Health values and prospect theory

Too many cooks could spoil the broth: choice overload and the provision of ambulatory health care

Patient empowerment calls for an intensified participation of (informed) patients with more treatment opportunities to choose from. A growing body of literature argues that confronting consumers with too many opportunities can lead to a choice overload (CO) resulting in uncertainty that the selected alternative dominates all other options in the choice set. We examine whether there is a CO effect in the demand for ambulatory health care in Germany by analyzing the association of medical specialists supply on so-called patients' health uncertainty. Further, we investigate if the CO effect is smaller in areas with a higher density of general practitioners (GPs). We find that patients who live in an area with a large supply of specialists are subject to a CO effect that is expressed by an increased health uncertainty. The coordinating role of GPs seems to be effective to reduce the CO effect, while preserving free consumer choice.

Risk perceptions and risk-averse attitude influenced older patients' first-diagnosis-seeking behaviour at tertiary hospitals

OBJECTIVE

This qualitative study aimed to investigate the associations of older patients' inappropriate healthcare-seeking behaviour at tertiary hospitals in China with their risk perceptions and attitude.

METHODS

The study was based on nine focus group interviews (involving 41 older patients, with three to six per group) and involved the grounded theory method. The participants were recruited at tertiary hospitals.

RESULTS

The results of this study showed that older patients' inappropriate first-diagnosis-seeking behaviour at tertiary hospitals was impacted by their risk perceptions and risk-averse attitude. Both external factors (family/friends and the Internet) and internal factors (preferences and habits) had played important roles in related processes.

CONCLUSION

Thus, to guide older patients' healthcare-seeking behaviour, changing the thoughts and behaviour of the older patients themselves, their spouses, adult children, other relatives, and friends are all important. More attention should be paid on guiding appropriate risk perceptions and attitude regarding lower-level medical institutions, increasing their preferences and habit formation regarding lower-level medical institutions, enhancing older patients' social support and improving and standardising online health information. These are important for the future development of the hierarchical medical system in China.

What "Family Affair?" Domestic Violence Awareness in China

Introduction

Domestic violence is toxic to society. With approximately one in three women on average falling victim to domestic violence, systematic solutions are needed. To further complicate the issue, mounting research shows that COVID-19 has further exacerbated domestic violence across the world. Situations could be even more pronounced in countries like China, where though domestic violence is prevalent, there is a dearth of research, such as intervention studies, to address the issue. This study investigates key barriers to domestic violence research development in China, with a close focus on salient cultural influences.

Methods

A review of the literature on domestic violence in China in PubMed, PsycINFO, and Scopus was conducted to answer the research question. The search was focused on three themes, domestic violence, China, research, and cultural influences.

Results

The study findings show that categorizing domestic violence as a "family affair" is a key barrier to domestic violence research development in China-an incremental hindrance that prevents the public and policymakers from understanding the full scale and scope of domestic violence in China. In addition to abusers, witnesses, and victims, even law enforcement in China often dismisses domestic violence crimes as "family affairs" that resides outside the reach and realm of the law. The results indicated that mistreating domestic violence crimes as "family affairs" is a vital manifestation of the deep-rooted cultural influences in China, ranging from traditional Confucian beliefs in social harmony to the assumed social norms of not interfering with other people's businesses.

Conclusion

Domestic violence corrupts public health and social stability. Our study found that dismissing domestic violence cases as "family affairs" is an incremental reason why China's domestic violence research is scarce and awareness is low. In light of the government's voiced support for women's rights, we call for the Chinese government to develop effective interventions to timely and effectively address the domestic violence epidemic in China.

Effects of message framing, psychological distance, and risk perception on exercise attitude in Chinese adolescents

OBJECTIVES

Health communication campaign that promotes physical activity may aid in reducing the prevalence of childhood and adolescent obesity in China. This study examined the effects of message framing and psychological distance on the exercise attitude of Chinese adolescents, along with the interactive role of risk perception.

METHODS

Participants in this study were between 10 and 19 years of age. Three experiments were conducted independently. In experiment 1, 76 participants were recruited to assess the effectiveness of message manipulation. In experiment 2, 40 participants were recruited to compare the effects of gain- and loss-framed messages on the exercise attitude. In experiment 3, 37 participants were recruited to explore the interaction between message framing (gain vs. loss), temporal distance (proximal vs. distal), and risk perception (low vs. high) on the exercise attitude. Exercise attitude and risk perception were assessed by Likert-type questionnaires.

RESULTS

There was a significant main effect of message framing (P < 0.05), with the gain-framed message inducing a stronger exercise attitude than the loss-framed message. There was a significant main effect of temporal distance (P < 0.05), with the proximal temporal distance condition inducing a stronger exercise attitude than the distal temporal distance condition. In addition, a significant interaction (P < 0.05) was observed, and the perception of obesity-related risk was a crucial moderator of the message framing and temporal distance. Regardless of whether they were exposed to a gain- or loss-framed message, the proximal temporal distance condition induced a stronger exercise attitude in participants with a high risk perception (P < 0.05).

CONCLUSION

Messages promoting exercise that are framed as having a near-future gain effect and that emphasize disease risks are effective in motivating adolescents to engage in physical activity.

Context-Dependent Risk & Benefit Sensitivity Mediate Judgments About Cognitive Enhancement

Opinions about cognitive enhancement (CE) are context-dependent. Prior research has demonstrated that factors like peer pressure, the influence of authority figures, competition, moral relevance, familiarity with enhancement devices, expertise, and the domain of CE to be enhanced can influence opinions. The variability and malleability of patient, expert, and public attitudes toward CE is important to describe and predict because these attitudes can influence at-home, clinical, research, and regulatory decisions. If individual preferences vary, they could influence opinions about practices and regulations due to disagreements about the desirable levels of risks and benefits. The study of attitudes about CE would benefit from psychological theories that explain judgments. In particular, we suggest that variability in risk and benefit sensitivity could psychologically mediate judgments about CE in many contexts. Drawing from prospect theory, which originated in behavioral economics, it is likely that framing effects, shifted reference points, and the tendency to weigh losses (risks) more heavily than gains (benefits) predict decisions about CE. We suggest that public policy could benefit from a shared conceptual framework, such as prospect theory, that allows us to describe and predict real-world decisions about CE by patients, experts, and the public.

Musicians' Hearing Handicap Index: A New Questionnaire to Assess the Impact of Hearing Impairment in Musicians and Other Music Professionals

Purpose We aimed to develop and validate the Musicians' Hearing Handicap Index (MHHI), a new self-evaluation tool for quantifying occupation-related auditory difficulties in music professionals. Although pure-tone audiometry is often considered the "gold standard" and is usually employed as the main instrument for hearing assessment, it cannot fully describe the impact of hearing dysfunction. The MHHI is an attempt to complement the hearing impairment assessment toolbox and is based on a unique approach to quantify the effects of hearing-related symptoms or hearing loss on the performance of musicians and other music industry professionals. Method An initial set of 143 questionnaire items was successively refined through a series of critical appraisals, modifications, and suggestions. This yielded an intermediate questionnaire consisting of 43 items, which was administered to 204 musicians and sound engineers. After exploratory factor analysis, the final form of the MHHI questionnaire was obtained, consisting of 29 items. The questionnaire's test-retest reliability, internal consistency, discriminating power, content validity, criterion validity, and aspects of construct validity and inherent conceptual structure were assessed. Results Exploratory factor analysis revealed a combination of four common factors for the 29 validated questionnaire items. They were named "impact on social and working lives," "difficulties in performance and sound perception," "communication difficulties," and "emotional distress." The MHHI was shown to be a valid and reliable instrument to assess musicians' and sound engineers' occupational difficulties due to hearing impairment and related symptoms. Conclusion The ability of the MHHI to discriminate between groups of music professionals with different auditory symptoms or pure-tone audiometry thresholds suggests that auditory symptoms might influence a professional's performance to an extent that cannot be assessed by a pure-tone audiogram.

An overview of the time trade-off method: concept, foundation, and the evaluation of distorting factors in putting a value on health

INTRODUCTION

Preference-based instruments measuring health status express the value of specific health states in a single number. One method used is time trade-off (TTO). Health-status values are key elements in calculating quality-adjusted life years (QALYs) and are pertinent for resource allocation. Since they are used in economic evaluations of healthcare, searching for a theoretical foundation of TTO in economics is justified.

AREA COVERED

This paper provides an overview of TTO, including its relation to economic theory, and discusses biases and distortions, compiled from recent and older research. Inconsistencies between TTO and random utility theory were detected; The TTO is confounded by time preferences and by respondents' life expectancies. TTO is cognitively challenging, therefore guidance during the interviews is needed, producing interview effects. TTO does not measure one thing at a time, nor are the values independent of other states that are being valued in the same task. That is, TTO does not exhibit theoretical measurement properties such as unidimensionality and the invariance principle.

EXPERT OPINION

We conclude that the TTO may be a pragmatic method of eliciting health state values, but the limitations in regard to measurement theory and practical elicitation problems makes it prone to inconsistencies and arbitrariness.

Living up to expectations: Experimental tests of subjective life expectancy as reference point in time trade-off and standard gamble

Earlier work suggested that subjective life expectancy (SLE) functions as reference point in time trade-off (TTO), but has not tested or modelled this explicitly. In this paper we construct a model based on prospect theory to investigate these predictions more thoroughly. We report the first experimental test of reference-dependence with respect to SLE for TTO and extend this approach to standard gamble (SG). In two experiments, subjects' SLEs were used to construct different versions of 10-year TTO and SG tasks, with the gauge duration either described as occurring above or below life expectation. Our analyses suggest that both TTO and SG weights were affected by SLE as predicted by prospect theory with SLE as reference point. Subjects gave up fewer years in TTO and were less risk-tolerant in SG below SLE, implying that weights derived from these health state valuation methods for durations below SLE will be biased upwards.

Assessment of Patient and Caregiver Attitudes and Approaches to Decision-Making Regarding Bone Marrow Transplant for Sickle Cell Disease: A Qualitative Study

IMPORTANCE

Bone marrow transplant (BMT) is a potentially curative treatment for sickle cell disease (SCD). Patient and caregiver attitudes toward BMT for SCD and the willingness to accept risks of BMT vary, but these attitudes are not well understood.

OBJECTIVE

To understand patient and caregiver perceptions of and attitudes toward BMT for SCD and decision-making about BMT.

DESIGN, SETTING, AND PARTICIPANTS

Qualitative study of interview transcripts from a convenience sample. Transcripts were from adults with SCD and caregivers of patients with SCD recruited from national and regional SCD conferences, symposia, and sickle cell clinics in 2 cities. Interview transcripts were used from the needs assessment phase to develop a patient-decision aid in 2013 to 2014 (group 1) and from the baseline point in 2015 to 2016 (group 2) of the parent trial, a randomized clinical trial of adults and caregivers of patients with SCD to evaluate the effectiveness of a patient decision aid.

MAIN OUTCOMES AND MEASURES

Participant perspectives on decision-making regarding BMT for SCD.

RESULTS

Fifty-seven transcripts from adults with SCD and 50 transcripts from caregivers of patients with SCD were included. Median (interquartile range [IQR]) age of adults with SCD was 34 (21-50) years in group 1 and 30 (23-38) years in group 2. The median (IQR) age of caregivers was 42.5 (31-52) years in group 1 and 41 (35-46.5) years in group 2. Most transcripts from adults with SCD (75.0% in group 1 and 72.4% in group 2) and caregivers of patients with SCD (76.7% in group 1 and 85.0% in group 2) were from female participants. Bone marrow transplant was perceived as a treatment option associated with serious risks. Reported attitudes toward BMT occurred on a continuum ranging from unfavorable to favorable. Participants reported serious decisional dilemma regarding BMT for SCD. Most participants expressed interest in learning about BMT or curative treatments.

CONCLUSIONS AND RELEVANCE

This qualitative study found a continuum in attitudes toward BMT for SCD and highlights the complexity of decision-making in BMT for SCD. Patients and families with SCD expressed an interest in learning about BMT. Future prospective studies of patient decision-making regarding BMT, especially in the context of emerging curative and novel disease-modifying therapies for SCD, are warranted.

Neuroeconomics, health psychology, and the interdisciplinary study of preventative health behavior

The goal of this article is to introduce readers to theories, tools, and evidence from the field of neuroeconomics and to describe how health psychology and neuroeconomics can be mutually informative in the study of preventative health behaviors. Preventative health behavior here refers to both individual actions that impact one's health (e.g., exercise) and broader behavioral patterns, such as those captured in personality constructs. Although neuroeconomic researchers have begun to incorporate health-relevant behaviors into their studies, the full potential of this research to inform preventative health models is as yet unrealized. What is needed to "translate up" is the unification of rich theoretical content from health psychology with investigations by neuroeconomic researchers of the decision-making process during health-relevant choices. We identify choice as a central, shared feature across models of preventative health behavior that can serve as an inroad for neuroeconomics to contribute to existing models and highlight commonalities that might not otherwise be apparent. A central premise of our argument is that, because health decisions are nearly always multiply determined, a more precise and mechanistic understanding of how choices are made is an important but understudied topic in health psychology. A partnership between health psychologists and neuroeconomic researchers can yield valuable insights into how preventative health choice is made and to identify targets and methods for intervention.

QALYs without bias? Nonparametric correction of time trade-off and standard gamble weights based on prospect theory

Common health state valuation methodologies, such as standard gamble (SG) and time trade-off (TTO), typically produce different weights for identical health states. We attempt to alleviate these differences by correcting the confounding influences modeled in prospect theory: loss aversion and probability weighting. Furthermore, we correct for nonlinear utility of life duration. In contrast to earlier attempts at correcting TTO and SG weights, we measure and correct all these tenets simultaneously, using newly developed nonparametric methodology. These corrections were applied to three less-than-perfect health states, measured with TTO and SG. We found considerable loss aversion and probability weighting for both gains and losses in life years, and we observe concave utility for gains and convex utility for losses in life years. After correction, the initially significant differences in weights between TTO and SG disappeared for all health states. Our findings suggest new opportunities to account for bias in health state valuations but also the need for further validation of resulting weights.

The Corrective Approach: Policy Implications of Recent Developments in QALY Measurement Based on Prospect Theory

BACKGROUND AND OBJECTIVES

Common health state valuation methodology, such as time tradeoff (TTO) and standard gamble (SG), is typically applied under several descriptively invalid assumptions, for example, related to linear quality-adjusted life years (QALYs) or expected utility (EU) theory. Hence, the current use of results from health state valuation exercises may lead to biased QALY weights, which may in turn affect decisions based on economic evaluations using such weights. Methods have been proposed to correct responses for the biases associated with different health state valuation techniques. In this article we outline the relevance of prospect theory (PT), which has become the dominant descriptive alternative to EU, for health state valuations and economic evaluations.

METHODS AND RESULTS

We provide an overview of work in this field, which aims to remove biases from QALY weights. We label this "the corrective approach." By quantifying PT parameters, such as loss aversion, probability weighting, and nonlinear utility, it may be possible to correct TTO and SG responses for biases in an attempt to produce more valid estimates of preferences for health states. Through straightforward examples, this article illustrates the effects of this corrective approach and discusses several unresolved issues that currently limit the relevance of corrected weights for policy.

CONCLUSIONS

Suggestions for research addressing these issues are provided. Nonetheless, if validly corrected health state valuations become available, we argue in favor of using these in economic evaluations.

Prospect Theory Concepts Applied to Family Members of Nursing Home Residents with Cancer: A Good Ending Is a Gain

Family members are often involved in medical decision-making on behalf of a nursing home resident. Prospect theory provides a framework for understanding how people weigh decisions. In the current study, prospect theory concepts are used to build understanding about how family members weigh medical decisions for an NH resident diagnosed with cancer. This is a secondary analysis of qualitative interview data from 24 family members of nursing home residents. Prospect theory concepts of gain, loss, risk, and reference point were used deductively in qualitative content analysis. Themes were developed by comparing content related to these four concepts, across the transcripts from the 24 participants. Three themes comprise the main findings, including "Don't prolong this," "A good ending is a gain," and "Experience can facilitate seeing the big picture." Prospect theory concepts applied to decisions faced by family members were useful in building an understanding of what participants considered as gains, losses, risks, and reference points. Many participants framed the medical decisions within the larger context of the resident's life and concluded that jeopardizing the chance for a peaceful dying process was too high a risk. Medical interventions were selected or avoided because of the impact on a comfortable dying process; considered a gain. Advance care planning discussions and goals of care discussions can benefit by directly addressing what residents/patients, families, and health practitioners consider outcomes worth pursuing and avoiding.

Stories about HPV vaccine in social media, traditional media, and conversations

How stories from media and social interactions shape parents' HPV vaccination decisions is poorly understood. We sought to characterize parents' exposure to such stories, as well as associations between story exposure and vaccination behavior. Study participants were 1263 parents of U.S. adolescents who had not yet completed the HPV vaccine series. In 2017, these parents completed an online survey about whether they had heard stories of people who were harmed by HPV vaccine or who got diseases HPV vaccine could have prevented. Almost half of parents had heard HPV vaccine stories, which were about vaccine harms only (19%), vaccine preventable diseases only (11%), or both (15%). Stories of harms more often came from social and traditional media; stories of preventable diseases more often came from conversations (all p < 0.01). Parents who heard only stories about harms were less likely than those who heard no stories to have initiated HPV vaccination (23% vs. 33%, aOR:0.48; 95% CI:0.33:0.69). They were more likely to have delayed (79% vs. 66%, aOR:2.00; 95% CI:1.09:3.71) or refused (72% vs. 24%, aOR:8.87; 95% CI:4.09:19.25) HPV vaccination. Exposure to both stories about harms and preventable diseases was similarly associated with initiation, delay and refusal. Exposure to only stories about preventable diseases was not associated with initiation, delay or refusal. In conclusion, stories of HPV vaccine harms may be associated more strongly with vaccination behavior than stories of HPV vaccine preventable diseases. Communication campaigns should consider strategies to elevate stories of preventable diseases in social and traditional media.

Hearing in Real-Life Environments (HERE): Structure and Reliability of a Questionnaire on Perceived Hearing for Older Adults

Supplemental Digital Content is available in the text.

Objectives:

The ability to hear in a variety of social situations and environments is vital for social participation and a high quality of life. One way to assess hearing ability is by means of self-report questionnaire. For questionnaires to be useful, their measurement properties, based on careful validation, have to be known. Only recently has consensus been reached concerning how to perform such validation and been published as COSMIN (consensus-based standards for the selection of health status measurement instruments) guidelines. Here the authors use these guidelines to evaluate the measurement properties of the “Hearing in Real-Life Environments” (HERE) questionnaire, a newly developed self-report measure that assesses speech perception, spatial orientation, and the social-emotional consequences of hearing impairment in older adults. The aim is to illustrate the process of validation and encourage similar examinations of other frequently used questionnaires.

Design:

The HERE questionnaire includes 15 items with a numeric rating scale from 0 to 10 for each item and allows the assessment of hearing with and without hearing aids. The evaluation was performed in two cohorts of community-dwelling older adults from Finland (n = 581, mean 82 years) and the United Kingdom (n = 50, mean 69 years). The internal structure of the questionnaire and its relationship to age, hearing level, and self-reported and behavioral measures of speech perception was assessed and, when possible, compared between cohorts.

Results:

The results of the factor analysis showed that the HERE’s internal structure was similar across cohorts. In both cohorts, the factor analysis showed a satisfactory solution for three factors (speech hearing, spatial hearing, and socio-emotional consequences), with a high internal consistency for each factor (Cronbach’s α’s for the factors from 0.90 to 0.97). Test–retest analysis showed the HERE overall mean score to be stable and highly replicable over time (intraclass correlation coefficient = 0.86, standard error of measurement of the test score = 0.92). The HERE overall mean score correlated highly with another self-report measure of speech perception, the Speech Spatial Qualities of Hearing questionnaire (standardized regression coefficient [β] = −0.75, p < 0.001), moderately highly with behaviorally assessed hearing level (best-ear average: β = 0.45 to 0.46), and moderately highly with behaviorally measured intelligibility of sentences in noise (β = −0.50, p < 0.001).

Conclusions:

Using the COSMIN guidelines, the authors show that the HERE is a valid, reliable, and stable questionnaire for the assessment of self-reported speech perception, sound localization, and the socio-emotional consequences of hearing impairment in the context of social functioning. The authors also show that cross-cultural data collected using different data collection strategies can be combined with a range of statistical methods to validate a questionnaire.

New findings from the time trade-off for income approach to elicit willingness to pay for a quality adjusted life year

In this paper we empirically investigate how to appropriately model utility of wealth and health. We use a recently proposed alternative approach to value willingness to pay (WTP) for health, making use of trade-offs between income and life years or quality of life, which we extend to allow for a more realistic multiplicative utility function over health and money. Moreover, we show how reference-dependency can be incorporated into this model and derive its predictions for WTP elicitation. We propose three experimental elicitation procedures and test these in a feasibility study, analysing the responses under different assumptions about the discount rate. Several interesting results are reported: first, the data are highly skewed, but if we trim the 5% lowest and highest values, we obtain plausible WTP estimates. Second, the results differ considerably between procedures, indicating that WTP estimates are sensitive to the assumed utility function. Third, respondents appear to be loss averse for both health and money, which is consistent with assumptions from prospect theory. Finally, our results also indicate that respondents are more willing to trade quality of life than life years.

Considering the CPR Decision Through the Lens of Prospect Theory in the Context of Advanced Chronic Illness

It is common for people with advanced chronic illness to have many health care providers and many health care-related visits. It is also common, during those visits, to be asked whether attempts at cardiopulmonary resuscitation (CPR) are desired, in the event of cardiac arrest. Although the question is common, the implications of a "yes" or a "no" may not be well understood. Although CPR can be a life-saving procedure, it is not always in the patient's best interest. This article discusses experiences with CPR of 2 older women (and their adult children) during their last years of life, and uses concepts from prospect theory to make suggestions for changes in the way health care providers and patients approach advance care planning including the CPR decision.

Exploring the Reference Point in Prospect Theory: Gambles for Length of Life

Attitude toward risk is an important factor determining patient preferences. Risk behavior has been shown to be strongly dependent on the perception of the outcome as either a gain or a loss. According to prospect theory, the reference point determines how an outcome is perceived. However, no theory on the location of the reference point exists, and for the health domain, there is no direct evidence for the location of the reference point. This article combines qualitative with quantitative data to provide evidence of the reference point in life-year certainty equivalent (CE) gambles and to explore the psychology behind the reference point. The authors argue that goals (aspirations) in life influence the reference point. While thinking aloud, 45 healthy respondents gave certainty equivalents for life-year CE gambles with long and short durations of survival. Contrary to suggestions from the literature, qualitative data argued that the offered certainty equivalent most frequently served as the reference point. Thus, respondents perceived life-year CE gambles as mixed. Framing of the question and goals set in life appeared to be important factors behind the psychology of the reference point. On the basis of the authors' quantitative and qualitative data, they argue that goals alter the perception of outcomes as described by prospect theory by influencing the reference point. This relationship is more apparent for the near future as opposed to the remote future, as goals are mostly set for the near future.

Preferences For Prolonging Life: A Prospect Theory Approach

Kahneman and Tversky's (1979) Prospect theory was tested as a model of preferences for prolonging life under various hypothetical health statuses. A sample of 384 elderly people living in congregate housing (263 healthy, 131 frail) indicated how long (if at all) they would want to live under each of nine hypothetical health conditions (e.g., limited to bed or chair in a nursing home). Prospect theory, a decision model which takes into account the individual's point of reference, would predict that frail people would view prospective poorer health conditions as more tolerable and express preferences to live longer in worse health than would currently healthy people. In separate analyses of covariance, we evaluated preferences for continued life under four conditions of functional ability, four conditions of cognitive impairment, and three pain conditions—each as a function of participant's current health status (frail vs. healthy). The predicted interaction between frailty and declining prospective health status was obtained. Frail participants expressed preferences for longer life under more compromised health conditions than did healthy participants. The results imply that such preferences are malleable, changing as health deteriorates. They also help explain disparities between proxy decision-makers' and patients' own preferences as expressed in advance directives.

An elicitation of utility for quality of life under prospect theory

This paper performs several tests of decision analysis applied to the health domain. First, we conduct a test of the normative expected utility theory. Second, we investigate the possibility to elicit the more general prospect theory. We observe risk aversion for gains and losses and violations of expected utility. These results imply that mechanisms governing decisions in the health domain are similar to those in the monetary domain. However, we also report one important deviation: utility is universally concave for the health outcomes used in this study, in contrast to the commonly found S-shaped utility for monetary outcomes, with concave utility for gains and convex utility for losses.

Bounded rationality alters the dynamics of paediatric immunization acceptance

Interactions between disease dynamics and vaccinating behavior have been explored in many coupled behavior-disease models. Cognitive effects such as risk perception, framing, and subjective probabilities of adverse events can be important determinants of the vaccinating behaviour, and represent departures from the pure "rational" decision model that are often described as "bounded rationality". However, the impact of such cognitive effects in the context of paediatric infectious disease vaccines has received relatively little attention. Here, we develop a disease-behavior model that accounts for bounded rationality through prospect theory. We analyze the model and compare its predictions to a reduced model that lacks bounded rationality. We find that, in general, introducing bounded rationality increases the dynamical richness of the model and makes it harder to eliminate a paediatric infectious disease. In contrast, in other cases, a low cost, highly efficacious vaccine can be refused, even when the rational decision model predicts acceptance. Injunctive social norms can prevent vaccine refusal, if vaccine acceptance is sufficiently high in the beginning of the vaccination campaign. Cognitive processes can have major impacts on the predictions of behaviour-disease models, and further study of such processes in the context of vaccination is thus warranted.

A novel approach to increasing inventory with the current panel: increasing donation frequency by asking for a different blood product

BACKGROUND

Ongoing shortages of blood products may be addressed through additional donations. However, donation frequency rates are typically lower than medically possible. This preliminary study aims to determine voluntary nonremunerated whole blood (WB) and plasmapheresis donors' willingness, and subsequent facilitators and barriers, to make additional donations of a different type.

STUDY DESIGN AND METHODS

Forty individual telephone interviews were conducted posing two additional donation pattern scenarios: first, making a single and, second, making multiple plasmapheresis donations between WB donations. Stratified purposive sampling was conducted for four samples varying in donation experience: no-plasma, new-to-both-WB-and-plasma, new-to-plasma, and plasma donors. Interviews were analyzed yielding excellent (κ values > 0.81) inter-rater reliability.

RESULTS

Facilitators were more endorsed than barriers for a single but not multiple plasmapheresis donation. More new-to-both donors (n = 5) were willing to make multiple plasma donations between WB donations than others (n = 1 each) and identified fewer barriers (n = 3) than those more experienced in donation (n = 8 no plasma, n = 10 new to both, n = 11 plasma). Donors in the plasma sample were concerned about the subsequent reduced time between plasma donations by adding WB donations (n = 3). The no-plasma and new-to-plasma donors were concerned about the time commitment required (n = 3).

CONCLUSION

Current donors are willing to add different product donations but donation history influences their willingness to change. Early introduction of multiple donation types, variation in inventory levels, and addressing barriers will provide blood collection agencies with a novel and cost-effective inventory management strategy.

Does diabetes have an impact on health-state utility? a study of Asians in Singapore

OBJECTIVE

Our objective was to compare the time trade-off (TTO) values of EQ-5D-3L health states elicited from Singaporeans with and without type 2 diabetes mellitus (T2DM) and T2DM patients with and without complications.

METHODS

The TTO values of ten EQ-5D-3L health states were elicited from a consecutive sample of T2DM patients and a general Singaporean population sample using similar valuation protocols. In face-to-face interviews, T2DM patients and members of the general population were asked to value five and ten health states, respectively. The difference in TTO values between the two samples and between T2DM patients with and without complications was examined using multiple linear regression models.

RESULTS

A total of 109 T2DM patients and 46 individuals without T2DM provided data. All ten health states considered, the mean TTO value was -0.02 for the general population sample and -0.04 for T2DM patients, with the unadjusted and adjusted difference being -0.06 (95 % confidence interval [CI] -0.16, 0.03) and 0.02 (95 % CI -0.12, 0.15). The general population sample had systematically lower TTO values for mild health states, with the adjusted difference being -0.13 (95 % CI -0.25, -0.02); while the two samples had similar TTO values for severe health states, with the adjusted difference being 0.02 (95 % CI -0.16, 0.19). T2DM patients without complications had systematically lower TTO values than those with complications, with the adjusted difference being -0.10 (95 % CI -0.23, 0.03).

CONCLUSIONS

It appears that diabetes and its complications affect patients' valuation of health states. Hence, the EQ-5D-3L health-state values based on the general population may underestimate the utility of health interventions for T2DM.

Individual patient monitoring in daily clinical practice: a critical evaluation of minimal important change

PURPOSE

In daily practice, physicians translate knowledge from clinical trials to practice, to improve health in individual patients. To help interpret meaningful change on disease outcome measures, the concept of minimal important change (MIC) was conceived. The objective of this study was to investigate whether MIC values are suited for individual patient monitoring.

METHODS

Three main elements of the MIC concept were evaluated: (1) MIC values for improvement and deterioration were determined, and the amount of misclassification present in quantifying minimal change was analyzed. (2) Discordance between change categories (improved, unchanged, deteriorated), defined by the MIC values, and patients' satisfaction with their health was inspected. (3) Discordance between change categories, defined by MIC values, and patients' willingness to alter therapy was inspected.

RESULTS

MIC value analysis was based on 469 patients with RA seen in daily practice. The chance of falsely classifying health change of an individual patient was high (false-positive range 19-30 % and false-negative range 43-72 %). Of patients classified as improved, 24 % were not satisfied with their health and 69 % were not willing to change therapy. Of patients classified as deteriorated, 54 % were satisfied with their health and 57 % were not willing to change therapy.

CONCLUSIONS

The misclassification in the quantification of change and high proportions of discordance between change categories defined by MIC cutoff values and patients' satisfaction and willingness to alter therapy indicate that MIC values as such are not suited for individual patient monitoring.

Prospect theory in the health domain: a quantitative assessment

It is well-known that expected utility (EU) has empirical deficiencies. Cumulative prospect theory (CPT) has developed as an alternative with more descriptive validity. However, CPT's full function had not yet been quantified in the health domain. This paper is therefore the first to simultaneously measure utility of life duration, probability weighting, and loss aversion in this domain. We observe loss aversion and risk aversion for gains and losses, which for gains can be explained by probabilistic pessimism. Utility for gains is almost linear. For losses, we find less weighting of probability 1/2 and concave utility. This contrasts with the common finding of convex utility for monetary losses. However, CPT was proposed to explain choices among lotteries involving monetary outcomes. Life years are arguably very different from monetary outcomes and need not generate convex utility for losses. Moreover, utility of life duration reflects discounting, causing concave utility.

Elders' preferences for life-prolonging treatment and their proxies' substituted judgment: influence of the elders' current health

OBJECTIVE

People in poor health tend to view life-prolonging treatments (e.g., tube feeding) as more acceptable than do healthier people. Do proxies' substituted judgments reveal a similar tendency, showing greater acceptance when the elder is in worse health?

METHOD

In a cross-sectional telephone-based survey of 202 elderly individuals and their proxies, preferences for 4 life-prolonging treatments in 7 health prospects were examined in relation to the elder's current health status, operationalized as number of deficits in activities of daily living.

RESULTS

Stronger preferences for life-prolonging treatments in worse-health prospects were expressed by both elders and proxies when the elders' current health was relatively poor. The interaction effect was at least as pronounced for proxies' substituted judgment as for elders' own preferences.

DISCUSSION

Findings provide important insight into proxy decision making and have particular implications for proxy decision making on behalf of elders with dementia or other causes of decisional incapacity.

Estimates of prospective change in self-rated health in older people were biased owing to potential recalibration response shift

OBJECTIVE

Evidence shows that self-rated health (SRH) remains remarkably stable during aging. Individuals may change their conceptualization of health or revise their standard of good health when facing health decline. Although this "response shift" phenomenon is potentially beneficial to the individual, it also challenges comparison of SRH assessments over time. The present study investigates this response shift.

STUDY DESIGN AND SETTING

Data come from two waves (T1 and T2) of the Longitudinal Aging Study Amsterdam (N: 1,274; age: 55-89 years; mean follow-up: 3.6 years). Linear regression models were used for predicting SRH at T1 and T2. To capture changes in individual health standards, we administered a then-test at T2, asking respondents to retrospectively rate their health at T1 again.

RESULTS

No support was found for a changed conceptualization of SRH after health decline: predictive models for SRH at T1 and T2 were not significantly different. In the subgroup that reported identical SRH at T1 and T2, participants who experienced incident diseases were three times more likely to retrospectively overrate health at T1 with the then-test, suggesting that they had a lowered health standard.

CONCLUSION

Older people's concept of health remains stable when they encounter significant health problems, but they potentially lower their standard of good health over time.

The impact of educational message framing on adherence to continuous positive airway pressure therapy

Although of proven health benefit to persons with obstructive sleep apnea (OSA), adherence to continuous positive airway pressure (CPAP) therapy is suboptimal, with patterns of use that are established early and that are not easily altered after the initial experience. In a randomized controlled trial, 70 participants with OSA and cardiovascular disease were assigned to receive either positively or negatively framed education about CPAP. Objective adherence was measured following 30 days of home CPAP therapy. Daytime sleepiness, dispositional optimism, self-efficacy, and depression were also evaluated at baseline and after 30 days. CPAP use was greater in the group receiving negative message framing (p = .015).

The relationship between change in subjective outcome and change in disease: a potential paradox

BACKGROUND

Response shift theory suggests that improvements in health lead patients to change their internal standards and re-assess former health states as worse than initially rated when using retrospective ratings via the then-test. The predictions of response shift theory can be illustrated using prospect theory, whereby a change in current health causes a change in reference frame. Therefore, if health deteriorates, the former health state will receive a better rating, whereas if it improves, the former health state will receive a worse rating.

OBJECTIVE

To explore the predictions of response shift and prospect theory by relating subjective change to objective change.

METHODS

Baseline and 3-month follow-up data from a cohort of rheumatoid arthritis patients (N = 197) starting on TNFalpha-blocking agents were used. Objective disease change was classified according to a disease-specific clinical outcome measure (DAS28). Visual analogue scales (VAS) for general health (GH) and pain were used as self-reported measures. Three months after starting on anti-TNFalpha, patients used the then-test to re-rate their baseline health with regard to general health and pain. Differences between then-test value and baseline values were calculated and tested between improved, non-improved and deteriorated patients by the Student t-test.

RESULTS

At 3 months, 51 (25.9%) patients had good improvement in health, 83 (42.1%) had moderate improvement, and 63 (32.0%) had no improvement or deteriorated in health. All patients no matter whether they improved, did not improve, or even became worse rated their health as worse retrospectively. The difference between the then-test rating and the baseline value was similarly sized in all groups.

CONCLUSION

More positive ratings of retrospective health are independent of disease change. This suggests that patients do not necessarily change their standards in line with their disease change, and therefore it is inappropriate to use the then-test to correct for such a change. If a then-test is used to correct for shifts in internal standards, it might lead to the paradoxical result that patients who do not improve or even deteriorate increase significantly on self-reported health and pain. An alternative explanation for differences in retrospective and prospective ratings of health is the implicit theory of change which is more successful in explaining our results than prospect theory.

Affective Forecasting and Advance Care Planning

That sicker people evaluate quality of life in future health status more positively, compared to healthier people, is viewed as an instance of affective forecasting error and explained by Prospect Theory, which holds that two prospects (poor health vs death) are more distinguishable when they are imminent than when distant. In a sample of 230 elderly people, we tested whether life in nine health scenarios would be more acceptable to less healthy individuals than to healthier ones. An interaction between current health status and health scenario supported the relative acceptability of poor-health prospects to sicker individuals, confirming the hypothesis.

Methodological challenges confronting researchers of wheeled mobility aids and other assistive technologies

PURPOSE

To identify gaps in assistive technology (AT) research and solutions, with a focus on wheeled mobility.

METHODS

Literature review.

RESULTS

AT researchers have identified a need to move beyond determining whether a device works well in the laboratory or is perceived favorably by users. The vital next step in AT research is to determine the effects of AT when used for day-to-day activities by typical consumers. Four challenges affect AT research on everyday mobility: (1) the heterogeneity of the population using AT, the environments in which AT is used, and the devices themselves; (2) the dependency of empirical research on objective data for valid causal inference; (3) the need for detailed information to capture the interaction between the person, the device, and the environment in which it is used; and (4) the extent to which success or failure of AT is dependent on the personal perspectives of the individual using the device. These challenges are being addressed by AT researchers through use of new measures, novel data collection methods, and by linking quantitative with qualitative data.

CONCLUSIONS

AT researchers are adapting traditional research designs and analytic methods to examine that effects of AT on everyday life.

Rethinking the objectives of decision aids: a call for conceptual clarity

Health decision aids are a potentially valuable adjunct to patient-physician communication and decision making. Although the overarching goal of decision aids--to help patients make informed, preference-sensitive choices--is widely accepted, experts do not agree on the means to achieve this end. In this article, the authors critically examine the theoretical basis and appropriateness of 2 widely accepted criteria used to evaluate decision aids: values clarification and reduction of decisional conflict. First, they argue that although clarifying values is central to decision making under uncertainty, it is not clear that decision aids--as they have been conceived and operationalized so far--can and should be used to achieve this goal. The pursuit of clarifying values, particularly values clarification exercises, raises a number of ethical, methodological, and conceptual issues, and the authors suggest research questions that should be addressed before values clarification is routinely endorsed. Second, the authors argue that the goal of reducing decisional conflict is conceptually untenable and propose that it be eliminated as an objective of decision aids.

Current health and preferences for life-prolonging treatments: an application of prospect theory to end-of-life decision making

As a substantial body of research attests, the acceptability of life-prolonging treatment (e.g., tube feeding) tends to be greater among people in worse health than among healthier ones. Because a decision for or against a life-prolonging treatment represents a choice between two prospects-life (usually in poor health) and death-we propose a decision model, Prospect Theory, as a theoretical account of this phenomenon. Prospect Theory postulates that pairs of distant prospects are less distinguishable than pairs of closer ones. Thus, to healthy individuals, the prospects of death and life in poor health would both be remote, and therefore, the distinction between them, small. To less healthy individuals, however, the difference between the same pairs of prospects would appear greater, and therefore, life-prolonging treatment may be more acceptable. In a cross-sectional study of 304 community-dwelling people, aged 60 years and over in the Philadelphia area, USA, preferences for 4 life-prolonging treatments in 9 health scenarios were examined in relation to participants' current health, operationalized as number of deficits in physical functioning. As predicted, less healthy people expressed stronger preferences for all life-prolonging treatments compared with healthier ones, with differences greatest in the worse-health scenarios. Preferences also varied by health scenario, with any treatment preferred in the better health scenarios. Treatment preferences did not differ by type of treatment, depressed mood or any demographic characteristic except race, with African-Americans expressing stronger treatment preferences. Implications for advance care planning are discussed.

Effect of Motorized Scooters on Physical Performance and Mobility: A Randomized Clinical Trial

OBJECTIVE

To investigate the effects of providing a motorized scooter on physical performance and mobility.

DESIGN

Randomized clinical trial comparing scooter users with usual care.

SETTING

One academic and 1 Veterans Affairs medical center.

PARTICIPANTS

Ambulatory, community-dwelling outpatients with rheumatoid arthritis or osteoarthritis of the knee.

INTERVENTION

Provision of a motorized scooter for 3 months.

MAIN OUTCOME MEASURES

Six-minute walk distance (6MWD) and mobility methods in diverse locations at baseline, 1 month, and 3 months, and accidents while using the scooter.

RESULTS

The majority of scooter subjects (n=16/22 [72.7%]) used the scooter 4 or more days per week. The difference+/-standard deviation between the 2 groups in change in 6MWD over the study period was not statistically significant (scooter users, 16.9+/-73.0 m [55.5+/-239.6 ft]; usual care, 17.2+/-72.5 m [56.5+/-238.0 ft], P=.55). Four (18.1%) scooter users reported 9 accidents. Over the study period, the proportion of persons reporting use of a scooter (provided by the study or otherwise available) increased in the scooter-users group (eg, food stores, 16.7% to 52.6%; doctor's office, 0% to 35.7%) but not the usual-care group (food stores, 9.1% to 9.5%; doctor's office, 0% to 0%).

CONCLUSIONS

Motorized scooters provided to ambulatory persons with arthritis were used intermittently. The greatest short-term risk from scooter usage appeared to be minor collisions.

Valuing the health state 'tinnitus': differences between patients and the general public

OBJECTIVE

In recent years, prioritisation in health care has gained increasing attention. However, rankings of interventions might depend on whom valuations of health states are elicited from. This paper's objective is to compare tinnitus valuations by patients and the general public.

METHODS

Groups of 210 patients and 210 adults not (currently) affected were interviewed to elicit valuations using visual analogue scale (VAS), time trade-off (TTO) and standard gamble (SG). MANOVA is used to test for group differences, controlling for sex and age.

RESULTS

For all elicitation methods, valuations significantly differ in that patients report higher values than the general public respondents. Most notably, on the visual analogue scale which varies between 0 ('worst imaginable health') and 1 ('best imaginable health'), patients elicit a mean score of 0.54, and the general public 0.34 (those with former tinnitus experience) and 0.35 (without experience), respectively (F(2,377)=55.67, p<0.001). That is, patients valuate tinnitus as less severe than unaffected people.

CONCLUSION

As for other health states, tinnitus valuations differ depending on whether values of patients or the general public are elicited. These differences should be taken into account in health care evaluation and planning.

Understanding Medical Decision Making in Hand Surgery

The practice of medicine takes place in an environment of uncertainty. Expected value decision making, prospect theory, and regret theory are three theories of decision making under uncertainty that may be used to help us learn how patients and physicians make decisions. These theories form the underpinnings of decision analysis and provide the opportunity to introduce the broad discipline of decision science. Because decision analysis and economic analysis are underrepresented in upper extremity surgery, the authors believe these are important areas for future research.

Patient Preferences in Prostate Cancer: A Clinician's Guide to Understanding Health Utilities

Prostate cancer treatments have positive and negative outcomes that must be taken into account when deciding how to proceed with a patient's care. One way to quickly determine a patient's preferences in this situation is to ascertain their health utilities for various health states. Health utilities are underutilized but powerful tools in aiding shared decision making between patients and physicians. This review is intended to inform physicians about the different techniques available, help the physician choose among them, and aid initial development of utilities for use in the clinic by way of the tables' references. A brief history, summary of applications and current directions of health utilities, and collection of references are provided to increase the reader's overall knowledge of health utilities and encourage their use in the clinic. Ultimately, the use and choice of one of these direct preference-based measures depends on the needs of the physician.

Patient Utilities for Advanced Cancer

BACKGROUND

Utilities are critical inputs to economic analyses, yet some things remain unclear about their elicitation and application, particularly the impact of health status on values. Prospect theory predicts that current health affects values, and that losses loom larger than gains. If true, the use of utilities requires that additional complexities be considered.

OBJECTIVE

To determine the effect of current health on patient utilities for advanced cancer health states.

RESEARCH DESIGN

The research was a cross-sectional survey (n=100 patients) of utilities for 4 hypothetical advanced cancer health states. Chained gamble utilities for gains and losses in health were compared, correlations between current health status and utilities were measured, and patient utilities for experienced versus hypothetical health states were compared.

RESULTS

In this sample, gains in health were valued equivalently to losses, health status was not correlated with utility values, and patients' valuation of states equivalent to their current health did not differ from valuations of the same states by patients with better or worse current health.

CONCLUSION

This research confirms the uncertainty surrounding the effect of health status on utilities and the question of whose values to use in analyses. The findings suggest that values for health states may be independent of current health status, supporting an objective view of utilities. This research also suggests that patients may be able to provide "experienced utilities" for states other than their own, expanding the population from whom such values can be elicited. These results may dispute prospect theory's predictions regarding health state valuations.

Decision analysis in orthopaedics

Orthopaedic surgeons are faced with an ever-growing amount of clinical information from which they are required to make treatment decisions. Many of these decisions can be approached with relative certainty. However, there are many situations where the optimal decision is less clear. These treatment decisions will have competing risks, benefits, or costs. Decision analysis is one method to critically evaluate alternative treatment options with multiple potential outcomes. This method of decision making can be extremely valuable because of the growing number of treatment alternatives, and to the ever-increasing complexity of medical scenarios.

Different reference frames can lead to different hand transplantation decisions by patients and physicians

Different frames of reference can affect one's assessment of the value of hand transplantation. This can result in different yet rational decisions by different groups of individuals, especially patients and physicians. In addition, factors other than frames of reference can affect one's evaluation of hand transplantation, which can result in different decisions.

Health values and prospect theory: a comment

In a recent volume of Medical Decision Making, Treadwell and Lenert stated that under prospect theory, community members compared with patients underestimate the utility of health improvements. In this comment, the authors show that this statement holds only for a subset of possible preference functions. Furthermore, the authors provide arguments that, in general, the rater's current health state is not the appropriate reference level if applying prospect theory to health valuations.

Measuring health state preferences in women with breast hypertrophy

The purpose of this article is to introduce the measurement of utilities, or patient preferences, to the plastic surgery community. Specifically, the study demonstrated the development and validation of a utility measure for estimating the health-related quality of life in women with breast hypertrophy. Two self-administered instruments were developed, a Wheel and a Table. All subjects completed the utility assessments for their "current health" and again for "breast-related symptoms." The reliability of the instruments was assessed in repeat (test-retest) interviews of 47 women within 10 to 18 days. Utilities obtained with the new instruments were also compared with the performance of other validated utility assessment instruments, including a visual analogue scale, a computer-based instrument (U-Titer), and a preference classification system (EuroQol). Of the 47 women in the test-retest reliability study, 21 had experienced breast hypertrophy (13 had not had reduction surgery and 8 had undergone reduction mammaplasty). Mean utility values for breast-related symptoms among women with breast hypertrophy (n = 13) were: Table, 0.85; Wheel, 0.90; and U-Titer, 0.66. Current health utility scores were significantly lower for women with breast hypertrophy (n = 13), as measured by all instruments except the Wheel. The Table had good reliability and distinguished women with breast hypertrophy from those without. Although the Table provided higher utility values for the same health state compared with the computer-based interview (U-Titer), it is much less costly to implement. The Table is recommended as a reasonable alternative for use in multicenter studies of women with breast hypertrophy. The reported utility value for breast hypertrophy of 0.86 is much lower than predicted. It is comparable with the reported burden of living with other health conditions, such as moderate angina (0.90) and a kidney transplant (0.84).