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Blood Donor Selection: Guidelines on Assessing Donor Suitability for Blood Donation. Geneva: World Health Organization; 2012.

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Blood Donor Selection: Guidelines on Assessing Donor Suitability for Blood Donation.

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3Assessing donor suitability

Donors should be in good health at the time of donation and free of infections transmissible by blood. The BTS should provide clear and unambiguous guidance for staff involved in donor selection. Rigorous donor selection should be consistently applied to all blood donors either donating whole blood or through apheresis, whether first-time or repeat donors. The process should be planned to make best use of staff and donor time, and make blood donation as convenient as possible for blood donors, without long waiting periods.

Key principles of blood donor selection are as follows:

  • The health and safety of the donor as well as the recipient must be safeguarded
  • Only individuals in good health should be accepted as donors of whole blood and blood components
  • The selection of blood donors should be based on regularly reviewed selection criteria, without discrimination of any kind including gender, race, nationality or religion
  • A prospective donor's health status and medical history should be evaluated for each donation, on the day of donation prior to blood collection
  • The BTS should provide appropriate donor information and a simple donor questionnaire for health and risk assessment and obtain the donor's informed consent to blood donation
  • Staff should be suitably qualified and trained in the donor selection process
  • Good communication should be established between the BTS staff and the donor, and donor confidentiality should be assured
  • The BTS has a duty of care to provide counselling to all deferred donors and referral for their further management.


The purpose of donor selection is to assess the suitability of an individual to be a blood donor so that blood donation is safe for the donor and the blood products derived from this donation are safe for the recipients. The donor selection process should be carried out in accordance with written standard operating procedures.

The steps involved in the donor selection process, prior to blood collection, are shown in Figure 1:

Figure 1. The blood donor selection process.

Figure 1

The blood donor selection process.

  1. Donor registration
  2. Pre-donation information
  3. Completion of donor questionnaire
  4. Donor interview and pre-donation counselling
  5. Donor health and risk assessment
  6. Informed consent.

Compliance with all donor selection criteria is crucial to ensure a safe blood donation process and outcomes. All potential and existing donors should be asked to adhere to the blood donor selection criteria by providing accurate information and answers to all questions asked, both for the protection of their health and that of patients who receive transfusion.

Donor registration

All prospective donors who meet the general criteria for blood donation such as age and good health should be registered when they attend a blood donation session, even if they are subsequently not accepted for donation.

Essential donor registration information includes the individual's full name, date of birth, gender and contact details. A unique donor number should be assigned at first registration. At each occasion of donation, a unique identifier using a numeric or alphanumeric system should be allotted to the donation; this should be attached to the donor questionnaire, primary blood collection bag, its corresponding satellite bags and the blood sample tubes. During donor registration, prospective donors should be provided with donor information and education materials and the donor questionnaire, which should be completed on each occasion of donation.

Pre-donation information

Pre-donation information is an important step in the blood donor selection. The process of donor selection begins even before donors come to give blood through public awareness campaigns and donor education. At the donation session, pre-donation information should be provided either orally or through printed, graphic, audio-visual or online materials, presented in a simple and clear format and in appropriate languages.

Pre-donation information provides an opportunity for the prospective donors to know about health conditions or high-risk behaviour that would make them unsuitable to donate blood. This information assists the donors in deciding whether to self-defer; it may also assist in donor return if they understand the reason why they should not donate blood on this occasion (36,37).

Pre-donation information has the following objectives, to:

  • Increase donor awareness of the donor selection criteria, the process of blood donation and the tests that will be performed on donors' blood
  • Encourage prospective donors to inform the BTS of any medical conditions or TTI-related risks that may affect their suitability to donate blood
  • Encourage individuals to self-defer from blood donation if they recognize that they are not suitable to donate blood due to general health or medical conditions or risk for TTI.

Pre-donation information should cover:

  • Nature and use of blood and its components; the need for voluntary non-remunerated blood donors; and the importance of maintaining healthy lifestyles
  • The blood donation process, including the donor questionnaire, donor medical history, health and risk assessment, venepuncture, blood collection as whole blood or apheresis procedure, post-donation care and the screening tests performed on donated blood
  • Rationale for the donor questionnaire and pre-donation health assessment and the importance of donor compliance in the donor selection process; and donor's duties, responsibilities and rights (21)
  • Options for the donor to decide about blood donation prior to proceeding further, to withdraw or self-defer at any time during or after the donation process, without any undue embarrassment or questioning
  • Transfusion-transmissible infections, including HIV, HBV, HCV and syphilis, routes of their transmission, natural history and prevention; types of screening tests performed; and window period of infection and alternative testing sites for individuals seeking to ascertain their infection status
  • Possible consequences for donors and the donated blood in the case of abnormal TTI test results; the mechanism for notification about abnormal test results and post-donation counselling, assurance of confidentiality and if necessary, referral for further testing, treatment and care
  • The possibility of adverse donor reactions.

Completion of donor questionnaire

Each prospective blood donor should complete a donor questionnaire to provide information in relation to the donor selection criteria defined in the national guidelines. In most situations, the donor questionnaire is given to donors at the time of registration for completion before the donor interview and assessment.

Alternatively, the donor questionnaire may be sent to the donor's residence to be completed before donation. This has the advantage of allowing donors time to think about the answers and saves time at a blood donation session. However, donors may misunderstand some of the questions and self-defer for the wrong reasons.

The donor questionnaire may also be administered electronically as a computer-based questionnaire. A wide literature is developing around computerized questionnaires and computer assisted self-interviews (CASI). CASI is shown to elicit more information on risk behaviour than traditional face-to-face interviews and may reduce the proportion of donors with a history of high-risk behaviour by encouraging personal disclosure and self-deferral (38,39).

A particular focus is required on first-time donors as they are not familiar with the questionnaire and its purpose and may take longer to complete it; however, it has been reported that regular donors may take less care in in the questionnaire (40).

It is essential that donors are aware of the importance of the questionnaire, the significance of the questions and the need for providing accurate information (41). The information provided by the donor can then be further elaborated on during the interview.

Donor interview and pre-donation counselling

The completed donor questionnaire should be reviewed prior to donation in a one-to-one confidential interview between the donor and a donor selection staff member so that an assessment can be made of the donor's general health, medical history and any TTI risks. It also provides an opportunity to check whether the donor has understood the questions and has answered them correctly. Many people do not understand medical terms and may be so eager to give blood that they do not recognize the significance of their answers for their own health. Assistance should therefore be provided to anyone who has difficulty in understanding the questions.

Assurance about the confidentiality of the donor's medical history is essential. If donors understand why it is in their own interests to give accurate and complete information about their health, it will reassure them that their welfare is important to the BTS and may motivate them to become regular donors. The donor's ability to understand the blood donation process and provide informed consent should be assessed.

Whenever possible, the medical history should be further elaborated by a donor selection staff member, particularly for new donors. An initial question such as “When did you last see a health care professional?” may avoid multiple questions and lead to further information about the donor's medical history. Similarly, relevant travel information may be elicited by a simple question such as “When did you last travel to another region or country?”

Pre-donation counselling is an integral part of the donor interview. It enables donor selection staff to:

  • Check that the donor has understood all questions and responded accurately to the questionnaire
  • Answer the donor's questions and provide reassurance in case of anxiety
  • Explain reasons for any deferral and give advice about further medical care, if needed
  • Ensure that the donor is able to give informed consent to donate and recognizes that his/her signature is an affirmation that responses provided to the questionnaire are accurate.

Donor health and risk assessment

The assessment of the donor health and TTI risks requires privacy, a sensitive, non-judgemental approach and an assurance of confidentiality. The reason for questions aimed at eliciting any health and TTI risks should be explained and the donor should be offered an opportunity to self-defer. The assessment of donor suitability and deferral, where appropriate, aims to exclude donations from individuals at risk of TTI, particularly from those with recently acquired infection that cannot or may not be detected by routine screening tests or with infections for which no effective blood screening tests are available. An in-depth discussion may be needed, particularly with new donors who may not know about the “window period” or the signs and symptoms of an infection. Individuals who visit the BTS to obtain HIV testing pose a risk to the blood supply (42).

The donor assessment not only enables the review of the donor's medical history and medications, but also provides an opportunity for a basic health check to assess whether the donor is in general good health. Any signs of debility, under-nutrition, pallor, jaundice, cyanosis, dyspnoea or intoxication from alcohol or drugs should also be noted (also refer to Section 4.2 on donor appearance and inspection).

Physical examination, weighing and/or measurement of vital signs (pulse, blood pressure) are part of the basic health check and are carried out at this stage. The venepuncture site should be examined to check that the donor's veins are accessible and suitable to enable easy venepuncture.

The basic health check also enables an assessment to be made of any physical disabilities that may impede the donation process, such as:

  • Mobility: the donor should be able to easily access the donor bed or couch
  • Sight or hearing impairment: assistance should be provided by a staff member.

Issues that require special attention during donor health and risk assessment include:

  • The prevalent culture and context of the environment for donation; in some situations, a donor may simply be overawed by the medical setting and procedures
  • The provision of sufficient privacy and assurance of confidentiality to make the donor comfortable when answering probing and sensitive questions
  • Identifying and overcoming language barriers or lack of understanding of questions in the donor questionnaire
  • Ensuring good communication by using simple jargon-free language and explaining any medical terms.

Informed consent

Informed consent is a voluntary agreement given by the prospective donor to the donation of blood, to the testing of a blood sample for TTI, for the transfusion of the donated blood to patients and if required, for the use of the blood for additional tests, quality assurance or research purposes. To obtain informed consent, the BTS should provide the following minimum information to the potential donor:

  • The donation process and potential adverse donor reactions
  • The tests that will be performed (TTI and others) on the samples taken from the donated blood and the reasons for these tests
  • Confidentiality of all personal information, including test results.

The donor should sign and provide informed consent to the donation of blood or blood components on a voluntary basis. Informed consent signifies that the donor has understood the questionnaire, has provided accurate answers and is willing to donate blood (43). It also indicates that the donor understands the blood donation process, the possibility of adverse reactions to blood donation, the risks of the transmission of infections through donated blood and the implications of any abnormalities that may be detected during the donation process and blood screening, and is providing consent for post-donation notification and counselling, if detected to have a positive viral infection marker or any other abnormality. The donor's understanding of the questionnaire and its implications is of particular importance in countries where donors may be held legally liable if they give incorrect information.

In countries in which young people under the legal age of majority may be accepted as blood donors, written consent to donate blood may be obtained from a parent or guardian, prior to donation, in accordance with national requirements.


Donors who do not to meet the selection criteria should be deferred on a temporary or permanent basis. All deferred donors should be treated with respect and care in a confidential manner and should be given a clear explanation of the reason for deferral and an opportunity to ask questions. They should be informed whether the deferral is to safeguard their own health and/or that of the recipient. It is the responsibility of the BTS to ensure that donors who are deferred due to medical conditions are referred for further investigations and management, as appropriate.

Studies have found that deferral has a negative impact on future donor return, particularly by first-time donors and those deferred for more than a year (37,44).

Temporarily deferred donors should be advised on when they could donate and encouraged to return. Donors are less likely to return to donate blood if unclear or unsatisfactory information is given about the reason for deferral. Many temporarily deferred donors do not spontaneously return to donate blood and may need to be recalled after the deferral period is over. Counselling of deferred blood donors could enhance the compliance of donors to seek follow-up medical care (45).

A system should be in place for donor counselling and referral if any further investigations, treatment and care are indicated. Refer to Blood donor counselling: Implementation guidelines (6).


The record of the donor's general health, medical history and TTI risk assessment as part of the donor questionnaire should always be signed by the donor as being correct. The questionnaire becomes part of the donor's records and documents the informed consent.

Records should be kept of each activity associated with blood donation, ideally in an electronic database capable of generating reports. In addition to donor identification, assessment and selection, records should reflect donor deferrals, adverse reactions or unexpected events and any unsuccessful donations.

Donor records should be confidential, easily retrievable and should allow traceability: from the donor to the patient receiving transfusion and vice versa. Records should be retained for a period of time defined by local or national legislation or guidelines. Donor records should be reviewed regularly and donor data (e.g. male: female ratio, donor deferrals, adverse donor events and reactions) should be analysed in order to monitor the effectiveness of donor selection so that remedial action can be taken, where necessary.

Key records, including dates, times and signatures, to be maintained and retained during the donor selection process include:

  • Donor registration information
  • Completed donor questionnaires and informed consent
  • Outcomes of donor interview and assessment
  • Unique donation number for each donation
  • Donor counselling and follow-up records
  • Adverse donor events and reactions
  • Donor deferral registry.

Data on donor deferrals should be collected and regularly reviewed to enable the BTS to assess the major causes of deferral, particularly those that result in the greatest numbers of donor deferrals and those presenting high risk to patients. These vary from country to country; hence there is a need to collect local data on which to base relevant decisions. The most common causes of donor deferral are of particular interest as these will indicate whether donor information and education may need to be improved or donor selection criteria should be reviewed. A deferral database will also indicate whether staff are interpreting the selection guidelines correctly and where further education and training should be focused.

Donor deferral records also enable the previous deferral status of donors to be checked and decisions made on the re-entry of temporarily deferred donors. A donor deferral registry (DDR) is a confidential list of donors who are positive for a transfusion-transmissible infection and who have been permanently deferred. A DDR is used to monitor the incidence and prevalence of such infections in the donor population and may also assist in identifying areas that require strengthening in the donor selection process.


The system of confidential unit exclusion (CUE) offers donors the opportunity to inform the BTS immediately after donation or subsequently if they consider that their blood may be unsafe for transfusion; this may be particularly useful if donors have been persuaded or coerced to donate. Where CUE is used, donors should be given information to enable them to contact the BTS and to communicate that their blood should not be used for transfusion.

The CUE system is designed to add an additional level of safety to the donor selection and blood screening processes and has been found to be effective in some settings (46). However, there is some evidence that it may have limited effect on reducing the transmission of infections through window-period donations (47) and may lead to the discard of safe donations (48,49). One study suggested that its use may have negative consequences by reducing the perceived responsibility of staff in eliciting a history of high-risk behaviour (40).


Donors should be managed in a way that ensures high standards of care and assures them of the importance accorded to their health and well-being by the BTS. Nevertheless, there are recognized adverse reactions that can occur during blood donation; these can generally be minimized or avoided by appropriate donor selection and care, and appropriately trained staff (50,51). Donors who have suffered an adverse reaction have been shown to be less likely to return to donate again (37).

Vasovagal episodes and soft tissue injuries (bruises and haematomas at the venepuncture site) are the most common donor reactions. The majority of these are minor and donors usually recover quickly; however, these reactions can be of concern to donors and reassurance should be provided. In some cases, a reaction may prompt the donor to reveal a relevant medical history. A minority of adverse reactions may require medical care outside the BTS and may lead to prolonged symptoms or incapacity.

Staff should be trained in the recognition and management of adverse donor reactions, including the provision of first aid. The incidence of bruising should be monitored so that further venepuncture training may be provided to staff as necessary. A system for the reporting and investigation of adverse donor events and reactions should be in place as part of the donor haemovigilance system.

Donors should be provided with oral and written advice on the management of bruises and delayed vasovagal events and should also be given information about how to contact the BTS for further advice, if necessary.

Copyright © 2012, World Health Organization.

All rights reserved. Publications of the World Health Organization are available on the WHO web site (www.who.int) or can be purchased from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: tni.ohw@sredrokoob). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncommercial distribution – should be addressed to WHO Press through the WHO web site (http://www.who.int/about/licensing/copyright_form/en/index.html).

Bookshelf ID: NBK138211


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