Standardization and regulatory guidelines may inhibit science and reduce the usefulness of analyses based on the application of preference-based measures for policy decisions

Commentary. In Praise of Studies That Use More Than One Generic Preference-Based Measure

OBJECTIVES AND BACKGROUND

Generic preference-based (GPB) measures of health-related quality of life (HRQL) are widely used as outcome measures in cost-effectiveness and cost-utility analyses (CEA, CUA). Health technology assessment agencies favor GPB measures because they facilitate comparisons among conditions and because the scoring functions for these measures are based on community preferences. However, there is no gold standard HRQL measure, scores generated by GPB measures may differ importantly, and changes in scores may fail to detect important changes in HRQL. Therefore, to enhance the accumulation of empirical evidence on how well GPB measures perform, we advocate that investigators routinely use two (or more) GPB measures in each study.

METHODS

We discuss key measurement properties and present examples to illustrate differences in responsiveness for several major GPB measures across a wide variety of health contexts. We highlight the contributions of longitudinal head-to-head studies.

RESULTS

There is substantial evidence that the performance of GPB measures varies importantly among diseases and health conditions. Scores are often not interchangeable. There are numerous examples of studies in which one GPB measure was responsive while another was not.

CONCLUSIONS

Investigators should use two (or more) GPB measures. Study protocols should designate one measure as the primary outcome measure; the other measure(s) would be used in secondary analyses. As evidence accumulates it will better inform the relative strengths and weaknesses of alternative GPB measures in various clinical conditions. This will facilitate the selection and interpretation of GPB measures in future studies.

The time horizon matters: results of an exploratory study varying the timeframe in time trade-off and standard gamble utility elicitation

INTRODUCTION

The purpose of this study was to examine whether the time horizon of time trade-off (TTO) and standard gamble (SG) utility assessment influences utility scores and discrimination between health states.

METHODS

In two phases, UK general population participants rated three osteoarthritis health states in TTO and SG procedures with two time horizons: (1) 10-year and (2) a time horizon derived from self-reported additional life expectancy (ALE). The two time horizons were compared in terms of mean utilities and discrimination among health states.

RESULTS

In Phase 1, the 10-year tasks were completed by 80 participants, 35 of whom also completed utility assessment with the ALE. In Phase 2, all 101 participants completed procedures with both time horizons. Utility scores tended to be lower with the ALE than the 10-year, a difference that was statistically significant for two health states with SG in Phase 1 (P < 0.05), two health states with TTO in Phase 2 (P < 0.01), and one health state with SG in Phase 2 (P < 0.001). In Phase 1, rates of discrimination between mild and moderate osteoarthritis health states were significantly higher with the ALE than the 10-year (TTO: P = 0.03; SG: P = 0.001). This pattern of discrimination was similar in Phase 2.

DISCUSSION

Results suggest that the time horizon could influence utility scores and discrimination among health states. When designing utility evaluations, researchers should carefully consider the time horizon so that the value of health states is accurately represented in cost-utility models.

Valuation of Child Health-Related Quality of Life in the United States

Many economic analyses fail to incorporate evidence on child health-related quality of life because of a paucity of quality-adjusted life year (QALY) estimates. This health valuation study is the first to summarize the EQ-5D-Y on a QALY scale. Drawn from a nationally representative panel, 5207 adult respondents were asked to choose between two losses in child health-related quality of life. Based on their choices, a 1-year increase in child pain/discomfort from 'some' to 'a lot' equals a loss of 4 QALYs (95% CI, 3.8-4.4). Likewise, a 1-year increase in child anxiety/depression from 'a bit' to 'very worried, sad, or unhappy' equals a loss of 2 QALYs (95% CI, 1.9-2.2). These findings enable the integration of child-reported outcomes with adult preferences to inform economic analysis. Results inform both clinical practice and resource allocation decisions by enhancing understanding of difficult tradeoffs in child-reported outcomes. Copyright © 2015 John Wiley & Sons, Ltd.

Health Condition Impacts in a Nationally Representative Cross-Sectional Survey Vary Substantially by Preference-Based Health Index

IMPORTANCE

Many cost-utility analyses rely on generic utility measures for estimates of disease impact. Commonly used generic preference-based indexes may generate different absolute estimates of disease burden despite sharing anchors of dead at 0 and full health at 1.0.

OBJECTIVE

We compare the impact of 16 prevalent chronic health conditions using 6 utility-based indexes of health and a visual analog scale.

DESIGN

Data were from the National Health Measurement Study (NHMS), a cross-sectional telephone survey of 3844 adults aged 35 to 89 years in the United States.

MAIN OUTCOME MEASURES

The NHMS included the EuroQol-5D-3L, Health and Activities Limitation Index (HALex), Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3), preference-based scoring for the SF-36v2 (SF-6D), Quality of Well-Being Scale, and visual analog scale. Respondents self-reported 16 chronic conditions. Survey-weighted regression analyses for each index with all health conditions, age, and sex were used to estimate health condition impact estimates in terms of quality-adjusted life years (QALYs) lost over 10 years. All analyses were stratified by ages 35 to 69 and 70 to 89 years.

RESULTS

There were significant differences between the indexes for estimates of the absolute impact of most conditions. On average, condition impacts were the smallest with the SF-6D and EQ-5D-3L and the largest with the HALex and HUI3. Likewise, the estimated loss of QALYs varied across indexes. Condition impact estimates for EQ-5D-3L, HUI2, HUI3, and SF-6D generally had strong Spearman correlations across conditions (i.e., >0.69).

LIMITATIONS

This analysis uses cross-sectional data and lacks health condition severity information.

CONCLUSIONS

Health condition impact estimates vary substantially across the indexes. These results imply that it is difficult to standardize results across cost-utility analyses that use different utility measures.

Valuation of Child Behavioral Problems from the Perspective of US Adults

OBJECTIVE

To assess preferences between child behavioral problems and estimate their value on a quality-adjusted life year (QALY) scale.

METHODS

Respondents, age 18 or older, drawn from a nationally representative panel between August 2012 and February 2013 completed a series of paired comparisons, each involving a choice between 2 different behavioral problems described using the Behavioral Problems Index (BPI), a 28-item instrument with 6 domains (Anxious/Depressed, Headstrong, Hyperactive, Immature Dependency, Anti-social, and Peer Conflict/Social Withdrawal). Each behavioral problem lasted 1 or 2 years for an unnamed child, age 7 or 10 years, with no suggested relationship to the respondent. Generalized linear model analyses estimated the value of each problem on a QALY scale, considering its duration and the child's age.

RESULTS

Among 5207 eligible respondents, 4155 (80%) completed all questions. Across the 6 domains, problems relating to antisocial behavior were the least preferred, particularly the items related to cheating, lying, bullying, and cruelty to others.

CONCLUSIONS

The findings are the first to produce a preference-based summary measure of child behavioral problems on a QALY scale. The results may inform both clinical practice and resource allocation decisions by enhancing our understanding of difficult tradeoffs in how adults view child behavioral problems. Understanding US values also promotes national health surveillance by complementing conventional measures of surveillance, survival, and diagnoses.

The Value Adults Place on Child Health and Functional Status

OBJECTIVES

To summarize the value adults place on child health and functional status and provide a new quantitative tool that enhances our understanding of the benefits of new health technologies and illustrates the potential contributions of existing data sets for comparative effectiveness research in pediatrics.

METHODS

Respondents, ages 18 years and older, were recruited from a nationally representative panel between August 2012 and February 2013 to complete an online survey. The survey included a series of paired comparisons that asked respondents to choose between child health and functional status outcomes, which were described using the National Survey of Children with Special Health Care Needs, a 14-item descriptive system of child health outcomes. Using respondent choices regarding an unnamed 7- or 10-year-old child, generalized linear model analyses estimated the value of child health and functional status on a quality-adjusted life-year scale.

RESULTS

Across the domains of health and functional status, repeated or chronic physical pain, feeling anxious or depressed, and behavioral problems (such as acting out, fighting, bullying, or arguing) were most valuable, as indicated by adult respondents' preference of other health problems to avoid outcomes along these domains.

DISCUSSION

These findings may inform comparative effectiveness research, health technology assessments, clinical practice guidelines, and public resource allocation decisions by enhancing understanding of the value adults place on the health and functional status of children.

CONCLUSIONS

Improved measurement of public priorities can promote national child health by drawing attention to what adults value most and complementing conventional measures of public health surveillance.

Estimates of utility weights in hemophilia: implications for cost-utility analysis of clotting factor prophylaxis

Estimates of preference-weighted health outcomes or health state utilities are needed to assess improvements in health in terms of quality-adjusted life-years. Gains in quality-adjusted life-years are used to assess the cost-effectiveness of prophylactic use of clotting factor compared with on-demand treatment among people with hemophilia, a congenital bleeding disorder. Published estimates of health utilities for people with hemophilia vary, contributing to uncertainty in the estimates of cost-effectiveness of prophylaxis. Challenges in estimating utility weights for the purpose of evaluating hemophilia treatment include selection bias in observational data, difficulty in adjusting for predictors of health-related quality of life and lack of preference-based data comparing adults with lifetime or primary prophylaxis versus no prophylaxis living within the same country and healthcare system.

Health state descriptions to elicit stroke values: do they reflect patient experience of stroke?

Background

To explore whether stroke health state descriptions used in preference elicitation studies reflect patients’ experiences by comparing published descriptions with qualitative studies exploring patients’ lived experience.

Methods

Two literature reviews were conducted: on stroke health state descriptions used in direct preference elicitation studies and the qualitative literature on patients’ stroke experience. Content and comparative thematic analysis was used to identify characteristics of stroke experience in both types of study which were further mapped onto health related quality of life (HRQOL) domains relevant to stroke. Two authors reviewed the coded text, categories and domains.

Results

We included 35 studies: seven direct preference elicitation studies and 28 qualitative studies on patients’ experience. Fifteen coded categories were identified in the published health state descriptions and 29 in the qualitative studies. When mapped onto domains related to HRQOL, qualitative studies included a wider range of categories in every domain that were relevant to the patients’ experience than health state descriptions.

Conclusions

Variation exists in the content of health state descriptions for all levels of stroke severity, most critically with a major disjuncture between the content of descriptions and how stroke is experienced by patients. There is no systematic method for constructing the content/scope of health state descriptions for stroke, and the patient perspective is not incorporated, producing descriptions with major deficits in reflecting the lived experience of stroke, and raising serious questions about the values derived from such descriptions and conclusions based on these values.

Demographic differences in health preferences in the United States

BACKGROUND

The United States has a culturally and demographically diverse populace, and the aim of this study was to examine differences in health preferences by sex, age, ethnicity, and race.

METHODS

We assessed preferences for health outcomes defined by the PROMIS-29 survey in a sample of the US population. On the basis of the survey's 540 paired-comparisons trading off lifespan and 7 domains of health-related quality of life (HRQoL), we compared the choices between men and women, adults age 18-54 years and 55 years and older, Hispanics and non-Hispanics, and non-Hispanic blacks and whites. For each subgroup, we estimated the value of 122 HRQoL outcomes on a quality-adjusted life year scale and tested for subgroup differences.

RESULTS

Compared with men, women preferred reduced lifespan over losses in HRQoL, particularly for depression. Compared with the younger adults, older adults preferred reduced lifespan over the symptoms of depression, anxiety, and fatigue. Compared with non-Hispanic whites, Hispanics preferred reduced lifespan over depression and sleep disturbance, but held similar values on losses in physical functioning. Among non-Hispanics, blacks preferred reduced lifespan over losses in ability to climb stairs and to fall asleep compared with whites, but held similar values on mental health outcomes.

CONCLUSIONS

With the growing emphasis on patient-centeredness and culturally sensitive treatment, it is important to recognize the diversity in values placed on potential losses in HRQoL, particularly mental health outcomes. Demographic differences in preferences may influence comparative or cost effectiveness of treatments as perceived by one or another subgroup.