Perceptions in Transfusion Medicine: A Pilot Field Study on Risk and Ethics for Blood and Blood Substitutes

Abstract

A pilot study was undertaken in the UK in February 2005 to identify the perceptions of risk, effectiveness and ethicality of different hypothetical transfusion options, including blood substitutes derived from different sources, among young adults. Forty-nine men and 92 women completed the questionnaire, aging between 18 and 25 years old (mean ± standard deviation = 19.7 ± 1.2 years). Twenty-three percent of respondents had donated blood, an average of 3.1 times. The study assessed the perceptions of donor blood versus 3 different types of potential “artificial blood” [i.e. “chemical” (synthetic), “grown from bacteria” (recombinant hemoglobin), or “based on cow blood” (bovine hemoglobin)] on three dimensions, namely risk, effectiveness, and ethicality, each scored on a 1 (least) to 7 (most) Likert-type scale. Donor blood was rated as significantly (P < 0.05) less risky, more effective and more ethical than any of the blood substitutes. The chemical-based blood substitute was rated second least risky, second most effective and second most ethical followed by bacteria grown substitute. The bovine-based blood substitute was rated as significantly riskier, least effective and least ethical. All the blood products differed significantly for perceived ethicality, with donor blood considered as most ethical and a blood substitute derived from bovine blood as least ethical. Judgments of risk correlated negatively with effectiveness (all transfusion options) and ethicality (all the blood substitutes). Overall, these results indicate that donor blood is currently preferred over blood substitutes in the UK and that judgments of risk about different hypothetical transfusion options are related to perceptions of effectiveness and ethicality.

INTRODUCTION

Blood transfusion is a remarkably safe, routine clinical procedure. However, the need for sophisticated blood processing, storage and cross matching, coupled with increasing public concerns about the safety of blood products [[1]], is driving the search for safe and efficacious substitutes. Currently, such substitutes include materials based on (1) the naturally occurring oxygen carrier, hemoglobin (Hb), processed from human or animal blood; (2) synthetic, oxygen-carrying fluorinated compounds [perfluorochemical (PFC) liquids); or (3) encapsulated Hbs [[2-12]]. Advanced clinical trials have been performed with the first two materials and one bovine Hb-based product, known commercially as Hemopure (Biopure Corporation, USA), has received regulatory approval in South Africa for clinical use as an alternative to blood during surgery in adults.

There is a growing body of research exploring factors that influence people's perceptions of safety and risk that are associated with blood transfusion [[1], [13-17]]. Such research is also a focus of a new European Union-funded project (“EuroBloodSubstitutes”) where field studies will elicit the views of relevant societal stakeholder groups (public, blood donors, healthcare professionals, policy makers) on perceptions of benefit and risk associated with the transfusion of blood and potential substitutes. Issues on the perceived benefits and risks of using blood substitutes have only been studied recently [[18]], most probably because such products are not used routinely. However, an understanding of the extent to which potential blood substitutes are (1) perceived to be safe and (2) preferable over donor blood will inform the development of public health information materials and the training of physicians and other healthcare personnel. Thus, this study reports the findings of a pilot field study to identify the perceptions and interrelations of risk, effectiveness and ethicality of different hypothetical transfusion options, including blood substitutes derived from different sources, among young adults in the UK. The study extends an earlier investigation on perceptions of risk of blood substitutes [[18]] but the data on risk is included here to enable new correlations with effectiveness and ethicality judgments to be made. A key question to ask is whether people hold a consequentialist view about the morality of bio-engineering [[19]]. That is, products are viewed as ethical if the consequences of the procedure are viewed as effective (i.e., the treatment works). This would be demonstrated by a positive correlation between ethicality judgments and effectiveness judgments.

Study Design and Research Methodology

Participants

The study design consisted of assessing perceptions of donor blood and blood substitutes on three dimensions using an opportunity sample of adult undergraduate students at The University of Nottingham, UK. The total sample consisted of 148 adult participants. The students were recruited during a class on human physiology at the University Park campus in February 2005. This societal group was targeted because they are quasi-experts with some pre-existing knowledge of the issues and technologies in use for donated blood and blood substitutes. Participants were unpaid and completed the questionnaire voluntarily.

Assessment of Perceptions

The survey instrument asked participants to score one of four hypothetical transfusion options, namely donor blood, a blood from chemicals, a blood substitute grown produced from a so-called bacterial “cell factory,” and a blood substitute based on cow blood. The risk of having a blood transfusion of each was assessed using a Likert-type rating scale from 1 (not risky) to 7 (extremely risky). Participants were also asked to rate their assessment of how effective each transfusion type would be from 1 (not effective) to 7 (extremely effective) and to rate how ethical they rated each transfusion type from 1 (not ethical at all) to 7 (extremely ethical).

Data Analyses

Means and standard deviations (s.d.) were used throughout where appropriate. Statistical differences between responses were determined by repeated-measures ANOVAs and paired sample t-test, with correlations assessed by Pearson's r. A probability of P < 0.05 was considered significant.

RESULTS

Responses

Forty-nine men and 92 women (7 undeclared) completed the questionnaire, aging between 18 and 25 years old (mean ± s.d. = 19.7 ± 1.2 years). Twenty-three percent of respondents had donated blood (an average of 3.1 times).

Perceptions about Transfusion Options

The mean scores for the ratings of risk (from [[18]]), together with effectiveness and ethicality for the different transfusion options, are listed in Table 1. ANOVAs showed significant differences between transfusion options for risk [F (3, 122) = 45.1, p < 0.0001], effectiveness [F (3, 122) = 21.6, p < 0.001], and ethicality [F (3, 124) = 25.8, p < 0.001]. T-tests were used for pair-wise comparisons; they revealed that donor blood was rated as significantly less risky, more effective and more ethical than any of the blood substitutes. Chemical-based artificial blood was perceived as second least risky, second most effective and second most ethical followed by artificial blood grown from bacteria. Cow-blood-based artificial blood was rated by respondents as significantly riskier, least effective and least ethical. All the blood products differed significantly from one another for ratings of ethicality (Table 1).

Table 1. Rating perceptions for blood products

	Risk	Effectiveness	Ethicality
Having a transfusion of donated blood	3.2 ± 1.2^1	5.9 ± 1.1^1	6.0 ± 1.3^1
Having a transfusion of artificial blood made from chemicals	3.9 ± 1.5^2	5.1 ± 1.2^2	5.3 ± 1.7^2
Having a transfusion of artificial blood grown from bacteria	4.0 ± 1.3^2	5.0 ± 1.3^2	5.2 ± 1.6^3
Having a transfusion of artificial blood based on cow blood	4.7 ± 1.4^3	4.8 ± 1.2^2	4.8 ± 1.8^4

Values are mean ± s.d. throughout; superscript notations indicate significant differences (e.g., 1 = significantly different to 2, etc.).

Table 2 lists the relationships between perceived risk, effectiveness and ethicality determined using Pearson's r correlations. For all four transfusion options, perceived risk correlated negatively with both effectiveness and ethicality. That is, high risk ratings were accompanied by low effectiveness and ethicality ratings. Interestingly, effectiveness and ethicality correlated positively (i.e. blood products that were perceived as effective were also perceived as ethical). Concerning perceived risk and ethicality, whilst there was a negative relationship for all transfusion options, only for the blood substitutes was this significant. Furthermore, the predicted positive relationship was observed between perceived effectiveness and ethicality, but was only significant for the blood substitutes based on chemicals and that derived from bovine blood.

Table 2. Correlations between perceived risk, effectiveness and ethicality

	Risk and effectiveness	Risk and ethicality	Effectiveness and ethicality
Having a transfusion of donated blood	−0.195*	−0.100	0.159
Having a transfusion of artificial blood made from chemicals	−0.331**	−0.206*	0.229**
Having a transfusion of artificial blood grown from bacteria	−0.272**	−0.240**	0.021
Having a transfusion of artificial blood based on cow blood	−0.304**	−0.239*	0.238**

n = 122–144; *p < 0.05, **p < 0.01 (two-tailed tests).

DISCUSSION

The results of this pilot field investigation into the perceptions of risk, effectiveness and ethicality of different hypothetical transfusion options among young adults in the UK show that donor blood was considered significantly more effective and more ethical than all the potential blood substitutes evaluated. Synthetic (chemical) blood substitutes were rated by respondents as similar to recombinant hemoglobin substitutes in terms of effectiveness, but were viewed as more ethical. Bovine hemoglobin substitute was perceived as the least ethical. However, all the blood substitutes were perceived as having similar effectiveness, albeit to a lower extent than for donor blood.

Respondents also made judgments of higher risk in tandem with perceptions of lower effectiveness for all of the transfusion options. Previous studies have found that benefit, which here can be equated with effectiveness, is often correlated negatively with risk [[20], [21]]. Low risk medical interventions are not necessarily effective (and vice versa) and therefore it appears that a cognitive bias is operating in which a judgment on one dimension is made to relate to a judgment on another dimension. A similar correlation of judgments occurred for risk and ethicality for all the blood substitute options. The respondent's perceptions of high risk correlated with low ethicality and vice-versa. It is possible that such judgments of risk are influenced by perceived ethicality or that considerations of ethicality are influenced by perceived risk. Interestingly, for the more familiar option of a transfusion with donor blood, ethicality was unrelated to risk. It may be the case that when something is less familiar, people search more to find meaning and understanding Effectiveness and ethicality were positively associated for both the chemical and cow blood-based blood substitute options. This indicates that for these options a consequentialist approach to moral judgments may be operating.

The present results provide information to inform how physicians' dialogue and public information might be presented to patients about blood substitutes. Such information could be used to design new decision aids that might assist patients in making informed choices between available transfusion options. Decision aids have been evaluated for helping patients decide whether to pre-donate their own blood for autologous transfusion during heart surgery, leading to improved knowledge and risk perceptions of blood donation and transfusion [[22]]. Decision aids offer a multi-format approach for communicating information on healthcare issues that appeal to people with different educational backgrounds. In this respect, Lee and Mehta [[23]] evaluated the impact of a visual risk communication tool on knowledge and perception of risk associated with blood transfusion among the Canadian public. Risk communication with both written and visual presentational formats increased knowledge of transfusion risk and decreased the perceived dread and severity of the transfusion risk. However, neither format changed the perceived knowledge and control of transfusion risk, nor the perceived benefit of transfusion. The authors emphasized that risk communication materials using a multi-format approach may provide added value to patients.

Overall, an interesting pattern of results has emerged from this pilot study regarding the perceptions of hypothetical transfusion options. It would be useful to follow up this study with expert, patient and lay perceptions of the blood substitutes and extend the investigation to a national or multi-national level.

This research was supported by the European Union, 6th Framework Programme Priority (FP6-2002-LIFESCIHEALTH), Specific Targeted Research Project (STREP), “Genomics and blood substitutes for 21st Century Europe” (“EuroBloodSubstitutes,” Contract No. 503023). It is a pleasure to acknowledge the expert administrative assistance provided by the EuroBloodSubstitutes Project Managers, Mrs Bethany York and Miss Bridget Lewis.