Evidence-based patient decision making: the development of a decision aid on blood transfusion

Moxey, Annette Jane

Title: Evidence-based patient decision making: the development of a decision aid on blood transfusion
Creator: Moxey, Annette Jane
Relation: University of Newcastle Research Higher Degree Thesis
Resource Type: thesis
Date: 2007
Description: Research Doctorate - Doctor of Philosophy (PhD)
Description: Background: Decision aids are structures education packages designed to foster shared decision making between patient physician. They are often used when there is confusion or disagreement associated with the values patients assigned to, and the evidence on, the various outcomes of the intervention in question. Blood transfusion relation to elective surgery is an area that requires both physicians and patients to carefully consider different treatment options. The issues of variation in transfusion practices, different personal values in regards to receiving blood, and the uncertainty as to whether the benefits of technologies aimed at minimising allogeneic blood use (e.g. pre-operative autologous donation or PAD) outweigh the potential harms justify attempts to design a patient decision aid in this area. Aims: The overall aim of the thesis was to develop and pilot test a decision aid describing blood transfusion options to patients planning any type of major elective surgery (such as hip replacement or heart bypass). A series of studies and reviews were necessary to adequately inform the development of the decision aid. Hence, additional aims of the thesis were: to investigate whether the manner in which treatment effects are presented influence the healthcare decisions made by patients (information framing). ; To systematically review the evidence on the benefits and harms of PAD (e.g. need for allogeneic/autologous blood, other clinical outcomes). ; To examine the attitudes, beliefs, understanding and possible misconceptions of the general public, patients, special interest group members (e.g. Hepatitis C Council), and physicians regarding blood transfusion. Methods: The following studies were undertaken to inform the development of the decision aid: a systematic review and meta-analysis exploring the impact of information framing on patient treatment decision making; a systematic review and meta-analysis of controlled observational studies on PAD; and a survey (administered as a computer assisted telephone interview) of the views and opinions of physicians, patients, patients, and the public about blood transfusion. Decision aid development was guided by the Ottawa Decision Support Framework. The initial evaluation stages involved drafting and re-drafting the decision content by a group of experts in the fields of haematology, internal medicine, epidemiology, and health psychology. The final draft of the decision aid was reviewed by health professionals and patients who were about to have or had recently undergone major elective surgery. Participants provided feedback on its acceptability and identified areas for improvement during a semi-structures telephone interview. The decision aid was also quality assessed using the CREDIBLE criteria. Results: The results of a systematic review on information framing indicated that numerical data should be presented in more than one way to ensure patients form an accurate perception of treatment worth. In general, surgical and medical treatments tended to be preferred when information was expressed in a survival (positive) frame compared to a mortality (negative) frame, or when expressed as relative risk reduction (RRR) as opposed to absolute risk reduction (ARR) or number needed to treat (NNT) frames. The systematic review of controlled observational studies on PAD produced similar results to those from randomised controlled trials: PAD statistically significantly decreased the need for allogeneic blood yet increased the likelihood of receiving any transfusion (allogeneic/autologous) compared to usual care. Most studies (75%) did not use a transfusion protocol and seven studies reported using a more liberal protocol for the transfusion of autologous blood compared to allogeneic blood. Due to the paucity of research examining other clinical outcomes such as infection and thrombosis, there is insufficient data to determine the impact PAD may have on these outcomes. In surveys with patients, special interest group members and the public, one-third of respondents voiced concern with receiving an allogeneic blood transfusion, and most respondents overestimated the probability of contracting HIV and HCV through a blood transfusion when compared to other events of equal risk (e.g. being struck by lightning). Approximately 80% of respondents preferred PAD due to the perception that it eliminated all risks associated with a blood transfusion, is 100% compatible, and that it helps others through contributing to the blood supply. Although approximately half of the physicians interviewed used a transfusion trigger or protocol, individual patient characteristics were the main factor driving the decision of whether to transfuse. However, some respondents were critical of those who either did (or did not) use protocols, while others modified the "science of the guidelines" according to the needs of the individual. The final draft of the decision aid asked patients to consider the point at which they would prefer to receive a blood transfusion after major elective surgery (using haemoglobin values or transfusion "triggers" as a guide) and to decide whether or not to use PAD. The decision aid, "Blood Transfusion Options for Planned Surgery: A Decision Aid for Patients", consisted of a 32-page A5 size booklet and 28-minute audio tape or CD. The decision aid included the following sections: information about blood and blood loss; facts about blood transfusions; blood transfusions an you; your transfusion preference after surgery; approaches to replacing blood less; the differences between volunteer-donated and self-donated blood; adverse effects of blood transfusion; frequently asked questions; steps in decision making; and scientific references. A decision slip was included at the back of the booklet for patients to complete and return to their surgeon. Patients felt that the decision aid removed fears and common misconceptions associated with blood transfusion by providing them with more knowledge and realistic expectations of transfusion risks. Importantly, health professionals and patients felt that the information in the decision aid was presented in a balanced way and that it did not coerce patients to choose one particular option over another. Pilot data revealed that although the decision aid was generally well received, a number of revisions will be required before successful implementation. Important changes include; updating all information for recency; providing better explanations of numerical data; reducing the amount of information where appropriate; tailoring the decision aid for use in orthapaedic surgery (due to reduced utilisation rates of PAD); and clarifying the role of transfusion triggers in the decision aid, including whether it is appropriate to involved patients in that stage of the decision making process. The format of the decision aid also needs to be reconsidered (i.e. computer-based or continue with print and audio material) as costs and time restraints were highlighted as potential barriers to its use in practice. Based on the CREDIBLE criteria, the decision aid requires an updating policy, accessible documentation of the development process, and formal evaluation using a before-after pilot-study/randomised controlled trial. Conclusion: The task of developing and evaluating a decision aid on blood transfusion was found to be very complex and demanding. For instance, a number of in-depth studies were needed to adequately inform decision aid development and the decision aid still requires formal evaluation. However, the findings from the research undertaken in the thesis also reinforced the need for a decision aid on blood transfusion - the evidence on the benefits and harms of blood transfusion and PAD is controversial, practice variation exists, and personal values influenced patient and physician views of blood transfusion and PAD. Despite receiving positive feedback from health professionals and patients, the decision aid requires some significant modifications. Reduced utilisation rates of PAD indicate that a generic decision aid for procedures other than major orthopaedic surgery may not be relevant in practice. Although the issues surrounding blood transfusion justify the need for a decision aid, the desire for both patients and physicians for limited patient involvement regarding the decision of when to give a blood transfusion (using transfusion triggers as a guide) suggests that the aims of the decision aid in this area need to be reconsidered. However, as the number of older Australians undergoing major elective surgery rises due to population ageing, the availability of decision aids that adequately inform patients of the benefits and harms of blood transfusion and the option of PAD will be imperative. With further revision and evaluation, this decision aid should fulfill its promise as an effective tool for education patients about blood transfusion.
Subject: blood transfusions; decision aid; evidence-based decision making; patient care; elective surgery; systematic review; telephone interview
Identifier: http://hdl.handle.net/1959.13/1312391
Identifier: uon:22377
Language: eng

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