Assessing Differences in Utility Scores: A Comparison of Four Widely Used Preference-Based Instruments

OBJECTIVES: To characterize the differences in utility scores (dUTY) among four commonly used preference-based Health-Related Quality of Life instruments, to evaluate the potential impact of these differences on cost-utility analyses (CUA), and to determine if sociodemographic/clinical factors influenced the magnitude of these differences. METHODS: Consenting adult Chinese, Malay and Indian subjects in Singapore were interviewed using Singapore English, Chinese, Malay or Tamil versions of the EQ-5D, Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), and SF-6D. Agreement between instruments was assessed using Bland-Altman (BA) plots. Changes in incremental cost-utility ratio (ICUR) from dUTY were investigated using eight hypothetical decision trees. The influence of sociodemographic/clinical factors on dUTY between instrument pairs was studied using multiple linear regression (MLR) models for English-speaking subjects (circumventing structural zero issues). RESULTS: In 667 subjects (median age 48 years, 59% female), median utility scores ranged from 0.80 (95% confidence interval [CI] 0.80, 0.85) for the EQ-5D to 0.89 (95% CI 0.88, 0.89) for the SF-6D. BA plots: Mean differences (95% CI) exceeded the clinically important difference (CID) of 0.04 for four of six pairwise comparisons, with the exception of the HUI2/EQ-5D (0.03, CI: 0.02, 0.04) and SF-6D/HUI2 (0.02, CI: 0.006, 0.02). Decision trees: The ICER ranged from $94,661/QALY (quality-adjusted life-year; 6.3% difference from base case) to 100,693 dollars/QALY (0.3% difference from base case). MLR: Chronic medical conditions, marital status, and Family Functioning Measures scores significantly (P-value < 0.05) influenced dUTY for several instrument pairs. CONCLUSION: Although CIDs in utility measurements were present for different preference-based instruments, the impact of these differences on CUA appeared relatively minor. Chronic medical conditions, marital status, and family functioning influenced the magnitude of these differences.     

The Health Utilities Index (HUI<Superscript>®</Superscript>): concepts,measurement properties and applications

This is a review of the Health Utilities Index (HUI^®) multi-attribute health-status classification systems, and single- and multi-attribute utility scoring systems. HUI refers to both HUI Mark 2 (HUI2) and HUI Mark 3 (HUI3) instruments. The classification systems provide compact but comprehensive frameworks within which to describe health status. The multi-attribute utility functions provide all the information required to calculate single-summary scores of health-related quality of life (HRQL) for each health state defined by the classification systems. The use of HUI in clinical studies for a wide variety of conditions in a large number of countries is illustrated. HUI provides comprehensive, reliable, responsive and valid measures of health status and HRQL for subjects in clinical studies. Utility scores of overall HRQL for patients are also used in cost-utility and cost-effectiveness analyses. Population norm data are available from numerous large general population surveys. The widespread use of HUI facilitates the interpretation of results and permits comparisons of disease and treatment outcomes, and comparisons of long-term sequelae at the local, national and international levels.     

Comparison of three societally derived health-state classification values among older African Americans with depressive symptoms

Purpose

To compare societal values across three health-state classification systems in older African Americans with depression and to describe the association of these instruments to depression severity.

Methods

We summarized baseline values for EQ-5D (US weights) and HUI2/3 (Canadian weights) and their subscales for 118 older African American participants enrolled in a randomized depression treatment trial and calculated correlations between the different instruments. We evaluated ceiling and floor effects for each instrument by comparing the proportion at the highest and lowest possible score for each tool. Also, utility scores were assessed by level of depression severity (mild, moderate, moderate severe, severe) scores as measured by the Patient Health Questionnaire (PHQ-9).

Results

Mean utility values were 0.58 (SD = 0.21) for EQ-5D, 0.52 (SD = 0.21) for HUI2, and 0.36 (SD = 0.31) for HUI3. For the EQ-5D, 72 % of participants reported having some problems on the anxiety/depression domain. On the emotion domain for the HUI2, 23 % reported the highest level of impairment compared to only 3 % on the HUI3. No participant scored at the floor for the EQ-5D, HUI2, or HUI3 index; one participant scored at the ceiling value on the HUI3 index. Correlations ranged from 0.63 to 0.82 (all of which were significant at an alpha level of 0.05). In general, utility scores trended inversely with depression level.

Conclusion

Small differences in the three preference-weighted health-state classification systems were evident for this sample of older African Americans with depressive symptoms, with HUI scores lower than EQ-5D. For this sample, utility scores were lower (i.e., poorer) than the general United States population with depression on each utility measure.     

Choosing between measures: comparison of EQ-5D,HUI2 and HUI3 in persons with hearing complaints

Objectives To generate insight into the differences between utility measures EuroQol 5D (EQ-5D), Health Utilities Index Mark II (HUI2) and Mark III (HUI3) and their impact on the incremental cost-effectiveness ratio (ICER) for hearing aid fitting Methods Persons with hearing complaints completed EQ-5D, HUI2 and HUI3 at baseline and, when applicable, after hearing aid fitting. Practicality, construct validity, agreement, responsiveness and impact on the ICER were examined. Results All measures had high completion rates. HUI3 was capable of discriminating between clinically distinctive groups. Utility scores (n = 315) for EQ-5D UK and Dutch tariff (0.83; 0.86), HUI2 (0.77) and HUI3 (0.61) were significantly different, agreement was low to moderate. Change after hearing aid fitting (n = 70) for HUI2 (0.07) and HUI3 (0.12) was statistically significant, unlike the EQ-5D UK (0.01) and Dutch (0.00) tariff. ICERs varied from €647,209/QALY for the EQ-5D Dutch tariff to €15,811/QALY for HUI3. Conclusion Utility scores, utility gain and ICERs heavily depend on the measure that is used to elicit them. This study indicates HUI3 as the instrument of first choice when measuring utility in a population with hearing complaints, but emphasizes the importance of a clear notion of what constitutes utility with regard to economic analyses.     

The association of survey language (Spanish vs. English) with Health Utilities Index and EQ-5D index scores in a United States population sample

Objective  

To explore whether variations in the EQ-5D, Health Utilities Index (HUI) Mark II (HUI2), and HUI Mark III (HUI3) index scores were associated with the survey language (Spanish vs. English) in the US Valuation of the EQ-5D Health States study.     

Cost-utility analysis of patient care in children with meningeal signs

OBJECTIVES: We designed a model of diagnostic and therapeutic interventions applied in children with meningeal signs. Using this model, we determined in a cost-utility analysis the consequences for society of different diagnostic strategies in terms of quality-adjusted life-years (QALYs) and costs. METHODS: Data were used from 360 children (0.1-15 years) visiting the pediatric emergency department of the Sophia Children's Hospital Rotterdam, The Netherlands (1988-98) with meningeal signs. Model inputs included probabilities of meningitis and adverse outcome, QALYs for years lived with long-term sequelae, and costs of tests and treatments. Mean outcome measures were costs and effects of diagnostic and therapeutic interventions in children suspected of bacterial meningitis, key determinants of the model outcomes, and evaluation of alternative diagnostic strategies and two vaccination programs in an analysis. RESULTS: The population comprised 99 children with bacterial meningitis (adverse outcome in 10), 36 with serious other bacterial infections, and 225 with self-limiting diseases. Key determinants were the risk of bacterial meningitis or sequelae, costs of treatment, and long-term morbidity. Minimizing lumbar punctures and empirical treatments using a diagnostic decision rule, without missing a single case of meningitis, was a dominant strategy to actual practice. Vaccination strategies of Streptococcus pneumoniae and Neisseria meningitidis resulted in our model in incremental cost-utility ratios of 401,965 Euro dollar ([symbol: see text])/QALY and [symbol: see text]22,635/QALY, respectively. CONCLUSIONS: Costs of long-term morbidity of bacterial meningitis largely outweigh diagnostic and treatment costs. Modeling interventions in children at risk of bacterial meningitis should include long-term consequences in terms of costs and QALYs.     

Responsiveness of generic health-related quality of life measures in stroke

Objective: To compare five preference-based generic measures of health-related quality of life (HRQOL) in terms of change scores, correlations among change scores, responsiveness, and quality adjusted life-years (QALYs) gained. Design: Observational longitudinal cohort study where clinical measures and self-assessed HRQOL measures were administered to stroke patients at baseline and at 6 months. Patients were categorized as ‘stable’, ‘some improvement’ and ‘large improvement’ using the Barthel Index, Modified Rankin Scale (MRS), and Center for Epidemiologic Studies Depression Scale (CES-D). For each group, paired t -tests and variants of effect size were used to compare the responsiveness of preference-based HRQOL summary scores, including the EQ-5D VAS and index-based score, SF-6D, and Health Utilities Index (HUI) Mark 2 (HUI2) and Mark 3 (HUI3) overall utility scores. Results: Ninety-eight of 124 (79%) patients completed the 6-month follow-up. Change scores of the EQ-Index, HUI2, and HUI3 were strongly correlated with changes in the Barthel Index and MRS, while the EQ-5D VAS had higher correlation with CES-D change scores than the other measures. The SF-6D, HUI3, and EQ-Index were generally more responsive than the HUI2 and EQ-5D Visual analogue scale (EQ-VAS). QALY estimates based on the EQ-5D index and HUI3 were twice as large as estimates based on the SF-6D and HUI2. Conclusions : The results of this study may assist in informing the selection of a preference-based generic HRQOL measure, although choice will also depend on study goals and context. We would caution against the generalization of the study results on responsiveness to conditions when more subtle change is expected.     

Comparing utility scores before and after hearing-aid provision

Utility scores were estimated for 609 hearing-impaired adults who completed EQ-5D, Health Utilities Index Mark III (HUI3) and SF-6D survey instruments both before and after being provided with a hearing aid. Pre-intervention, the mean utility scores for EQ-5D (0.80) and SF-6D (0.78) were significantly higher than the mean HUI3 utility score (0.58). Post-intervention, the mean improvement in the HUI3 (0.06 change) was significantly higher than the mean improvement according to the EQ-5D (0.01 change) or SF-6D (0.01 change). The estimated cost effectiveness of hearing-aid provision is therefore likely to be dependent on which instrument is used to measure utility.     

Comparison of the Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D in patients treated for intermittent claudication

The Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D (EQ-5D) were compared to each other and to other quality-of-life (QoL) measures in patients treated for intermittent claudication. A total of 88 patients with intermittent claudication completed the HUI3, EQ-5D, RAND 36-Item Health Survey 1.0, time tradeoff, standard gamble, and rating scale before revascularization and at follow-up at 1 month, 3 months, and 1 year. The effect of treatment on the HUI3 and EQ-5D dimensions and the overall scores, calculated using published formulas based on societal preferences, were compared. After 1 month of treatment, the majority of patients showed improvement on the HUI3 dimensions ambulation and pain and on the EQ-5D dimensions mobility, usual activities, and pain/discomfort. The mean HUI3 score was significantly higher than the mean EQ-5D score (0.66 and 0.57, respectively, p < 0.01) before treatment. After treatment, however, they were not significantly different from each other (e.g., 12 months after treatment: 0.77 and 0.75, respectively (p > 0.05). After 1 month, the scores did not change significantly over time (p > 0.05). The intraclass correlation coefficient between changes over time in the HUI3 and EQ-5D scores was 0.30, with other health-related quality-of-life (HRQoL) measures the correlations for HUI3 and EQ-5D were very similar. In conclusion, both the HUI3 and EQ-5D demonstrated an effect of treatment in patients with intermittent claudication; in addition, they showed similar relationships with other (HRQoL) measures. To demonstrate the effect of revascularization in patients with intermittent claudication, however, clinicians and researchers should be aware of the differences in the mean HUI3 and EQ-5D scores. This revised version was published online in June 2006 with corrections to the Cover Date.     

A Review of the Psychometric Performance of Selected Child and Adolescent Preference-Based Measures Used to Produce Utilities for Child and Adolescent Health

ObjectiveThis review examined the psychometric performance of 4 generic child- and adolescent-specific preference-based measures that can be used to produce utilities for child and adolescent health.MethodsA systematic search was undertaken to identify studies reporting the psychometric performance of the Child Health Utility (CHU9D), EQ-5D-Y (3L or 5L), and Health Utilities Index Mark 2 (HUI2) or Mark 3 (HUI3) in children and/or adolescents. Data were extracted to assess known-group validity, convergent validity, responsiveness, reliability, acceptability, and feasibility. Data were extracted separately for the dimensions and utility index where this was reported.ResultsThe review included 76 studies (CHU9D n = 12, EQ-5D-Y-3L n = 20, HUI2 n = 26,HUI3 n = 43), which varied considerably across conditions and sample size. EQ-5D-Y-3L had the largest amount of evidence of good psychometric performance in proportion to the number of studies examining performance. The majority of the evidence related to EQ-5D-Y-3L was based on dimensions. CHU9D was assessed in fewer studies, but the majority of studies found evidence of good psychometric performance. Evidence for HUI2 and HUI3 was more mixed, but the studies were more limited in sample size and statistical power, which was likely to have affected performance.ConclusionsThe heterogeneity of published studies means that the evidence is based on studies across a range of countries, populations and conditions, using different study designs, different languages, different value sets and different statistical techniques. Evidence for CHU9D in particular is based on a limited number of studies. The findings raise concerns about the comparability of self-report and proxy-report responses to generate utility values for children and adolescents.     

Not all "quality-adjusted life years" are equal

BACKGROUND: There is evidence that utility elicitation methods used in the calculation of quality-adjusted life years (QALYs) yield different results. It is not clear how these differences impact economic evaluations. METHODS: Using a mathematical model incorporating data on efficacy, costs, and utility values, we simulated the experiences of 100,000 hypothetical rheumatoid arthritis patients over 10 years (50,000 exposed to infliximab plus methotrexate [MTX] and 50,000 exposed to MTX alone). QALYs, were derived from the Health Utilities Index 2 and 3 (HUI2 and HUI3), the Short Form 6-D (SF-6D), and the Euroqol 5-D (EQ-5D). Incremental cost-utility ratios were determined using each instrument to calculate QALYs and the results were compared using cost-effectiveness acceptability curves. RESULTS: Using the different utility measurement methods, the mean difference in QALYs between the infliximab plus MTX and MTX groups ranged from a high of 1.95 QALYs (95% CI=1.93-1.97) using the HUI3 to 0.89 QALYs (95% CI=0.88-0.91) using the SF-6D. Adopting the commonly cited value of society's willingness to pay for a QALY of $50,000, 91% of the simulations favored the cost utility of infliximab plus MTX when using the HUI3 to calculate QALYs. However, when using the EQ-5D, HUI2, or the SF-6D utility values to calculate QALYS, the proportion of simulations that favored the cost utility of infliximab were 63%, 45%, and 12%, respectively. CONCLUSION: Depending on the method for determining utility values used in the calculation of QALYs, very different incremental cost-utility ratios are generated.     

Evidence on the longitudinal construct validity of major generic and utility measures of health-related quality of life in teens with depression

Purpose

To examine the longitudinal construct validity in the assessment of changes in depressive symptoms of widely used utility and generic HRQL instruments in teens.

Methods

392 teens enrolled in the study and completed HRQL and diagnostic measures as part of the baseline interview. HRQL measures included EuroQol (EQ-5D-3L), Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), Quality of Well-Being Scale (QWB), Pediatric Quality of Life Inventory (PEDS-QL), RAND-36 (SF-6D), and Quality of Life in Depression Scale (QLDS). Youth completed follow-up interviews 12 weeks after baseline. Sixteen youth (4.1%) were lost to follow-up. We examined correlations between changes in HRQL instruments and the Children’s Depression Rating Scale-Revised (CDRS-R) and assessed clinically meaningful change in multi-attribute utility HRQL measures using mean change (MC) and standardized response mean (SRM) among youth showing at least moderate (20%) improvement in depression symptomology.

Results

Spearman’s correlation coefficients demonstrated moderate correlation between changes in CDRS-R and the HUI2 (r?=?0.38), HUI3 (r?=?0.42), EQ-5D-3L (r?=?0.36), SF-6D (r?=?0.39), and PEDS-QL (r?=?0.39) and strong correlation between changes in CDRS-R and QWB (r?=?0.52) and QLDS (r?=???0.71). Effect size results are also reported. Among multi-attribute utility measures, all showed clinically meaningful improvements in the sample of youth with depression improvement (HUI2, MC?=?0.20, SRM?=?0.97; HUI3, MC?=?0.32, SRM?=?1.17; EQ-5D-3L, MC?=?0.08, SRM?=?0.51; QWB, MC?=?0.11, SRM?=?0.86; and SF-6D, MC?=?0.12, SRM?=?1.02).

Conclusions

Findings support the longitudinal construct validity of included HRQL instruments for the assessment of change in depression outcomes in teens. Results of this study can help inform researchers about viable instruments to include in economic evaluations for this population.

     

A Review of the Methods Used to Generate Utility Values in NICE Technology Assessments for Children and Adolescents

ObjectiveThis review summarizes and critically examines methods used to generate utilities for child and adolescent health states in previous National Institute for Health and Care Excellence (NICE) technology assessments (TA) and highly specialized technology (HST) evaluations.MethodsWe identified all NICE TA and HST evaluations in which the licensed indication for the technology included people younger than 18 and included in the review all evaluations using a cost-utility analysis.ResultsThe review includes 40 TA and HST evaluations. Most assessments generated utility values with the EQ-5D scored using the adult version of the EQ-5D either exclusively (n = 16) or alongside other utility measures and direct elicitation methods of patient own utility (n = 17), although 7 did not use the EQ-5D. Eight assessments used both the EQ-5D child- and adolescent-specific preference-based measures: Health Utilities Index Mark 2 (n = 6), child- and adolescent-specific preference-based measure for atopic dermatitis (n = 1), and youth version of the EQ-5D (EQ-5D-Y) valued using the adult EQ-5D value set (n = 1) or generated using mapping and valued using the adult EQ-5D value set (n = 2). Some cost-utility analyses used age adjustment (utility subtractions, weights, and published mapping formulae) from the adult EQ-5D UK population norms to reflect the general population or disease-free health for children and adolescents (n = 9), and 1 assessment assumed full health (utility value of 1).ConclusionThe review found limited use of child and adolescent population-specific measures to generate health state utility values for children and adolescents in NICE technology assessments. Often assessments involve the use of an adult-specific measure to reflect the health of children.     

A comparison of generic, indirect utility measures (the HUI2, HUI3, SF-6D, and the EQ-5D) and disease-specific instruments (the RAQoL and the HAQ) in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common, chronic disease where health-related quality of life (HRQL) is one of the main goals of therapy. As such, instruments used to measure HRQL in RA must be able to discriminate across RA severity. The two basic categories of instruments used to measure HRQL are generic instruments and disease-specific instruments. Generic instruments can be further subdivided into preference-based measures which yield both single and multi-attribute utility values anchored at zero (death) and 1.00 (perfect health) as a measure of HRQL. The scores from these types of instruments can be integrated into cost-utility analyses as the weightings for quality adjusted life years. We assessed the construct validity of utility scores from four generic preference-based measures (the Health Utilities Index 2 and 3 (HUI2, HUI3), the EuroQol 5D (EQ-5D), and the Short Form 6-D (SF-6D) and disease specific measures (the Rheumatoid Arthritis Quality of Life Questionnaire (RAQoL) and the Health Assessment Questionnaire (HAQ)) in a sample of 313 RA patients in British Columbia, Canada. We also estimated the minimally important differences (MID) for each of the measures. Generally, as anticipated, the disease-specific measures were better able to discriminate across groups with higher RA severity; however, utility scores from each of the scales also appeared to discriminate well across RA severity categories. The MID values agreed with those previously reported in the literature for the HUI2, SF-6D and the HAQ and provided new information for the HUI3, EQ-5D and the RAQoL. We conclude that the all of the preference-based utility measures that were evaluated appear to adequately discriminate across levels of RA severity.     

Are indirect utility measures reliable and responsive in rheumatoid arthritis patients?

Background: Preference-based, generic measures are increasingly being used to measure quality of life and as sources for quality weights in the estimation of Quality Adjusted Life Years (QALYs) in rheumatoid arthritis (RA). However, among the most commonly used instruments (the Health Utilities Index 2 and 3 [HUI2 and HUI3], the EuroQoL-5D [EQ-5D], and the Short Form-6D [SF-6D], there has been little comparative research. Therefore, we examined the reliability and responsiveness of these measures and the Rheumatoid Arthritis Quality of Life (RAQoL) and the Health Assessment Questionnaire (HAQ) in a sample of RA patients. Major findings: Test–retest reliability was acceptable for all of the instruments with the exception of the EQ-5D. Using two external criteria to define change (a patient transition question and categories of the patient global assessment of disease activity VAS), the RAQoL was the most responsive of the instruments. For the indirect utility instruments, the HUI3 and the SF-6D were the most responsive for measuring positive change. On average, for patients whose RA improved, the absolute change was highest for the HUI3. Conclusions: The HUI3 and the SF-6D appear to be the most responsive of the preference-based instruments in RA. However, differences in the magnitude of the absolute change scores have important implications for cost-effectiveness analyses.     

Measuring health outcomes of adolescents: report from a pilot study

There is a need to understand the practicality, validity and reliability of using utility measures with children and adolescents. We designed a pilot study in order to help guide the selection of an appropriate health-related quality-of-life (HRQoL) questionnaire for adolescents to be used in the context of a large randomised controlled trial (RCT) of family therapy versus standard treatment for adolescents aged 11–17 years. The pilot study was carried out on a school sample of adolescents in the same age range as the RCT. Adolescents were asked to fill in three HRQoL questionnaires: the standard EQ-5D, the licensed Health Utilities Index HUI, and the child-friendly version of the standard EQ-5D: the EQ-5D for youth (EQ-5D-Y). This report explores the problems with the language and concepts embodied within those HRQoL questionnaires and open discussion regarding how we can value the health of adolescents for cost-utility analysis in a larger study.     

Comparison of EQ-5D,HUI, and SF-36-derived societal health state values among Spine Patient Outcomes Research Trial (SPORT) participants

Purpose: To compare societal values across health-state classification systems and to describe the performance of these systems at baseline in a large population of persons with confirmed diagnosis of intervertebral disc herniation (IDH), spinal stenosis (SpS), or degenerative spondylolisthesis (DS). Methods: We compared values for EQ-5D (York weights), HUI (Mark 2 and 3), SF-6D, and the SF-36-derived estimate of the Quality of Well Being (eQWB) score using signed rank tests. We tested each instruments ability to discriminate between health categories and level of symptom satisfaction. Correlations were assessed with Spearman rank correlations. We evaluated ceiling and floor effects by comparing the proportion at the highest and the lowest possible score for each tool. In addition, we compared proportions at the highest and lowest levels by dimension. The number of unique health states assigned was compared across instruments. We calculated the difference between those who were very dissatisfied and all others. Results: Mean values ranged from 0.39 to 0.63 among 2097 participants ages 18–93 (mean age 53, 47 female) with significant differences in pair-wise comparisons noted for all systems. Correlations ranged from 0.30 to 0.78. Although all systems showed statistically significant differences in health state values when baseline comparisons were made between those who were very dissatisfied with their symptoms and those who were not, the magnitude of this difference ranged widely across systems. Mean differences (95 CI) between those very dissatisfied and all others were 0.30 (0.269, 0.329) for EQ-5D, 0.22 (0.190, 0.241) for HUI(3), 0.18 (0.161, 0.201) for HUI(2), 0.11 (0.095, 0.117) for SF-6D, 0.04 (0.039, 0.049) for eQWB, and 0.07 (0.056, 0.077) for VAS (with transformation applied to group means). Conclusion: Differences in preference-weighted health state classification systems are evident at baseline in a population with confirmed IDH, SpS, and DS. Caution should be used when comparing health state values derived from various systems.