This Dead or That Dead: Framing Effects in the Evaluation of Health States

OBJECTIVES

Current approaches to health state valuation rely on credible classification of states as either "better than dead" or "worse than dead" (WTD). We investigate how such evaluations of health states are affected by the framing in pairwise comparison tasks.

METHODS

We conducted an online survey with 361 participants to compare the propensity to evaluate a state as WTD under 6 frames: (A) using a regular time trade-off (TTO) choice task, (B) using a lead-time TTO choice task, (C) excluding the immediacy of death, (D) avoiding reference to the process of dying, (E) focusing on longevity, and (F) focusing on improvements in quality of life. Each participant evaluated 9 EQ-5D-5L health states using 3 frames. The frames were compared using several statistical approaches to confirm robustness to indirect comparisons or respondent heterogeneity and inattentiveness.

RESULTS

The odds of a state being evaluated as WTD, compared with frame A, increase 2.7-fold and 1.5-fold in frame B and E, respectively, and decrease >5-fold in frame F. Frames C and D do not differ significantly from frame A.

CONCLUSIONS

Different framings for questions about whether a state is WTD or better than dead, even if theoretically equivalent, yield substantially different results. Notably, whether a state is evaluated as WTD differs greatly between the regular TTO and lead-time TTO choice tasks and when either final outcomes or improvements over time are considered.

Health-Related Quality of Life Scores and Values as Predictors of Mortality: A Scoping Review

Health-related quality of life (HRQoL) can be assessed through measures that can be generic or disease specific, encompass several independent scales, or employ holistic assessment (i.e., the derivation of composite scores). HRQoL measures may identify patients with differential risk profiles. However, the usefulness of generic and holistic HRQoL measures in identifying patients at higher risk of death is unclear. The aim of the present study was to undertake a scoping review of generic, holistic assessments of HRQoL as predictors of mortality in general non-patient populations and clinical sub-populations with specified conditions or risk factors in persons 18 years or older. Five databases were searched from 18 June to 29 June 2020 to identify peer-reviewed published articles. The searches were updated in August 2022. Reference lists of included and cited articles were also searched. Of 2552 articles screened, 110 met criteria for inclusion. Over one-third of studies were from North America. Most studies pertained to sub-populations with specified conditions and/or risk factors, almost a quarter for people with cardiovascular diseases. There were no studies pertaining to people with mental health conditions. Nearly three-quarters of the studies used a RAND Corporation QoL instrument, predominantly the SF-36, and nearly a quarter, a utility instrument, predominantly the EQ-5D. HRQoL was associated with mortality in 67 of 72 univariate analyses (92%) and 100 of 109 multivariate analyses (92%). HRQoL was found to be associated with mortality in the general population and clinical sub-populations with physical health conditions. Whether this relationship holds in people with mental health conditions is not known. HRQoL assessment may be useful for screening and/or monitoring purposes to understand how people perceive their health and well-being and as an indicator of mortality risk, encouraging better-quality and timely patient care to support and maximize what may be a patient's only modifiable outcome.

Should the Preference-Based Index Set of Values Be Country or Disease Specific? An Analysis Using Data From Women With Symptoms of Overactive Bladder

OBJECTIVES

Overactive bladder (OAB) and urinary incontinence (UI) are common conditions among women. We aimed to verify the difference between the preference-based index extracted from short-form six-dimension version one (SF-6Dv1) in women with OAB using different country-specific value sets, translate and cross-culturally adapt the King's Health Questionnaire Five Dimension (KHQ-5D) into Brazilian Portuguese, and examine the association between preference-based index obtained by the SF-6Dv1 and KHQ-5D.

METHODS

This cross-sectional study included 387 women with OAB, divided into groups with and without UI. The participants answered the sociodemographic questionnaire, KHQ, KHQ-5D, and SF-6Dv1. A two-way mixed analysis of variance, with post hoc to multiple comparisons were applied and a Spearman's test was applied to verify the correlation between the preference-based index of SF-6Dv1 and KHQ-5D.

RESULTS

The main analysis showed a statistically significant interaction between the presence of UI and the value set obtained from the different countries (P = .005, Cohen's d = 0.02). The post hoc analyses showed that there was a statistically significant main effect of the value sets obtained from different countries (P < .001, d = 0.63) and in the presence of UI (P = .012, d = 0.02). The correlations between the preference-based index obtained from different countries using the SF-6Dv1 and KHQ-5D were significant.

CONCLUSIONS

Differences were observed between the preference-based index obtained in different countries and presence of UI, although positive and significant results were observed in the correlation between preference-based index from different countries. The correlation between general and specifics preference-based index was small; the SF-6Dv1 could be used in cost-utility studies for this population.

A Systematic Literature Review of Health Utility Values in Breast Cancer

BACKGROUND

Health utility values (HUVs) are important inputs to the cost-utility analysis of breast cancer interventions.

PURPOSE

Provide a catalog of breast cancer-related published HUVs across different stages of breast cancer and treatment interventions.

DATA SOURCES

Systematic searches of MEDLINE, MEDLINE In-Process, EMBASE, Web of Science, CINAHL, PsycINFO, EconLit, and Cochrane databases (2005-2017).

STUDY SELECTION

Studies published in English that reported mean or median HUVs using direct or indirect methods of utility elicitation for breast cancer.

DATA EXTRACTION

Independent reviewers extracted data on a preestablished and piloted form; disagreements were resolved through discussion.

DATA ANALYSIS

Mixed-effects meta-regression using restricted maximum likelihood modeling was conducted for intervention type, stage of breast cancer, and typical clinical and treatment trajectory of breast cancer patients to assess the effect of study characteristics (i.e., sample size, utility elicitation method, and respondent type) on HUVs.

DATA SYNTHESIS

Seventy-nine studies were included in the review. Most articles (n = 52, 66%) derived HUVs using the EQ-5D. Patients with advanced-stage breast cancer (range, 0.08 to 0.82) reported lower HUVs as compared with patients with early-stage breast cancer (range, 0.58 to 0.99). The meta-regression analysis found that undergoing chemotherapy and surgery and radiation, being diagnosed with an advanced stage of breast cancer, and recurrent cancer were associated with lower HUVs. The members of the general public reported lower HUVs as compared with patients.

LIMITATIONS

There was considerable heterogeneity in the study population, health states assessed, and utility elicitation methods.

CONCLUSION

This review provides a catalog of published HUVs related to breast cancer. The substantial heterogeneity in the health utility studies makes it challenging for researchers to choose which HUVs to use in cost-utility analyses for breast cancer interventions.

Health-Related Quality of Life Associated With Pain Health States in Spinal Cord Stimulation for Chronic Neuropathic Pain

OBJECTIVES

A substantial proportion of patients have recently reported pain reduction levels of ≥80% following treatment with Evoked Compound Action Potential (ECAP) spinal cord stimulation (SCS). The additional health-related quality of life (HRQoL) utility gain that can be achieved in this patient group is unclear. The aim of this study is to quantify the HRQoL utility values seen in a remission health state (defined as ≥80% pain reduction) and contrast with more traditional health states of <50% and ≥50% pain relief.

MATERIALS AND METHODS

Pain intensity assessed using a 100 mm visual analogue scale (VAS) and EQ-5D-5L questionnaires were collected from 204 patients treated with ECAP SCS for chronic back and leg pain and followed up to 12 months. Utility values were derived using EQ-5D-5L responses crosswalked to EQ-5D-3L. Linear regression models adjusted for baseline utility values and patient demographics were used to compare differences in utility values across health states.

RESULTS

Patients in the remission health state (i.e., ≥80% pain reduction) consistently reported statistically significant greater utility values (+0.09 to +0.15, all p < 0.003) compared to patients reporting ≥50% pain relief at 3- and 12-month follow-up for overall, back, and leg VAS pain. The gain in utility values per percent unit of pain reduction was statistically significant at 3- and 12-month follow-up with a mean increase in HRQoL utility score between 0.003 and 0.005 observed for each percent of pain reduction.

CONCLUSION

Our analyses show that patients in a remission health state report statistically and clinically significant better HRQoL than patients experiencing lesser pain relief.

Risk Prediction for Adverse Outcomes for Frail Older Persons with Complex Healthcare and Social Care Needs Admitted to a Community Virtual Ward Model

Purpose

Population ageing is challenging healthcare systems with limited resources, necessitating the development of new care models to address the needs of older, frail community-dwellers. Community Virtual Wards (CVW) reduce adverse events in these patients. We examined the effect of an established CVW on pre-defined health trajectories (between “stable”, “deteriorating”, and “unstable” states) and characteristics that increased the likelihood of adverse healthcare outcomes (hospitalization, institutionalization and death).

Patients and Methods

We collected prospective data on frail patients admitted to a CVW in a single centre in Ireland. Relationships between risk scores, health states and adverse outcomes at 30, 60 and 90 days after admission were examined using multinomial regression analysis.

Results

In total, 88 community-dwellers, mean (±SD) age of 82.8 ±6.4 years, were included. Most were severely frail on the Rockwood Clinical Frailty Scale (mean 6.8/9 ±1.33). Reaching stability (“stable” state) within 30 days was a predictor for stability at 60 and 90 days and remaining at home. Stability was also associated with fewer care episodes (<2) (p=<0.001), a requirement for fewer healthcare professionals (HCP) (<7) (p<0.001) and lower risk of delirium (p<0.001). By contrast, being “unstable” at 60 days increased the numbers of HCP referrals (>7) and was predictive of more acute episodes (>2) and institutionalization or death (p<0.001). Predictors of adverse outcomes of either institutionalization or death included frailty status, function, mobility, nutrition, pressure ulcer risk and cognition.

Conclusion

A CVW model can provide a framework for monitoring and case management to support older people to remain at home or identify those at risk of institutional care. The use of defined health states helped to stratify those at lower or higher risk in an already high-risk frail population. Level of frailty, function, mobility, nutrition, pressure ulcer risks and cognition were predictive of remaining at home and reaching a level of stability or instability/deterioration and institutional care.

Valuing Health Status in the First Year of Life: The Infant Health-Related Quality of Life Instrument

OBJECTIVES

Efforts to evaluate HRQoL and calculate quality-adjusted life years (QALYs) for infants less than 12 months of age are hampered by the lack of preference-based HRQoL instruments for this group. To fill this gap, we developed the Infant Quality of life Instrument (IQI), which is administered through a mobile application. This article explains how weights were derived for the 4 levels of each health item.

METHODS

The IQI includes 7 health items: sleeping, feeding, breathing, stooling/poo, mood, skin, and interaction. In an online survey, respondents from the general population (n = 1409) and primary caregivers (n = 1229) from China, the United Kingdom, and the United States were presented with 10 discrete choice scenarios. Coefficients for the item levels were obtained with a conditional logit model.

RESULTS

The highest coefficients were found for sleeping, feeding, and breathing. All coefficients for these items were negative and logically ordered, meaning that more extreme levels were less preferred. Stooling, mood, skin, and interaction showed some irregularities in the ordering of coefficients. Results for caregivers and the general population were about the same.

CONCLUSIONS

The IQI is the first generic instrument to assess overall HRQoL in infants up to 1 year of age. It is short and easy to administer through a mobile application. We demonstrated how to derive values for infant health states with a discrete choice methodology. Our next step will be to normalize these values into utilities ranging from 0 (dead) to 1 (best health state) and to collect IQI values in a clinical population.

Health-related quality of life and well-being health state values among Dutch oldest old

Background: Valuing hypothetical health states is a demanding personal process, since it involves the psychological evaluation of hypothetical health states. It seems plausible that elderly individuals will value hypothetical health states differently than the general population. It is, however, important to understand the psychological division that oldest old subgroups construct between acceptable and unacceptable health states. This information can produce important evidence regarding well-being and disability conceptualization. Objective: To investigate how Dutch oldest old, conceptualize health-related quality of life health states when compared to well-being health states. In addition, we aim to compare subgroups, based on dependency classification. Methods: Ninety-nine elderly living in the Groningen, Hoogeveen and Veendam areas of the Netherlands participated in the study. Respondents were classified into three groups based on dependency levels. The respondents were asked to value hypothetical health states, a generic preference-based HRQoL and a well-being instrument, using a visual analog scale. Results: All three groups ranked the same health states, from both questionnaires, below the average across the health states. The health-related quality of life health states was consistently ranked lower than the current well-being health states. Conclusions: Health state valuations performed by the oldest old indicate that conceptually, respondents view below average health-related and well-being health states as undesirable. The results indicated that the oldest old do view deficits in health-related health states as more important than deficits in well-being health states. Since the oldest old performed the valuations, focused interventions to improve below average health-related outcomes might be the most cost-effective way to increase oldest old well-being outcomes.

Dynamic Distribution of Gut Microbiota in Goats at Different Ages and Health States

The importance of the gut microbiota (GM) of animals is widely acknowledged because of its pivotal roles in metabolism, immunity, and health maintenance. The level of health can be reflected by the dynamic distribution of GM. In this study, high-throughput sequencing of the bacterial 16S rRNA gene was used to compare the microbial populations from feces in healthy and diarrheic kids, which reflected the dynamic shift of microbiota in kids and investigated differences from adult healthy goats. Healthy kids and goats not only displayed higher species richness but also exhibited higher bacterial diversity than diarrheic kids based on the results of the operational taxonomic unit analysis, alpha diversity, and beta diversity. Firmicutes and Bacteroidetes were the most dominant phyla in all samples. At the genus level, the differences in diversity and abundance between diarrheic kids and the other two groups were gradually observed. In the diarrheic kid intestine, Bacteroides remained the dominant species, and the proportion of Clostridium_sensu_stricto_1 and Paeniclostridium increased, whereas Rikenellaceae_RC9_gut_group, Ruminococcaceae_UCG-005, and Christensenellaceae_R-7_group were significantly reduced. The results showed the differences of GM in diarrheic kids and healthy kids were significant while in kids and goats were not obvious. Differences in the composition of intestinal microbiota may not be the cause of diarrhea, and some changes of bacterial richness may guide our interpretation of diarrhea. This study is the first to investigate the distribution of GM in Boer goats with different ages and health states. Furthermore, this study will provide a theoretical basis for the establishment of a prevention and treatment system for goat diarrhea.

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.

Improving scope sensitivity in contingent valuation: Joint and separate evaluation of health states

We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called "evaluability," does not apply here. The paper presents new explanations based on the role of preference imprecision.

A Simple and Practical Index to Measure Dementia-Related Quality of Life

BACKGROUND

Research on new treatments for dementia is gaining pace worldwide in an effort to alleviate this growing health care problem. The optimal evaluation of such interventions, however, calls for a practical and credible patient-reported outcome measure.

OBJECTIVES

To describe the refinement of the Dementia Quality-of-life Instrument (DQI) and present its revised version.

METHODS

A prototype of the DQI was adapted to cover a broader range of health-related quality of life (HRQOL) and to improve consistency in the descriptions of its domains. A valuation study was then conducted to assign meaningful numbers to all DQI health states. Pairs of DQI states were presented to a sample of professionals working with people with dementia and a representative sample of the Dutch population. They had to repeatedly select the best DQI state, and their responses were statistically modeled to obtain values for each health state.

RESULTS

In total, 207 professionals working with people with dementia and 631 members of the general population completed the paired comparison tasks. Statistically significant differences between the two samples were found for the domains of social functioning, mood, and memory. Severe problems with physical health and severe memory problems were deemed most important by the general population. In contrast, severe mood problems were considered most important by professionals working with people with dementia.

DISCUSSION

The DQI is a simple and feasible measurement instrument that expresses the overall HRQOL of people suffering from dementia in a single meaningful number. Current results suggest that revisiting the discussion of using values from the general population might be warranted in the dementia context.

A Quality-Adjusted Life-Year Measure for Multiple Sclerosis: Developing a Patient-Reported Health State Classification System for a Multiple Sclerosis-Specific Preference-Based Measure

BACKGROUND

Increasingly, generic preference-based measures of health-related quality of life (HRQOL) are used to estimate quality-adjusted life-years to inform resource allocation decisions. Evidence suggests that generic measures may not be appropriate for multiple sclerosis (MS).

OBJECTIVES

To report the first stage in the development of an MS-specific preference-based measure to quantify the impact of MS and its treatment: deriving a health state classification system, which is amenable to valuation, from the 29-item Multiple Sclerosis Impact Scale (MSIS-29), a widely used patient-reported outcome measure in MS.

METHODS

The dimensional structure of the MSIS-29 was determined using factor analysis and a conceptual framework of HRQOL in MS. Item performance was assessed, using Rasch analysis and psychometric criteria, to enable the selection of one item to represent each dimension of HRQOL covered by the MSIS-29. Analysis was undertaken using a sample (N = 529) from a longitudinal study of people with MS. Results were validated by repeating the analysis with a second sample (N = 528).

RESULTS

Factor analysis confirmed the two-subscale structure of the MSIS-29. Both subscales covered several conceptually independent dimensions of HRQOL. Following Rasch and psychometric analysis, an eight-dimensional classification system named the MSIS-8D was developed. Each dimension was represented by one item with four response levels.

CONCLUSIONS

Combining factor analysis with conceptual mapping, and Rasch analysis with psychometric criteria, provides a valid method of constructing a classification system for an MS-specific preference-based measure. The next stage is to obtain preference weights so that the measure can be used in studies investigating MS.

CHILDSPLA: a collaboration between children and researchers to design and animate health states

AIM

The children's health state preferences learnt from animation (CHILDSPLA) project developed an interactive application presented on a touch screen device using an animated character to collect information from children about their health.

BACKGROUND

The underlying hypothesis was that health information could be directly collected from children as young as 4 years old by the use of animated characters. This paper describes in detail how children were involved in the development of the application, and recounts both the challenges and benefits of that process. A child psychologist and an animation filmmaker worked closely with children to design a character and to animate it to represent different health states. Children were recruited from a local primary school (n = 38) and a paediatric specialist hospital (n = 36). Diverse interactive activities were organized to help children give feedback and guide the design process. The activities for each session were adjusted to the children's needs, based on the experience of previous sessions.

RESULTS

The character and the animations were modified according to the feedback provided by the children.

CONCLUSIONS

Developing the CHILDSPLA app in collaboration with children was a worthwhile and enriching experience, despite the required iteration and extension of the design process, as it enabled us to adjust the tool to the children's needs.

Cost-effectiveness of ranibizumab versus aflibercept in the treatment of visual impairment due to diabetic macular edema: a UK healthcare perspective

BACKGROUND

Ranibizumab and aflibercept are alternative anti-vascular endothelial growth factor agents approved for the treatment of visual impairment (VI) due to diabetic macular edema (DME).

OBJECTIVE

To estimate, from a UK healthcare perspective, the cost-effectiveness of ranibizumab 0.5 mg pro re nata (PRN) and ranibizumab 0.5 mg treat and extend (T&E) compared with aflibercept 2 mg every 8 weeks after five initial monthly doses (2q8) in the treatment of VI due to DME.

METHODS

A Markov model previously reviewed by the National Institute for Health and Care Excellence was used to simulate the long-term outcomes and costs of treating DME. Health states were defined by increments of ten letters in best-corrected visual acuity (BCVA), with a 3-month cycle length. Patients could gain (or lose) a maximum of two health states between cycles. A 3-year treatment time frame and a lifetime horizon were used. Future costs and health outcomes were discounted at 3.5% per annum. Patient baseline characteristics and the efficacy of ranibizumab PRN were derived using data from the RESTORE study. The relative efficacies of ranibizumab PRN, ranibizumab T&E, and aflibercept were assessed with a network meta-analysis. Different utilities were assigned based on BCVA and whether the treated eye was the better- or the worse-seeing eye. Sensitivity analyses tested the robustness of the model.

RESULTS

Lifetime costs per patient of treating DME were £20,019 for ranibizumab PRN, £22,930 for ranibizumab T&E, and £25,859 for aflibercept 2q8. Ranibizumab was dominant over aflibercept, with an incremental gain of 0.05 quality-adjusted life-years (QALYs) and cost savings of £5,841 (PRN) and £2,930 (T&E) compared with aflibercept. Ranibizumab PRN and ranibizumab T&E had 79% and 67% probability, respectively, of being cost-effective relative to aflibercept at a willingness-to-pay threshold of £20,000/QALY. When assuming the higher end of PRN injection frequency (15.9 over 3 years), the cost savings associated with ranibizumab were £3,969.

CONCLUSION

From a UK healthcare perspective, ranibizumab provides greater health gains with lower overall costs than aflibercept in patients with VI due to DME.

Utility values in health technology assessments: a statistician's perspective

This paper provides an introduction to utilities for statisticians working mainly in clinical research who have not had experience of health technology assessment work. Utility is the numeric valuation applied to a health state based on the preference of being in that state relative to perfect health. Utilities are often combined with survival data in health economic modelling to obtain quality-adjusted life years. There are several methods available for deriving the preference weights and the health states to which they are applied, and combining them to estimate utilities, and the clinical statistician has valuable skills that can be applied in ensuring the robustness of the trial design, data collection and analyses to obtain and handle this data. In addition to raising awareness of the subject and providing source references, the paper outlines the concepts and approaches around utilities using examples, discusses some of the key issues, and proposes areas where statisticians can collaborate with health economic colleagues to improve the quality of this important element of health technology assessment.

Valuing the health states associated with Chlamydia trachomatis infections and their sequelae: a systematic review of economic evaluations and primary studies

OBJECTIVES

Economic evaluations of interventions to prevent and control sexually transmitted infections such as Chlamydia trachomatis are increasingly required to present their outcomes in terms of quality-adjusted life-years using preference-based measurements of relevant health states. The objectives of this study were to critically evaluate how published cost-effectiveness studies have conceptualized and valued health states associated with chlamydia and to examine the primary evidence available to inform health state utility values (HSUVs).

METHODS

A systematic review was conducted, with searches of six electronic databases up to December 2012. Data on study characteristics, methods, and main results were extracted by using a standard template.

RESULTS

Nineteen economic evaluations of relevant interventions were included. Individual studies considered different health states and assigned different values and durations. Eleven studies cited the same source for HSUVs. Only five primary studies valued relevant health states. The methods and viewpoints adopted varied, and different values for health states were generated.

CONCLUSIONS

Limitations in the information available about HSUVs associated with chlamydia and its complications have implications for the robustness of economic evaluations in this area. None of the primary studies could be used without reservation to inform cost-effectiveness analyses in the United Kingdom. Future debate should consider appropriate methods for valuing health states for infectious diseases, because recommended approaches may not be suitable. Unless we adequately tackle the challenges associated with measuring and valuing health-related quality of life for patients with chlamydia and other infectious diseases, evaluating the cost-effectiveness of interventions in this area will remain problematic.

Societal Preferences for EQ-5D Health States from a Brazilian Population Survey

OBJECTIVE

To elicit preference weights for a subset of EuroQol five-dimensional (EQ-5D) questionnaire health states from a representative sample for the state of Minas Gerais, Brazil, using a time trade-off (TTO) method and to analyze these data so as to estimate social preference weights for the complete set of 243 states.

METHODS

Data came from a valuation study with 3362 literate individuals aged between 18 and 64 years living in urban areas. The present study was based on quota sampling by age and sex. Face-to-face interviews were conducted in participants' own homes. A total of 99 EQ-5D questionnaire health states were selected, presorted into 26 blocks of six unique health states. Each participant valued one block together with the full health, worst health, and dead states. Each health state was evaluated by more than 100 individuals. TTO data were modeled at both individual and aggregate levels by using ordinary least squares and random effects methods.

RESULTS

Values estimated by different models yielded very similar results with satisfactory goodness-of-fit statistics: the mean absolute error was around 0.03 and fewer than 25% of the states had a mean absolute error greater than 0.05. Dummies coefficients for each level within the EQ-5D questionnaire dimensions of health displayed an internally consistent ordering, with the mobility dimension demonstrating the largest value decrement. The values of mean observed transformed TTO values range from 0.869 to-0.235.

CONCLUSIONS

The study demonstrates the feasibility of conducting face-to-face interviews using TTO in a Brazilian population setting. The estimated values for EQ-5D questionnaire health states based on this Minas Gerais survey represent an important first step in establishing national Brazilian social preference weights for the EQ-5D questionnaire.

Descriptions of health states associated with increasing severity and frequency of hypoglycemia: a patient-level perspective

AIMS

We sought to develop descriptions of health states associated with daytime and nocturnal hypoglycemia in a structured fashion from the patient's perspective under different combinations of severity and frequency of hypoglycemic events.

METHODS

An expert meeting followed by two patient focus groups was used to develop comprehensive descriptions of acute consequences of severe and non-severe, daytime and nocturnal hypoglycemia. Patients with diabetes (type 1 = 85, type 2 = 162) from a survey panel then validated these descriptions and assessed how often they worried and took different actions to prevent hypoglycemia. Severity and frequency of hypoglycemia were compared with respect to how often people worried and took actions to prevent an event. The effect of hypoglycemia on 35 different life activities was quantitatively compared for patients who had and had not experienced a severe hypoglycemic event.

RESULTS

At least 95% of respondents agreed that the detailed patient-level descriptions of health states accurately reflected their experience of severe and non-severe, daytime and nocturnal hypoglycemia, thereby validating these descriptions. Respondents who had experienced a severe hypoglycemic event were generally more adversely affected in their worries and actions and life events than those who experienced only non-severe events; those who experienced nocturnal events were more affected than those who experienced only daytime events.

CONCLUSION

The negative psychosocial consequences and undesirable compensatory behaviors arising from hypoglycemia underscore the importance of preventing severe episodes, particularly severe nocturnal episodes. These validated descriptions for hypoglycemia from the patient's perspective may also help inform future qualitative and quantitative research.

Health states of women after conservative surgery and radiation for breast cancer

The aim of the study is to use the EQ-5D instrument to evaluate the long-term health states of women with early stage breast cancer treated by breast-conserving surgery and radiation. A total of 1,050 women treated with conservative surgery and radiation with or without systemic therapy completed 2,480 questionnaires during follow-up visits. The EQ-5D is a standardized and validated instrument for measuring quality of life outcomes. The descriptive system uses 5 dimensions of health with three possible levels of response that combine into 243 (3(5)) possible unique health states that are each assigned a values-based index score from 0 to 1. The visual analog scale (VAS) rates health on a simple vertical line from 0 to 100. Higher scores correspond to better health status. The mean index scores were 0.89 (95% CI: 0.87-0.91) at 5 years, 0.9 (95% CI: 0.86-0.94) at 10 years, and 0.9 (95% CI: 0.83-1.0) at 15 years. There were no significant differences in health states between patients by age when compared with U.S. controls. There was a statistically significant positive correlation between the results of the VAS and descriptive system. Significant trends in health dimensions over 15 years were increased problems with self-care and decreased problems with anxiety/depression, pain/discomfort, and performing usual activities. This study of EQ-5D is unique and demonstrates very high quality of life in patients long-term after breast-conserving surgery and radiation. These health states are comparable to the adult female U.S. population. These data will provide valuable patient utility information for informing decision analyses investigating new treatments in women with breast cancer.