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Why Cancer Patients Enter Randomized Clinical Trials: Exploring the Factors That Influence Their Decision

From the Juravinski Cancer Centre, Hamilton Health Sciences; Department of Medicine, Supportive Care Cancer Research Unit, School of Nursing, Faculty of Health Sciences, Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton; Department of Nursing, Hospital for Sick Children; Sunnybrook and Women's College Hospital; University of Toronto, Toronto, Ontario

Address reprint requests to J.R. Wright, MD, FRCP(C), Juravinski Cancer Centre, 699 Concession St, Hamilton, Ontario, L8V 5C2; e-mail: jim.wright{at}hrcc.on.ca

	ABSTRACT

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PURPOSE: Few interventions have been designed and tested to improve recruitment to clinical trials in oncology. The multiple factors influencing patients' decisions have made the prioritization of specific interventions challenging. The present study was undertaken to identify the independent predictors of a cancer patient's decision to enter a randomized clinical trial.

METHODS: A list of factors from the medical literature was augmented with a series of focus groups involving cancer patients, physicians, and clinical research associates (CRAs). A series of questionnaires was developed with items based on these factors and were administered concurrently to 189 cancer patients, their physicians, and CRAs following the patient's decision regarding trial entry. Forward logistic regression modeling was performed using the items significantly correlated (by univariate analysis) with the decision to enter a clinical trial.

RESULTS: A number of items were significantly correlated with the patient's decision. In the multivariate logistic regression model, the patient's perception of personal benefit was the most important, with an odds ratio (OR) of 3.08 (P < .05). CRA-related items involving supportive aspects of the decision-making process were also important. These included whether the CRA helped with the decision (OR = 1.71; P < .05), and whether the decision was hard for the patient to make (OR = 0.52; P < .05).

CONCLUSION: Strategies that better address the potential benefits of trial entry may result in improved accrual. Interventions or aids that focus on the supportive aspects of the decision-making process while respecting the need for information and patient autonomy may also lead to meaningful improvements in accrual.

	INTRODUCTION

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The conduct of clinical trials in the field of oncology facilitates the sequential scientific evaluation of promising new therapies. Unfortunately, it is well recognized that low proportions of eligible cancer patients are recruited to such studies.^1-4 This obvious threat to timely completion leads to delays and decreased access to effective treatments for patients.

Recruitment to a clinical trial involves detailed discussions between the patient and their physician, and more commonly now, between the patient and a clinical research associate (CRA).⁵ Most research dealing with recruitment of cancer patients into clinical trials has been from the perspective of either the patient or the physician.^{6, 7} Interactive effects between patients and physicians, and the influence of the CRA on the patient's decision to enter a clinical trial have not been well studied.

The primary objective of this study was to establish the independent predictors of a cancer patient's decision to enter a phase III clinical trial. Initially, our group discussed the development of an informational decision aid for patients approached for trials, but decided that a greater understanding of the role of patient, physician, and CRA factors, and their interactions, on influencing the process of decision-making was necessary before development of an intervention. We hoped that the findings of the present study would provide the insight necessary to optimally devise a strategy to improve cancer patient recruitment to phase III clinical trials.

	METHODS

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A single-institution observational cohort study design was employed, using a series of questionnaires developed to capture the trials-related attitudes and opinions of the three major participants—patients, their physicians, and their CRAs. The study was performed at the Juravinski Cancer Centre (formerly the Hamilton Regional Cancer Centre), a comprehensive regional cancer center serving a population of 2.3 million in Central West Ontario, Canada.

Separate questionnaires were developed for patients, physicians, and CRAs to examine their attitudes and beliefs regarding the various issues surrounding the process of trials recruitment. First, a literature search was performed to identify factors previously reported to influence recruitment to clinical trials in oncology. The list was classified as physician-, patient-, or CRA-based. These broader classifications were divided into general, trial-specific, or encounter-specific factors. We then conducted a series of six focus groups with patients, physicians, and CRAs to identify any other factors thought to influence trial entry. The focus groups ranged in size from three to seven participants. Three focus groups were held with patients, one with physicians, and two with CRAs. All discussions were audiotaped, reviewed, summarized, and coded by two authors (J.W. and D.C.) to identify any items that were thought to influence clinical trial accrual that had not previously been identified. Details of the analysis and the results from the CRA focus groups have been previously reported.⁸ New items raised through the focus group process supplemented the original list. The only focus group that added substantively to the existing list of factors identified from the literature was the CRA group, as the influence of the CRA had not been well studied in the past.⁵ The final list is presented in Table 1.

The following four separate questionnaires were developed: a "Physician Baseline Form" to capture general and trial specific attitudes of physicians; a "Physician Encounter Form" to capture encounter specific issues from the physician's perspective; a "Patient Form" to capture patients' responses; and a "CRA Form" to capture all CRA-related responses. Additionally, a separately developed "Information Transfer" questionnaire was included to measure patient knowledge of trials-related issues. The details of its development and testing are not reported here, but copies of this and all other questionnaires are available from the authors.¹⁰ The Patient Form, including the Information Transfer aspect, was pilot tested and modified in two phases involving five and 17 patients, respectively, to ensure interpretability, clarity, and readability. Four physicians and five CRAs completed similar pilot testing for their respective questionnaires.

The use of focus groups and extensive consultation with patients through the process of development and pilot testing resulted in greater than 95% response rates for all questions. The CRA and the physician forms were completed equally well. One week after completing the questionnaire, a consecutive sample of 46 patients from the study was mailed a second copy of the patient questionnaire. Test-retest scores were obtained from the 36 patients (78%) that returned completed questionnaires. From paired t tests, test-retest scores were supportive of stability in the responses for all items in the questionnaire.

Patients approached regarding entry to active phase III trials were eligible for the cohort study. Trials that had limited activity or that had only single physicians recruiting were not included. The list of potential trials was reviewed biannually during the course of the study. A total of 10 different trials were selected and included an array of adjuvant therapy, follow-up, and primary treatment trials of radiation, systemic, hormonal, biologic, and immunotherapy. Patients were approached within 2 working days of their decision regarding the original phase III trial. The physicians and CRAs of these patients were asked to complete their respective forms after the patients were provided the questionnaire.

The Hamilton Health Sciences/McMaster University Research Ethics Board approved the study protocol and copies of the developed questionnaires.

The data generated from the questionnaires were entered into an Access version 9.0 SP3 (Microsoft, Redmond, WA) database. For analysis, the data were exported to Excel version 9.0 SP3 (Microsoft) for use with SPSS version 11.0.1 (SPSS Corp, Chicago, IL) software. After ranking all factors by their Pearson correlation coefficients (Pccs) with the trial entry decision, logistic regression modeling was performed.¹¹ Multiple strategies were employed to serve as a sensitivity analysis for the generated results. Forward regression was first performed with all nine items with a Pcc of 0.2 or greater; this cutoff was arbitrarily selected to include only the most highly correlated items. A subsequent model using all variables with significant Pccs was generated.

	RESULTS

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The study was conducted from April 2000, through November 2001. A total of 220 patients were approached after their decisions to enter a phase III trial. Eight patients were ineligible. Twenty-three patients (10%) refused to complete the survey. Of the 189 eligible patients who agreed to complete the questionnaire, 134 (70.9%) consented to enter the initial trial.

The mean age of the 189 patients who completed the questionnaire was 60 years, with a range of 38 to 93 years. Sixty-seven percent of the patients were female, and 76% reported living with their spouse or significant other. Just fewer than 40% of patients reported completing high school as their highest level of education, while 34% completed college or university. The mean reported travel distance to the cancer center was 38 km, with a range of 1 to 166 km. Household annual income was well distributed, with 27%, 20%, 13%, and 24% reporting less than $30,000, $30,000 to $49,999, $50,000 to $69,999, and greater than $70,000, respectively (Can $). Sixty-one percent of patients were involved in decisions for breast cancer trials; 26% in head and neck cancer trials; and the remainder, in prostate, lung, and colon cancer trials.

Patients reported that a physician or CRA first presented the option of a phase III clinical trial in 56% and 40% of cases, respectively. More than 53% believed that the person who discussed most of the trial-related issues with them spent between 16 and 30 minutes doing so. An additional 33% believed the total time was 15 minutes or less.

With respect to preferred levels of decision making in general, 5% indicated that, "the doctor should make the decision"; 20%, that "the doctor should decide but consider my opinion"; 36%, that "the doctor and I should make the decision together"; 33%, that "I should make the decision but consider the doctor's opinion"; and 7%, that "I should make the decision."

Eighteen percent of patients indicated that they made a decision regarding trial entry "as soon as the option was suggested"; 20% indicated making a decision "once the initial details were reviewed"; 25%, "after all the details were reviewed"; and the remaining 36%, "sometime later after thinking about it."

Patients indicated a strong level of agreement with a number of the items that influenced their decision to enter a clinical trial. As examples, 98% of patients agreed that "clinical trials are important for the sake of future patients"; 93% and 95% agreed with the statements supportive of their physicians or CRAs, respectively; 94% agreed that they had enough information to make a decision; and 93% suggested they had enough time to make a decision. Responses that are so consistently strong, though encouraging evaluations of the recruitment process and informed consent, are unlikely to provide any meaningful ability to predict which patients will or will not enter clinical trials. Other patient-reported attitudes are summarized in Table 2.

	DISCUSSION

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This study was a unique attempt to measure the expressed attitudes and opinions of patients, physicians, and CRAs close to the time of an actual decision to enter a clinical trial. Our main purpose was to identify factors that might lead to interventions to improve accrual to clinical trials. Overall, 19 items were significantly correlated with the decision to enter a phase III trial. Statistical significance and clinical significance are important to distinguish in this setting. Other important interpretation issues include the difference between association and causation, and the potential for manipulating the items found to be significant. For example, patient sex is correlated with the decision to enter a trial, and although it may be an important factor to include when developing a model to maximize the extent of variation that can be explained, sex cannot be manipulated. With the hope of facilitating a broader understanding of the issues, all items were included in the developed models in our study despite these limitations.

The predictors identified in this study are not unique, but they do present possible targets for intervention to increase clinical trial accrual. Patients' perception of personal benefit or "benefit to me" was the best predictor of clinical trial entry. The odds ratio from the initial regression model suggests that when the amount of perceived benefit increases from a mean response score of 3.8 up to a level of 4.8, the odds of clinical trial entry increases by 3.08 times. In terms of accrual, such an increase would result in an increase from a baseline rate of 71% up to 88.3% in this sample, assuming that all other factors were held constant. Historically, this hope of personal benefit has been strongly linked with the conduct of phase I and II trials where patients are hopeful that the new therapies being tested will result in treatment success.¹² In contrast, other work has suggested that the identification of disadvantages, such as risks, is more strongly associated with the decision to enter a phase III trial.¹³ In 1984, Penman et al¹⁴ reported the results of a questionnaire administered to a cohort of patients that had entered into either a phase II or III investigational chemotherapy trial. One of the most common reasons selected for entering the trial was the hope for personal benefit or cure. In the present day, there remain legitimate reasons to hope for personal benefit by entering a phase III trial. This may include improved access to newer drugs, technology that has suggested promise in early-phase trials, or the more intensive clinical evaluations that are commonly required in clinical research protocols. In our cohort of patients, the fulfillment of an altruistic act and the aid to future patients may also have provided them with a sense of personal benefit. Clearly, a better understanding of what patients mean by, or perceive as benefits, is required. Perhaps such benefits could be more fairly and consistently reflected in consent forms and other trials-related information with the same degree of enthusiasm that we demand for potential treatment-related toxicity. However, as Joffe et al^{15, 16} have discussed, there needs to be a balance between promoting the possibility of individual benefit with the need to understand the larger societal purpose of clinical trials, as the hope of personal benefit has the potential to conflict with the major purpose of clinical research, which is to optimize future patient care.

The other items included in the initial regression model point toward the importance of decision support. From both models, a number of significant factors reflect the importance of helping the patient make a decision regarding trial entry. These included the patient's perception of help from the CRA, time spent with the patient, and patient difficulty making a decision. These factors suggest that interventions aimed at decision support could maximize trials accrual. The fact that the CRAs reported, "helping" in only 6% of patient decisions clearly underappreciates the patient's perception of their value, and, as expected, the separate patient and CRA reporting of this issue was not correlated. This ambivalence is consistent with CRAs reporting recommending trial entry to less than 1% of patients, and likely reflects an understandable desire not to directly bias patients. This also possibly explains why physicians, while more likely to recommend trial entry, still only did so in 22% of encounters. However, total impartiality to the patient's predicament in an effort to avoid coercion, may not be the most appropriate strategy. Communication approaches that acknowledge, and are empathetic to the difficulties patients' face when deciding on entry to clinical trials, may be more appropriate. The sometimes-fine line between coercion and information must be respected as ethical strategies are developed and tested.^{17, 18} The results of this study should not be interpreted to suggest that specific information regarding a trial is not of core importance. In this series, 94% of patients agreed that they received sufficient information to make a decision regarding the specific trial for which they were approached. This suggests that when communication about trials participation is successful, other factors such as perceived benefits and decision support maybe more likely to influence a cancer patient's decision. It also suggests that, in our setting, communication-based interventions geared solely at improving knowledge about trials may not be particularly useful strategies to improve recruitment. Instead, decision-support strategies targeted specifically at CRAs may be more useful to improve accrual. Although formal training workshops directed at physicians to improve their approach to discussing clinical trial entry have yielded mixed results, such training for CRAs may yield benefits.^19-22 Typically from a nursing background, CRAs are more likely to see the supportive aspect of the decision-making process as an important aspect of their responsibility.^{8, 23} The physicians and CRAs in our Center have not previously received formal training in ethically seeking consent.

The final factors identified in the second regression model included the patient's expectations with standard therapy, the physician's sense of importance of the study, and the CRA's sense of study toxicity. The first two factors are supported by previous research.^{24, 25} Patient expectations with standard therapy may obviously influence their expectations of personal benefit from trial entry. How a health care professional's assessment of the importance of a study relates to the individual encounter is difficult to predict but may reflect the enthusiasm with which trial benefits are relayed to patients. The third factor has not been previously identified, and again supports the important role of the CRA in the local accrual process. It is not surprising that CRAs who are active in front-line patient care may be less inclined to support the entry of a patient into a trial that has the potential for more clinical toxicity. Similar findings from the physician's perspective have been reported in the past.²⁶

An important consideration in the interpretation of this study relates to the generalizability of the findings. In comparison to our historical rates of consent, the 71% overall entry rate into the available clinical trials was high in this sample of patients.⁸ If the 23 patients who refused to participate are included, this ratio falls to 64% (135 of 212), as only one of these 23 patients actually consented to the phase III trial. Patients who were more likely to enter the phase III trials were more likely to participate in the cohort study. This issue may have affected the strength of the various correlations, but was likely to have had a modest impact on the ability to identify items that were important in the decision-making process. As future studies that attempt to improve overall rates of trial accrual are designed, patients suspect of the research enterprise must be included.

An important issue not addressed in this study is the proportion of potentially eligible patients who were identified or approached about trial participation. The individual physician was not a predictor of trial accrual, suggesting no significantly different levels of success at recruitment once a patient was identified. However, based on the differences in patient-encounter levels for the various physicians, which ranged from one to 33, there seemed to be large differences in the ability to identify patients in the first place. It is possible that physician attitudes were more important for identifying potentially eligible patients, whereas patient attitudes were more important for the actual decision to enter a trial.

The common goal of the growing interest in clinical trials–related research is to increase patient accrual and accelerate the pace of clinical advances. The results of this study suggest, perhaps not surprisingly, that a simple straightforward solution to increase patient accrual is not forthcoming. Future approaches will likely be multifactorial by design and will require dedicated research to achieve incremental improvements. We do not yet know what proportion of patients should be entered into clinical trials. The high accrual rates achieved in pediatric oncology seem unrealistic for adult patients regardless of whether this is an age bias issue or trial design issue.^27-30 Achieving a 5% to 10% entry rate for all new patients would be a significant advance. Efforts to improve our understanding of those factors involved and the development of interventions to improve informed consent and support patients in their decision-making should continue.

	Authors' Disclosures of Potential Conflicts of Interest

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION Authors' Disclosures of... REFERENCES

 
The authors indicated no potential conflicts of interest.

	NOTES

 
Supported by a grant from the Hamilton Regional Cancer Centre Foundation.

Presented in part at the Annual Meeting of the American Society of Clinical Oncology, Chicago, IL, May 31-June 3, 2003, and at the Annual Meeting of the Canadian Association of Radiation Oncologists in Montreal, Quebec, Canada, October 3-5, 2003.

Authors' disclosures of potential conflicts of interest are found at the end of this article.

	REFERENCES

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION Authors' Disclosures of... REFERENCES

 
1. Cassileth BR: Clinical trials: Time for action. J Clin Oncol 21:765-766, 2003[Free Full Text]

2. Wittes RE, Friedman MA: Accrual to clinical trials. J Natl Cancer Inst 90:884-885, 1998[Free Full Text]

3. American Medical Association Council on Scientific Affairs: Viability of cancer clinical research: Patient accrual, coverage, and reimbursement. J Natl Cancer Inst 83:254-259, 1991[Free Full Text]

4. Winn RJ: Obstacles to the accrual of patients to clinical trials in the community setting. Semin Oncol 21:112-117, 1994[Medline]

5. Tattersall M: Cancer clinical trial recruitment. Cancer 95:1397-1400, 2002[CrossRef][Medline]

6. Ross S, Grant A, Counsell C, et al: Barriers to participation in randomised controlled trials: A systematic review. J Clin Epidemiol 52:1143-1156, 1999[CrossRef][Medline]

7. Ellis PM: Attitudes towards and participation in randomised clinical trials in oncology: A review of the literature. Ann Oncol 11:939-945, 2000[Abstract/Free Full Text]

8. Wright JR, Crooks D, Mings D, et al: Factors influencing recruitment to phase III studies in oncology: The perspective of the clinical research associate. Cancer 95:1584-1591, 2002[CrossRef][Medline]

9. O'Connor A: Validation of a decisional conflict scale. Med Decis Making 15:25-30, 1995[Abstract/Free Full Text]

10. Wright JR, Whelan T, Dubois S, et al: Measuring cancer patients knowledge of clinical trials at the time of a decision to enter a phase III trial. Radiother Oncol 69:100-125, 2003

11. Hosmer DW, Lemeshow S: Applied Logistic Regression. New York, NY, John Wiley & Sons, 1989

12. Seldon JM, Fetting JH, Siminoff LA: Offering the option of randomized clinical trials to cancer patients who overestimate their prognosis with standard therapies. Cancer Invest 11:57-62, 1993[Medline]

13. Sutherland HJ, Lockwood GA, Till JE: Are we getting informed consent from patients with cancer? J R Soc Med 83:439-443, 1990[Abstract]

14. Penman DT, Holland JC, Bahna GF, et al: Informed consent for investigational chemotherapy: Patients' and physicians' perceptions. J Clin Oncol 2:849-855, 1984[Abstract]

15. Joffe S, Cook EF, Cleary PD, et al: Quality of informed consent in cancer clinical trials: A cross-sectional survey. Lancet 358:1772-1777, 2001[CrossRef][Medline]

16. Joffe S, Weeks JC: Views of American oncologists about the purposes of clinical trials. J Natl Cancer Inst 94:1847-1853, 2002[Abstract/Free Full Text]

17. Brown RF, Butow PN, Butt DG, et al: Developing ethical strategies to assist oncologists in seeking informed consent to cancer clinical trials. Soc Sci Med 58:379-390, 2004

18. Loh WY, Butow PN, Brown RF, et al: Ethical communication in clinical trials. Cancer 95:2414-2421, 2002[CrossRef][Medline]

19. Albrecht TL, Blanchard C, Ruckdeschel JC, et al: Strategic physician communication and oncology clinical trials. J Clin Oncol 17:3324-3332, 1999[Abstract/Free Full Text]

20. Grant CH, Cissna KN, Rosenfeld LB: Patients' perceptions of physicians communication and outcomes of the accrual to trial process. Health Commun 12:23-39, 2000[CrossRef][Medline]

21. Fleissig A, Jenkins V, Fallowfield L: Results of an intervention study to improve communication about randomized clinical trials of cancer therapy. Eur J Cancer 37:322-331, 2001

22. Sawka CA, Pritchard KI: Can improved communication increase patient participation in randomized clinical trials? Eur J Cancer 37:297-299, 2001

23. Burnett CB, Koczwara B, Pixley L, et al: Nurses' attitudes toward clinical trials at a comprehensive cancer centre. Oncol Nurs Forum 28:1187-1192, 2001[Medline]

24. Sutherland HJ, da Cunha R, Lockwood GA, et al: What attitudes and beliefs underlie patients' decisions about participating in chemotherapy trials? Med Decis Making 18:61-69, 1998[Abstract/Free Full Text]

25. Langley GR, Sutherland HJ, Wong S, et al: Why are (or are not) patients given the option to enter clinical trials? Control Clin Trials 8:49-59, 1987[CrossRef][Medline]

26. Winn RJ, Miransky J, Kerner JF, et al: An evaluation of physician determinants in the referral of patients for cancer clinical trials in the community setting. Prog Clin Biol Res 156:63-73, 1984[Medline]

27. Sateren WB, Trimble EL, Abrams J, et al: How sociodemographics, presence of oncology specialists, and hospital cancer programs affect accrual to cancer treatment trials. J Clin Oncol 20:2109-2117, 2002[Abstract/Free Full Text]

28. Lewis JH, Kilgore ML, Goldman DP, et al: Participation of patients 65 years of age or older in cancer clinical trials. J Clin Oncol 21:1383-1389, 2003[Abstract/Free Full Text]

29. Yee KW, Pater JL, Pho L, et al: Enrollment of older patients in cancer treatment trials in Canada: Why is age a barrier? J Clin Oncol 21:1618-1623, 2003[Abstract/Free Full Text]

30. Fuks A, Weijer C, Freedman B, et al: A study in contrasts: eligibility criteria in a twenty year sample of NSABP and POG clinical trials: National Surgical Adjuvant Breast And Bowel Program—Pediatric Oncology Group. J Clin Epidemiol 51:69-79, 1998[CrossRef][Medline]

Submitted January 29, 2004; accepted August 20, 2004.

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This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Save to my personal folders Download to citation manager Rights & Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wright, J. R. Articles by Levine, M. N. Search for Related Content PubMed PubMed Citation Articles by Wright, J. R. Articles by Levine, M. N.