Relationship between psychometric and utility-based approaches to the measurement of health-related quality of life

Impact of direct-acting antiviral treatment on health utility in patients with chronic hepatitis C in hospital and community settings

BACKGROUND

Direct-acting antiviral agents (DAAs) have transformed chronic hepatitis C (CHC) treatment. Continued affordable access to DAAs requires updated cost-effectiveness analyses (CEA). Utility is a preference-based measure of health-related quality of life (HRQoL) used in CEA. This study evaluated the impact of DAAs on utilities for patients with CHC in two clinical settings.

METHODS

This prospective longitudinal study included patients aged ≥18 years, diagnosed with CHC and scheduled to begin DAA treatment, from two tertiary care hospital clinics and four community clinics in Toronto, Calgary, and Montreal. Patients completed two utility instruments (EQ-5D-5L and Health Utilities Index 2/3 (HUI2/3)) before treatment, 6 weeks after treatment initiation, and 12 weeks and 1 year after treatment completion. We measured utilities for all patients, and for hospital-based and community-based groups.

RESULTS

Between 2017 and 2020, 209 patients (126 hospital-based, 83 community-based; average age 53 years; 65% male) were recruited, and 143 completed the 1-year post-treatment assessment. Pre-treatment, utilities were (mean ± standard deviation) 0.77 ± 0.21 (EQ-5D-5L), 0.69 ± 0.24 (HUI2) and 0.58 ± 0.34 (HUI3). The mean changes at 1-year post-treatment were 0.035, 0.038 and 0.071, respectively. While utilities for hospital-based patients steadily improved, utilities for the community-based cohort improved between baseline and 12-weeks post-treatment, but decreased thereafter.

DISCUSSION

This study suggests that utilities improve after DAA treatment in patients with CHC in a variety of settings. However, community-based patients may face challenges related to comorbid health and social conditions that are not meaningfully addressed by treatment. Our study is essential for valuing health outcomes in CHC-related CEA.

Disparities in health utilities among hepatitis C patients receiving care in different settings

BACKGROUND: Although chronic hepatitis C (CHC) disproportionately affects marginalized individuals, most health utility studies are conducted in hospital settings which are difficult for marginalized patients to access. We compared health utilities in CHC patients receiving care at hospital-based clinics and socio-economically marginalized CHC patients receiving care through a community-based program. METHODS: We recruited CHC patients from hospital-based clinics at the University Health Network and community-based sites of the Toronto Community Hep C Program, which provides treatment, support, and education to patients who have difficulty accessing mainstream health care. We elicited utilities using six standardized instruments (EuroQol-5D-3L [EQ-5D], Health Utilities Index Mark 2/Mark 3 [HUI2/HUI3], Short Form-6D [SF-6D], time trade-off [TTO], and Visual Analogue Scale [VAS]). Multivariable regression analysis was performed to examine factors associated with differences in health utility. RESULTS: Compared with patients recruited from the hospital setting (n = 190), patients recruited from the community setting (n = 101) had higher unemployment (87% versus 67%), history of injection drug use (88% versus 42%), and history of mental health issue(s) (79% versus 46%). Unadjusted health utilities were lower in community than hospital patients (e.g., EQ-5D: 0.722 [SD 0.209] versus 0.806 [SD 0.195]). Unemployment and a history of mental health issue(s) were significant predictors of low health utility. CONCLUSIONS: Socio-economically marginalized CHC patients have lower health utilities than patients typically represented in the CHC utility literature. Their utilities should be incorporated into future cost-utility analyses to better represent the population living with CHC in health policy decisions.

Item Selection for a New Health-Related Quality of Life Measure for Parkinson's Disease: The Preference-Based Parkinson's Disease Index (PB-PDI)

Background

Parkinson's disease (PD) is a neurodegenerative condition, predominantly affecting older adults. Preference-based measures (PBMs) can be used to make decisions about the cost-utility of different treatments. There are currently no PBMs for health-related quality of life (HRQoL) for PD. A previous study identified important health domains for individuals with PD and developed an item pool from existing measures per domain. The current study aims to contribute to the development of a new disease-specific PBM of HRQoL for PD by reducing the current pool of items according to the preferences of individuals with PD.

Methods

Fifty-three participants completed a visual analogue scale (VAS) of self-perceived health, the prototype PBM measure, and an item importance rating. To reduce the item pool, the following were calculated: (1) inter-item correlations; (2) impact of each item based on item performance and importance rating; (3) directionality of response options by comparing the VAS scores against each item.

Results

Participants (male = 54.7%, age = 60.0 ± 10.2) had a median Hoehn and Yahr score of 2.5 (interquartile range = 1). Items supported for inclusion by this analysis were sleep, fatigue, tremor, mood, walking, memory, and dexterity. Items demonstrating a logical decrease in VAS score with each increasing severity level were sleep, memory, tremor, fatigue, and mood.

Conclusion

This PBM will be critical for informing decisions about the cost-utility of PD treatments, guiding the resource allocation within our healthcare system. Future research will include cognitive debriefing with individuals with PD to refine item response options.

The Use of Generic Patient-Reported Outcome Measures in Emergency Department Surveys: Discriminant Validity Evidence for the Veterans RAND 12-Item Health Survey and the EQ-5D

OBJECTIVES

This study aimed to compare discriminant validity evidence of 2 generic patient-reported outcome measures (PROMs), the Veterans RAND 12-Item Health Survey (VR-12) and level 5 of EQ-5D (EQ-5D-5L), for use in emergency departments (EDs).

METHODS

Data were obtained via a cross-sectional survey of 5876 patients in British Columbia (Canada) who completed a questionnaire after visiting an ED in 2018. We compared the extent to which the VR-12 and the EQ-5D-5L distinguished among groups of ED patients with different levels of comorbidity burden and self-reported physical and mental or emotional health status. Multivariable logistic regression was used to evaluate the ability of the 2 PROMs to identify patients presenting with a mental health (MH) condition.

RESULTS

All the measures produced small effect sizes (ESs) for discriminating comorbidity levels (R² range: 0.00 [VR-12 mental component summary {MCS}] to 0.10 [VR-12 physical component summary score]). The EQ-5D visual analog scale offered the largest ES for discriminating self-reported physical health (R² = 0.48), whereas the MCS, the VR-12 MH domain, and the EQ-5D-5L anxiety/depression dimension had the largest ESs for discriminating self-reported mental or emotional health (R² = 0.42, 0.40, and 0.38, respectively). The MCS produced a medium ES (R² = 0.42) along with the VR-12 utility score (R² = 0.27) compared with the EQ-5D-5L index (R² = 0.19). Having a MH condition was predominantly identified by the MCS (Pratt index = 0.56).

CONCLUSIONS

The VR-12 PROM provides a more comprehensive measurement of MH than the EQ-5D-5L, which is important to inform healthcare service needs for patients who present in EDs with MH challenges.

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

Background

The time trade-off (TTO) is a commonly used preference based method to assess health related values used in health economic analyses. Surprisingly little is known about the factors influencing the TTO. Since self-esteem is a predictor for health status measurements, and health status affects the TTO, we studied the relation between self-esteem and TTO values.

Methods

Data of 128 patients treated with vitamin K antagonists for venous thromboembolism on Short Form-36 (SF-36), Rosenberg self-esteem and patient characteristics were collected. TTO values were obtained for ‘current health’ and three chronic health states related to thrombosis, in face-to-face interviews with patients. Regression analyses were performed with the TTO as dependent variable. Analyses were performed in two groups; the complete sample, and traders only. Selected predictors were entered in four blocks: socio-demographic factors, medical-clinical factors, health status, and self-esteem.

Results

In the complete sample (N = 128), bivariate regression analysis showed that self-esteem explained 14% of the variance in TTO values for current health (p < .000, N = 117). In traders, multivariate regression analysis showed a significant relationship between self-esteem and TTO values for current health. Self-esteem increased the variance explained (R²) by 8.8%, from 28.1 to 36.9%, (p = 0.01; N = 57). For hypothetical health states, the effect of self-esteem was weaker and mostly absent after controlling for selected variables.

Conclusions

In patients willing to trade-off time, higher self-esteem was associated with higher TTO values for own current health. Self-esteem explained an appreciable proportion of the variance in TTO values in traders. For hypothetical health states such associations were weak or absent.

Validity of the EQ-5D in assessing and valuing health status in patients with schizophrenic, schizotypal or delusional disorders

Purpose

The EQ-5D is a generic questionnaire generating a health profile and a single index score for health-related quality of life. This study aimed to analyse the discriminative ability and validity of the EQ-5D in patients with schizophrenic, schizotypal or delusional disorders.

Subjects and methods

One hundred sixty-six patients with schizophrenic, schizotypal or delusional disorders (ICD-10 F2) completed the EQ-5D. Measures of quality of life (WHOQOL-BREF), utility (TTO), subjective (SCL-90R) and objective (PANSS, CGI-S) psychopathology, and functioning (GAF, GARF, SOFAS, HoNOS) provided comparison. Discriminative ability was analysed by assessing frequency distributions of EQ-5D scores. Validity of the EQ-5D self-classifier was analysed by assessing differences in related other scores grouped by response levels of EQ-5D items. Validity of the visual analogue scale (EQ VAS) and the EQ-5D index (UK social tariff) was analysed by assessing their correlation with all other scores.

Results

Seventy-nine percent of respondents reported problems in at least one of the EQ-5D dimensions (anxiety/depression 57%, usual activities 45%, pain/discomfort 44%, self-care 29%, mobility 22%). The mean EQ VAS score/EQ-5D index was 65.7/0.71. The four most frequently reported EQ-5D health states covered 45% of all respondents. For almost all EQ-5D dimensions, different response levels were associated with significantly different scores of measures used for comparison. Correlation of EQ VAS score and EQ-5D index were largest with scores of subjective measures (SCL-90R: −0.50 and −0.73; WHOQOL mental subscore 0.62 and 0.58; always P < 0.001).

Discussion and conclusion

The EQ-5D showed a moderate ceiling effect and seems to be reasonably valid in this patient group.

Utilizing the Time Trade-Off, Standard Gamble, and Willingness to Pay Utility Measures to Evaluate Health-Related Quality of Life Prior to Knee or Hip Arthroplasty

BACKGROUND

Time trade-off, standard gamble, and willingness to pay assess the number of years, risk of death, and income a patient would give up for perfect health. These questions were used to evaluate the impact knee arthritis, hip arthritis, or failed total knee (TKA) or hip arthroplasty (THA) has on patients' health-related quality of life prior to surgery.

METHODS

Three hundred sixty patients including 176 undergoing primary TKA, 127 undergoing primary THA, 31 undergoing revision TKA, and 26 undergoing revision THA were assessed. Time trade-off and standard gamble were converted to utility scores with 1.0 suggesting perfect health and 0 suggesting preference for death rather than living in current state. Willingness to pay is the percentage of yearly income that a patient would pay for perfect health.

RESULTS

The mean time trade-off, standard gamble, and willingness to pay scores were 0.74, 0.83, and 0.32 without significant difference between procedures with the numbers available for study (P = .16, .31, and 0.41, respectively). Increasing body mass index was correlated with decreasing time trade-off scores (P = .014).

CONCLUSION

Patients scheduled for primary or revision THA and TKA would accept an average 17% risk of death, lose 2.6 years of an additional 10-year life expectancy, and pay 32% of their income for perfect health. The time trade-off (0.74) was similar to patients with history of acute myocardial infarction (0.74) or minor stroke (0.72) and worse than those with chronic hepatitis C (0.83) or human immunodeficiency virus/acquired immunodeficiency syndrome infection (0.86). These data highlight the high value that patients place on adult reconstructive procedures.

Disability Weights for Pediatric Surgical Procedures: A Systematic Review and Analysis

BACKGROUND

Metrics to measure the burden of surgical conditions, such as disability weights (DWs), are poorly defined, particularly for pediatric conditions. To summarize the literature on DWs of children's surgical conditions, we performed a systematic review of disability weights of pediatric surgical conditions in low- and middle-income countries (LMICs).

METHOD

For this systematic review, we searched MEDLINE for pediatric surgery cost-effectiveness studies in LMICs, published between January 1, 1996, and April 1, 2017. We also included DWs found in the Global Burden of Disease studies, bibliographies of studies identified in PubMed, or through expert opinion of authors (ES and HR).

RESULTS

Out of 1427 publications, 199 were selected for full-text analysis, and 30 met all eligibility criteria. We identified 194 discrete DWs published for 66 different pediatric surgical conditions. The DWs were primarily derived from the Global Burden of Disease studies (72%). Of the 194 conditions with reported DWs, only 12 reflected pre-surgical severity, and 12 included postsurgical severity. The methodological quality of included studies and DWs for specific conditions varied greatly.

INTERPRETATION

It is essential to accurately measure the burden, cost-effectiveness, and impact of pediatric surgical disease in order to make informed policy decisions. Our results indicate that the existing DWs are inadequate to accurately quantify the burden of pediatric surgical conditions. A wider set of DWs for pediatric surgical conditions needs to be developed, taking into account factors specific to the range and severity of surgical conditions.

High-dose versus standard-dose amoxicillin/clavulanate for clinically-diagnosed acute bacterial sinusitis: A randomized clinical trial

Background

The recommended treatment for acute bacterial sinusitis in adults, amoxicillin with clavulanate, provides only modest benefit.

Objective

To see if a higher dose of amoxicillin will lead to more rapid improvement.

Design, setting, and participants

Double-blind randomized trial in which, from November 2014 through February 2017, we enrolled 315 adult outpatients diagnosed with acute sinusitis in accordance with Infectious Disease Society of America guidelines.

Interventions

Standard-dose (SD) immediate-release (IR) amoxicillin/clavulanate 875 /125 mg (n = 159) vs. high-dose (HD) (n = 156). The original HD formulation, 2000 mg of extended-release (ER) amoxicillin with 125 mg of IR clavulanate twice a day, became unavailable half way through the study. The IRB then approved a revised protocol after patient 180 to provide 1750 mg of IR amoxicillin twice a day in the HD formulation and to compare Time Period 1 (ER) with Time Period 2 (IR).

Main measure

The primary outcome was the percentage in each group reporting a major improvement—defined as a global assessment of sinusitis symptoms as “a lot better” or “no symptoms”—after 3 days of treatment.

Key results

Major improvement after 3 days was reported during Period 1 by 38.8% of ER HD versus 37.9% of SD patients (P = 0.91) and during Period 2 by 52.4% of IR HD versus 34.4% of SD patients, an effect size of 18% (95% CI 0.75 to 35%, P = 0.04). No significant differences in efficacy were seen at Day 10. The major side effect, severe diarrhea at Day 3, was reported during Period 1 by 7.4% of HD and 5.7% of SD patients (P = 0.66) and during Period 2 by 15.8% of HD and 4.8% of SD patients (P = 0.048).

Conclusions

Adults with clinically diagnosed acute bacterial sinusitis were more likely to improve rapidly when treated with IR HD than with SD but not when treated with ER HD. They were also more likely to suffer severe diarrhea. Further study is needed to confirm these findings.

Trial registration

ClinicalTrials.gov Identifier: NCT02340000.

Engagement with health care providers as a mediator between social capital and quality of life among a sample of people living with HIV in the United States: Path-analysis

Background

Social capital is “features of social organizations—networks, norms, and as trust that facilitate coordination and cooperation for mutual benefit”. People with high social capital have lower mortality and better health outcomes. Although utilization of social networks has grown, social capital continues to be a complex concept in relation to health promotion. This study examined 1) associations between social capital and quality of life (QoL), 2) factors of social capital leading to higher QoL among people living with HIV (PLWH), 3) role of health care providers (HCP) as a mediator between social capital and QoL.

Methods

This is a secondary analysis of the International Nursing HIV Network for HIV/AIDS Research. This cross-sectional study included 1673 PLWH from 11 research sites in the United States in 2010. Using path analysis, we examined the independent effect of social capital on QoL, and the mediating effect of PLWH engagement with HCP.

Results

The majority of participants were male (71.2%), and 45.7% were African American. Eighty-nine percent of the participants were on antiretroviral therapy. Social capital consisted of three factors — social connection, tolerance toward diversity, and community participation — explaining 87% of variance of social capital. Path analysis (RMSEA = 0, CFI = 1) found that social connection, followed by tolerance toward diversity, were the principal domain of social capital leading to better QoL (std. beta = 0.50, std. error = 0.64, p<.05). Social capital was positively associated with QoL (p<.05). About 11% of the protective effect of social capital on QoL was mediated by engagement with HCP (p<.05).

Conclusions

This study emphasizes importance of social connections and mediating role of HCP in improving QoL for PLWH. To develop social capital effectively, interventions should focus on strengthening PLWH's social connections and engagement to HCP.

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Social capital improves quality of life.

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Social capital has three factors: social connection, community participation, and tolerance towards diversity.

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Social connection is seminal domain of social capital to improve quality of life for people living with HIV.

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Engagement with health care provider mediates the relationships between social capital and quality of life.

Understanding United States Investigational Device Exemption Studies-Clinical Relevance and Importance for Healthcare Economics

INTRODUCTION

The US Food and Drug Administration allows a previously unapproved device to be used clinically to collect safety and effectiveness data under their Investigational Device Exemption (IDE) category. The process usually falls under 3 different trial categories: noninferiority, equivalency, and superiority. To confidently inform our patients, understanding the basic concepts of these trials is paramount. The purpose of this manuscript was to provide a comprehensive review of these topics using recently published IDE trials and economic analyses of cervical total disc replacement as illustrative examples.

CASE STUDY MOBI-C ARTIFICIAL CERVICAL DISC

In 2006, an IDE was initiated to study the safety and effectiveness of total disc replacement controlled against the standard of care, anterior cervical discectomy, and fusion. Under the IDE, randomized controlled trials comparing both 1 and 2 level cervical disease were completed. The sponsor designed the initial trial as noninferiority; however, using adaptive methodology, superiority could be claimed in the 2-level investigation.

REVIEWING HEALTHCARE ECONOMICS

Healthcare economics are critical in medical decision making and reimbursement practices. Once both cost- and quality-adjusted life-year (QALY) are known for each patient, the incremental cost-effectiveness ratio is calculated. Willingness-to-pay is controversial, but a commonly cited guideline considers interventions costing below 20 000 $/QALY strongly cost effective and more than 100 000 $/QALY as not cost effective.

CONCLUSION

While large Food and Drug Administration IDE studies are often besieged by complex statistical considerations and calculations, it is fundamentally important that clinicians understand at least the terminology and basic concepts on a practical level.

Preferences for public involvement in health service decisions: a comparison between best-worst scaling and trio-wise stated preference elicitation techniques

Stated preference elicitation techniques, such as discrete choice experiments and best-worst scaling, are now widely used in health research to explore the public's choices and preferences. In this paper, we propose an alternative stated preference elicitation technique, which we refer to as 'trio-wise'. We explain this new technique, its relative advantages, modeling framework, and how it compares to the best-worst scaling method. To better illustrate the differences and similarities, we utilize best-worst scaling Case 2, where individuals make best and worst (most and least) choices for the attribute levels that describe a single profile. We demonstrate this new preference elicitation technique using an empirical case study that explores preferences among the general public for ways to involve them in decisions concerning the health care system. Our findings show that the best-worst scaling and trio-wise preference elicitation techniques both retrieve similar preferences. However, the capability of our trio-wise method to provide additional information on the strength of rank preferences and its ability to accommodate indifferent preferences lead us to prefer it over the standard best-worst scaling technique.

Relationship between symptom burden and health status: analysis of the MDASI-BT and EQ-5D

Background

Patients with glioma are highly symptomatic and often have functional limitations from the time of diagnosis. Measuring health status may have value in determining impact of disease. This study provided a description of health status and utility scores in glioma patients throughout the illness trajectory using the EQ-5D (a functional measure of general health status). Furthermore, it evaluated the information provided by the MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT; a measure of symptom burden and interference) in describing health-related quality of life as assessed by the EQ-5D.

Methods

Glioma patients completed the EQ-5D and MDASI-BT. Disease and clinical details were collected by medical record review. Linear regression evaluated whether MDASI-BT scores adequately predict patient health outcomes measured by the EQ-5D.

Results

The sample included 100 patients (65% male, 78% with a glioblastoma, median age 52 [range, 20-75], 56% in active treatment). Seventy-two percent of patients reported functional limitations in at least 1 area. Extreme cases reported inability to perform usual activities (8%) and significant anxiety/depression (5%). The MDASI-BT neurologic factor and activity-related interference (walking/activity/work) explained 52% of the variability in the EQ-5D in this patient population while adjusting for the effect of tumor grade, recurrence status, and performance status.

Conclusions

The majority of glioma patients reported at least 1 functional limitation on the EQ-5D. Over half of the variance in the EQ-5D was explained by the MDASI-BT, performance status, tumor grade, and recurrence status. The resultant model demonstrates the significant contribution of symptom burden on health status in glioma patients.

Establishing disability weights for congenital pediatric surgical conditions: a multi-modal approach

BACKGROUND

Burden of disease (BoD) as measured by Disability-Adjusted Life Years (DALYs) is one of the criteria for priority-setting in health care resource allocation. DALYs incorporate disability weights (DWs), which are currently expert-derived estimates or non-existent for most pediatric surgical conditions. The objective of this study is to establish DWs for a subset of key pediatric congenital anomalies using a range of health valuation metrics with caregivers in both high- and low-resource settings.

METHOD

We described 15 health states to health professionals (physicians, nurses, social workers, and therapists) and community caregivers in Kenya and Canada. The health states summaries were expert- and community-derived, consisting of a narrated description of the disease and a functional profile described in EQ-5D-5 L style. DWs for each health state were elicited using four health valuation exercises (preference ranking, visual analogue scale (VAS), paired comparison (PC), and time trade-off (TTO)). The PC data were anchored internally to the TTO and externally to existing data to yield DWs for each health state on a scale from 0 (health) to 1 (dead). Any differences in DWs between the two countries were analyzed.

RESULTS

In total, 154 participants, matched by profession, were recruited from Kijabe, Kenya (n = 78) and Hamilton, Canada (n = 76). Overall calculated DWs for 15 health states ranged from 0.13 to 0.77, with little difference between countries (intra-class coefficient 0.97). However, DWs generated in Kenya for severe hypospadias and undescended testes were higher than Canadian-derived DWs (p = 0.04 and p < 0.003, respectively).

CONCLUSIONS

We have derived country-specific DWs for pediatric congenital anomalies using several low-cost methods and inter-professional and community caregivers. The TTO-anchored PC method appears best suited for future use. The majority of DWs do not appear to differ significantly between the two cultural contexts and could be used to inform further work of estimating the burden of global pediatric surgical disease. Care should be taken in comparing the DWs obtained in the current study to the existent list of DWs because methodological differences may impact on their compatibility.

Using Linear Equating to Map PROMIS(®) Global Health Items and the PROMIS-29 V2.0 Profile Measure to the Health Utilities Index Mark 3

BACKGROUND

Preference-based health-related quality of life (HR-QOL) scores are useful as outcome measures in clinical studies, for monitoring the health of populations, and for estimating quality-adjusted life-years.

METHODS

This was a secondary analysis of data collected in an internet survey as part of the Patient-Reported Outcomes Measurement Information System (PROMIS(®)) project. To estimate Health Utilities Index Mark 3 (HUI-3) preference scores, we used the ten PROMIS(®) global health items, the PROMIS-29 V2.0 single pain intensity item and seven multi-item scales (physical functioning, fatigue, pain interference, depressive symptoms, anxiety, ability to participate in social roles and activities, sleep disturbance), and the PROMIS-29 V2.0 items. Linear regression analyses were used to identify significant predictors, followed by simple linear equating to avoid regression to the mean.

RESULTS

The regression models explained 48 % (global health items), 61 % (PROMIS-29 V2.0 scales), and 64 % (PROMIS-29 V2.0 items) of the variance in the HUI-3 preference score. Linear equated scores were similar to observed scores, although differences tended to be larger for older study participants.

CONCLUSIONS

HUI-3 preference scores can be estimated from the PROMIS(®) global health items or PROMIS-29 V2.0. The estimated HUI-3 scores from the PROMIS(®) health measures can be used for economic applications and as a measure of overall HR-QOL in research.

A Review and Meta-Analysis of Prostate Cancer Utilities

Background. Health-related quality of life is a key issue in prostate cancer (PC) management. The authors summarized published utilities for common health-related quality of life outcomes of PC and determined how methodological factors affect them. Methods. In their systematic review, the authors identified 23 articles in English, providing 173 unique utilities for PC health states, each obtained from 2 to 422 respondents. Data were pooled using linear mixed-effects modeling with utilities clustered within the study, weighted by the number of respondents divided by the variance of each utility. Results. In the base model, the estimated utility of the reference case (scenario of a metastatic PC patient with severe sexual symptoms, rated by non-PC patients using time tradeoff) was 0.76. Disease stage, symptom type and severity, source of utility, and scaling method were associated with utility differences of 0.10 to 0.32 (P < 0.05). Utilities from PC patients rating their own health were 0.14 higher than those from the reference case, but utilities from PC patients rating scenarios were lowest. Time tradeoff yielded the highest utilities. Computer administration yielded lower utilities than personal interview (P = 0.02). Neither the scale's high anchor nor study purpose had significant effects on utilities. Conclusions. This study provides pooled utility estimates for common PC health states and describes how clinical and methodological factors can significantly affect these values. When possible, utility estimates for a modeling application should be derived similarly. Formal data synthesis methods might be useful to researchers integrating utility data from heterogeneous sources. Further exploration of these methods for this purpose is warranted.

Time Trade-Off as a Measure of Health-Related Quality of Life: Long Bone Nonunions Have a Devastating Impact

BACKGROUND

Long bone nonunions have an important impact on a patient's quality of life. The purpose of this study was to compare long bone nonunions with use of the Time Trade-Off direct measure to compute utility scores and to determine which nonunion anatomic location had the lowest health-related quality of life. The Time Trade-Off assesses the percentage of a patient's remaining life that the patient would be willing to trade for perfect health.

METHODS

Eight hundred and thirty-two consecutive long bone nonunions with Time Trade-Off data were identified and were retrospectively studied from a prospectively collected patient database. Nonunions with infections and those involving the articular portion of the bone were recorded. Time Trade-Off utility scores were obtained for all nonunion cases upon their initial clinical evaluation by a single surgeon specializing in reconstructive trauma.

RESULTS

The mean utility score of our nonunion cohort was 0.68 and it differed significantly by long bone (p = 0.037). Nonunions of the forearm had the lowest utility score (0.54), followed by the clavicle (0.59), femur (0.68), tibia or fibula (0.68), and humerus (0.71). Post hoc tests showed that patients with nonunions of the forearm had significantly lower utility scores (p = 0.031) compared with all other bones.

CONCLUSIONS

Patients diagnosed with a long bone nonunion have a very low health-related quality of life. We found that this single cohort's mean utility score was 0.68. This result is well below that of illnesses such as type-I diabetes mellitus (0.88), stroke (0.81), and acquired immunodeficiency syndrome (0.79). We found that patients with forearm nonunions had the lowest utility scores.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Measuring Quality of Life

Demonstrating the effectiveness of health care interventions requires valid measurement of the impact, or outcome of those interventions. It is increasingly suggested that Quality of Life (QoL) is the ‘gold standard’ outcome internationally (Bowling 1995) and in Australasia (Mordue & Parkin, 1997). Although a number of QoL measures are now available, questions remain about the definition of the concept itself and the psychometric properties of those measures. A consequence of major concern is that health services research or clinical studies of healthcare interventions using inadequately defined outcomes or invalid measures will in turn produce results that lack validity. This paper explores a number of such issues concerning the concept of QoL and the way it is measured.

Health impact and economic analysis of NGO-supported neurosurgery in Bolivia

OBJECT

Bolivia, one of the poorest countries in the world, ranks 108th on the 2013 Human Development Index. With approximately 1 neurosurgeon per 200,000 people, access to neurosurgery in Bolivia is a growing health concern. Furthermore, neurosurgery in nonindustrialized countries has been considered both cost-prohibitive and lacking in outcomes evaluation. A non-governmental organization (NGO) supports spinal procedures in Bolivia (Solidarity Bridge), and the authors sought to determine its impact and cost-effectiveness.

METHODS

In a retrospective review of prospectively collected data, 19 patients were identified prior to spinal instrumentation and followed over 12 months. For inclusion, patients required interviewing prior to surgery and during at least 2 follow-up visits. All causes of spinal pathology were included. Sixteen patients met inclusion criteria and were therefore part of the analysis. Outcomes measured included assessment of activities of daily living, pain, ambulation, return to work/school, and satisfaction. Cost-effectiveness was determined by cost-utility analysis. Utilities were derived using the Health Utilities Index. Complications were incorporated into an expected value decision tree.

RESULTS

Median (± SD) preoperative satisfaction was 2.0 ± 0.3 (on a scale of 0-10), while 6-month postoperative satisfaction was 7 ± 1.4 (p < 0.0001). Ambulation, pain, and emotional disability data suggested marked improvement (56%, 69%, and 63%, respectively; p = 0.035, 0.003, and 0.006). Total discounted incremental quality-adjusted life year (QALY) gain was 0.771. The total discounted cost equaled $9036 (95% CI $8561-$10,740) at 2 years. Computing the incremental cost-effectiveness ratio resulted in a value of $11,720/QALY, ranging from $9220 to $15,473/QALY in a univariate sensitivity analysis.

CONCLUSIONS

This NGO-supported spinal instrumentation program in Bolivia appears to be cost-effective, especially when compared with the conventional $50,000/QALY benchmark and the WHO endorsed country-specific threshold of $16,026/QALY. However, with a gross domestic product per capita in Bolivia equaling $4800 per year and 30.3% of the population living on less than $2 per day, this cost continues to appear unrealistic. Additionally, the study has several significant limitations, namely its limited sample size, follow-up period, the assumption that patients not receiving surgical intervention would not make any clinical improvement, the reliance on the NGO for patient selection and sustainable practices such as follow-up care and ancillary services, and the lack of a randomized prospective design. These limitations, as well as an unclear understanding of Bolivian willingness-to-pay data, affect the generalizability of the study findings and impede widespread economic policy reform. Because cost-effectiveness research may inevitably direct care decisions and prove that an effort such as this can be cost saving, a prospective, properly controlled investigation is now warranted.

A Study of the Construct Validity of the Health Utilities Index Mark 3 (HUI3) in Patients with Schizophrenia

This study assessed the construct validity of the Health Utilities Index Mark 3 (HUI3) in patients with schizophrenia. Patients with schizophrenia recruited from a tertiary mental hospital in Singapore completed the HUI3, the Short-Form 36 Health Survey (SF-36) and the Schizophrenia Quality of Life Scale (SQLS). Patients were assessed for presence and absence of 22 common psychiatric symptoms. Construct validity was assessed using 6 a priori hypotheses. Two hundred and two patients (mean age: 37.8 years, female: 52%) completed the survey. As hypothesized, overall HUI3 utility scores were correlated with SF-36 measures (Spearman's rho: 0.19 to 0.51), SQLS scales (Spearman's rho: -0.56 to -0.36), and the number of psychiatric symptoms (Spearman's rho: -0.49). The HUI3 emotion attribute was moderately correlated with SF-36 mental health (Spearman's rho: 0.45) and SQLS psychosocial scales (Spearman's rho: -0.43), and HUI3 pain attribute was strongly correlated with SF-36 bodily pain scale (Spearman's rho: 0.58). The mean HUI3 overall, emotion, cognition, and speech scores for patients with schizophrenia were 0.07, 0.09, 0.04 and 0.04 points lower than respective age-, sex- and ethnicity-adjusted population norms (p<0.001 for all, ANCOVA). This study provides evidence for the construct validity of the HUI3 in patients with schizophrenia.

Using existing data to identify candidate items for a health state classification system in multiple sclerosis

PURPOSE

In multiple sclerosis (MS), the use of preference-based measures is limited to generic measures such as Health Utilities Index Mark 2 and 3, the EQ-5D and the SF-6D. However, the challenge of using such generic preference-based measures in people with MS is that they may not capture all domains of health relevant to the disease. Therefore, the main aim of this paper is to describe the development of a health state classification system for MS patients. The specific objectives are: (1) to identify items best reflecting the domains of quality of life important to people with MS and (2) to provide evidence for the discriminative capacity of the response options by cross-walking onto a visual analog scale of health rating.

METHODS

The data come from an epidemiologically sampled population of people with MS diagnosed post-1994. The dataset consisted of 206 items relating to impairments, activity limitations, participation restrictions, health perception and quality of life. Important domains were identified from the responses to the Patient Generated Index, an individualized measure of quality of life. The extent to which the items formed a uni-dimensional, linear construct was estimated using Rasch analysis, and the best item was selected using the threshold map.

RESULTS

The sample was young (mean age 43) and predominantly female (n = 140/189; 74%). The P-PBMSI classification system consisted of five items, with three response levels per item, producing a total of 243 possible health states. Regression coefficient values consistently decreased between response levels and the linear test for trend were statistically significant for all items. The linear test for trend indicated that for each item the response options provided the same discriminative ability within the magnitude of their capacity. A scoring algorithm was estimated using a simple additive formula. The classification system demonstrated convergent validity against other measures of similar constructs and known-groups validity between different clinical subgroups.

CONCLUSION

This study produced a health state classifier system based on items impacted upon by MS, and demonstrated the potential to discriminate the health impact of the disease.

Predicting utility scores for prostate cancer: mapping the Prostate Cancer Index to the Patient-Oriented Prostate Utility Scale (PORPUS)

BACKGROUND

The Prostate Cancer Index (PCI) is a health profile instrument that measures health-related quality of life with six subscales: urinary, sexual, and bowel function and bother. The Patient-Oriented Prostate Utility Scale (PORPUS-U) measures utility (0=dead and 1=full health). Utility is a preference-based approach to measure health-related quality of life, required for decision analyses and cost-effectiveness analyses. We developed a function to estimate PORPUS-U utilities from PCI scores.

METHODS

The development data set included 676 community-dwelling prostate cancer (PC) survivors who completed the PCI and PORPUS-U by mail. We fit three linear regression models: one used original PORPUS-U scores and two used log-transformed PORPUS-U scores, one with a hierarchy constraint and one without. The model selection was performed using stepwise selection and fivefold cross validation. The validation data included 248 PC outpatients with three assessments on the PCI and PORPUS-U. Scores were retransformed for validation, with Duan's smearing estimator applied to correct potential bias. The predictive ability of the models was assessed with R(2), root mean square error (RMSE) and by comparing predicted and observed utilities.

RESULTS

The best-fitting model used the log-transformed PORPUS-U with no hierarchy constraint. The R(2) was 0.72. The RMSE ranged from 0.040 to 0.061 for the three validation data sets. Differences between predicted and observed utilities ranged from 0.000 to 0.006 but predicted utilities overestimated the lowest 5% of observed PORPUS-U scores and underestimated the highest observed scores.

CONCLUSIONS

Our algorithm can calculate PORPUS-U utility scores from PCI scores, thus supplementing descriptive quality of life measures with utility scores in PC patients. Utilities derived from mapping algorithms are useful for assigning utility to groups of patients but are less accurate at predicting utility of individual patients. We are exploring statistical methods to improve the mapping of utilities from descriptive instruments.

Factors to inform clinicians about the end of life in severe chronic obstructive pulmonary disease

CONTEXT

Palliative services have historically been offered to terminal patients with cancer, but much less so in other chronic illnesses such as chronic obstructive pulmonary disease (COPD) because of difficulties in predicting the trajectory to death.

OBJECTIVES

The goal of this study was to determine if the change over time of the key parameters (trajectory) in patients with severe COPD can independently predict short-term mortality.

METHODS

We analyzed data from 1218 patients with severe COPD. Multivariate models for trajectory change were used to forecast mortality at 12 months.

RESULTS

Changes in several variables by defined cutpoints increase significantly and independently the odds of dying in 12 months. The earliest and strongest predictors were the decrease in gait speed by 0.14 m/s or six-minute walk by 50 m (odds ratio [OR] 4.40, P<0.0001). Alternatively, if six-minute walk or gait speed were not used, change toward perceiving a very sedentary state using a single question (OR 3.56, P=0.0007) and decrease in maximal inspiratory pressure greater than 11 cmH2O (OR 2.19, P=0.0217) were predictive, followed by change toward feeling upset or downhearted (OR 2.44, P=0.0250), decrease in room air resting partial pressure of oxygen greater than 5 mmHg (OR 2.46, P=0.0156), and increase in room air resting partial pressure of carbon dioxide greater than 3 mmHg (OR 2.8, P=0.0039). Change over time models were more discriminative (higher c-statistics) than change from baseline models.

CONCLUSION

The changes in defined variables and patient-reported outcomes by defined cutpoints were independently associated with increased 12-month mortality in patients with severe COPD. These results may inform clinicians when to initiate end-of-life communications and palliative care.

Standardizing cost-utility analysis in neurosurgery

This review seeks to introduce the concept of cost-utility analysis in neurosurgery and to highlight its essential components. It also includes a suggested approach to standardization, which would help bring more credence to this research and potentially affect management choices, reimbursement, and policy.

A reference set of health utilities for long-term survivors of prostate cancer: population-based data from Ontario, Canada

PURPOSE

To measure quality of life (QOL) and utilities for prostate cancer (PC) patients and determine their predictors.

METHODS

A population-based, community-dwelling, geographically diverse sample of long-term PC survivors in Ontario, Canada, was identified from the Ontario Cancer Registry and contacted through their referring physician. Consenting patients completed questionnaires by mail: Health Utilities Index (HUI 2/3), Patient Oriented Prostate Utility Scale PORPUS-U (utility), PORPUS-P (health profile), Functional Assessment of Cancer Therapy-Prostate (FACT-P), and Prostate Cancer Index (PCI). Clinical data were obtained from chart reviews. Regression models determined the effects of a series of variables on QOL and utility.

RESULTS

We received questionnaires and reviewed charts for 585 patients (mean age 72.6, 2-13 years postdiagnosis). Mean utility scores were as follows: PORPUS-U = 0.92, HUI2 = 0.85, and HUI3 = 0.78. Mean health profile scores were as follows: PORPUS-P = 71.7, PCI sexual, urinary, and bowel function = 23.7, 79.1, and 84.6, respectively (0 = worst, 100 = best), and FACT-P = 125.1 (0 = worst, 156 = best). In multiple regression analyses, comorbidity and PCI urinary, sexual, and bowel function were significant predictors of other QOL measures. With all variables, 32-50 % of the variance in utilities was explained.

CONCLUSIONS

Many variables affect global QOL of PC survivors; only prostate symptoms and comorbidity have independent effects. Our model allows estimation of the effects of multiple factors on utilities. These utilities for long-term outcomes of PC and its treatment are valuable for decision/cost-effectiveness models of PC treatment.

Social relationships as a major determinant in the valuation of health states

PURPOSE

To empirically determine the impact of the capacity to sustain social relationships on valuing health states.

METHODS

68 clinical experts conducted a health state valuation exercise in five sites using pairwise comparison, ranking, and person trade-off as elicitation methods. 23,840 pairwise comparisons of a total of 379 health states were analyzed by conditional logistic regression.

RESULTS

Social relationships had a clear monotonic association with perceived disability: the more limited the capacity to sustain social relationships, the more disabling the resulting health state valuations. The highest level of limitations with respect to social relationships was associated with slightly lower impact on health state valuations compared to the highest level of limitations in physical functioning.

CONCLUSIONS

Social relationships showed an independent contribution to health state valuations and should be included in health state measures.

Developing an algorithm to convert routine measures of vision into utility values for glaucoma

PURPOSE

Measures of quality of life called utility values (UVs) are needed to deliver the most cost-effective health care for glaucoma patients. UVs are rarely measured in clinical research and practice whereas clinical outcomes such as visual field are routinely collected. The aim of this study was to develop an algorithm that calculates UVs directly from combinations of routine measures of binocular visual field, visual acuity, and contrast sensitivity.

METHODS

A total of 132 outpatients with primary open angle glaucoma were recruited. The Time Trade-off (TTO) question was administered during face-to-face interviews. Binocular ETDRS logMAR visual acuity (VA(B)), binocular Pelli-Robson contrast sensitivity (CS(B)), and Humphrey 24-2 monocular visual field tests were performed on the same day. Integrated (binocular) visual field (IVF) scores were derived. Tobit regression analyses were used to model utility values based on combinations of IVF, VA(B), CS(B) and other controlling factors.

RESULTS

UVs recorded for 123 cases correlated significantly with both clinical measures of binocular visual function (r = -0.47, IVF; r = -0.48, VA(B); r = 0.50, CS(B); P <0.0001) and measures of vision-specific quality of life (r = 0.54-0.6, P <0.0001). Two final models incorporate terms for IVF and VA(B), with or without living arrangements, and explain 22% and 31% of variation in utilities. CS(B) was not included in either model due to co-linearity between CS(B) and VA(B) confounding the models.

CONCLUSION

The models provide preliminary algorithms for predicting the expected UVs for glaucoma populations directly from clinical outcomes collected routinely in clinical practice.

[Validation of the Brazilian version of the generic six-dimensional short form quality of life questionnaire (SF-6D Brazil)]

OBJECTIVE

This study seeks to present the translation and validation of the SF-6D in the Brazilian context, based on the model and the version developed in the United Kingdom in 2002.

METHODS

An observational and transversal study. The tools for assessing quality of life were applied, namely HAQ, SF-36, EQ-5D and SF-6D (2002 version). Descriptive statistics and correlation coefficients were used for data analysis.

RESULTS

200 patients with rheumatoid arthritis, with a mean age of 49.22 years, 11.16 years of disease and mean HAQ 1.02 were studied. Preferences measured by the SF-6D, the EQ-5D and the techniques of EVA, TTO and SG were found to correlate among themselves, with Pearson coefficients from 0.19 to 0.66 (p <0.01).

CONCLUSION

The SF-6D Brazil questionnaire represents a valid option for assessing preferences on economic analysis conducted in Brazil.

Development and validation of a utility weighting function for the patient-oriented prostate utility scale (PORPUS)

BACKGROUND

Previously, we developed a prostate cancer (PC)-specific health state classification system, the Patient Oriented Prostate Utility Scale (PORPUS). In this study, we developed a scoring system to allow indirect calculation of utilities from the PORPUS.

METHODS

We interviewed 234 PC outpatients, including those with newly diagnosed and metastatic disease, to obtain rating scale (RS) values on 4 to 6 levels of each of the 10 attributes of the PORPUS, and on 10 corner states (worst level on 1 attribute, best on 9). Patients also completed standard gamble (SG) and RS tasks on 4 multiattribute states (impotence and pain corner states, mild and severe PC symptoms). We used the RS and SG scores for multiattribute states to determine a risk aversion function for mapping values to utilities. We then tested 15 different strategies to estimate the multiattribute utility function (MAUF), using the single attribute disutilities for each level of the 10 PORPUS attributes, and the disutilities for the corner states. The root mean squared error (RMSE) of prediction of the SG on the 4 multiattribute states was used to identify the optimal strategy and scoring system.

RESULTS

The optimal strategy gave an RMSE of 0.06. Comparison of mean MAUF-predicted utilities to directly elicited SG utilities for the 2 multiattribute states from patients in 2 previously published studies (n = 248 and n = 141) supported the validity of the MAUF.

CONCLUSIONS

The scoring system together with the PORPUS comprise an indirect utility instrument, the PORPUS-U, which can be used in clinical and research settings.

Effect of adaptive abilities on utilities, direct or mediated by mental health?

Background

In cost-utility analyses gain in health can be measured using health state utilities. Health state utilities can be elicited from members of the public or from patients. Utilities given by patients tend to be higher than utilities given by members of the public. This difference is often suggested to be explained by adaptation, but this has not yet been investigated in patients. Here, we investigate if, besides health related quality of life (HRQL), persons' ability to adapt can explain health state utilities. Both the direct effect of persons' adaptive abilities on health state utilities and the indirect effect, where HRQL mediates the effect of ability to adapt, are examined.

Methods

In total 125 patients with Rheumatoid Arthritis were interviewed. Participants gave valuations of their own health on a visual analogue scale (VAS) and time trade-off (TTO). To estimate persons' ability to adapt, patients filled in questionnaires measuring Self-esteem, Mastery, and Optimism. Finally they completed the SF-36 measuring HRQL. Regression analyses were used to investigate the direct and mediated effect of ability to adapt on health state utilities.

Results

Persons' ability to adapt did not add considerably to the explanation of health state utilities above HRQL. In the TTO no additional variance was explained by adaptive abilities (Δ R² = .00, β = .02), in the VAS a minor proportion of the variance was explained by adaptive abilities (Δ R² = .05, β = .33). The effect of adaptation on health state utilities seems to be mediated by the mental health domain of quality of life.

Conclusions

Patients with stronger adaptive abilities, based on their optimism, mastery and self-esteem, may more easily enhance their mental health after being diagnosed with a chronic illness, which leads to higher health state utilities.

Comparison of the quality of life between patients with non-small-cell lung cancer and healthy controls

PURPOSE

We explored covariates of the quality of life (QOL) in non-small-cell lung cancer (NSCLC) patients and made a comparison with healthy controls.

METHODS

We assessed the QOL of 220 consecutive NSCLC patients at a university hospital. The QOL data were measured by the brief version of the World Health Organization's Quality of Life and by utility using the standard gamble method. We selected demographically matched healthy controls from the 2001 National Health Interview Survey for comparison. Multiple linear regression models were constructed to explore significant factors of QOL after controlling for covariates.

RESULTS

Patients with more advanced stages of NSCLC had poorer scores than did the healthy controls in the physical and psychological domains. Patients with disease duration of longer than 1 year tended to report higher physical and environment QOL than did those with NSCLC diagnosed for less than 1 year. Insight into one's own illness was associated with a higher utility, better social support, and improved financial resources.

CONCLUSIONS

QOL was significantly associated with staging and duration of NSCLC. Disease insight appears to be a positive factor for operable NSCLC patients of the Taiwanese culture, which implies that clinicians should respect patient autonomy in diagnosis disclosure.

Valuation of health states in the US study to establish disability weights: lessons from the literature

The metric of disability-adjusted life years (DALYs) has become the global standard of measuring burden of disease. DALYs are comprised of years of life lost due to premature mortality and years of healthy life lost due to living with disability. In order to calculate the second part of the DALY equation, disease specific disability weights have to be established, i.e. measures for the decline of health associated with these disease states, which vary between zero for perfect health and one for death. Although these disability weights are key for estimating DALYs, there have not been many comprehensive studies with empirical determinations of them. This article describes a systematic review on the state of the art with respect to empirically determining disability weights. Based on this review, a multi-method approach is outlined, which has also been implemented in a US study to measure burden of disease. This approach involves the use of psychometric methodology as well as economic trade-off methods for determining the value of health states. It is conceptualized as a disaggregated approach, where the disability weight of any health state can be calculated if the attributes of this health state are known. The US study received the collaboration of experts from more than 20 institutes of the National Institutes of Health and of the Centers for Disease Control and Prevention. First results will be available by the end of this year.

Cost-effectiveness of the Boston keratoprosthesis

PURPOSE

To conduct a cost-utility analysis and determine the cost-effectiveness of the Boston Keratoprosthesis (Boston Kpro).

DESIGN

Retrospective cohort study.

METHODS

setting: The Massachusetts Eye and Ear Infirmary corneal service. patients: Inclusion required a minimum 2-year follow-up. Patients with autoimmune diseases and chemical burns were excluded. Eighty-two patients were included with various indications for surgery. intervention: The keratoprosthesis is a collar button-shaped polymethylmethacrylate (PMMA) device consisting of 2 curved plates sandwiched around a corneal donor (allo)graft. The device is assembled intraoperatively and sutured to a patient's eye after removing the diseased cornea.

MAIN OUTCOME MEASURES

Average cost-effectiveness of the keratoprosthesis was determined by cost-utility analysis, using expected-value calculations and time-tradeoff utilities. The comparative effectiveness, or gain in quality-adjusted life years (QALYs), was also sought. Cost-effectiveness was compared to recently published data on penetrating keratoplasty (PK).

RESULTS

A total discounted incremental QALY gain for the Boston Kpro of 0.763 correlated with a conferred QALY gain of 20.3% for the average patient. The average cost-effectiveness of the keratoprosthesis was $16 140 per QALY.

CONCLUSIONS

Comparable to corneal transplantation, with a cost-effectiveness between $12 000 and $16 000 per QALY, the keratoprosthesis can be considered highly cost-effective.

Population-based utilities for upper extremity functions in the setting of tetraplegia

PURPOSE

People with tetraplegia face substantial physical and financial hardships. Although upper extremity reconstruction has been advocated for people with tetraplegia, these procedures are markedly underused in the United States. Population-based preference evaluation of upper extremity reconstruction is important to quantify the value of these reconstructive procedures. This study sought to establish the preferences for 3 health states: tetraplegia, tetraplegia with corrected pinch function, and tetraplegia with corrected elbow extension function.

METHODS

A computer-based, time trade-off survey was administered to a cohort of 81 able-bodied second-year medical students who served as a surrogate for the general public. This survey instrument has undergone pilot testing and has established face validity to evaluate the 3 health states of interest. Utilities were calculated based on an estimated 20 years of remaining life.

RESULTS

The mean utility for the tetraplegic health state was low. On average, respondents gave up 10.8 +/- 5.0 out of a hypothetical 20 years for perfect health, for a utility of tetraplegia equal to 0.46. For recovery of pinch function, respondents gave up an average of 6.5 +/- 4.3 years, with a corresponding health utility of 0.68. For recovery of elbow extension function, respondents gave up an average of 7.6 +/- 4.5 years, with a corresponding health utility of 0.74.

CONCLUSIONS

This study established the preferences for 2 upper extremity surgical interventions: tetraplegia with pinch and tetraplegia with elbow extension. The findings from this study place a high value on upper-limb reconstructive procedures with tetraplegia.

Measuring Preference-Based Quality of Life Using the Euroqol Eq-5D in Patients with Cerebral Aneurysms

OBJECTIVE

Cerebral aneurysms can adversely affect quality of life (QOL) via mass effect, subarachnoid hemorrhage, anxiety, or treatment sequelae. The EuroQol EQ-5D is a popular generic 5-item multiple-choice survey questionnaire that measures preference-based QOL on a 0 to 1 scale. We assessed the validity and reliability of the EQ-5D in patients with cerebral aneurysms.

METHODS

We collected data from 178 neurosurgery clinic patients with cerebral aneurysms. Patients were assigned Glasgow Outcome Scale, Rankin scale, Barthel index, and Physical Performance Test scores, and completed the Short-Form 12, Hospital Anxiety and Depression scale, and the EQ-5D. We assessed the construct validity of the EQ-5D by comparing the EQ-5D and the other scales using rank-order methods and multivariate linear regression. Reliability was assessed with Cronbach's α.

RESULTS

Patients had a mean age of 54.7 years (standard deviation, 12.6 years), 131 (74%) were women, and 98 (55%) had survived a subarachnoid hemorrhage. The mean EQ-5D score was 0.80 (standard deviation, 0.19). Construct validity of the EQ-5D was confirmed by statistically significant associations between EQ-5D and Glasgow Outcome Scale, Rankin scale, Barthel index, Physical Performance Test, Short-Form 12 Physical Component Summary, and Hospital Anxiety and Depression scores (for all, P ≤ 0.05). Multivariate regression showed that the EQ-5D scores were independently associated with the Barthel index, Short-Form 12 Physical Component Summary, and Hospital Anxiety and Depression scale anxiety and depression subscales (pseudo R2 = 0.40). Reliability was demonstrated by Cronbach's α of 0.70.

CONCLUSION

The EQ-5D is a valid and reliable instrument for measuring QOL in patients with cerebral aneurysms. The EQ-5D provides a single QOL value incorporating functional status, physical functioning, and mental health.

Predicting EuroQol (EQ-5D) scores from the patient-reported outcomes measurement information system (PROMIS) global items and domain item banks in a United States sample

Background

Preference-based health index scores provide a single summary score assessing overall health-related quality of life and are useful as an outcome measure in clinical studies, for estimating quality-adjusted life years for economic evaluations, and for monitoring the health of populations. We predicted EuroQoL (EQ-5D) index scores from patient-reported outcomes measurement information system (PROMIS) global items and domain item banks.

Methods

This was a secondary analysis of health outcome data collected in an internet survey as part of the PROMIS Wave 1 field testing. For this study, we included the 10 global items and the physical function, fatigue, pain impact, anxiety, and depression item banks. Linear regression analyses were used to predict EQ-5D index scores based on the global items and selected domain banks.

Results

The regression models using eight of the PROMIS global items (quality of life, physical activities, mental health, emotional problems, social activities, pain, and fatigue and either general health or physical health items) explained 65% of the variance in the EQ-5D. When the PROMIS domain scores were included in a regression model, 57% of the variance was explained in EQ-5D scores. Comparisons of predicted to actual EQ-5D scores by age and gender groups showed that they were similar.

Conclusions

EQ-5D preference scores can be predicted accurately from either the PROMIS global items or selected domain banks. Application of the derived regression model allows the estimation of health preference scores from the PROMIS health measures for use in economic evaluations.

Health utilities in patients with HIV/AIDS in Thailand

OBJECTIVES

We measured health utility (HU) in Thai HIV/AIDS patients using visual analog scale (VAS), EuroQOL (EQ-5D), and standard gamble (SG), determine the relationships between these HU measures and health-related quality of life (HRQOL) measures of HIV and patient characteristics, and assess the feasibility of the HU methods.

METHODS

A sample of 120 HIV/AIDS patients was identified at Bamrasnaradura Infectious Disease Institute, Thailand, during September to December, 2004. Face-to-face interviews included VAS, SG, and EQ-5D, HRQOL assessment using the Thai abbreviated version of the World Health Organization quality of life (WHOQOL-BREF THAI) and HIV-related symptom instruments, questions about ease of understanding HU approaches and sociodemographic items. Data were analyzed with repeated-measures ANOVA, followed by Dunn-Bonferroni t-test, intraclass coefficients (ICC), Spearman's rank correlation, and multiple linear regressions.

RESULTS

The mean (95% confidence interval) HUs were as follows: VAS, 0.79 (0.76-0.82); EQ-5D, 0.80 (0.77-0.84); and SG, 0.65 (0.60-0.70). A significant difference in HU by method was found (P < 0.001). Agreement by ICC was 0.71 for VAS versus EQ-5D, 0.41 for VAS versus SG, and 0.38 for EQ-5D and SG. The regression models showed that WHOQOL-BREF THAI, frequency of HIV symptoms, and patient characteristics could explain approximately 50% of the variation in the VAS and the EQ-5D and 20% in the SG(2). Among these three HU methods, the SG was the most difficult task.

CONCLUSION

VAS, EQ-5D and SG yielded different HUs for this sample. VAS and EQ-5D showed stronger construct validity with other health measures than SG. From a feasibility perspective, the SG was the least satisfactory of the three approaches.

Utility assessment in patients with mental disorders: validity and discriminative ability of the time trade-off method

BACKGROUND

Preference-based health-state values, also referred to as utility scores, are considered an important measure of outcome in the evaluation of healthcare. A common approach to elicit utility scores is the use of the time trade-off (TTO) method; however, the data on TTO utility scores in patients with mental disorders are scarce.

OBJECTIVE

To analyse the TTO method in patients with mental disorders in terms of discriminative ability, validity and the refusal to trade life time (zero trade).

METHODS

In patients with affective (n = 172), schizophrenia spectrum (n = 166) and alcohol-related (n = 160) mental disorders, TTO utilities were administered through a standardized interview. Measures of quality of life (QOL) EQ-5D, WHOQOL-BREF, subjective (SCL-90R) and objective (CGI-S) psychopathology, and functioning (GAF, GARF, SOFAS, HoNOS) provided comparison. Discriminative ability was analysed by assessing frequency distributions of TTO utilities. Validity was analysed by assessing the correlation of TTO utilities with all other scores. The association of a patient's QOL, sociodemographic and disease-related variables with zero trade was analysed by logistic regression.

RESULTS

Of patients with affective/schizophrenic/alcohol-related mental disorders, 153/143/145 (89/86/91%), respectively, completed the TTO elicitation; 29/43/28% of the respondents were zero traders. The mean TTO utility was 0.66/0.75/0.61 and the median was 0.85/0.95/0.75. TTO utility scores discriminated well among more impaired mental health states, but discrimination was limited among less impaired health states. In patients with affective and alcohol-related mental disorders, TTO utility scores were significantly correlated (mostly moderate: 0.3 < r < 0.5) with all other scores. However, in schizophrenic patients, TTO utility scores were only a little correlated with other subjective measures and not correlated with objective measures. QOL was significantly associated with zero trade; the influence of the other variables on zero trade was negligible.

CONCLUSIONS

TTO utility scores in patients with affective or alcohol-related mental disorders were reasonably valid, but discriminative ability was compromised by a ceiling effect due to zero trade. In schizophrenic patients, validity of TTO utility scores was not demonstrated.

Explaining the characteristics of the power (CRRA) utility family

The power family, also known as the family of constant relative risk aversion (CRRA), is the most widely used parametric family for fitting utility functions to data. Its characteristics have, however, been little understood, and have led to numerous misunderstandings. This paper explains these characteristics in a manner accessible to a wide audience.

Health state utilities: a framework for studying the gap between the imagined and the real

OBJECTIVES

Health state utilities play an important role in decision analysis and cost-utility analysis. The question whose utilities to use at various levels of health-care decision-making has been subject of considerable debate. The observation that patients often value their own health, but also other health states, higher than members of the general public raises the question what underlies such differences? Is it an artifact of the valuation methods? Is it adaptation versus poor anticipated adaptation? This article describes a framework for the understanding and study of potential mechanisms that play a role in health state valuation. It aims at connecting research from within different fields so that cross-fertilization of ideas may occur.

METHODS

The framework is based on stimulus response models from social judgment theory. For each phase, from stimulus, through information interpretation and integration, to judgment, and, finally, to response, we provide evidence of factors and processes that may lead to different utilities in patients and healthy subjects.

RESULTS

Examples of factors and processes described are the lack of scope of scenarios in the stimulus phase, and appraisal processes and framing effects in the information interpretation phase. Factors that play a role in the judgment phase are, for example, heuristics and biases, adaptation, and comparison processes. Some mechanisms related to the response phase are end aversion bias, probability distortion, and noncompensatory decision-making.

CONCLUSIONS

The framework serves to explain many of the differences in valuations between respondent groups. We discuss some of the findings as they relate to the field of response shift research. We propose issues for discussion in the field, and suggestions for improvement of the process of utility assessment.

Cost-effectiveness of omalizumab in adults with severe asthma: results from the Asthma Policy Model

BACKGROUND

Omalizumab (trade name Xolair) is approved by the US Food and Drug Administration for treatment of moderate-to-severe allergic asthma. Given the high acquisition cost of omalizumab, its role and cost-effectiveness in disease management require definition.

OBJECTIVE

We sought to identify the clinical and economic circumstances under which omalizumab might or might not be a cost-effective option by using a mathematic model.

METHODS

We merged published data on clinical and economic outcomes (including acute event incidence, frequency/severity of hospitalizations, and health-related quality of life) to project 10-year costs, quality-adjusted life years (QALYs), and cost-effectiveness of treatment with omalizumab in addition to inhaled corticosteroids. Sensitivity analyses were conducted by using input data ranges from a variety of sources (published clinical trials and observational databases).

RESULTS

For patients with baseline acute event rates, omalizumab conferred an additional 1.7 quality-adjusted months at an incremental cost of $131,000 over a 10-year planning horizon, implying a cost-effectiveness ratio of $821,000 per QALY gained. For patients with 5 times the baseline acute event rate, the cost-effectiveness ratio was $491,000 per QALY gained. The projected cost-effectiveness ratio could fall within a range of other programs that are widely considered to be cost-effective if the cost of omalizumab decreases to less than $200.

CONCLUSION

Omalizumab is not cost-effective for most patients with severe asthma. The projected cost-effectiveness ratios could fall within a favorable range if the cost of omalizumab decreases significantly.

CLINICAL IMPLICATIONS

Based on the high cost of omalizumab, it is especially important that clinicians explore alternative medications for asthma before initiating omalizumab.

Mapping MOS Sleep Scale scores to SF-6D utility index

OBJECTIVE

Deriving preference scores for the Medical Outcomes Study (MOS) Sleep Scale would enable its use in cost-utility analyses. The objective of this study was to map scores of the MOS Sleep Scale to a preference-based health-state utility index (SF-6D) scored from the SF-36 Health Survey (SF-36).

RESEARCH DESIGN AND METHODS

Three datasets were used: (1) the MOS study, a 4-year observational study of chronically ill patients, (2) a 7-week open-label, non-comparative clinical trial of an osmotic controlled-release oral delivery system (OROS) hydromorphone in the treatment of chronic low back pain (CLBP), and (3) a 6-week open-label randomized controlled trial of OROS hydromorphone in the treatment of pain associated with chronic osteoarthritis (OA). Various models were tested, where SF-6D was regressed onto the Sleep Problem Index-II (SLP9) in 1000 random half (developmental) samples of the MOS (n = 1413). The best fitting model was applied to the other 1000 random half (cross-validation) samples of the MOS (n = 1412), and to the two trial samples (n = 199 in the CLBP trial; n = 124 in the OA trial).

RESULTS

The best fitting model in the MOS samples included a quadratic term for the SLP9 which explained 34% of the variance in SF-6D in the developmental samples. Errors in prediction were greatest at higher SLP9 scores. Addition of demographic and clinical variables to the model explained minimal incremental amounts of variance (< 5%) in SF-6D scores. These results were replicated in the cross-validation MOS samples. In both developmental and cross-validation MOS samples, mean predicted and observed SF-6D scores were nearly identical. When the mapping algorithm developed in the MOS was applied to the CLBP sample, mean predicted SF-6D scores were 0.09 points higher than observed SF-6D scores at both baseline and final visits, while changes in predicted and observed SF-6D scores were identical.

CONCLUSION

Results indicate that it is possible to map MOS SLP9 to SF-6D yielding useable preference-based scores essential for cost-utility analyses. A limitation concerns the interpretation of SF-6D scores estimated from SLP9 scores above 60, where the prediction errors increased considerably.

Global Cost-effectiveness of Cataract Surgery

OBJECTIVE

To determine the cost-effectiveness of cataract surgery worldwide and to compare it with the cost-effectiveness of comparable medical interventions.

DESIGN

Meta-analysis.

PARTICIPANTS

Approximately 12,000 eyes in the studies selected.

METHODS

Articles were identified by searching the literature using the phrase cataract surgery, in combination with the terms cost, cost-effectiveness, and cost-utility. Terms used for the comparable medical interventions search included epileptic surgery, hip arthroplasty, knee arthroplasty, carpal tunnel surgery, and defibrillator implantation. The search was restricted to the years 1995 through 2006. Cataract surgery costs were converted to 2004 United States dollars (US$). Cost-utility was calculated using: (1) costs discounted at 3% for 12 years with a discounted quality-adjusted life years (QALY) gain of 1.25 years, and (2) costs discounted at 3% for 5 years with a discounted QALY gain of 0.143 years. The Cataract Surgery Affordability Index (CSAI) for each country was calculated by dividing the cost of cataract surgery by the gross national income per capita for the year 2004.

MAIN OUTCOME MEASURES

Cost-utility in 2004 US$/QALY and affordability of cataract surgery relative to the United States.

RESULTS

Cost-utility values for cataract surgery (first eye) varied from $245 to $22,000/QALY in Western countries and from $9 to $1600 in developing countries. In developed countries, the cost-effectiveness of cataract surgery estimated by Choosing Interventions That Are Cost Effective ranged from, in international dollars (I$), I$730 to I$2400/disability-adjusted life years (DALY) averted, and I$90 to I$370/DALY averted in developing countries. The CSAI varied from 17% to 189% in developed countries and 29% to 133% in developing countries compared with the United States. The cost-utility of other comparable medical interventions was: epileptic surgery, $4000 to $20,000/QALY; hip arthroplasty, $2300 to $4800/QALY; knee arthroplasty, $6500 to $12,700/QALY; carpal tunnel surgery, $140 to $280/QALY; and defibrillator implantation, $700 to $23,000/QALY.

CONCLUSIONS

The cost-utility of cataract surgery varies substantially, depending how the benefit is assessed and on the duration of the assumed benefit. Cataract surgery is comparable in terms of cost-effectiveness to hip arthroplasty, is generally more cost-effective than either knee arthroplasty or defibrillator implantation, and is cost-effective when considered in absolute terms. The operation is considerably cheaper in Europe and Canada compared with the United States and is affordable in many developing countries, particularly India.

Economic evaluation of tegaserod vs. placebo in the treatment of patients with irritable bowel syndrome: an analysis of the TENOR study

OBJECTIVES

Tegaserod is effective, safe, and well-tolerated in the treatment of patients with irritable bowel syndrome (IBS) with constipation. The aim of this study was to assess, from a payer perspective, the cost-effectiveness of tegaserod in the treatment of IBS patients, based on the TEgaserod in NORdic region (TENOR) trial data.

METHODS

Female and male patients (Rome II criteria) were randomized to receive tegaserod 6 mg b.i.d. or placebo for 12 weeks. Patients (247 tegaserod; 238 placebo) completed the EuroQol EQ-5D questionnaire at baseline, Week 4, and Week 12. A 12-week economic study was undertaken to assess the incremental cost-effectiveness ratio (ICER) of tegaserod in terms of cost per quality-adjusted life-year (QALY) gained. Cost-effectiveness acceptability curves were calculated to estimate the probability of tegaserod being cost-effective at different benchmark values of cost per QALY gained.

RESULTS

By assuming a daily drug cost to payers of Euro 2, Euro 3, and Euro 4, the ICER of tegaserod ranges between Euro 19,000 and Euro 38,000 per QALY gained, with the percentage of the bootstrap estimates below the willingness to pay level of Euro 50,000 per QALY gained ranging between 90% and 69%.

CONCLUSIONS

This study established directly from a randomized controlled clinical trial that tegaserod is cost-effective in the treatment of non-D-IBS patients.