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© 2001 American Society for Clinical Oncology Phase I Study of a Decision Aid for Patients With Locally Advanced Non–Small-Cell Lung CancerFrom the Radiation Oncology Research Unit; the Departments of Oncology, Community Health and Epidemiology, and Psychology, Queen’s University; Kingston Regional Cancer Clinic, Cancer Care Ontario; and Kingston General Hospital, Kingston, Ontario, Canada. Address reprint requests to M.D. Brundage, MD, Radiation Oncology Research Unit, Apps Level 4, Kingston General Hospital, Kingston, Ontario, Canada K7L 2V7; email: mbrundage{at}cancercare.on.ca
PURPOSE: Many patients with locally advanced non–small-cell lung cancer (LA-NSCLC) are eligible for combined-modality therapy (CMT; chemotherapy and radiotherapy). Although CMT offers slightly higher chances of survival than radiotherapy alone (RT), it also carries a higher probability of toxicity, raising the possibility that some patients may prefer to decline CMT. We report a pilot study of a decision aid designed for patients in this setting. PATIENTS AND METHODS: The aid included a structured description of the treatment options and trade-off exercises designed to help clarify the patient’s values for the relevant outcomes by determining the patient’s survival advantage threshold (SAT; the increase in survival conferred by CMT over RT that the patient deemed necessary for choosing CMT). Additional outcome measures included each patient’s strength of treatment preference, decisional conflict, objective understanding of survival information, and decisional role preference.
RESULTS: Twenty-seven patients met the eligibility criteria for the study. Of these, seven declined the decision aid because they had a clear treatment preference. The remaining 20 participants completed the decision aid; 18 chose CMT, and two chose RT. All 20 patients wished to participate in the decision to some extent. All patients reported that using the decision support was useful to them and recommended its use for others. No patient or physician reported that the aid interfered with the physician-patient relationship. Patients’ 3-year SATs and median SATs were each strongly correlated with their strengths of treatment preference ( CONCLUSION: We conclude that implementing the decision-aid for patients with LA-NSCLC is feasible, that it demonstrates convergent validity, and that it is favorably evaluated by patients and their physicians. The aid seems to help patients understand the benefits and risks of treatment and to choose the treatment that is most consistent with their values. Further evaluation of the aid is warranted.
MANY PATIENTS with locally advanced non–small-cell lung cancer (LA-NSCLC) are eligible for treatment either with radiation (RT) alone or with combined-modality treatment (CMT) using chemotherapy and RT. The latter treatment is associated with slightly higher survival rates, but the former has fewer treatment-related side effects. The preferred treatment for each patient is, thus, sensitive to how the individual values the relevant treatment outcomes.1-3 The purpose of this article is to report a pilot evaluation of a decision aid for patients with LA-NSCLC facing a choice between the two treatments. The decision aid was designed to help patients understand information relevant to the decision and to help clarify their values, thereby improving their decision satisfaction and the process of informed consent.4 LA-NSCLC (clinical stage III) accounts for approximately one third of incident NSCLC cases and is defined as disease that is too extensive for primary surgical resection, with no detectable metastatic disease beyond the thorax.5 A large amount of clinical research has been undertaken to find strategies that improve survival rates of such patients.6 A meta-analysis of clinical trials comparing CMT (cisplatin-based chemotherapy plus RT) with RT alone estimates that patient survival after 3 years is increased from 6%, when patients are treated with RT, to 9% with CMT.7 Individual trials have shown a smaller,8 larger,9 and similar10 magnitude of benefit, as was estimated in the meta-analysis. Although the estimated differences in patient survival between treatments are statistically significant, their clinical significance is less certain. Clinical guidelines have supported the routine use of CMT given its demonstrated survival benefit.11 Lack of consensus among physicians about the optimal management strategy, however, has been illustrated by the range of management approaches described in the literature,12 the wide range of physicians’ treatment preferences,13-15 diversity of clinical trial design,6 and diversity of patterns of practice.16 We previously demonstrated that the attitudes of surrogate patients considering a choice between CMT and RT vary considerably.2 We used a probability trade-off method17 to determine the magnitude of survival advantage that cancer patients, acting as surrogate NSCLC patients, deemed necessary to choose the more toxic CMT. We showed that this survival advantage could be determined reliably and that it varied widely among individuals.18 For example, if the probability of 3-year survival were 10% higher with CMT than with RT, then 60% of surrogate patients would prefer CMT, whereas 40% would prefer RT. In keeping with this variation among individuals, some clinical guidelines1,19 have highlighted that the treatment decision is sensitive to patients’ values regarding the treatment risks and benefits. In light of the variation in surrogate patients’ preferences revealed by the trade-off method, we explored the method as part of a decision aid in actual LA-NSCLC patients facing the treatment choice. Decision aids are intended to improve the decision-making process by informing patients systematically and by helping patients to clarify their values pertaining to the decision4 in keeping with the ethical principles underlying informed consent.20 Existing evidence suggests that the current practice of informed consent falls short of its goals21-23 and, thus, that improvement in the decision process is necessary. Our exploration of the decision aid interview in this setting may be seen as analogous to the phase I/II study of a new cancer therapy in which treatment toxicity and response rates are estimated before larger studies of efficacy. The elements of toxicity and response, however, in the evaluation of a decision-aid intervention, are not well defined.4 In addition, some outcome measures are relevant to both benefits and risks of the aid. Patients’ understanding of salient information, for example, may be an outcome measure of benefit, should the aid improve understanding, or of risk, should the aid confuse patients. We argue that for a decision aid to be considered effective, its benefits should outweigh its risks as determined by the following criteria of improved decision making: the aid should improve patient autonomy by improving objective understanding and by improving patients’ sense of voluntariness; it should provide a net psychologic benefit (eg, a reduction in decisional uncertainty24 or an increase in decisional satisfaction4); it should influence patients’ strength of treatment preference through improved understanding and clarification of values; and it should be acceptable to both patients and physicians. Although we would not expect that all criteria for an effective decision aid would be met for every patient, we would argue that they should be demonstrable across a series of patients using the aid. The goal of this study was to determine whether a decision aid designed for patients in this setting could be implemented in a regional cancer center and to examine preliminary findings regarding the criteria for an effective decision aid. The specific primary objectives of the study were as follows: (1) to determine if using the decision aid in the setting of a regional cancer clinic was feasible, that is, if patients wished to participate in their treatment decision and if the aid was acceptable to patients and physicians, and (2) to determine the internal consistency of different components of the decision aid. The secondary objective was to report preliminary data regarding the consistency of patients’ treatment preferences with their values; the degree to which patients acted with understanding and whether the decision aid improved their understanding of information; and whether patients’ treatment preferences or level of decisional conflict were influenced by using the decision aid. Favorable preliminary data would provide evidence for a larger multicenter phase II evaluation. To allow appropriate evaluation of our method, we report this in detail.
Study Participants Between January 1997 and September 1998 consecutive eligible patients at a regional cancer center were invited to participate. Eligible patients were those with unresectable LA-NSCLC (clinical stages IIIA/B) who were candidates for treatment with RT alone or with CMT using induction chemotherapy and RT, and who had not already commenced systemic therapy at the time of referral for RT. Patients with any of the following characteristics, in the opinion of the attending physician, were deemed ineligible: insufficient fluency in English; diagnosis of major affective disorder or at high risk for severe emotional distress; and a condition that placed major limitations on the patient’s ability to understand the content of the interview. Patients were evaluated for study eligibility by the attending oncologist after the initial medical consultation. Eligible patients then met individually with a research associate and were invited to participate. All participants provided written consent before commencing the interview.
Interview Method After describing the treatment options, we used two treatment trade-off exercises to help clarify participants’ values pertaining to survival outcomes in light of the treatment descriptions. One exercise was designed to determine the absolute increase in 3-year survival probability that the participant believed justified choosing CMT; the other was designed to determine the increase in median survival time that the participant believed justified choosing CMT. In the exercises, survival information was expressed as a frequency and was explained to participants as the number of people out of 100 who would be alive at a given point in time.25 This information was represented graphically using a sliding vertical bar that indicated the number of people alive (out of 100 people receiving treatment). The scale was placed at a particular point on a 1 meter-long time line, as displayed schematically in Fig 1.
The trade-off involving the probability of surviving 3 years was performed first. At the 3-year point on the time line, the survival for RT was shown to be five of 100 patients and that for CMT was shown to be 10 of 100 (Fig 1A). Each participant was asked which treatment he or she would prefer given the treatment descriptions and the displayed 3-year survival probabilities. To determine his/her trade-off threshold, the probability of surviving 3 years with CMT was then systematically increased (if the initial preference was for RT) or decreased (if the initial preference was for CMT) until the participant indicated a change in treatment preference. The survival percentage with CMT at the participant’s point of treatment preference switch is the threshold that represents the minimum survival advantage required by the participant to choose the more toxic CMT treatment.18 The trade-off involving the median survival time was then performed. The median survival was explained to the participant as the time when 50 of the initial 100 patients had died and 50 remained alive. It was further explained that differences in median survival time between treatments was an expression of the average increase in length of life afforded by the more toxic treatment, emphasizing that some people live longer than the average and some people live not as long as the average. The median survivals were initially displayed as 12 months with RT and as 14.5 months with CMT. Each participant was asked which treatment he or she would prefer given the treatment descriptions and the displayed median survival probabilities. The median survival time with CMT was then adjusted (as described for the 3-year survival trade-off) until the participant reached a threshold increase in median survival (Fig 1B). Participants were then told that the initial displays of 3-year survivals (5% v 10% for RT and CMT, respectively) and of median survival differences (12 months v 14.5 months, respectively) represented the actual estimated survival benefits of CMT, and these differences were again displayed (Fig 1). Participants were asked if they wished to revise either of their declared preference switch points, given their new knowledge of the actual benefit conferred by CMT. Finally, participants were asked which of the two survival end points (3-year survival or median survival time) was more important to them when making a treatment choice. For each trade-off, each participant’s survival advantage threshold (SAT) was calculated as illustrated in Fig 1. For the 3-year trade-off, the SAT is the percent survival conferred by CMT minus the 5% survival conferred by RT. For example, if a participant preferred CMT when the survival (with that treatment) was 7%, the SAT for that participant was (7% to 5%) = 2%. The SAT was less than 0% if the participant preferred the more toxic treatment with a survival percentage lower than that offered by RT. Likewise, for the median survival time trade-off, the SAT is the median survival time conferred by CMT minus that conferred by RT. The treatment descriptions were those used in a previous study of surrogate stage III NSCLC patients.18 Survival data were arrived at by a consensus view of the clinicians treating lung cancer in the center, based on the meta-analysis of clinical trials comparing cisplatin-based chemotherapy with RT alone7 and the results of individual trials.9,10
Integration of the Interview Into Usual Clinical Practice
Additional Study End Points As illustrated in Fig 2, the baseline assessment included an evaluation of the participant’s decisional-role preference, strength of treatment preference, decisional conflict, and understanding of the information. The participant chose the decision-role statement ( Table 1) that best described his/her preferred role in decision making, based on Degner and Sloan’s card sort method.26 The participant indicated his/her strength of treatment preference on a seven-point Likert scale, anchored with definitely wish RT and definitely wish CMT. We used O’Connor’s Decisional Conflict Scale24 to evaluate participants’ degree of decisional conflict. We evaluated each participant’s objective understanding of information using four open-ended questions with the following format: Out of 100 people treated with radiotherapy alone, how many would be alive after 3 years? Analogous questions targeted the same survival end point for CMT and the median survival end point for both treatments. In addition, we asked participants to indicate (using four questions parallel in structure to those above) what they believed about their own future using the following format: What do you think your personal chances are of being alive after 3 years with radiation alone?
Finally, physician and patient acceptance of the decision aid were addressed using two questionnaires analogous in design to the Decisional Conflict Scale, using a balance of positive and negative frames and requesting responses on a five-point Likert scale (anchored with strongly agree and strongly disagree). We asked participants to respond to three questions ( Table 2) and asked each patient’s attending physician to respond to three corresponding questions (Table 2).
Our experience implementing the study caused us to make two changes to our method. Initially, we intended to test postdecision aid measures at a second study interview (Fig 2) conducted after the decision was made but before treatment started; this strategy proved difficult to integrate into a busy oncology clinic, thus, some postinterview measures were not obtained on participants enrolled early onto the study period. In addition, events occurring between our initial and follow-up interviews caused us to be concerned about confounding effects on patients’ understanding of the information presented. Thus, we moved the evaluation of understanding to the end of the main study interview after the sixth study participant (Fig 2).
Evaluation of the Study Objectives and Statistical Considerations For each end point (1-year and median survival), we computed a cumulative distribution of participants’ final SATs and calculated the proportion of participants declaring SATs less than or equal to the estimate of actual treatment benefit. We calculated 95% confidence limits around the estimated proportion based on the binomial distribution.
We evaluated the internal consistency of the aid’s components by comparing each participant’s SAT for 3-year and median survival to his/her strength of treatment preference. We argued that participants with low 3-year SATs ought to also have low median survival SATs, and we tested this hypothesis by calculating a Spearman correlation coefficient ( We determined whether each participant’s expressed treatment preference was consistent with his/her values by comparing it with his/her SATs. For example, consistent outcomes would occur when a participant with a 3-year SAT lower than the actual survival benefit estimated for CMT had a preference for CMT, or, when a participant with a SAT higher than the estimated benefit of CMT had a preference for RT. We examined if participants acted with understanding and if the decision aid improved their understanding of information, by comparing participants’ answers to the open-ended questions about expected survival before and after using the decision aid. We refer to these responses as measures of participants’ objective understanding. We compared these responses with participants’ sense of being informed as determined by item no. 5 of the Decisional Conflict Scale: "I feel I know the benefits of each treatment for my lung cancer." We refer tothese responses as a measure of participants’ subjective understanding. Finally, we examined the influence of the decision aid on participants’ degree of decisional conflict and on their treatment preferences, by determining decisional conflict scores and strength of treatment preference scores before and after using the decision aid.
Feasibility Twenty-seven patients met the eligibility criteria for the study and were invited to participate by the attending physician. Seven patients (26%) declined participation in the study; four chose CMT and three chose RT. The remaining 20 patients (74%) agreed to participate; 18 chose CMT and two chose RT. Characteristics of participants are listed in Table 1. All patients had good performance status in keeping with their eligibility for CMT. All participants completed the interview, which required from 50 minutes to 2 hours. Typically, the interview required 1 hour. Participants completed all tasks, with the exception of one patient who could not declare a threshold for median survival time. All participants wanted to participate to some extent in the treatment decision, but they held a variety of decisional-role preferences, as listed in Table 1. Seven wished a predominantly active role, and no participant wished to leave all treatment decisions to the physician. Participants had favorable or neutral responses to the three questions addressing their evaluation of the decision aid, as listed in Table 2. For all but one participant, physicians had favorable or neutral responses to the threequestions addressing their evaluation of the decision aid (Table 2). For one patient with a strong preference for CMT, the physician disagreed with the statement indicating the aid helped the participant understand the risks and benefits of each treatment.
Patients’ Survival Advantage Thresholds and Internal Consistency
Nineteen of 20 participants were able to state thresholds for both time points and indicate a treatment preference (one could not declare a median survival SAT). As anticipated, the median and 3-year SATs were associated (
Patients’ Survival Advantage Thresholds and Their Treatment Preferences As Fig 4 illustrates, most participants had SATs that were consistent with their treatment preferences. With regard to 3-year SATs, 18 participants had SATs that were consistent with their preference. Of the two participants who indicated discordant 3-year SATs, one had a median SAT that was consistent with his preference. He indicated that both end points were important to his decision. For the other participant, both his SATs were discordant with his preference for CMT. With regard to the median SATs, 15 participants indicated median SATs that were consistent with their treatment preference. Of the four participants with discordant median SATs, three indicated 3-year SATs that were consistent with their preference and further indicated that this was the more important end point to their decision. The fourth participant was the patient with both SATs discordant with his treatment preference.
Patients’ Understanding of Survival Information
Assessment of patients’ subjective understanding of information after using the decision aid showed that this often differed from their objective knowledge. After completing the interview, nine patients (60%) estimated their personal chances of surviving 3 years with CMT as substantially higher than that of the population (20 of 100 to 100 of 100 patients). In addition, seven (47%) estimated their personal chances of survival with RT as lower than that of the population (0 of 100). Only two (13%) patients felt their personal chances of survival were the same as those of the population. All but three participants felt that they knew the benefits of treatment. All 11 participants with a definite preference for chemotherapy felt informed, and all but two had personal expectations for success with CMT higher than that described for the population.
Influence of the Decision Aid on Treatment Preferences and Decisional Conflict
The primary purpose of this report was to describe the implementation of a decision aid for patients with locally advanced NSCLC and to demonstrate its feasibility. With regard to the latter, we have shown that the aid can be successfully integrated into a busy multidisciplinary cancer center, that most patients can complete the tasks demanded by the strategy, and that the strategy is acceptable both to patients and to their physicians. Our results show that the aid is internally consistent and that it seems to clarify patients’ understanding of information relevant to their treatment decision. The majority of patients who were eligible to use the aid welcomed the opportunity to do so. All participants wanted to participate in the decision process to some extent, with the majority wanting an active or shared role. This finding is consistent with our previous work in surrogate cancer patients27 and with other studies in cancer patients.26-30 Although not every patient wishes to participate in deciding what cancer treatment they will receive, the substantial proportion of cancer patients who prefer to be involved are the potential beneficiaries of a decision-support strategy. Our presentations of the treatment information and values-clarifying exercises were understood by most participants. Our findings that participants’ survival advantage thresholds were highly correlated with their stated treatment preferences provides evidence of convergent validity of the study measures. Moreover, discordances between participants’ survival thresholds and their stated treatment preferences were explained, in most cases, by that survival end point being deemed by the participant to be less important to their decision. Our findings of variation in participants’ attitudes are, thus, unlikely to be because of their poor understanding of the interview tasks. The variation among patients’ survival advantage thresholds observed in this pilot study highlights the importance of patients participating in decisions that are sensitive to their values. The variation is consistent with similar studies in other oncologic contexts2,31-33 and suggests that guidelines addressing the use of CMT in this setting are correct in acknowledging the value-sensitive nature of the treatment choice.34 Thus, although inductive reasoning would suggest that the results of clinical trials should be generalized to cases classified as similar to those participating in the trials, our results suggest that this cohort of patients varies in their strengths of preference for CMT. The application of a decision aid serves to further classify such patients into those who prefer or do not prefer CMT. A larger study is clearly required to confirm this finding and to better estimate the variance in patients’ treatment preferences. Although patients understood the interview tasks and provided consistent responses, some patients could not recall information that we believed to be important. Quirt et al23 provided evidence that, in the context of usual clinical practice, lung cancer patients often do not seem to understand their situation well enough to make a truly autonomous decision. The present study demonstrates that with explicit disclosure and display of survival information, many patients can accurately recall survival statistics, but some other patients seem to remain uninformed. It is possible that some patients could not grasp the information or that they forgot the exact details after the interview was completed. It is also possible that some patients could not recall the survival information because their treatment preferences were based on considerations other than the potential survival benefit. We chose to focus on survival outcomes because few randomized clinical trials have reported symptom response rates35 or quality-of-life evaluations,36 and meta-analyses of clinical trials have focussed exclusively on survival outcomes. In contrast, Silvestri et al33 reported that over two thirds of surrogate lung cancer patients would prefer chemotherapy if it substantially reduced symptoms without prolonging life, and Davidson et al27 demonstrated patients’ need for information on quality of life and symptom response in the setting of LA-NSCLC. The influence of these clinical end points on actual patients’ decisions requires further study. Given that patients’ expressed thresholds for accepting CMT were consistent with their choices and that most patients could recall the direction and magnitude of survival differences between treatments, it would seem that some elements of autonomous decision making were met in patients using the aid. It is unclear, however, on what information patients were basing their decision. When asked about their own personal chances of survival, patients systematically substituted survival likelihoods that differed from those of the hypothetical population, tending to underestimate their potential survival with RT and/or overestimate their potential survival with CMT. There are a number of potential reasons for the observed disparity between patients’ perceptions of their own chances for success and the population-based probabilities. The disparity may be a reflection of the inherent philosophical difficulties in ascribing a population-based probability to a single event for the individual.37,38 Thus, a patient’s perception of his or her individual chances of cure is a subjective probability in the sense that it will be based on his or her knowledge and opinions,39 and the discrepancy between the frequency-based population statistic and the patient’s perception can not be viewed as incorrect.39 Alternatively, the discrepancy may be because of a lack of complete identification,38 wherein a patient does not identify himself or herself as a member of the described population and, thus, does not make direct inferences from the described population to his or her own situation. Patients’ positive attitudes could also be an expression of optimism or positive thinking as a means of embracing hope for the future.40 Finally, the fact that patients’ subjective probabilities regarding RT outcomes tended to be lower than those for the population, whereas their subjective probabilities regarding CMT tended to be higher, suggests they may have been attempting to differentiate the treatments and consolidate their decision by amplifying the difference in expected outcomes.41 These considerations are all relevant to finding the most effective ways of supporting patients’ decisions, and further exploration of these possible explanations in a larger series of patients would seem warranted. Returning to the analogy of this study to a phase I/II clinical trial, we have established that the systematic disclosure and values-clarification exercises did not seem to impose unwanted information on patients, given their endorsement of the decision aid and the consolidation of treatment preferences. We are presently expanding the study of the aid to other cancer centers to determine the extent to which these benefits are realized in a larger series of patients. A randomized comparison to standard care will be required to fully evaluate the efficacy of the aid. Some limitations in the interpretation of our findings are noteworthy. First, we do not know what proportion of all potentially eligible patients were screened by attending physicians, and the generalizability of our findings will require further study. Second, some early study patients did not have the opportunity to have postdecision measures evaluated, hence the before and after interview outcomes are based on a subset of the enrolled patients. Third, we used survival data based on a meta-analysis of cisplatin-based polychemotherapy, which some clinicians consider outdated. New CMT regimens promise higher response rates and lower toxicity, but there is no reason to believe that all patients would willingly accept such treatment, and decision support may still be appropriate. Third, our use of median survival as a representation of average benefit may be challenged. We chose not to display life-expectancy information because oncologic clinical trials typically report median survival differences between treatment regimens, and because physicians are more familiar with the median survival end point. Fourth, we did not examine the effect of altering the frame used in describing the treatment outcomes,42,43 deciding instead to frame the treatment descriptions in the conventional way clinicians would present the information to patients. Fifth, the aid is somewhat labor-intensive, requiring an average of 1 hour per patient. Wider implementation of the aid will require the development of self-administered or nurse-assisted tools using computer-based technologies. Further research is required to determine how to optimize the use of such technology based on how patients use the relevant information and benefit from clarification of their personal values in their decision making. Moreover, we interviewed patients alone, and it is, thus, unclear how interactions with family members would influence patients’ understanding of the information, their SATs, or their preferences declared in the interview. Finally, we did not examine the possibility that an explicit display of the uncertainty in treatment descriptions (for example, the variance of survival outcomes) would influence patient’s willingness to accept chemotherapy differently than would a display of the point estimates of survival, as was used in this study. We conclude that a decision-support strategy for patients with LA-NSCLC is feasible, that it demonstrates convergent validity, and that it is favorably evaluated by patients and their physicians. The aid seems to help patients understand the benefits and risks of treatment and to choose the treatment that is most consistent with their values. In doing so, it seems to improve the process of informed consent. In addition, it may reduce decisional conflict and increase patients’ satisfaction with their decision. Further evaluation of the aid is warranted.
Supported in part by a grant from the National Cancer Institute of Canada.
Preliminary results of this study were presented in part at the The Royal College of Physicians and Surgeons of Canada Annual Meeting (Canadian Association of Radiation Oncology), Toronto, Ontario, Canada, September 25, 1998, and at the Annual Meeting of the Society for Medical Decision Making, Cambridge, MA, October 27, 1998.
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Copyright © 2001 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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ABSTRACT
INTRODUCTION
= 0.83, P < .001 and 
