1 Medical Oncologist Hamilton Regional Cancer Center, Hamilton, Ontario, Canada; 2 Medical Psychology Unit, 3 Department of Cancer Medicine, University of Sydney, Sydney, Australia
Received 7 January 2002; revised 4 April 2002; accepted 12 April 2002
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Abstract |
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To evaluate the impact of an educational booklet on womens knowledge of and willingness to participate in a randomized clinical trial of treatment for breast cancer.
Materials and methods:
Women undergoing surgery for newly diagnosed early stage breast cancer were randomized to receive, or not, an information booklet explaining the need for and manner in which randomized trials are conducted.
Results:
Eighty-three women with newly diagnosed early stage breast cancer completed a questionnaire assessing attitudes to random clinical trials (RCTs) and were randomized to receive usual information treatment options provided from their oncologist, or the educational booklet in addition to usual information from their oncologist (42 usual information, 41 booklet). Fewer women who received the clinical trials booklet (40% versus 47%) would consider participating in the hypothetical clinical trial (P = 0.6). Mean knowledge scores increased for both groups; moreover, women who did not receive the booklet showed similar improvements to women who received the booklet [mean difference 0.09, 95% confidence interval (CI) 0.66 to 0.83]. In a multivariate analysis women who would consider participating in the clinical trial were more anxious [odds ratio (OR) 5.9, P = 0.02] had involved lymph nodes (OR 5.8, P = 0.02) and were less influenced by negative aspects of clinical trials (OR 7.7, P = 0.0001). After adjustment for these variables women who received the educational booklet were significantly less likely to consider trial participation (OR 0.22, P = 0.05).
Conclusions:
Educating women about clinical trials in this manner appears ineffective in improving recruitment to RCTs. Women appear to be more influenced by their perception of risk than understanding. This finding has ethical implications for communication of information about RCTs.
Key words: attitude to health, breast neoplasm, patient compliance, patient education, randomized controlled trials
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Introduction |
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In order to safeguard individual autonomy, additional ethical requirements are imposed upon treatment received as part of a RCT [4]. There is an ethical obligation that trials be of sufficient quality to have a favorable impact on society in the future [5, 6]. Additionally, requirements for informed consent for clinical trials are often more stringent than those for treatment outside of the setting of a clinical trial [711]. The goal is to provide sufficient information about the treatments offered on the trial, the benefits, side effects and alternative treatment approaches, plus procedural information about the clinical trial for patients to make an autonomous decision.
Review of the literature suggests that the goals of informed consent for clinical trials are not always met [12]. A number of researchers have found that patients fail to recall much of the information presented to them during a consent interview [1316]. Patient information sheets for clinical trials are often too complex for many patients to read [17, 18]. Poor recall and understanding may also arise due to variation in the amount of information provided by doctors during the informed consent consultation. Williams and Zwitter [19] found considerable variation in the information that investigators state they would routinely give to patients considering entry into phase III clinical trials.
Several studies have examined ways to improve the provision of information about randomized trials. Davis et al. [20] randomized cancer patients to receive or not, the National Cancer Institute (NCI) booklet on clinical trials. Patients receiving the NCI booklet were more knowledgeable about clinical trials in general. Simes et al. [21] and Aaronson et al. [22] randomized patients considering entry into a specific clinical trial to receive more detailed information about the trial that was being discussed versus their standard practice. They found that patients who received more detailed information were more knowledgeable about the trial, but both authors observed a small (statistically insignificant) reduction in willingness to participate in the trial.
Earlier research by our group suggested that cancer patients and members of the general public have a poor understanding about the need for RCTs to establish the worth of new and existing treatments, or the manner in which this would happen [23, 24]. Many patients did not appear to understand the rationale for randomization. A number of women attending focus group interviews indicated that they would be more willing to consider participating in a clinical trial once they were better informed. The findings of a more recent larger survey suggested that women who were more knowledgeable about RCTs, in general, were more willing to consider participating in a trial themselves [25].
Many cancer patients are approached to participate in clinical trials soon after their diagnosis when they are feeling stressed and vulnerable [26]. Discussions about RCTs at this point may add to feelings of anxiety and uncertainty. In order to overcome this Baum [27, 28] has suggested that there is a need to educate the public about the need for RCTs and the manner in which they are conducted.
Patient education booklets are one type of intervention that has been evaluated in a number of different settings to improve information exchange. Educational booklets have been shown to increase knowledge in patients with arthritis and hypertension [29, 30]. Other authors report additional benefits including improved satisfaction [31], fewer GP visits, less referrals to physiotherapy and fewer hospital admissions among patients with back pain [32]; and reduced anxiety, greater physiologic recovery and improved mood among patients undergoing coronary artery bypass graft surgery [33]. This study reports the results of a RCT evaluating the impact of an informational booklet, explaining the need for and manner in which RCTs are conducted, on womens knowledge of and willingness to participate in a RCT of treatment for breast cancer.
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Patients and methods |
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Women were identified via a multidisciplinary breast cancer meeting in which all new breast cancer cases from the preceding week were discussed. Women were approached after they had received news of their own histopathology results, but prior to seeing a medical oncologist to discuss further treatment options. The purpose of the research was explained and women were given an information sheet to read. Written informed consent for this study was obtained from women who agreed to participate. Institutional ethics committee approval was obtained from Central Sydney Area Health Service.
Women were asked to complete a baseline questionnaire (see below), then randomized centrally to a usual discussion about treatment options from their doctor (including clinical trials if appropriate), or an information booklet about clinical trials in addition to usual discussion about treatment options from their doctor. No attempt was made to try to standardize the usual information provided by the doctor. The information booklet explained the need for and manner in which RCTs are conducted. This was a short booklet which discussed what clinical trials are, how treatment is decided on a RCT, potential advantages and disadvantages of participating in a clinical trial and common misunderstandings about randomized trials identified from earlier research [23, 24]. It also provided a list of questions to help women find out more information from their medical oncologist about specific clinical trials appropriate to their own situation. The booklets were printed in black and white on neutral colored paper. Women receiving the booklet who wanted additional general information about clinical trials could also receive a more detailed booklet produced by the New South Wales Cancer Council. Four to six weeks later women were mailed a follow-up questionnaire to complete and return in a reply paid envelope. Information was collected from the womens medical oncologist concerning disease data (tumor size, nodal involvement, histological grade, hormone receptor status), eligibility for inclusion into a randomized trial of adjuvant therapy, whether clinical trials were discussed with the patient, the outcome of such discussions and the actual treatment received.
Survey instruments
The baseline questionnaire measured:
The follow-up questionnaire measured:
Data analysis was undertaken using SPSS, version 6.1 (SPSS, Chicago, IL, USA) [41]. Analysis was by intention-to-treat. At the time of this study, few women were invited to participate in an actual clinical trial, therefore the main outcome of the randomized trial was willingness to join the clinical trial described in a hypothetical scenario. However, women were asked to make this decision at a salient time point (soon after making decisions about their own breast cancer treatment). Secondary outcomes included changes over time in womens knowledge and attitudes towards randomized trials, plus womens satisfaction. Descriptive information was collected on womens reasons for agreeing, or not agreeing, to participate in the hypothetical trial. Differences in baseline variables between the randomized groups were assessed using 2-tests or Students t-test. Differences in willingness to participate in the hypothetical breast cancer trial were assessed using
2-test. Change scores for knowledge and attitudes to clinical trials were assessed using paired Students t-tests. A stepwise backward multivariate logistic regression was conducted to examine the impact of receiving the information booklet on willingness to participate in the hypothetical RCT after adjustment for the effects of confounding variables. Information on womens use of the clinical trials booklet, other sources of information and their recollection of discussions about clinical trials will be presented in a separate paper.
Earlier research suggested that 1520% of women with early stage breast cancer treated in the Medical Oncology Department at Royal Prince Alfred Hospital were recruited onto clinical trials [42]. A sample of 122 would be able to detect an increase from 20 to 45% with a power of 0.80 and a significance level of 0.05. An interim analysis was planned when approximately two thirds of women had been recruited. At this point 83 women had been recruited. A decision was made to close the trial at this time because of both a lack of efficacy and low salience of the intervention. Assuming a best case scenario (i.e. all the remaining women in the intervention group decided to join the trial) the difference between the groups would not have achieved statistical significance. The final study had a power of 0.60 to detect a difference of 25% and a power of 0.80 to detect a 35% difference in willingness to join the hypothetical trial.
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Results |
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Knowledge scores were calculated by summing the number of correct responses to the seven items (range 07). The mean knowledge score was 4.1 (SD 2.0). Baseline knowledge was slightly higher among women randomized to receive the clinical trials booklet (difference 0.9, 95% CI 0.05 to 1.7, P = 0.06). There was a small increase in knowledge between baseline and reassessment 46 weeks later (mean 0.6 95% CI 0.2 to 0.9, P = 0.003). However, women who received the clinical trials booklet showed no greater improvement in knowledge than women in the control group (difference 0.09, 95% CI 0.66 to 0.83, P = 0.82).
Comparison was made of the four factor scores assessing attitudes to RCTs between women randomized to receive the clinical trials booklet and the control group. Higher scores equate to greater willingness to participate in randomized trials (range 07). There were no differences in baseline attitudes to randomized trials. Womens attitudes to randomized trials changed over time. At follow-up, women were less influenced by positive aspects of clinical trials (0.22, 95% CI 0.04 to 0.4, P = 0.02) and altruistic motivations (0.23, 95% CI 0.04 to 0.43, P = 0.02). Their was no evidence of any change in womens perceptions of the negative aspects of clinical trials (0.03, 95% CI 0.16 to 0.22, P = 0.73) or about practical issues/loss of control (0.06, 95% CI 0.17 to 0.28, P = 0.63).
In response to the initial questionnaire, 20 women (25%) would consider participating in clinical trials, 24 women (30%) would not and 35 women (45%) were unsure. In the follow-up questionnaire a scenario describing a hypothetical woman with a node-positive breast cancer was presented (see Appendix 1). Treatment options of tamoxifen or chemotherapy were described along with a hypothetical RCT in which women may receive tamoxifen alone, chemotherapy alone or chemotherapy followed by tamoxifen. Twenty-six women (43%) indicated they would be prepared to join the clinical trial, while 34 women (57%) were not prepared to. Data were missing for the remaining seven women. Fourteen women (47%) randomized to the standard information arm were prepared to join the clinical trial, compared with 12 women (40%) randomized to receive the clinical trials booklet. Therefore slightly fewer women (7%) receiving the clinical trials booklet than women in the standard information arm were willing to join the clinical trial, but this difference was not statistically significant (95% CI 32% to 18%, P = 0.60). There was no evidence of any difference between the groups in womens satisfaction with the consultation (P = 0.65).
A multivariate logistic regression analysis was conducted to examine the impact of the clinical trials booklet on womens decision to join the hypothetical clinical trial of adjuvant therapy for breast cancer, after adjustment for potential confounding factors. Demographic variables (age, education, medical/allied health training), disease variables (tumor size, nodal involvement) preferences for involvement in clinical decision-making, anxiety, depression, along with the four factor scores measuring attitudes to clinical trials were entered into the model. The results are summarized in Table 3. After adjustment for other variables, women who received the clinical trials booklet were significantly less likely to join the hypothetical clinical trial (OR 0.22, 95% CI 0.041.0, P = 0.05). Women with possible or definite cases of anxiety were more likely to join the clinical trial (OR 5.9, 95% CI 1.230.1, P = 0.02), as were women with involved lymph nodes (OR 5.8, 95% CI 1.128.8, P = 0.02). Women who were less likely to be influenced by negative aspects of clinical trials were also significantly more likely to join the hypothetical clinical trial (OR 7.7, 95% CI 2.325.2, P <0.0001).
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Discussion |
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Previous studies have demonstrated that patients receiving more detailed information about specific clinical trials have improved knowledge about those trials [21, 22]. However, women in this trial who received the clinical trial booklet showed no greater improvement in knowledge than women who received usual information about treatment options from their doctor. These findings suggest that factors other than knowledge or understanding about a trial may be more important in the decision to enter a clinical trial.
Characteristics associated with the womens cancer were influential in the decision to join the clinical trial. We did not directly measure womens estimate of their prognosis. However, nodal status is one of the major prognostic factors for breast cancer. Women with involved lymph nodes would be aware that this fact carries a greater risk of future relapse and death from breast cancer. These findings are supported by observations from Siminoff and others that women with early stage breast cancer who overestimate their prognosis with standard therapies are less likely to consider participating in a clinical trial [4345]. By chance, significantly more women randomized to the information booklet were classified as cases of anxiety and depression. Following adjustment for this imbalance, anxiety was still associated with increased willingness to join a clinical trial. Therefore womens perception of the implications of their illness appears influential in their decision to join a randomized trial. The findings highlight the potential for subtle coercion when discussing both standard treatment options and clinical trials.
The results of this study suggest that womens perceptions of the negative aspects of clinical trials (randomization, experimental aspects, greater uncertainty) are far more influential in decision-making than their perceptions about the advantages. Previous research has suggested that the main reasons patients give for joining a clinical trial are the potential to receive more effective treatments and helping future patients [46, 47]. In the follow-up questionnaire, women in this study appear less likely to be influenced by potential advantages of clinical trials. This finding may reflect a satisfaction bias with the treatment decision women made as only two women received adjuvant therapy as part of a clinical trial. However, an additional explanation is that women, having reflected on the issues over a few weeks, believed there were fewer advantages to participating in clinical trials than they originally considered.
There were a variety of reasons given by women for not agreeing to join the clinical trial of adjuvant therapy. The major reasons reflected specific concerns about the treatments offered on the trial (concern about side effects or wanting to avoid one of the treatments), or dislike about the allocation of treatment (want themselves or doctor to select treatment or dislike of random allocation). A desire by patients for a specific treatment recommendation from the doctor appears to be an important obstacle to recruitment to clinical trials [48], although a recent study by Fallowfield et al. [49] demonstrated that clearer explanations about randomization increased patients willingness to participate in trials in general.
Common reasons given by women for agreeing to join the clinical trial included any of the treatments appear to be helpful and there did not appear to be anything to lose by joining the trial. These responses suggest an understanding of issues relating to equipoise. Equipoise exists when either individually or collectively, doctors are uncertain about the comparative merits of different treatment approaches. It is a crucial issue for doctors when deciding whether to participate in RCTs [3, 5, 50]. These findings support those of Fallowfield et al. [49, 51], that greater understanding of this issue by patients may also be an important factor in their decision to enter a randomized trial.
Unlike previous interventions [21, 22], we were unable to document any effect from the clinical trial booklet in this study in improving knowledge about clinical trials among women with breast cancer. Despite the lack of effectiveness on womens knowledge, receiving the clinical trial booklet was associated with reduced willingness to participate in a clinical trial of adjuvant therapy for breast cancer. Patient education booklets have been shown to have a number of improved outcomes in a number of different settings [29, 32, 33, 52, 53]. In general, the information contained in these educational interventions was immediately relevant to the problem with which the patient presented. Few women in this trial were presented the option of participating in an actual clinical trial. The clinical trial booklet may have been ineffective because the information contained in it was not particularly salient to decision-making for the majority of women in this study. If so, the results highlight the importance of physician reinforcement of information about clinical trials.
There are some limitations to this study. The number of women included in the study was relatively small and approximately 25% of women did not complete the follow-up assessment. However, there were no major differences in baseline characteristics of those women not completing the follow-up assessment and those included in the analysis (data not shown). This study was conducted among women with early stage breast cancer. It is not clear whether these findings can be generalised to patients with other cancers considering entry into a clinical trial. Additionally, the motivation to participate in a clinical trial for patients with advanced or metastatic cancer may be quite different from those of patients with early stage disease.
Nevertheless, the findings of this study suggest that the decision to enter clinical trials in oncology is a complex interaction of patients pre-existing beliefs, the perception of the seriousness of their disease and endorsement of the trial by the physician. Strategies designed to educate patients about trials in general, or about specific clinical trials, have not proven effective in improving recruitment. Further research should examine more closely the exchange of information that takes place during the informed consent interview(s). In the interim it is important that patients concerns about the negative aspects of randomized trials be aired in consultation to ensure patient understanding and avoid undue coercion.
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Acknowledgements |
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Appendix 1. Hypothetical clinical trial scenario |
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Sheila is a 56-year-old woman who has recently had a mastectomy for breast cancer. The cancer spread to several of her lymph glands. Radiotherapy was not recommended for Sheila. She has gone to talk to a medical oncologist who recommended that she have some additional treatment to reduce the chances of the cancer returning. In Sheilas situation, both tamoxifen and chemotherapy, have been shown to be beneficial.
Tamoxifen is a hormonal tablet taken once per day for 5 years. The major side effects include hot flushes, vaginal dryness or itching, weight gain, mood changes and occasionally some nausea. Not all patients experience these side effects. Chemotherapy is given as a combination of injections and tablets over 6 months. The major side effects include nausea and vomiting, hair loss, sore mouth and eyes and diarrhea. There may also be an increased risk of infection. Not every patient experiences side effects and many of these side effects can be managed with medication.
Sheilas doctor explained that either tamoxifen or chemotherapy would be beneficial to her. She (or Sheilas doctor) could choose to have either one of these treatments. However, it is not known whether tamoxifen is better than chemotherapy, or whether combining tamoxifen and chemotherapy is better than either one on its own. Sheilas doctor invites her to participate in an international clinical trial comparing these treatments. If she were to agree, she would either receive tamoxifen on its own, chemotherapy on its own, or tamoxifen plus chemotherapy. Her treatment would be chosen at random (neither Sheila nor her doctor would pick her treatment).
Sheila has the option of choosing either chemotherapy or tamoxifen, or joining the clinical trial comparing these treatments. Given the experience you have gained making decisions about breast cancer treatments, if you were Sheila, would you agree to participate in the clinical trial?
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Footnotes |
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