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Journal of Clinical Oncology, Vol 22, No 16 (August 15), 2004: pp. 3293-3301 © 2004 American Society of Clinical Oncology. DOI: 10.1200/JCO.2004.05.066 Randomized Trial of a Shared Decision-Making Intervention Consisting of Trade-Offs and Individualized Treatment Information for BRCA1/2 Mutation CarriersFrom the Department of Radiotherapy, Department of Human Genetics and Hereditary Cancer Clinic, University Medical Center Nijmegen; Medical Technology Assessment, University of Nijmegen, Nijmegen; Department of Medical Psychology, Department of Clinical Genetics, University Hospital Groningen, Groningen; and Department of Clinical Genetics, University Hospital Maastricht, Maastricht, the Netherlands Address reprint requests to Mariëlle van Roosmalen, MD, Department of Radiotherapy (341), University Medical Center Nijmegen, PO Box 9101, 6500 HB Nijmegen, the Netherlands; e-mail: m.vanroosmalen{at}rther.umcn.nl
PURPOSE: To evaluate a shared decision-making intervention (SDMI) for BRCA1/2 mutation carriers who have to make a choice between screening and prophylactic surgery for breasts and/or ovaries. PATIENTS AND METHODS: The SDMI consisted of two value assessment sessions, using the time trade-off method, followed by individualized treatment information based on (quality-adjusted) life expectancy. After the baseline assessment (2 weeks after a positive DNA test result), women were randomly assigned to the SDMI group (n = 44), receiving the SDMI 2 months after the test result, or to the control group (n = 44). The short- and long-term effects, 3 and 9 months after the test result, were assessed using questionnaires. Data were collected on well-being, treatment choice, and decision-related outcomes. RESULTS: In the short term, the SDMI had no effect. In the long term, with respect to well-being, patients in the SDMI group had less intrusive thoughts (P = .05) and better general health (P = .01) and tended to be less depressed (P = .07). With respect to decision-related outcomes for the breasts, the SDMI group held stronger preferences (P = .02) and agreed more strongly to having weighed the pros and cons (P = .01). No effect was found on treatment choice. In the long term, interaction effects between the SDMI and cancer history were found. The SDMI showed an overall beneficial effect for unaffected women, whereas affected women tended to experience detrimental effects. CONCLUSION: We conclude that the SDMI improved decision making in unaffected BRCA1/2 mutation carriers. Supporting decision making in a systematic way using trade-offs is beneficial for these women.
The identification of the BRCA1 and BRCA2 genes has created the possibility to test for inherited susceptibility of breast and ovarian cancer.1,2 BRCA1/2 mutation carriers, unaffected with cancer, have a high lifetime risk of developing breast (56% to 85%) and ovarian cancer (16% to 63%).3-5 BRCA1/2 mutation carriers already affected with breast cancer have a high risk of developing a second breast cancer (up to 63%).6 In the Netherlands, options available to BRCA1/2 mutation carriers are intensive screening or prophylactic surgery, including prophylactic mastectomy and prophylactic oophorectomy. Screening of breasts and ovaries is associated with the risk of cancer that may be detected too late for effective treatment. Although prophylactic surgery gives a significant reduction in cancer risk and can also be successful in reducing cancer worries,7 it may cause adverse psychologic and social outcomes in some women.8 Thus BRCA1/2 mutation carriers are confronted with a difficult dilemma in which a trade-off between duration and quality of life plays a crucial role. There is a movement toward greater patient involvement in treatment decisions, which is often referred to as shared decision making. Shared decision making recognizes that there are complex trade-offs in the treatment choice. Shared decision making also addresses the ethical need to fully inform patients about the risks and benefits of the treatment options, as well as the need to ensure that patients' values play a prominent role. For medical decisions with more than one reasonable option, patient participation in decision making is necessary to make treatment decisions, taking patient values into account. The actual tools to help with shared decision making are called decision aids (DAs). DAs can be used as an adjunct to standard counseling to prepare patients for decision making. According to the Cochrane definition, DAs are interventions designed to help people make a specific and deliberative choice among options by providing information about the options and outcomes, relevant to a person's health status.9 A variety of formats can be used. The most common formats are brochures, audio- and videotapes, decision boards, and interactive computer programs.9 Some DAs include tasks to clarify individual values to promote better congruence between the individual values and the treatment choice; however, this is an understudied area.10 A systematic review of randomized trials has shown that DAs improve patient knowledge, comfort, and participation in decision making.9 It is not clear which type of DA is most powerful, although more comprehensive programs seem to have larger effects.9 The goal of our study was to evaluate the use of DAs in women testing for a BRCA1/2 mutation. DAs may facilitate decision making for these women by helping them to arrive at an informed, preference-based treatment choice. We conducted a shared decision-making study that included two different interventions. In the first part of the study, we evaluated the effects of an informative DA and its timing before or after testing positive for a BRCA1/2 mutation.11 This DA consisted of a brochure and video providing information on screening and prophylactic surgery. In the second part of the study, reported here, we evaluated the effects of a shared decision-making intervention (SDMI) in BRCA1/2 mutation carriers on well-being, treatment choice, and decision-related outcomes. The SDMI consisted of two value assessment sessions, by use of the time trade-off (TTO) method12 followed by individualized treatment information based on life expectancy (LE) and quality-adjusted life expectancy (QALE) derived from decision analysis.13 Decision analysis offers a method to combine individual values regarding treatment outcomes with individual risk profiles. For the treatment choice for BRCA1/2 mutation carriers, individual values were shown to be important.13-17 Although such interventions have been described previously,18-23 they have mainly concentrated on the impact of patient preferences on treatment choice, whereas in our study we focus on a much broader range of outcomes.
Study Population The study was implemented in the Family Cancer Clinics of the University Hospitals of Nijmegen (beginning March 1999), Groningen (beginning June 1999), and Maastricht (beginning January 2000). Study entry closed in November 2001. Both women affected and unaffected with breast/ovarian cancer who had chosen to undergo DNA testing were eligible. Women were excluded if they were unable to give informed consent, had insufficient knowledge of the Dutch language, were diagnosed with distant metastases, had undergone both bilateral mastectomy and oophorectomy, or had been treated with chemotherapy, radiotherapy, or surgery for breast/ovarian cancer less than 1 month before blood sampling. Women were ongoing in the study only when a deleterious BRCA1/2 mutation was found.
SDMI
TTO Interview
Study Procedure
In the first part of the study (T1 to T3; Fig 1),11 not reported here, women were randomly assigned to the DA group (the DA was provided 2 weeks after blood sampling) or to the control group (receiving usual care). The DA was added to usual care and was to be viewed at home. It consisted of a brochure and video providing information on screening and prophylactic surgery, and the physical, emotional, and social consequences. At T2 (4 weeks after blood sampling), the DA group was compared with the control group. After testing positive, the control group too received the DA. At T3, 2 weeks after disclosure of a positive test result, we compared the impact of timing (before of after a positive test result) of the DA. The DA had positive effects on information-related outcomes only (subjective knowledge, satisfaction with information, and risk perception); timing of the DA had no effect.11 Women were ongoing in the study only if a deleterious BRCA1/2 mutation was found. In the second part of the study (T3 to T5; Fig 1), described here, T3 formed the baseline assessment for the evaluation of the SDMI. After T3, women were randomly assigned to the SDMI group or to the control group (receiving usual care). The SDMI was added to usual care and was scheduled 2 months after the test result. This time point was chosen so that information from the consultations with the specialists from the Family Cancer Clinic could be weighed into the trade-offs. These consultations usually take place within 1 to 2 months after disclosure of a positive test result. At T4 and T5, 3 and 9 months after the test result, a follow-up questionnaire was sent to evaluate the short- and long-term effects of the SDMI.
Outcome Measures
Well-Being
Treatment Choice
Decision-Related Outcomes Strength of treatment preference. Strength of treatment preference was asked for the treatment options prophylactic surgery and screening on a four-point Likert scale (1, weak preference; 4, very strong preference). Those who had chosen undecided as treatment choice were assigned a value of zero (no preference). Decision uncertainty. Decision uncertainty was measured with three items related to the uncertainty subscale of the Decisional Conflict Scale by O'Connor.30 Our items were "I doubt what to choose," "This decision is hard for me to make," and "I am not sure what to choose," measured on a five-point scale (1, strongly disagree; 5, strongly agree). A sum score was created by averaging the items. Perceived participation in decision making. Perceived participation in decision making was measured with two decision-making items from the Problem-Solving Decision-Making Scale from Deber et al.31 The items were as follows: "Given the risks and benefits of the possible treatment options, who has decided how acceptable those risks and benefits are for you?" and "Who has decided which treatment option should be selected?" These were measured on a five-point scale (1, doctor alone; 3, doctor and I equally; 5, I alone). A sum score was created by averaging the items. This item had no baseline assessment. Weighing treatment choice. Because trade-offs were prominent in the SDMI, we included a single item, "I weighed the pros and cons," from a decision evaluation scale (Stalmeier et al, manuscript submitted for publication). It was measured on a five-point scale (1, strongly disagree; 5, strongly agree). This item had no baseline assessment. Perceived preference of the specialists. Women were asked whether they felt that the specialists held a treatment preference (yes/no) and, if so, its strength (strong/weak). We combined the two answers in strong preference versus weak or no preference. These items were only asked at T4. Support and advice from specialists. Women were asked whether they had wanted more support and advice from their specialists regarding their treatment choice on a seven-point scale (1, strongly disagree; 7, strongly agree). These items were only asked at T4.
Sample Size and Power
Randomization and Blinding
Statistics
To evaluate the effects of the SDMI, we compared the SDMI and control group on the outcome measures. For continuous measures, comparisons were done using analyses of covariance,32 including, when present, the baseline assessment as a covariate. Effect sizes were calculated as the adjusted mean of the SDMI group minus the adjusted mean of the control group divided by the SD of the difference score. When no baseline assessment was present, effect sizes were calculated from the unadjusted mean scores. For the two categoric variables of treatment choice and perceived preference of the specialists, comparisons were made using Because randomization took place by family, and because family members were not independent on the outcome measures, statistical significance will be inflated when all women are treated as independent units. The sample contained nine families with multiple members (range, two to three members), with a total of 21 women. To counter inflation, we further examined significant effects by incorporating only the first included family member in the analyses. Because previous findings showed that women affected with breast or ovarian cancer experienced worse well-being than unaffected women,33 we included cancer history in the primary analyses to examine the interaction effect between the SDMI and cancer history. Furthermore, we conducted separate analyses for women affected and unaffected with cancer to report the various effect sizes.
Participants Figure 1 presents the study design for the whole study (T1 to T5). At study entrance, 453 women were eligible and 390 patients (86%) gave informed consent.11 Of the women followed up to the test result, 89 had a deleterious BRCA1/2 mutation (positive test result). Thus after the first part of the study (T1 to T3), 89 women were eligible for the second part of the study reported here (T3 to T5). One woman withdrew after T3 because of high emotional distress. Of the remaining 88 women, 44 women were randomly assigned to the SDMI group and 44 women to the control group. In the SDMI group, two women did not receive the SDMI, one unaffected woman because her mother just had died of breast cancer, and one affected woman because she had already undergone both bilateral mastectomy and oophorectomy. The follow-up at T4 was 100%. At T5, one woman from the control group was lost to follow-up.
Baseline Characteristics
Well-Being In the short term (Table 2, T4), the SDMI had no effect on any of the well-being outcomes. In the long-term (Table 2, T5), the SDMI group had less intrusive thoughts about cancer in the family (F1,83 = 3.91; P = .05; effect size [d] = 0.30), a better general health (F1,79 = 6.53; P = .01; d = 0.40), and tended to be less depressed (F1,84 = 3.40; P = .07; d = 0.28). No effect was found on anxiety.
Treatment Choice Intended treatment choice was only asked when applicable. At baseline (T3), short (T4), and long term (T5), no differences were found between the SDMI and control group, neither on the intended treatment choice nor on the actually performed treatment for breasts and ovaries (data not shown). No differences were found for the ratings of the treatment options (data not shown). Overall, 33% (28 of 85 patients) intended to undergo prophylactic mastectomy at T3, of whom 50% (n = 14) had undergone this treatment at T5; none of the other women had undergone prophylactic mastectomy at T5. Overall, 68% (56 of 82 patients) intended to undergo prophylactic oophorectomy at T3, of whom 54% (n = 30) had undergone this treatment at T5; four of the other women had undergone prophylactic oophorectomy at T5.
Decision-Related Outcomes
With respect to the behavior of the specialists, more women in the SDMI group (29%) felt that the specialists held a strong preference for one or the other breast treatments compared with the control group (3%; 2 = 10.47; P = .001). This difference was not found for the ovaries; 33% in the SDMI group, and 35% in the control group experienced a strong preference ( 2 = 0.03; P = .87). Although not significant, women in the SDMI group wanted more support and advice from the specialists regarding their treatment choice for the breasts (F1,78 = 2.94; P = .09; d = 0.27); this finding was less strong for the ovaries (F1,74 = 2.22; P = .14; d = 0.24).
Additional Analyses: Controlling for Family
Interaction Effects Between SDMI and Cancer History The size of the differential impact in affected versus unaffected women is presented in Table 4. From the separate analyses for affected and unaffected women, only effect sizes are reported for well-being and decision-related outcomes for the breasts. In the short term (Table 4, T4), the SDMI had no effect on affected nor on unaffected women. In the long term (Table 4, T5), for unaffected women, beneficial effects were found on all outcome measures and most were significant. The effect sizes were larger for unaffected women compared with the whole group (Table 2, Table 3, T5). For affected women, insignificant detrimental effects were found on the above-mentioned outcomes for which an interaction effect was found.
We evaluated an SDMI for BRCA1/2 mutation carriers who were facing the choice between screening and prophylactic surgery for the breasts and/or ovaries. The SDMI consisted of trade-offs and individualized treatment information. To our knowledge, this is the first randomized study to evaluate such an intervention on a broad range of outcomes as a decision support tool. Previous studies, combining value assessment and decision analysis, have mainly concentrated on the impact of patient preferences on treatment choice.18-23 In the short term, 3 months after the test result, the SDMI had no effect. In the long term, 9 months after the test result, the SDMI group reported less intrusive thoughts about cancer in the family, better general health, and a trend toward less depressive thoughts. Moreover, they reported a stronger treatment preference and more strongly agreed to having weighed the pros and cons for the breast treatment. It is noteworthy that two previous studies on DAs also found stronger effects in the long term.34,35 Several types of DAs exist. The issue of what type of DA is most effective is still unresolved.9 Our randomized study shed some light on this issue. The informative DA had shown beneficial effects on information-related outcomes only,11 whereas the SDMI showed beneficial effects on a broader range of outcomes. In a previous uncontrolled before-after study of our group, we evaluated the informative DA and the SDMI as one package.36 Then we found beneficial effects on information-related outcomes as well as on more general outcomes, suggesting that the beneficial effects of the two interventions add up. Our current study design, with all participants receiving the initial informative DA before the randomization of the SDMI, precluded an evaluation of the interacting effects between the informative DA and the SDMI. This might be a subject for future research. Nevertheless, from the present study, it is unclear which specific element of the SDMI is effective. One possible explanation is the additional attention paid by the research assistant. However, the time spent with the research assistant was relatively short when compared with the time spent with the specialists from the Family Cancer Clinic. Perhaps the provision of individualized treatment information is effective. However, as our informative DA had only beneficial effects on information-related outcomes and none whatsoever on well-being and decision-related outcomes,11 this seems unlikely. Another explanation, which needs to be followed up in future work, is that during decision support, negative emotions are expressed more strongly.37 This is known to enhance well-being over the long term.38 On the basis of our own data, we hypothesize that the trade-offs are the effective component of the SDMI. These trade-offs explicitly required women to consider their values in the light of quality and length of life. The effect of the trade-offs is evident as women in the SDMI group more strongly agreed to having weighed the pros and cons, suggesting a more deliberated treatment choice. This might lead to stronger treatment preferences in women from the SDMI group, as indeed we found. Furthermore, as these women explored their own preferences, they might more easily discern their own preferences from the preferences of the specialists, as indeed we found. Our hypothesis is further supported by psychologic work showing that contrasting the future with reflections on present reality (the trade-offs have that effect) strengthens goal commitments, which may lead to improved well-being.39 If indeed the beneficial effects could be attributed to the trade-offs, decision making might be improved by actively exploring individual values for the treatment options in a systematic way using trade-offs. Next to establishing the essential elements of a DA, there is also a need to identify the people who are most likely to benefit.9 In the long term, we found various interaction effects between the SDMI and cancer history. Subgroup analyses revealed that the SDMI had an overall beneficial effect for unaffected women and detrimental effects for affected women, although the SDMI was evaluated equally by affected and unaffected women (data not shown). Several explanations may apply. First, affected women may have received individualized treatment information that was discordant with their treatment intention more often. However, the opposite was found: treatment intentions and the best option based on QALE agreed in 70% of the affected women and in 44% of the unaffected women. Second, affected women (45 years) were older then unaffected women (37 years), and it may be that the SDMI is less effective in older women. However, in the unaffected sample, the beneficial effects of the SDMI were independent of age. Furthermore, affected and unaffected women did not differ at baseline (T3) on other potential explanatory variables such as risk perception and preference for decision making (data not shown). So it remains unclear why the SDMI is not effective in affected women. Previously, we found that affected women tended to react more strongly toward a positive DNA test result.33 Perhaps the additional confrontation with trade-offs is simply too taxing for affected women, in view of the burden of being at risk for a second cancer. Further studies are needed with larger sample sizes to confirm these effects. In general, DAs are meant to supplement, not replace, the traditional process of patient counseling by clinicians. Can the present SDMI be implemented into a Family Cancer Clinic? The present study shows it is feasible to implement such an intervention in the clinic within a research context. Our study reveals that the SDMI is acceptable to women; further study is needed about the acceptability to counselors. However, the TTO interview is labor-intensive, requiring on average of 1 hour per patient when performed face-to-face and 30 minutes when repeated by telephone. The time needed to perform the decision analysis, including sensitivity analyses, depends on the cancer history. For affected women, the prognosis needs to be determined and included in the decision analysis, which may take some hours. For unaffected women, the decision analysis takes half an hour. Furthermore, performing TTO interviews, conducting individual decision analyses, and sharing treatment information requires well-trained personnel. Of course, the SDMI is not complete without using the informative DA.11 This information material and the decision model need to be kept up-to-date. Time pressure and costs of implementing decision aids are frequently cited as barriers for using decision aids.40 Despite these barriers, we believe that a simplified version of the SDMI, perhaps involving only the trade-offs, can be integrated into a consultation with a social worker or genetic counselor. This may not require much extra time per patient, as the trade-offs could be used as a basis for further deliberations. It is acknowledged that some of the significant differences observed in this study could be due to chance, given the number of statistical tests. However, for unaffected women, all measures consistently pointed in a beneficial direction. Furthermore, the sample size is relatively small. Other limitations are that we know nothing about its cost effectiveness and how the counselors view the SDMI. We conclude that the SDMI improved decision making in unaffected BRCA1/2 mutation carriers. Our advice is to support decision making in these women in a systematic way using trade-offs. The SDMI is not recommended for affected women. Future research should concentrate on how and for whom this intervention could be implemented profitably in the clinical practice of Family Cancer Clinics.
The appendix is included in the full-text version of this article, available online at www.jco.org. It is not included in the PDF (via Adober Acrobat Readerr) version.
The authors indicated no potential conflicts of interest.
We thank the women who participated in this study. We thank the research assistants Monique Oude Elberink and Ineke Bakker for their excellent work. We also thank the participating Family Cancer Clinics for their support.
Supported by a grant from the Dutch Cancer Society (grant No. 98-1585), Amsterdam, the Netherlands. Preliminary results of this study were presented at the 24th Annual Meeting of the Society for Medical Decision Making, Baltimore, MD, October 19-23, 2002. Authors' disclosures of potential conflicts of interest are found at the end of this article.
1. Miki Y, Swensen J, Shattuck Eidens D, et al: A strong candidate for the breast and ovarian cancer susceptibility gene BRCA1. Science 266:6671, 1994 2. Wooster R, Bignell G, Lancaster J, et al: Identification of the breast cancer susceptibility gene BRCA2. Nature 378:7891992, 1995[CrossRef][Medline] 3. Easton DF, Ford D, Bishop DT, et al: Breast and ovarian cancer incidence in BRCA1-mutation carriers. Am J Hum Genet 56:265271, 1995[Medline]
4. Struewing JP, Hartge P, Wacholder S, et al: The risk of cancer associated with specific mutations of BRCA1 and BRCA2 among Ashkenazi Jews. N Engl J Med 336:14011408, 1997 5. Ford D, Easton DF, Stratton M, et al: Genetic heterogeneity and penetrance analysis of the BRCA1 and BRCA2 genes in breast cancer families. Am J Hum Genet 62:676698, 1998[CrossRef][Medline] 6. Ford D, Easton DF, Bishop DT, et al: Risks of cancer in BRCA1-mutation carriers. Lancet 343:692695, 1994[CrossRef][Medline] 7. Tiller K, Meider B, Butow P, et al: Psychological impact of prophylactic oophorectomy in women at increased risk of developing ovarian cancer: A prospective study. Gynecol Oncol 86:212219, 2002[CrossRef][Medline]
8. Frost MH, Schaid DJ, Sellers TA, et al: Long-term satisfaction and psychological and social function following bilateral prophylactic mastectomy. JAMA 284:319324, 2000 9. O'Connor AM, Stacey D, Rovner D, et al: Decision aids for people facing health treatment or screening decisions (Cochrane Review). Cochrane Library, Issue 1. Oxford, United Kingdom, Update Software, 2003 10. O'Connor AM, Fiset V, DeGrasse C, et al: Decision aids for patients considering options affecting cancer outcomes: Evidence of efficacy and policy implications. Monogr Natl Cancer Inst 25:6780, 1999 11. Van Roosmalen MS, Stalmeier PFM, Verhoef LCG, et al: Randomised trial of a decision aid and its timing for women being tested for a BRCA1/2 mutation. Br J Cancer 90:333342, 2004[CrossRef][Medline] 12. Torrance GW, Thomas WH, Sackett DL: A utility maximization model for evaluation of health care programs. Health Serv Res 7:118133, 1972[Medline]
13. Van Roosmalen MS, Verhoef LCG, Stalmeier PFM, et al: Decision analysis of prophylactic surgery or screening for BRCA1 mutation carriers: A more prominent role for oophorectomy. J Clin Oncol 20:20922100, 2002
14. Tengs TO, Winer EP, Paddock S, et al: Testing for the BRCA1 and BRCA2 breast-ovarian cancer susceptibility genes: A decision analysis. Med Decis Making 18:365375, 1998 15. Grann VR, Panageas KS, Whang W, et al: Decision analysis of prophylactic mastectomy and oophorectomy in BRCA-1 positive or BRCA-2 positive patients. J Clin Oncol 16:979985, 1998[Abstract] 16. Grann VR, Jacobson JS, Whang W, et al: Prevention with tamoxifen or other hormones versus prophylactic surgery in BRCA1/2-positive women: A decision analysis. Cancer J Sci Am 6:1320, 2000[Medline]
17. Grann VR, Jacobson JS, Thomason D, et al: Effect of prevention strategies on survival and quality-adjusted survival of women with BRCA1/2 mutations: An updated decision analysis. J Clin Oncol 20:25202529, 2002 18. Pauker SP, Pauker SG: The amniocentesis decision: Ten years of decision analytic experience. Birth Defects 23:151169, 1987 19. Clancy MC, Cebul RD, Williams SV: Guiding individual decisions: A randomized, controlled trial of decision analysis. Am J Med 84:283288, 1988[CrossRef][Medline]
20. Heckerling PS, Verp MS, Albert N: Patient or physician preferences for decision analysis: The prenatal genetic testing decision. Med Decis Making 19:6677, 1999
21. Robinson A, Thomson RG: The potential use of decision analysis to support shared decision making in the case of uncertainty: The example of atrial fibrillation and warfarin anticoagulation. Qual Health Care 9:238245, 2000
22. Potheroe J, Fahey T, Montgomery AA, et al: The impact of patients' preferences on the treatment of atrial fibrillation: Observational study of patient based decision analysis. BMJ 320:13801384, 2000
23. Montgomery AA, Harding J, Fahey T: Shared decision making in hypertension: The impact of patient preferences on treatment choice. Fam Pract 18:309313, 2001
24. Unic I, Stalmeier PFM, Verhoef LCG, et al: Assessment of the time tradeoff values for prophylactic mastectomy of women with a suspected genetic predisposition to breast cancer. Med Decis Making 18:268277, 1998
25. Unic I, Verhoef LCG, Stalmeier PFM, et al: Prophylactic mastectomy or screening in women suspected to have the BRCA1/2 mutation: A prospective pilot study of women's treatment choices and medical and decision-analytic recommendations. Med Decis Making 20:251262, 2000
26. Bosch JL, Hunink MGM: The relationship between descriptive and valuational quality-of-life measures in patients with intermittent claudication. Med Decis Making 16:217225, 1996 27. Spielberger CD, Gorsuch RL, Lushene R, et al: Manual for the State-Trait Anxiety Inventory (Form Y). New York, NY, Consulting Psychologists Press, 1983 28. Radloff LS: The CES-D scale: A self-report depression scale for research in general population. Applied Psychological Measurement 1:385401, 1977
29. Horowitz M, Wilner N, Alvarez W: Impact of Event Scale: A measure of subjective stress. Psychosom Med 41:209218, 1979
30. O'Connor AM: Validation of decision conflict scale. Med Decis Making 15:2530, 1995
31. Deber RB, Kraetchmer N, Irvine J: What role do patients wish to play in treatment decision making? Arch Intern Med 156:14141420, 1996 32. Maxwell SE, Delaney HD: Designing Experiments and Analyzing Data: A Model Comparison Perspective. Pacific Groove, CA, Brooks/Cole Publishing, 1990, pp 353-420 33. Van Roosmalen MS, Stalmeier PFM, Verhoef LCG, et al: Impact of BRCA1/2 testing and disclosure of a positive test result on women affected and unaffected with breast or ovarian cancer. Am J Med Genet 124A:346-355, 2004 34. Barry MJ, Cherkin DC, Chang Y, et al: A randomized trail of a multimedia shared decision-making program for men facing a treatment decision for benign prosthetic hyperplasia. Dis Manage Clin Outcome 1:514, 1997
35. Molenaar S, Sprangers MAG, Rutgers EJTh, et al: Decision support for patients with early stage breast cancer: Effects of an interactive breast cancer CDROM on treatment decision, satisfaction, and quality of life. J Clin Oncol 19:1676-1687, 2001
36. Stalmeier PFM, Unic I, Verhoef LCG, et al: Evaluation of a shared decision making program for women suspected to have a genetic predisposition for breast cancer: Preliminary results. Med Decis Making 19:230241, 1999 37. Bekker HL, Hewison J, Thornton JG: Understanding why decision aids work: Linking process with outcome. Patient Educ Couns 50:323329, 2003[CrossRef][Medline] 38. Pennebaker JW: Writing about emotional experiences as a therapeutic process. Psychol Sci 8:162166, 1997[CrossRef] 39. Oettingen G, Pak H: Self-regulation of goal setting: Turning fantasies about the future into binding goals. J Pers Soc Psychol 80:736753, 2001[CrossRef][Medline] 40. Graham ID, Logan J, O'Connor A: A qualitative study of physicians' perceptions of three decision aids. Patient Educ Couns 50:279283, 2003[CrossRef][Medline] Submitted May 12, 2003; accepted May 17, 2004.
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Copyright © 2004 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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