19 guidelines, for example hand washing and social distancing (0 or 1). We expected that individuals with a vulnerable person at home might be dissuaded from donating to avoid exposing them to additional risk, for example through contact with blood donation staff, other donors and those encountered when travelling to the blood donation site. We therefore anticipated that people who were adherent to COVID guidelines would also be less likely to donate blood.

Additionally, we included variables used previously in the literature in our analysis of donation behaviour, which included a measure of donation experience (no. of self-reported donations in the 2 years prior to the COVID period), age, education level, gender and field of work. We included country fixed effects to account for differences between countries, for example donation eligibility requirements and the structure of country-specific blood donation systems.

Results

Of the 7122 people that responded to the survey, 1205 (16·9%) blood donors were identified across the seven European countries. Table 1 presents the characteristics of all survey respondents, and Table 2 presents the sample of blood donors and their background characteristics. Germany, closely followed by France, had the highest number of self-reported blood donors with 226 (21·5%) and 209 (20·8%) donors, respectively. In contrast, the Netherlands had the lowest number of donors with only 10·2% of the sample.

Table 1. Background characteristics of all survey respondents Country Overall sample Number of donors (%) Age (SE) Male % Years in full-time education (SE) Germany 1050 226 (21·5%) 48·7 (0·5) 48·6% 12·9 (0·1) United Kingdom 1041 186 (17·9%) 47·5 (0·5) 46·9% 14·2 (0·1) Denmark 1005 151 (15·0%) 49·4 (0·5) 48·0% 14·0 (0·1) The Netherlands 1000 102 (10·2%) 48·1 (0·5) 49·0% 13·0 (0·2) France 1003 209 (20·8%) 47·7 (0·5) 47·2% 13·8 (0·2) Portugal 1015 165 (16·3%) 44·6 (0·5) 47·6% 14·2 (0·1) Italy 1008 166 (16·5%) 48·6 (0·5) 48·0% 14·3 (0·1) All countries 7122 1205 (16·9%) 47·8 (0·2) 47·9% 13·8 (0·1) Table 2. Background characteristics of blood donors in sample Country Number of donors (% of country sample) % donating during COVID-19 period Mean age (SE) % Male Years in full-time education. Mean (SE) No. of donations 2 years pre-COVID-19. Mean (SE) Perceived COVID-19 infection risk whilst donating blood (SE)* Germany 226 (21·5%) 35·8% 41·4 (1·0) 54·0% 13·0 (0·4) 4·3 (0·2) 2·28 (0·1) United Kingdom 186 (17·9%) 40·9% 40·0 (1·1) 45·7% 15·1 (0·4) 4·1 (0·2) 2·44 (0·1) Denmark 151 (15·0%) 29·8% 43·8 (1·3) 55·0% 14·7 (0·3) 3·8 (0·3) 1·95 (0·1) The Netherlands 102 (10·2%) 37·3% 42·6 (1·6) 58·8% 12·9 (0·6) 4·5 (0·4) 2·41 (0·1) France 209 (20·8%) 31·1% 41·3 (1·0) 51·7% 14·3 (0·4) 3·8 (0·2) 2·16 (0·1) Portugal 165 (16·3%) 21·2% 40·5 (1·1) 52·7% 14·7 (0·3) 3·1 (0·2) 2·03 (0·1) Italy 166 (16·5%) 40·4% 43·5 (1·2) 57·2% 15·4 (0·4) 4·3 (0·3) 2·26 (0·1) All countries 1205 (16·9%) 33·8% 41·7 (0·4) 53·1% 14·3 (0·1) 4·0 (0·1) 2·21 (0·0) * (1 = no risk; 5 = very high risk).

Regarding the impact of COVID-19 on self-reported blood donation activity, the results suggest a high number of donors across countries donated less than they normally would compare to their individual reference point, with 61·2% of donors in Portugal selecting this option and around half of donors in France (49·3%) compared with 40-45% in the remaining countries (Fig. 1). Only a small proportion of donors donated more than they normally would during the COVID-19 period. Some differences between countries were observed, with only 4·8% of donors in Portugal stating that they donated more than normal, compared with 19·4% in the UK and 18·1% in Italy. In total, however, 407 (33·8%) of the identified donors stated that they donated during the COVID-19 period of 4–5 months, with some variation between countries, which can be seen in Table 2.

How has COVID-19 affected your blood donation activity? Self-reported impact on blood donation activity from 1205 blood donors identified in the sample.

For donors who donated during COVID-19 (n = 407), we saw that the majority of COVID-19 donors answered that they ‘yes, somewhat’ or ‘yes, definitely’ made extra effort to donate during the epidemic (Fig. 2). Portugal and the UK reported a high majority, making up 73·7% and 75·9% of donating donors. Furthermore, the Netherlands and France reported a number of donors who responded more explicitly with ‘yes, definitely’, with 37·8% and 34·7% of COVID-19 donors selecting this option, respectively. Denmark reported a large number (42·6%) of donors who answered ‘no’ to this question.

Did you make a special effort to donate in order to help your healthcare system during the COVID-19 epidemic? Responses from 407 blood donors who donated during COVID-19.

In Figure 3, we report how concerned donors were with their healthcare system being overloaded. Those who worried ‘quite a bit’ and ‘a lot’ were compared against the three remaining categories: worrying only moderately, slightly or not at all. We found that although the majority of donors (58·8%) were not worried or only moderately/slightly worried during the period, a substantial group were worried ‘quite a bit’ or ‘a lot’ (41·2%) including the majority of donors in Portugal (62·4%) and Italy (57·2%).

Worries among blood donors about the healthcare system being overloaded. Responses from 1205 blood donors identified in the sample.

Overall, the mean risk of infection whilst donating blood was perceived to be quite low among donors (M = 2·21 SE = 0·33). We found pairwise differences (one-way ANOVA with Bonferroni correction) between the UK (M = 2·44, SE = 0·08) and Denmark (M = 1·95, SE = 0·09), P-value = 0·002, and Portugal (M = 2·03, SE = 0·09), P-value = 0·020. Furthermore, we found differences between the Netherlands (M = 2·41, SE = 0·11) and Denmark (M = 1·95, SE = 0·09), P-value = 0·032.

The results suggest that the minority of donors reported to be aware that their blood was tested for COVID-19 antibodies by their blood collection service (Fig. 4). The exception being the Danish sample where more than half of donors (57.5%) reported being tested. Of those that reported that their blood was tested for COVID-19 antibodies, 81·3% answered that they had received the results.

Are you aware whether your blood sample was tested for COVID-19 antibodies? Responses from 407 blood donors who donated during COVID-19.

The results of the logistic regression analysis of donor turnout during the COVID period are presented in Table 3. Overall, we found that although the perceived risk of infection when donating blood was relatively low, those with a high perceived risk of infection were much less likely to donate (OR = 0·540; P-value = 0·006). Moreover, we identified that those who were quite strongly or fully adherent to COVID guidelines (handwashing, social distancing, etc.) were also less likely to donate (OR = 0·583; P-value = 0·000). We did not find evidence that those who worried about their healthcare system being overloaded were more likely to donate and that having a vulnerable person at home factored in the donation decision. Previous blood donation activity in the 2 years prior to COVID-19 was a strong predictor of donating during the crisis period, with each additional donation associated with a 87·7% higher donation likelihood (P-value < 0·000). We found that age was important, whereby individuals were incrementally less likely to donate by each age category (compared with 18-24 years olds). We did not find significant differences between countries in the analysis. Subsequently, we found that those working in the health or education sectors were over twice as likely to donate during COVID-19 compared with those working in other areas (not including food retail or research).

Table 3. Logistic regression analysis of donor turnout during COVID-19 Mean (SE)/% Odds Ratio SE z P-value 95% Confidence Interval No. of blood donations two years prior to COVID-19 period 0·67 (0·02) 1·872 0·043 27·260 0·000 1·790 1·958 Perceived high risk of COVID infection whilst donating blood (4 or 5) (Yes/no) 12·29% 0·540 0·121 −2·750 0·006 0·349 0·838 Worried quite a bit/a lot about healthcare system being overloaded (Yes/no) 41·85% 1·033 0·153 0·220 0·827 0·772 1·382 Vulnerable person in household (Yes/no) 29·30% 0·975 0·161 −0·150 0·877 0·705 1·347 Quite strongly/fully adhered to COVID guidelines (Yes/no) 74·40% 0·583 0·085 −3·690 0·000 0·438 0·777 Age category 18–24 9·66% Reference 25–34 16·22% 0·545 0·109 −3·030 0·002 0·368 0·807 35–44 18·23% 0·352 0·076 −4·830 0·000 0·230 0·538 45–54 17·99% 0·270 0·065 −5·480 0·000 0·169 0·432 55–64 16·29% 0·167 0·048 −6·280 0·000 0·096 0·292 65+ 21·60% 0·104 0·033 −7·070 0·000 0·055 0·195 Education (years) <10 16·15% Reference 10–12 20·31% 0·689 0·164 −1·560 0·118 0·432 1·099 13–15 26·11% 0·692 0·150 −1·700 0·089 0·453 1·057 16–18 22·37% 0·499 0·113 −3·070 0·002 0·320 0·778 18+ 15·06% 0·874 0·199 −0·590 0·552 0·559 1·364 Field of work Health-related sector (medical staff, pharmacist, medical student) 8·57% 2·362 0·479 4·240 0·000 1·587 3·514 Education (e.g. schools, nurseries) 7·82% 2·182 0·461 3·690 0·000 1·443 3·301 Food retail (Supermarkets) 3·97% 1·359 0·406 1·030 0·304 0·757 2·441 Research 2·37% 0·913 0·354 −0·230 0·815 0·427 1·954 Other 77·26% Reference Female 52·12% 0·835 0·119 −1·260 0·207 0·632 1·104 Country Germany 14·75% Reference United Kingdom 14·62% 1·052 0·249 0·210 0·831 0·662 1·672 Denmark 14·09% 0·647 0·169 −1·670 0·096 0·388 1·079 The Netherlands 14·04% 0·609 0·166 −1·820 0·068 0·357 1·038 France 14·09% 0·845 0·201 −0·710 0·480 0·530 1·348 Portugal 14·26% 0·725 0·192 −1·220 0·224 0·432 1·217 Italy 14·16% 1·083 0·264 0·330 0·745 0·671 1·745 Intercept 0·106 0·031 −7·770 0·000 0·060 0·187 CI, confidence interval; N, 7120; SE, standard error.

Lastly, for the active donor sample (n = 992) presented in the Appendix (Tables A1 and A2), we found comparable results whereby those with more donations in the past two years (OR = 1·370; P-value = 0·000) and highly adherent donors were more likely to donate during COVID-19 (OR = 0·569; P-value = 0·000). However, we did not find evidence that having a high perceived risk of infection whilst donating blood factored into the donation decision (OR = 0·853; P-value = 0·485).

Discussion

In the study, we found that around half of all donors reported that they donated less than they normally would, which suggests a concerning drop in blood donations throughout the COVID-19 period across Europe. However, we also identified a small number of donors who donated more than they normally would, perhaps identifying an opportunity to help in a time of need by responding to public appeals.

In terms of donor motivation, we observed that the majority of donors that donated made a special effort to help their healthcare system during the COVID-19 period. Many of them were also concerned with overcrowding of their healthcare system, indicating that altruistic motives (at least retrospectively) played an important role in donors’ decision to donate and were weighed up against potential risks [5, 21]. Blood donation centres may thus take advantage of this result by appealing to the altruistic nature of donors in times of crisis. As an example, specialist campaigns that focus on the continued need for blood donors during the pandemic could be employed. Such public appeals have been successful in past crises, where large influxes of donors were documented over short periods, for example mass shootings in the United States and bush fires in Australia [11, 12].

Although the perceived risk of infection whilst donating blood was relatively low for many respondents, those who anticipated a high risk of infection were much less likely to donate. Our results coincide with previous research from Hong Kong and China that found anxiety and fear of contracting COVID-19 were deterrents to donating blood [7, 8], and with studies on the SARS and avian flu outbreaks [9, 10]. Therefore, we suggest that blood donation centres emphasize the steps that have been taken to reduce risk of infection in order to maintain confidence in their services, for example handwashing, face coverings and social distancing. Key messages could assure the public that they can still safely donate blood whilst adhering to COVID-19 measures. We found that the result did not hold for the active donor sample, which may be explained by a high level of intrinsic donor motivation, even in those that anticipated a high infection risk whilst donating.

Despite all European countries being eventually affected by COVID-19, there were notable differences in the severity of the crisis and the government response. Italy was hit particularly hard early in the pandemic and was the first European country to apply interventional measures from the beginning of March 2020 in response to the outbreak of the virus [22]. Other EU countries followed soon after by introducing measures from around mid-March 2020 [22]. Despite this variation, we did not find evidence of country differences in our analysis of donor turnout, which suggests that the results are generalizable across Europe and states may face similar challenges in managing blood supply during the period.

With some countries including Finland, Germany and the United Kingdom discussing the use of ‘immunity passports’ [23-25], we conjecture that having evidence of COVID-19 antibodies could be valuable to many individuals and