Patient decision aids for patients with differentiated thyroid carcinoma: development process and alpha and beta testing.

Background: Patient decision aids (PtDAs) are structured clinical tools that facilitate shared decision-making. Two important treatment decisions for patients with differentiated thyroid cancer (DTC), which could benefit from PtDAs, are as follows (1): the extent of surgery decision in patients with low-risk DTC and (2) the decision to start or delay starting the treatment with tyrosine kinase inhibitors (TKIs) in patients with advanced tumors. Material and methods: PtDAs for these two decisions were developed using the International Patient Decision Aids Standards (IPDAS) quality criteria in an iterative process of prototype development via alpha and beta testing by patients and physicians. The information content of the PtDAs was based on the available literature, current guidelines, and patient's needs, preferences, and values. Results: The web-based PtDAs underwent two rounds of alpha testing, revisions, and beta testing. The PtDAs have the same structure, consisting of six steps: a general introduction, information about the treatment options, comparing the treatment options, knowledge questions, a values clarification exercise, and saving the information. The alpha testing (n = 8 patients, n = 10 physicians) showed that the PtDAs were highly acceptable and usable for decision-making. Results of the beta testing in 20 patients showed that two patients did not use the PtDA; the other 18 patients found that the PtDAs were readable (n = 17) and helpful (n = 14) for decision-making. All patients recommend using the PtDAs. Conclusions: Evidence-based PtDAs were created for patients with DTC for two different treatment decisions. Our final version was judged to be clear, balanced, and helpful in decision-making.

Position paper from the Endocrine Task Force of the European Organisation for Research and Treatment of Cancer (EORTC) on the management and shared decision making in patients with low-risk micro papillary thyroid carcinoma.

The incidence of differentiated thyroid cancer (DTC) has been increasing worldwide, mostly, as an increase in the incidental detection of micro papillary thyroid carcinomas (microPTCs), many of which are potentially overtreated, as suggested by the unchanged mortality. Several international guidelines have suggested a less aggressive approach. More recently, it has been shown that active surveillance or minimally invasive treatments (MIT) are good alternatives for the management of these patients. In this context, patient participation in the decision-making process is paramount. The Endocrine Task Force of the European Organisation for Research and Treatment of Cancer (EORTC) has undertaken the task to establish consensus and define its position based on the scientific evidence concerning, 1) the current state of diagnostic and management options in microPTCs, including the current opinion of physicians about shared decision making (SDM), 2) the available evidence concerning patients' needs and the available decision instruments, and 3) to provide practical suggestions for implementation of SDM in this context. To improve SDM and patients' participation, knowledge gaps and research directions were highlighted.

A Value Set for the EQ-5D-Y-3L in the Netherlands.

BACKGROUND AND OBJECTIVE: There is increasing interest in preference-accompanied measures of health for paediatric populations. The child-friendly EQ-5D version, EQ-5D-Y-3L, is one such instrument, but the lack of a Dutch value set prevents its use in economic evaluations of healthcare interventions in the Netherlands. This study aims at covering this gap by collecting preferences using a standardised protocol for deriving EQ-5D-Y-3L value sets. METHODS: Composite time trade-off data were collected using videoconferencing interviews, with each respondent completing ten composite time trade-off tasks. Discrete choice experiment data were collected using an online survey, with respondents each completing 15 paired comparisons. Respondents completed these tasks considering what they prefer for a hypothetical 10-year-old child. Discrete choice experiment data were analysed using a ten-parameter mixed-logit model and anchored to the quality-adjusted life-year scale using the mean observed composite time trade-off values. RESULTS: The study collected preferences for 197 respondents using composite time trade-off and for 959 respondents using a discrete choice experiment. The discrete choice experiment sample was representative for the Dutch population in terms of age and sex. The level 3 weight for pain/discomfort was the largest, followed by feeling worried, sad or unhappy, usual activities, mobility and self-care. Health state values ranged between -0.218 and 1. CONCLUSIONS: This study generated a Dutch value set for the EQ-5D-Y-3L, which can be used for the computation of quality-adjusted life-years for economic evaluations of healthcare interventions in paediatric populations.

In a Child's Shoes: Composite Time Trade-Off Valuations for EQ-5D-Y-3L with Different Proxy Perspectives.

BACKGROUND AND OBJECTIVES: EQ-5D-Y-3L health states are commonly valued by asking adults to complete stated preference tasks, 'given their views about a 10-year-old child' (hereafter referred to as proxy 1). The use of this perspective has been a source of debate. In this paper, we investigated an alternative proxy perspective: i.e. adults considered what they think a 10-year old-child would decide for itself (hereafter, proxy 2 (substitute)]. Our main objective was to explore how the outcomes, dispersion and response patterns of a composite time trade-off valuation differ between proxy 1 and proxy 2. METHODS: A team of four trained interviewers completed 402 composite time trade-off interviews following the EQ-5D-Y-3L protocol. Respondents were randomly allocated to value health states in either the proxy 1 or proxy 2 (substitute) perspective. Each respondent valued ten health states with the perspective they were assigned to, as well as one health state with the alternative perspective (33333). RESULTS: The use of different proxy perspectives yielded differences in EQ-5D-Y-3L valuation. For states in which children had considerable pain and were very worried, sad or unhappy, respondents' valuations were lower in proxy 1 than in proxy 2 (substitute) perspectives, by about 0.2. Within-subject variation across health states was lower for proxy 2 (substitute) than proxy 1 perspectives. Analyses of response patterns suggest that data for proxy 2 (substitute) perspectives were less clustered. CONCLUSIONS: There are systematic differences between composite time trade-off responses given by adults deciding for children and adults considering what children would want for themselves. In addition to warranting further qualitative exploration, such differences contribute to the ongoing normative discussion surrounding the source and perspective used for valuation of child and adolescent health.

A threshold explanation for the lack of variation in negative composite time trade-off values.

BACKGROUND: Recent studies concluded that for health states considered worse than dead (WTD), as measured with the time trade-off (cTTO) method, negative mean values were insensitive to health state severity, which represents a validity problem for the cTTO. However, the aforementioned studies analysed negative values in isolation, which causes selection bias as the value distribution is truncated. AIM: To investigate the validity of aforementioned studies and of negative values in general. METHODS: The 'threshold explanation' was formulated: beyond a certain severity threshold, preferences change from better than dead (BTD) to WTD. This threshold differs between respondents. Thus, negative values across severity are obtained from different respondents, and responses added for higher severity contribute negative values close to zero, explaining the aforementioned insensitivity. This explanation was tested using data from the Dutch EQ-5D-5L valuation study. Respondents valued 10 health states. Based on respondents' number of WTD preferences, segments were constructed, containing respondents with similar severity thresholds. Using regression models for each individual respondent, we examined the relation between values and severity and compared respondents between segments. RESULTS: Negative values, when analysed in isolation, were insensitive to severity. However, for individual respondents and within most segments, cTTO values and severity were negatively related. For individual respondents, negative slopes were steeper for segments with more WTD preferences, as predicted by the threshold explanation. DISCUSSION: Analysing negative values in isolation leads to biased estimates. Analyses of cTTO values for individual respondents refute the insensitivity of negative cTTO values.

Shared decision-making in the Netherlands: Progress is made, but not for all. Time to become inclusive to patients.

Dutch initiatives targeting shared decision-making (SDM) are still growing, supported by the government, the Federation of Patients' Organisations, professional bodies and healthcare insurers. The large majority of patients prefers the SDM model. The Dutch are working hard to realise improvement in the application of SDM in daily clinical practice, resulting in glimpses of success with objectified improvement on observed behavior. Nevertheless, the culture shift is still ongoing. Large-scale uptake of SDM behavior is still a challenge. We haven't yet fully reached the patients' needs, given disappointing research data on patients' experiences and professional behavior. In all Dutch implementation projects, early adopters, believers or higher-educated persons have been overrepresented, while patients with limited health literacy have been underrepresented. This is a huge problem as 25% of the Dutch adult population have limited health literacy. To further enhance SDM there are issues to be addressed: We need to make physicians conscious about their limited application of SDM in daily practice, especially regarding preference and decision talk. We need to reward clinicians for the extra work that comes with SDM. We need to be inclusive to patients with limited health literacy, who are less often actually involved in decision-making and at the same time more likely to regret their chosen treatment compared to patients with higher health literacy.

Self-esteem in patients with venous thromboembolism predicts time trade-off values for own health.

BACKGROUND: The time trade-off (TTO) is a commonly used preference based method to assess health related values used in health economic analyses. Surprisingly little is known about the factors influencing the TTO. Since self-esteem is a predictor for health status measurements, and health status affects the TTO, we studied the relation between self-esteem and TTO values. METHODS: Data of 128 patients treated with vitamin K antagonists for venous thromboembolism on Short Form-36 (SF-36), Rosenberg self-esteem and patient characteristics were collected. TTO values were obtained for 'current health' and three chronic health states related to thrombosis, in face-to-face interviews with patients. Regression analyses were performed with the TTO as dependent variable. Analyses were performed in two groups; the complete sample, and traders only. Selected predictors were entered in four blocks: socio-demographic factors, medical-clinical factors, health status, and self-esteem. RESULTS: In the complete sample (N = 128), bivariate regression analysis showed that self-esteem explained 14% of the variance in TTO values for current health (p < .000, N = 117). In traders, multivariate regression analysis showed a significant relationship between self-esteem and TTO values for current health. Self-esteem increased the variance explained (R2) by 8.8%, from 28.1 to 36.9%, (p = 0.01; N = 57). For hypothetical health states, the effect of self-esteem was weaker and mostly absent after controlling for selected variables. CONCLUSIONS: In patients willing to trade-off time, higher self-esteem was associated with higher TTO values for own current health. Self-esteem explained an appreciable proportion of the variance in TTO values in traders. For hypothetical health states such associations were weak or absent.

Needs, Preferences, and Values during Different Treatment Decisions of Patients with Differentiated Thyroid Cancer.

BACKGROUND: The purpose of this study was to identify the needs, preferences, and values of patients with differentiated thyroid cancer (DTC) and the physicians treating patients with DTC regarding two different treatment decisions, namely: the extent of primary surgery (low-risk patients) and the tyrosine kinase inhibitor (TKI) treatment (high-risk patients). METHODS: A qualitative study was conducted. There were two physician focus groups discussing the extent of primary surgery. One included endocrinologists (n = 4) and surgeons (n = 5), and the other included nuclear medicine physicians (n = 3) treating patients with low-risk DTC. The physicians focus group discussing waiting or starting TKIs included endocrinologists (n = 2) and oncologists (n = 5) treating patients with advanced radioactive iodide (RAI) refractory DTC. Moreover, one patient focus group per treatment decision took place. In total 13 patients and 19 physicians participated. Interviews were audio-taped, fully transcribed verbatim, and analyzed. RESULTS: Several themes were identified. Patients, but not physicians, mentioned the importance of a strong doctor-patient relationship. Patients in both treatment decision groups wanted to receive more detailed information, whereas physicians preferred providing more general information. Patients in the TKI decision group focused on palliative care, whereas physicians focused more on the effect and benefit of TKIs. CONCLUSIONS: Considering the identified themes in DTC, based on the patients' needs, preferences, and values, enables us to improve doctor-patient communication and to develop decision support tools.

Evaluating the conduct and application of health utility studies: a review of critical appraisal tools and reporting checklists.

BACKGROUND: Published health utility studies are increasingly cited in cost-utility analyses to inform reimbursement decision-making. However, there is limited guidance for investigators looking to systematically evaluate the methodological quality of health utility studies or their applicability to decision contexts. OBJECTIVE: To describe how health utility concepts are reflected in tools intended for use with the health economic literature, particularly with respect to the evaluation of methodological quality and context applicability. METHODS: We reviewed the critical appraisal and reporting tools described in a 2012 report published by the Agency for Healthcare Research and Quality (AHRQ), supplemented with a keyword search of MEDLINE and EMBASE, to identify existing tools which include health utility constructs. From these tools, a list of relevant items was compiled and grouped into domain categories based on the methodological or applicability aspect they were directed toward. RESULTS: Of the 24 tools we identified, 12 contained items relevant to the evaluation of health utilities. Sixty-five items were considered relevant to the evaluation of quality, while 44 were relevant to the evaluation of applicability. Items were arranged into four domains: health state descriptions; selection and description of respondents; elicitation and measurement methods; and other considerations. CONCLUSION: As key inputs to cost-utility analyses, health utilities have the potential to significantly impact estimates of cost-effectiveness. Existing tools contain only general items related to the conduct or use of health utility studies. There is a need to develop tools that systematically evaluate the methodological quality and applicability of health utility studies.

The Impact of the Extent of Surgery on the Long-Term Outcomes of Patients with Low-Risk Differentiated Non-Medullary Thyroid Cancer: A Systematic Meta-Analysis.

Recently, the management of patients with low-risk differentiated non-medullary thyroid cancer (DTC), including papillary and follicular thyroid carcinoma subtypes, has been critically appraised, questioning whether these patients might be overtreated without a clear clinical benefit. The American Thyroid Association (ATA) guideline suggests that thyroid lobectomy (TL) could be a safe alternative for total thyroidectomy (TT) in patients with DTC up to 4 cm limited to the thyroid, without metastases. We conducted a meta-analysis to assess the clinical outcomes in patients with low-risk DTC based on the extent of surgery. The risk ratio (RR) of recurrence rate, overall survival (OS), disease-free survival (DFS) and disease specific survival (DSS) were estimated. In total 16 studies with 175,430 patients met the inclusion criteria. Overall, low recurrence rates were observed for both TL and TT groups (7 vs. 7%, RR 1.10, 95% CI 0.61-1.96, I2 = 72%), and no statistically significant differences for OS (TL 94.1 vs. TT 94.4%, RR 0.99, CI 0.99-1.00, I2 = 53%), DFS (TL 87 vs. TT 91%, RR 0.96, CI 0.89-1.03, I2 = 85%), and DSS (TL 97.2 vs. TT 95.4%, RR 1.01, CI 1.00-1.01, I2 = 74%). The high degree of heterogeneity of the studies is a notable limitation. Conservative management and appropriate follow-up instead of bilateral surgery would be justifiable in selected patients. These findings highlight the importance of shared-decision making in the management of patients with small, low-risk DTC.

Patients' and gynecologists' views on sentinel lymph node mapping in low- and intermediate-risk endometrial cancer: a Dutch vignette study.

OBJECTIVE: Sentinel lymph node (SLN) mapping in endometrial cancer is gaining ground. However, patient views on this new technique are unknown. The aim of this study was to determine factors important to patients and gynecologists when considering SLN mapping in low- and intermediate-risk endometrial cancer. METHODS: We performed a vignette study. Patients who underwent a total hysterectomy for low- or intermediate-risk endometrial cancer between 2012 and 2015 were invited. Dutch gynecologists specializing in gynecologic oncology were also invited. We based the selection for attributes in the vignettes on literature and interviews: risk of complications of SLN mapping; chance of finding a metastasis; survival gain; risk of complications after radiotherapy; operation time; and hospital of surgery (travel time). We developed a questionnaire with 18 hypothetical scenarios. Each attribute level varied and for each scenario, participants were asked how strongly they would prefer SLN on a scale from 1 to 7. The strength of preference for each scenario was analyzed using linear mixed effects models. RESULTS: A total of 38% of patients (41/108) and 33% of gynecologists (42/126) participated in the study. Overall, they had a preference for SLN. The mean preference for patients was 4.29 (95% CI 3.72 to 4.85) and 4.39 (95% CI 3.99 to 4.78) for gynecologists. Patients' preferences increased from 3.4 in the case of no survival gain to 4.9 in the case of 3-year survival gain (P<0.05) and it decreased when travel time increased to >60 min (-0.4, P=0.024), or with an increased risk of complications after adjuvant radiotherapy (-0.6, P=0.002). For gynecologists all attributes except travel time were important. CONCLUSIONS: Overall, patients and gynecologists were in favor of SLN mapping in low- and intermediate-risk endometrial cancer. Most important to patients were survival gain, travel time, and complication risk after adjuvant radiotherapy. These preferences should be taken into account when counseling about SLN mapping.

A Head-On Ordinal Comparison of the Composite Time Trade-Off and the Better-Than-Dead Method.

OBJECTIVES: The valuation of health states worse than dead is challenging. Currently used time trade-off methods face problems in (1) detecting time-dependent preferences and (2) insensitivity toward severity for states worse than dead. The better-than-dead (BTD) method has the potential to detect time-dependent preferences. This study compares the BTD and composite time trade-off (cTTO) methods at the ordinal level. METHODS: An experiment was conducted in a convenience sample in which respondents (N = 200) valued the same set of 7 health states in the BTD method and cTTO method. Binary BTD responses were used, with response categories of better than dead and worse than dead. Ternary cTTO responses were used, with the additional equal-to-dead response category. Polychoric correlations were used to determine the agreement between these methods. Consistency and test-retest reliability were assessed within methods. RESULTS: Overall agreement between the cTTO and BTD method equaled 77.1% and differed between health states and respondents. For both methods, there were few inconsistencies, and the test-retest reliability was comparable (88%). Health states were more often considered worse than dead in the BTD method (BTD: 54.7%, cTTO: 37.2%). CONCLUSIONS: The high agreement between both methods and the comparable amount of inconsistencies and test-retest reliability suggest that the methods have similar measurement properties. The BTD method yielded higher frequencies of worse-than-dead responses while essentially asking respondents to make similar choices. This accounts for part of the disagreement between the methods. Several explanations are offered for this difference, yet more research is needed to explain this phenomenon.

Implementation of a decision aid for localized prostate cancer in routine care: A successful implementation strategy.

For the treatment choice of localized prostate cancer, effective patient decision aids have been developed. The implementation of decision aids in routine care, however, lags behind. Main known barriers are lack of confidence in the tool, lack of training on its use, lack of resources and lack of time. A new implementation strategy addresses these barriers. Using this implementation strategy, the implementation rate of a decision aid was measured in eight hospitals and questionnaires were filled out by 24 care providers and 255 patients. The average implementation rate was 60 per cent (range 31%-100%). Hardly any barriers remained for care providers. Patients who did not use the decision aid appeared to be more unwilling than unable to use the decision aid. By addressing known barriers, that is, informing care providers on the effectiveness of the decision aid, providing instructions on its use, embedding it in the existing workflow and making it available free of charge, a successful implementation of a prostate cancer decision aid was reached.

Introducing Decision Aids into Routine Prostate Cancer Care in The Netherlands: Implementation and Patient Evaluations from the Multi-regional JIPPA Initiative.

Uptake of decision aids (DAs) in daily routine is low, resulting in limited knowledge about successful DA implementation at a large scale. We assessed implementation rates after multi-regional implementation of three different prostate cancer (PCa) treatment DAs and patient-perceived barriers and facilitators to use a DA. Thirty-three hospitals implemented one out of the three DAs in routine care. Implementation rates for each DA were calculated per hospital. After deciding about PCa treatment, patients (n = 1033) completed a survey on pre-formulated barriers and facilitators to use a DA. Overall DA implementation was 40%. For each DA alike, implementation within hospitals varied from incidental (< 10% of eligible patients receiving a DA) to high rates of implementation (> 80%). All three DAs were evaluated positively by patients, although concise and paper DAs yielded higher satisfaction scores compared with an elaborate online DA. Patients were most satisfied when they received the DA within a week after diagnosis. Pre-formulated barriers to DA usage were experienced by less than 10% of the patients, and most patients confirmed the facilitators. Many patients received a DA during treatment counseling, although a wide variation in uptake across hospitals was observed for each DA. Most patients were satisfied with the DA they received. Sustained implementation of DAs in clinical routine requires further encouragement and attention.

Cultural Values: Can They Explain Differences in Health Utilities between Countries?

Introduction. Health utilities are widely used in health care. The distributions of utilities differ between countries; some countries more often report worse than dead health states, while mild states are valued more or less the same. We hypothesize that cultural values explain these country-related utility differences. Research Question. What is the effect of sociodemographic background, methodological factors, and cultural values on differences in health utilities? Methods and Analyses. Time tradeoff data from 28 EQ-5D valuation studies were analyzed, together with their sociodemographic variables. The dependent variable was Δu, the utility difference between mild and severe states. Country-specific cultural variables were taken from the World Values Survey. Multilevel models were used to analyze the effect of sociodemographic background, methodology (3L v. 5L), and cultural values on Δu. Intraclass correlation (ICC) for country variation was used to assess the impact of the predicting variables on the variation between countries. Results. Substantial variation in Δu was found between countries. Adding cultural values did not reduce ICCs for country variation. Sociodemographic background variables were only weakly associated with Δu and did not affect the ICC. Δu was 0.118 smaller for EQ-5D-5L studies. Discussion.Δu varies between countries. These differences were not explained by national cultural values. In conclusion, despite correction for various variables, utility differences between countries remain substantial and unexplained. This justifies the use of country-specific value sets for instruments such as the EQ-5D.

Patient and general population values for luminal and perianal fistulising Crohn's disease health states.

BACKGROUND: In patients with Crohn's disease (CD), luminal disease activity paralleled by perianal fistulas may seriously impair health-related quality of life (HRQoL). Health utility values are not available from patients with CD that reflect the health loss associated with both luminal and perianal CD. OBJECTIVE: To generate utilities for luminal and concomitant perianal fistulising CD health states directly from patients and from members of the general public. METHODS: A cross-sectional survey was undertaken enrolling CD patients and a convenience sample of members of the general population. Respondents were asked to evaluate four common CD heath states [severe luminal disease (sCD), mild luminal disease (mCD), severe luminal disease with active perianal fistulas (sPFCD), and mild luminal disease with active perianal fistulas (mPFCD)] by 10-year time trade-off (TTO). In addition, patients assessed their current HRQoL by the TTO method. RESULTS: Responses of 206 patients (40.8% with perianal fistulas) and 221 members of the general population were analysed. Mean ± SD utilities among patients for sPFCD, sCD, mPFCD and mCD states were 0.69 ± 0.33, 0.73 ± 0.31, 0.80 ± 0.29 and 0.87 ± 0.26. Corresponding values in the general public were: 0.59 ± 0.31, 0.65 ± 0.29, 0.80 ± 0.26 and 0.88 ± 0.25. Patients with active perianal fistulas, previous non-resection surgeries, and higher pain intensity scores valued their current health as worse (p < 0.05). CONCLUSIONS: TTO is a feasible method to assess HRQoL in patients with perianal fistulising disease, often not captured by health status questionnaires. Utilities from this study are intended to support the optimization of treatment-related decision making in patients with luminal disease paralleled by active perianal fistulas.

Shared decision-making for postoperative analgesia: A semistructured qualitative study.

BACKGROUND: Shared decision-making (SDM) and decision-support tools have attracted broad support in healthcare as they improve medical decision-making. Experts disagree on how these can help patients evaluate their present situation and possible outcomes of therapy, and how they might reduce decisional conflict. Little is known about their implementation, especially in anaesthesiology. OBJECTIVE: To obtain a more fundamental understanding of pre-operative SDM and evaluate the use of a decision-support tool for postoperative analgesia after major thoracic and abdominal surgery. DESIGN: A qualitative study with semistructured, in-depth interviews of patients and professionals. SETTING: Patient recruitment took place at the Radboud University Medical Centre in Nijmegen and the Canisius Wilhelmina Hospital in Nijmegen, a nonacademic teaching centre. Professionals of the Radboud University Medical Centre were invited to participate in the interviews. PARTICIPANTS: Interviews were performed with 10 individual patients and two focus groups both consisting of eight different professionals. MAIN OUTCOME MEASURES: To gain insight into the provision of pre-operative information, decision-making processes and the clarity and usability of a prototype decision-support tool. RESULTS: Professionals seemed to provide their patients with information directed towards the application of epidural analgesia, providing little attention to its negative effects. For many patients, the information was not tailored to their needs. Patients' involvement in decision-making was minimal, but they did not feel a need for more involvement. They were positive about the decision-support tool, although they indicated that it would not have influenced their treatment decision. Professionals expressed their doubt about the capacity of their patients to fully understand the decisions involved and about the clinical usability of the decision-support tool, because patients might misinterpret the information provided. CONCLUSION: The results of this study suggest that both patients and professionals did not adhere to some 'self-evident' principles of SDM when postoperative analgesia after major thoracic and abdominal surgery was discussed.

Quality-Adjusted Life-Years without Constant Proportionality.

BACKGROUND: A quality-adjusted life-year is a common unit of measurement in health valuation. Under its constant proportionality assumption, the value of a quality-adjusted life span is defined as the product of preference weight and life span. OBJECTIVES: To empirically identify an alternative functional relationship between life span and value by relaxing the constant proportionality assumption. METHODS: Using an online survey, 5367 respondents completed 30 to 40 paired comparisons where each involved a choice between two health outcomes: one with a longer life span and health problems (five-level EuroQol five-dimensional questionnaire) and the other with a shorter life span and no problems (time trade-off pair). Using 2670 pairs, a saturated model with indicator variables for 27 life spans and 90 health problems of varying duration and severity was estimated by maximum likelihood. Its coefficients empirically illustrate the relationship between life span and value on a quality-adjusted life-year scale. RESULTS: The results reject constant proportionality (P < 0.01) and support the use of a power function to describe the relationship between life span and value, namely, value = preference weight × life spanß. The estimate of power (ß = 0.415; 95% confidence interval 0.41-0.42) appears to depend on whether life span was expressed in a temporal unit of days (0.403), weeks (0.509), months (0.541), or years (0.654). CONCLUSIONS: Raising life span to a power less than 1 implies decreasing marginal value of life span and greatly improved model fit, and confirms previous violations of proportionality. This power function may replace conventional assumptions in health valuation studies. Nevertheless, governmental agencies may favor a longer time horizon than that of the general population.

Setting Dead at Zero: Applying Scale Properties to the QALY Model.

INTRODUCTION: Scaling severe states can be a difficult task. First, the method of measurement affects whether a health state is considered better or worse than dead. Second, in discrete choice experiments, different models to anchor health states on 0 (dead) and 1 (perfect health) produce varying amounts of health states worse than dead. RESEARCH QUESTION: Within the context of the quality-adjusted life year (QALY) model, this article provides insight into the value assigned to dead and its consequences for decision making. Our research questions are 1) what are the arguments set forth to assign dead the number 0 on the health-utility scale? And 2) what are the effects of the position of dead on the health-utility scale on decision making? METHODS: A literature review was conducted to explore the arguments set forth to assign dead a value of 0 in the QALY model. In addition, scale properties and transformations were considered. RESULTS: The review uncovered several practical and theoretical considerations for setting dead at 0. In the QALY model, indifference between 2 health episodes is not preserved under changes of the origin of the duration scale. Ratio scale properties are needed for the duration scale to preserve indifferences. In combination with preferences and zero conditions for duration and health, it follows that dead should have a value of 0. CONCLUSIONS: The health-utility and duration scales have ratio scale properties, and dead should be assigned the number 0. Furthermore, the position of dead should be carefully established, because it determines how life-saving and life-improving values are weighed in cost-utility analysis.

Explanation and elaboration of the Standards for UNiversal reporting of patient Decision Aid Evaluations (SUNDAE) guidelines: examples of reporting SUNDAE items from patient decision aid evaluation literature.

This Explanation and Elaboration (E&E) article expands on the 26 items in the Standards for UNiversal reporting of Decision Aid Evaluations guidelines. The E&E provides a rationale for each item and includes examples for how each item has been reported in published papers evaluating patient decision aids. The E&E focuses on items key to reporting studies evaluating patient decision aids and is intended to be illustrative rather than restrictive. Authors and reviewers may wish to use the E&E broadly to inform structuring of patient decision aid evaluation reports, or use it as a reference to obtain details about how to report individual checklist items.