Sylvia J. T. Jansen

Response shift in quality of life measurement in early-stage breast cancer patients undergoing radiotherapy

In medicine, response shift refers to a change — as a result of an event such as a therapy — in the meaning of ones self-evaluation of quality of life. Due to response shift, estimates of side effects of radiotherapy may be attenuated if patients adapt to treatment toxicities. The purpose of our study was to assess to what extent two components of response shift, scale recalibration and changes in values, occur in early-stage breast cancer patients undergoing radiotherapy and to examine what the implications would be for treatment evaluation. In the week before start of post-operative radiotherapy, 46 patients filled out a questionnaire consisting of quality of life items of the SF-36 and the Rotterdam symptom checklist (RSCL) (pretest). During radiotherapy, patients were asked to fill out the questionnaire twice: a posttest (quality of life at that moment) and a thentest (quality of life before treatment, retrospectively), supposedly using the same internal standard. Changes in values were studied by asking the patients on the two occasions to rate the importance of seven attributes representing various domains of quality of life. Patients were also asked whether their quality of life with respect to the measured aspects had changed since the pretest (subjective transition scores). Significant scale recalibration effects were observed in the areas of fatigue and overall quality of life. When the groups were divided according to their subjective transition scores, significant scale recalibration effects were found in case of worsened quality of life for fatigue and overall quality of life, and in case of improved quality of life for fatigue and psychological well-being. The mean importance ratings remained fairly stable over time, except for ‘skin reactions’, which obtained less importance at the end of radiotherapy than before. In conclusion, effects of scale recalibration were observed that would have significantly affected quality of life evaluations, in that the impact of radiotherapy on fatigue and overall quality of life would have been underestimated. Changes in internal values were observed only for ‘skin reactions’.

Unstable preferences : A shift in valuation or an effect of the elicitation procedure?

Objective. Many studies suggest that impaired health states are valued more positively when experienced than when hypothetical. This study investigated to what extent this discrepancy occurs and examined four possible explanations: non-corresponding description of the hypothetical health state, new understanding due to experience with the health state, valuation shift due to a new status quo, and instability of preference. Patients and methods. Fifty-five breast cancer patients evaluated their actually experienced health state, a radiotherapy scenario, and a chemotherapy control scenario before, during, and after postoperative radiotherapy. Utilities were elicited by means of a visual analog scale (VAS), a chained time tradeoff (TTO), and a chained standard gamble (SG). Results. The discrepancy was found for all methods and was statistically significant for the TTO (predicted utilities: 0.89, actual utilities: 0.92, p ≤ 0.05). During radiotherapy, significant differences (p ≤ 0.01) were found between the utilities for the radiotherapy scenario and the actual health state by means of the VAS and the SG, suggesting non-corresponding description as an explanation. The utilities of the radiotherapy scenario and the chemotherapy control scenario remained stable over time, and thus new understanding, valuation shift, and instability could be ruled out as explanations. Conclusion. Utilities obtained through hypothetical scenarios may not be valid predictors of the value judgments of actually experienced health states. The discrepancy in this study seems to have been due to differences between the situations in question (non-corresponding descriptions). Key words: stability; utility assessment; standard gamble; time tradeoff; breast cancer; chemotherapy; radiotherapy. (Med Decis Making 2000;20:62-71)

Patients' utilities for cancer treatments: a study of the chained procedure for the standard gamble and time tradeoff.

Objective. Temporary health states cannot be measured in the traditional way by means of techniques such as the time tradeoff (TTO) and the standard gamble (SG), where health states are chronic and are followed by death. Chained methods have been developed to solve this problem. This study assesses the feasibility of a chained TTO and a chained SG, and the consistency and concordance between the two meth ods. Patients and methods. Seventy female early-stage breast cancer patients were interviewed. In using both chained methods, the temporary health state to be evaluated was weighed indirectly with the aid of a temporary anchor health state. The patients were asked to evaluate their actual health states, a hypothetical radiotherapy scenario, and a hypothetical chemotherapy scenario. Results. Sixty-eight patients completed the interview. The use of the anchor health state yielded some problems. A significant difference between the means of the TTO and the SG was found for the anchor health state only. For the other health states, the results were remarkably close, because the design avoided some of the bias effects in traditional measurements. Conclusion. The feasibility and the consistency of the chained procedure were satisfactory for both methods. The problems regarding the anchor health state can be solved by adapting the methods and by the use of a carefully chosen anchor health state. The chained method avoids biases present in the conventional method, and thereby the TTO and the SG may be reconciled. Moreover, there are several psychological advantages to the method, which makes it useful for diseases with uncertain prognoses. Key words: utility assessment; time tradeoff; standard gamble; breast cancer; chemotherapy; ra diotherapy. (Med Decis Making 1998;18:391-399)

Patients’ preferences for adjuvant chemotherapy in early-stage breast cancer: is treatment worthwhile?

When making decisions about adjuvant chemotherapy for early-stage breast cancer, costs and benefits of treatment should be carefully weighed. In this process, patients’ preferences are of major importance. The objectives of the present study were: (1) to determine the minimum benefits that patients need to find chemotherapy acceptable, and (2) to explore potential preference determinants, namely: positive experience of the treatment, reconciliation with the treatment decision, and demographic variables. Preferences were elicited from patients scheduled for adjuvant chemotherapy (chemotherapy group: n = 38) before (T1), during (T2), and 1 month after chemotherapy (T3), and were compared to responses from patients not scheduled for chemotherapy (no-chemotherapy group: n = 38). The patients were asked, for a hypothetical situation, to indicate the minimum benefit (in terms of improved 5-year disease-free survival) to find adjuvant chemotherapy acceptable. In the chemotherapy group, the median benefit was 1% at all 3 measurement points. In the no-chemotherapy group the attitude towards chemotherapy became more negative over time, although not statistically significantly so (T1: 12%, T2: 15%, T3: 15%;P = 0.10). At all measurement points, the patients in the chemotherapy group indicated that they would accept chemotherapy for significantly (P< 0.01) less benefit than the patients in the no-chemotherapy group. Of the demographic variables, age was related to preferences, but only at T2and only in the no-chemotherapy group. The more positive attitude towards chemotherapy and the stability of preferences in the chemotherapy group indicated that reconciliation with the treatment decision was a more important determinant of patients’ preferences than positive experience of the treatment.

Stability of Patients’ Preferences for Chemotherapy The Impact of Experience

Background. Studies have shown that utilities for a particular treatment, elicited by means of a hypothetical treatment scenario, may remain stable within the same patients when examined before, during, and after experiencing that treatment (within-group stability). However, other studies have found that utilities for a particular health state may differ between patient groups who are and who are not experiencing the particular health state (between-group differences). Objective. The authors evaluated this apparent contradiction in the case of adjuvant chemotherapy for breast cancer. A related purpose was to examine whether a chemotherapy scenario adequately reflects the patients’ own experiences with chemotherapy. Method. Forty-three patients with early-stage breast cancer evaluated their actually experienced health state and a chemotherapy scenario before, during, and after undergoing adjuvant chemotherapy (chemotherapy group). A control group of 51 patients for whom chemotherapy was not part of the treatment plan was interviewed at similar points in time. Utilities were elicited by means of a visual analog scale (VAS), a chained time trade-off (TTO), and a chained standard gamble (SG). Results. The utilities for the chemotherapy scenario remained relatively stable over time in the 2 patient groups. Furthermore, the chemotherapy scenario was evaluated more positively by patients in the chemotherapy group than by control patients (e.g., utilities before chemotherapy: VAS 0.69 vs. 0.50, TTO 0.88 vs.0.50, SG 0.92 vs. 0.58, all Ps < 0.01). Finally, patients in the chemotherapy group evaluated their actually experienced health states during chemotherapy higher than the chemotherapy scenario that was assessed at the same time (VAS 0.79 vs. 0.69, TTO 0.93 vs. 0.87, SG 0.97 vs. 0.96, all Ps < 0.05). Conclusions. Both within-group stability and between-group differences were found. A possible explanation for within-group stability may be that the chemotherapy scenario did not fully correspond to the patients’ actual experiences with chemotherapy (“noncorresponding description”). Therefore, preferences did not change even when the patients’ own clinical health status had changed. The between-group differences may be explained by “anticipated adaptation.” Both explanations may work together to explain why utilities remain stable within the same patients but differ between different patient groups.

Review of Determinants of Patients' Preferences for Adjuvant Therapy in Cancer

PURPOSEnMany studies have determined cancer patients preferences for adjuvant therapy, for example, by asking patients the extent of benefit they would need in order to accept the therapy. However, little is known about the determinants that influence these preferences. Our research goal was to explore which determinants underlie patients preferences by means of a literature review.nnnMETHODSnPubMed searches were conducted to identify studies in which cancer patients preferences for adjuvant therapy had been elicited by means of a treatment preference instrument. Twenty-three papers were evaluated with regard to reported relationships between preferences and potential determinants. A total of 40 determinants were recorded and classified into one of seven categories: (1) treatment-related determinants, (2) sociodemographic characteristics and current quality of life, (3) clinical characteristics, (4) measurement instrument-related determinants, (5) time-related determinants, (6) cognitive/affective determinants, and (7) specialist-related determinants.nnnRESULTSnThe benefit and toxicity of treatment, experience of the treatment, and having dependents (eg, children) living at home were important determinants of patients preferences. Furthermore, qualitative data suggested that cognitive/affective and specialist-related determinants might have a large impact on patients treatment preferences.nnnCONCLUSIONnOur results show that patients preferences cannot fully be explained on the basis of treatment-related determinants and patient and clinical characteristics. More research is needed in the area of cognitive/affective and specialist-related determinants because of the lack of quantitative results. Furthermore, we recommend carrying out larger studies in which the (internal) relationships between determinants and preferences are assessed in the context of a cognitive cost-benefit model.

Value of the time trade off method for measuring utilities in patients with rheumatoid arthritis

OBJECTIVE To assess the feasibility, reliability, and validity of the time trade off (TTO) in patients with rheumatoid arthritis (RA). METHODS The TTO was applied in 194 patients with RA with increasing difficulty in performing activities of daily living. The test-retest reliability was determined in 35 of these patients and was calculated by the intraclass correlation coefficient (ICC). Construct validity was evaluated with the following sets of variables: measures of utility (rating scale), quality of life (RAND 36 item Health Status Survey (RAND-36) and RAQoL), functional status (Health Assessment Questionnaire, grip strength, and walk test), and disease activity (doctors global assessment, disease activity score, pain, and morning stiffness). RESULTS Ten patients (5%) did not complete the TTO. The median value of the TTO was 0.77 (range 0.03–1.0). The test-retest ICC of the TTO was 0.85 (p<0.001). Construct validity testing of the TTO showed poor to moderate correlations (Spearmans r sbetween 0.19 and 0.36, p<0.01) with all outcome measures except for the subscale role limitation (physical problem) of the RAND-36, the walk test, the doctors global assessment of disease activity, and morning stiffness. Multiple regression analysis showed that only 17% of the variance of the TTO scores could be explained. CONCLUSIONS The TTO method appeared to be feasible and reliable in patients with RA. The poor to moderate correlations of the TTO with measures of quality of life, functional ability, and disease activity suggest that the TTO considers additional attributes of health status. This may have implications for the application of the TTO in clinical trials in patients with RA.

The impact of the perception of treatment choice on satisfaction with treatment, experienced chemotherapy burden and current quality of life

Previous research has shown that involving patients in the decision-making process may improve their quality of life (QoL). Our purposes were to assess: (1) whether early-stage breast cancer patients perceived that they had treatment choice with regard to adjuvant chemotherapy, (2) what reasons patients provide for their perception of having had no choice of treatment and (3) whether the perception of treatment choice is related to satisfaction with the assigned treatment, experienced chemotherapy burden and current QoL. A total of 448 patients, treated between 1998 and 2003, filled in the questionnaire (response rate: 62%). Patients who indicated that they had not perceived a choice regarding chemotherapy could tick off one or more reasons out of 10 reasons, or provide their own reason(s). Quality of life was measured on a Visual Analogue Scale, by means of the EuroQol, and by means of the Hospital Anxiety and Depression Scale. Of the 405 patients who had answered the question on treatment choice, 316 patients (78%) had perceived no choice. The most frequently indicated reason for lack of choice was: ‘I follow the doctors advice.’ We found no differences in the levels of satisfaction with assigned treatment and in how much of a burden they found chemotherapy between patients who perceived a choice of treatment and those who did not. In general, the perception of choice seemed to have no impact on QoL. However, we found an interaction effect, which indicated that the impact of perception of treatment choice on QoL was dependent upon whether the patient had been treated with chemotherapy or not. Within the group of patients who had not been treated with chemotherapy, the perception of having had a choice was related to lower current QoL. In cases when the decision to be treated or not has potential consequences for the chance of survival, patients QoL may not be improved by the perception of having had a choice of treatment.

How important is the opinion of significant others to cancer patients’ adjuvant chemotherapy decision-making?

GoalsDecisions regarding adjuvant chemotherapy are difficult, since value tradeoffs are involved. Little is known about the importance of the significant others in patients’ decision-making regarding adjuvant treatment. We surveyed patients with breast and colorectal cancer about the importance they assigned to the opinions of their significant others and assessed correlates of these importance scores.Materials and methodsOne hundred and twenty-three patients rated on a five-point scale how much they cared about the opinion of six significant others.Main resultsMost important was the opinion of their treating specialist, followed by that of their partner, children, other family, friends, and colleagues. Women assigned higher scores to the opinion of their children, younger patients to that of their specialist, and patients who were about to undergo chemotherapy to that of their family. Patients with breast cancer and patients without paid employment assigned slightly more importance to the opinion of their partner.ConclusionsInformation on the influence of significant others may help clinicians when involving patients in treatment decision-making and discussing patients’ treatment preferences.

Factors affecting patients’ perceptions of choice regarding adjuvant chemotherapy for breast cancer

SummaryIntroductionPatients’ perceptions of having had freedom of choice in treatment decision-making are shown to have implications for their quality of life. It is, therefore, important to determine what factors underlie these perceptions. One factor that has been studied is whether or not patients believed that their doctor had offered choice of treatment. However, even when choice is actually offered, patients may still feel that they have no choice. Little attention has been paid to other factors that may contribute to patients’ perceptions of having had no choice. Our purpose was to explore (1) whether early-stage breast cancer patients perceived to have had a choice with regard to adjuvant chemotherapy, and (2) their reasons for having perceived no choice.Patients and methodsThe determinants of no choice that we examined were: (1) (preferred) involvement in treatment decision-making, (2) perceived clinical benefits of chemotherapy (e.g., cure), (3) perceived psychological benefits (e.g., less worries), and (4) perception of being able to cope with the side effects. All predictors, as well as patient and clinical characteristics, were entered simultaneously in a multiple logistic regression analysis and non-significant predictors were removed step-by-step, until only significant predictors (p<0.05) remained. Because determinants may differ between patients with experience of chemotherapy and those without, both treatment groups were analyzed separately.ResultsFour hundred and forty-six patients filled out the questionnaire (62%). Sixty-six percent of patients who had been treated with chemotherapy and 86% of inexperienced patients had perceived no treatment choice. In both treatment groups, patients who preferred a shared role or a passive role in treatment decision-making were statistically significantly more likely to have perceived no treatment choice than patients who preferred an active role. Surprisingly, beliefs about the clinical and psychological benefits of chemotherapy did not influence patients’ perceptions of having had choice of treatment.ConclusionIf we adhere to patient autonomy and shared decision making, we may consider the perception of no treatment choice as a negative outcome of treatment decision-making. However, if this is the result of the patients’ preference for less active involvement in treatment decision-making, the topic of perception of no treatment choice may be viewed in a different light.