Many people avoid blood donation due to the pain, physical discomfort, psychological fear and side effects (e.g., bruises, vomiting, dizziness) while donating blood (1, 2). Nevertheless, blood is composed of living cells and cannot be preserved for a long time, so continuous blood donation is needed (3). Accordingly, South Korean health organizations have recommended the possession of at least 5 days' worth of blood based on the amount of blood used in the previous year (4). However, anxiety during the COVID-19 pandemic has further reduced the motivation to participate in blood donation (5), and this decline has become a global problem (6, 7).

In general, various factors affect participation in blood donation; however, recently the number of donors has rapidly declined due to the social problems caused by the COVID-19 pandemic (5). According to the World Health Organization (WHO) (8), an average of more than 118.5 million blood donations are collected worldwide in a year; however, the participation rate decreased by 27% due to the COVID-19 pandemic (9, 10). Canada experienced a 22% decline in blood donation (11), and South Korea experienced a 10.4% decline in the number of donors since the outbreak of COVID-19, raising an alert worldwide (12, 13).

Blood shortage puts patients' lives in danger and makes it difficult to cope with national disasters that require large amounts of blood (14). Therefore, it is necessary to investigate people who have continuously participated in blood donation during the COVID-19 pandemic, to collect basic information, that can serve as a reference for maintaining stable amounts of blood in future pandemics.

Clear differences in social changes caused by the COVID-19 pandemic were observed before and after the outbreak. In particular, fear of the new infectious disease caused changes in people's behavior (15). The biggest change in people's behavior due to the COVID-19 pandemic was reflected in preventive health behavior (16). Šurina et al. (17) reported that, to prevent infectious diseases such as COVID-19, people started taking more preventive measures as compared to the past, such as sanitizing their hands, wearing facemasks, and washing their hands when returning home. Notably, people with high levels of preventive behavior engaged more in social activities than those with low levels of preventive behavior (18, 19). This preventive behavior is likely to affect blood donation. For example, even during times like the COVID-19 pandemic, one of the blood donors in the US continuously participated in blood donation until the age of 96 and donated 36 gallons of blood (20), which shows that he had different intentions behind preventive behavior than others.

In fact, previous studies have shown that attitude toward and knowledge of blood donation serve as key factors that affect continuous participation in blood donation (21, 22). Attitude is a key factor in predicting behavior in general (23, 24). In Kim and Yoon (22) and France et al. (25) it was reported that positive attitude toward blood donation affects donation behavior. Moreover, knowledge about blood donation indicates how much one knows about the standards pertaining to blood donation and related behavior, and the level of knowledge about blood donation is one of the key factors affecting donation behavior (26, 27).

Nevertheless, the results of previous studies differed depending with respect to the timing of investigation and the target group (donors and non-donors). The timing of the investigation is particularly important as it is reflective of the current national policy and social conditions. In other words, to obtain reliable indicators for blood donation policies during pandemics, we have to study the relationship among the basic environmental characteristics of blood donors, preventive health behaviors, blood donation attitudes, and knowledge of blood donation during the recent COVID-19 pandemic. Therefore, this study analyzes the characteristics and preferred environment of people who participated in blood donation during the COVID-19 pandemic and compares these participants with the non-donor group and the group of blood donors who donated blood before the COVID-19 pandemic. The objective of this study is to comparatively analyze blood donation attitudes, levels of blood donation knowledge, and preventive health behaviors depending on donation experience during the COVID-19 pandemic and explore the blood donation environment preferred by the group of participants who donated blood during the pandemic. The specific objectives are as follows.

First, this study identifies the differences in blood donation attitudes, donation experiences, and preventive health behaviors depending on the general characteristics of the participants.

Second, this study compares blood donation attitudes, donation experiences, and preventive health behaviors depending on the donation experience of participants during the COVID-19 pandemic.

Third, this study derives the blood donation environment preferred by the group of participants who donated blood during the COVID-19 pandemic.

This study analyzed the characteristics of those who participated in blood donation during the COVID-19 pandemic to obtain information that can increase their participation during pandemics. Specifically, it comparatively analyzed the characteristics of two donor groups: one without donation experience while the other that donated blood only before the outbreak of COVID-19. Moreover, this study found the blood donation environment that was preferred by those who participated in blood donation during the COVID-19 pandemic, thus providing valuable information to promote blood donation during infectious disease.

First, the comparison of donors and non-donors revealed that all factors pertaining to attitude, knowledge, and preventive health behavior were high in those with donation experience. This is consistent with the results of previous studies, indicating that attitude, knowledge, and preventive health behavior are closely related to participation in blood donation even during a pandemic (37–39).

Volunteering behavior such as blood donation was found to affect participation depending on the attitude, with more positive attitudes resulting in increased participation in blood donation (21). This study also revealed that those who participated in blood donation during the COVID-19 pandemic showed increased positive attitude than those who did not, proving that, despite the decrease in blood donors due to the pandemic, attitude toward donation still served as a key factor affecting participation. Moreover, since blood donors showed statistically high scores in all social characteristics during the COVID-19 pandemic, attitude toward blood donation proved to be a key variable that increased the rate of participation in blood donation during pandemics.

Further, knowledge of blood donation was identified as a factor that directly affected participation in blood donation, which varied depending on the social environment. In (40), donation knowledge in developing countries was examined, to find out the differences among countries. The current knowledge of blood donation of South Koreans differed as compared to the past when it was a developing country. A study on blood donation knowledge in the past showed that the blood donation knowledge of participants (rate of correct answers) was 46.8% (41). Meanwhile, more recently, according to (42), the rate increased to 76.4%. However, the current study showed a decrease to 66.4%. Notably, those who participated in blood donation during the COVID-19 pandemic scored relatively lower than those who donated blood before it. The results of this study showed that those who donated blood during the pandemic had generally low levels of knowledge about blood donation, but they showed high rates of correct answers for items related to illnesses, such as “People with hepatitis B cannot donate blood” (89% correct answers among participants after COVID-19 vs. 83% before COVID-19) and “You cannot donate blood after taking medicine” (88% correct answers among participants after COVID-19 vs. 81% before COVID-19). This shows that people with a high level of understanding about blood donation related to illness are more enthusiastic about donating blood. Therefore, when launching campaigns to promote blood donation during a pandemic, it will be effective to include information about blood donation in situations related to the pandemic.

Preventive health behavior is important in pandemics such as the COVID-19 (43), which also applies to blood donation. To supply blood during a pandemic, it is necessary to increase donors' compliance with public health (6). This is because COVID-19 may spread through blood donation. COVID-19 is a contagious disease that can cause damage by becoming a host and spreading to others (44). Interestingly, there was a difference among blood donors according to gender, with men showing a higher rate of blood donation during the COVID-19 pandemic, while women showed a lower rate. This could be because the virus affects men and women differently (45). In the United States, twice more male deaths from COVID-19 were reported as compared to female deaths, and in South Korea also number of male deaths was more than female deaths. In other words, as COVID-19 persists, men are more sensitive to preventive health behavior.

Finally, as a result of conjoint analysis to identify the environment preferred by blood donors during the COVID-19 pandemic, place was considered the most important factor. Interestingly, those who donated blood before the COVID-19 pandemic preferred hospitals, whereas those who donated blood after the COVID-19 pandemic preferred blood donation centers. According to a survey by (46), effective participation occurred when hospital doctors and nurses encouraged blood donation. This indicates the level of people's trust and their reliance on hospitals, including those in South Korea. The overseas expansion of South Korean medical institutions is three times higher than that of China and the United States, and the number of foreigners coming to South Korea for medical treatment had exceeded 260,000 (47). Moreover, the average life expectancy of South Koreans is higher than the OECD average, indicating high reliability on hospitals. However, since about 50% of people have avoided visiting hospitals after the outbreak of COVID-19 (48), those who participated in blood donation during the COVID-19 pandemic preferred blood donation centers, as an institution specializing in blood donation, over hospitals. Interestingly, blood donors preferred to visit with their families over visiting alone when donating blood. This is consistent with the previous results that family support during the COVID-19 pandemic is helpful for mental health in overcoming everyday difficulties and depression (49, 50). Moreover, COVID-19 is more likely to be transmitted by strangers, but families are more trustable because they spend most of the time together. Compiling the profile utilities of the environment preferred by blood donors during the COVID-19 pandemic, the most preferred environment was “going with family to a blood donation center that gives out free gifts in a region with no confirmed cases”. Therefore, to establish measures that can increase blood donors, it will be effective to come up with a promotional strategy based on the findings of this study.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by Institutional Review Board at Chung-Ang University (1041078-202101-HRSB-023-01). The patients/participants provided their written informed consent to participate in this study.

Y-JK and J-HC: conceptualization, methodology, validation, and review and editing. J-HC: formal analysis and data curation. Y-JK: investigation and writing original draft. All authors were involved in writing the manuscript and approved its final version.