Logical inconsistencies in survey respondents' health state valuations -- a methodological challenge for estimating social tariffs

Effectiveness of nicotine salt vapes, cytisine, and a combination of these products, for smoking cessation in New Zealand: protocol for a three-arm, pragmatic, community-based randomised controlled trial

BACKGROUND

Combining short-acting nicotine replacement therapy with varenicline increases smoking cessation rates compared with varenicline alone, but not all people tolerate these medications or find them helpful. We aim to investigate the therapeutic potential of an analogous combination, by evaluating the effectiveness, safety, and acceptability of combining nicotine salt e-cigarettes with cytisine, compared to nicotine salt e-cigarettes or cytisine only, on smoking abstinence at six months.

METHODS

A pragmatic, community-based, investigator-blinded, randomised superiority trial design will be utilised. Eligible participants will be people who smoke daily (N = 800, 90% power) from throughout New Zealand, who are: aged ≥ 18 years, motivated to quit in the next two weeks, able to provide online consent, willing to use e-cigarettes and/or cytisine, and have daily access to a mobile phone. Recruitment will utilise multi-media advertising. Participants will be randomised (3:3:2 ratio) to 12 weeks of: 1) e-cigarettes (closed pod system, 3% nicotine salt, tobacco flavour) plus cytisine; 2) e-cigarettes alone, or 3) cytisine alone. All groups will receive a six-month, text-message-based behavioural support programme. The primary outcome is self-reported, biochemically verified, continuous abstinence at six months post-quit date. Secondary outcomes, measured at quit date, then one, three, six, and 12 months post-quit date, include self-reported continuous abstinence, 7-day point prevalence abstinence, cigarettes smoked per day, withdrawal and urge to smoke, time to (re)lapse, treatment use and compliance, treatment crossover, dual-use, use of other cessation products, change in e-cigarette products, continuation of product use, acceptability, change in health state, health-related quality of life, change in body mass index, adverse events, and cost per quitter.

DISCUSSION

Pragmatic trials are of particular value as they reflect the 'real world' impact of interventions. The trial will provide some of the first evidence on the effectiveness of combining nicotine salt e-cigarettes with cytisine for smoking cessation, in a country with strong tobacco control policy. Findings will be incorporated into relevant systematic reviews, informing practice and policy.

TRIAL REGISTRATION

NCT05311085 ClinicalTrials.gov. Registered 5th April, 2022.

Are the outcomes of relative motion extension orthoses non-inferior and cost-effective compared with dynamic extension orthoses for management of zones V-VI finger extensor tendon repairs: A randomized controlled trial

INTRODUCTION

There is no comparative evidence for relative motion extension (RME) orthosis with dynamic wrist-hand-finger-orthosis (WHFO) management of zones V-VI extensor tendon repairs.

PURPOSE OF THE STUDY

To determine if RME with wrist-hand-orthosis (RME plus) is noninferior to dynamic WHFO for these zones in clinical outcomes.

STUDY DESIGN

Randomized controlled non-inferiority trial.

METHODS

Skilled hand therapists managed 37 participants (95% male; mean age 39 years, SD 18) with repaired zones V-VI extensor tendons randomized to RME plus (n = 19) or dynamic WHFO (n = 18). The primary outcome of percentage of total active motion (%TAM) and secondary outcomes of satisfaction, function, and quality of life were measured at week-6 and -12 postoperatively; percentage grip strength (%Grip), complication rates, and cost data at week-12. Following the intention-to-treat principle non-inferiority was assessed using linear regression analysis (5% significance) and adjusted for injury complexity factors with an analysis of costs performed.

RESULTS

RME plus was noninferior for %TAM at week-6 (adjusted estimates 2.5; 95% CI -9.0 to 14.0), %TAM at week-12 (0.3; -6.8 to 7.5), therapy satisfaction at week-6 and -12, and orthosis satisfaction, QuickDASH, and %Grip at week-12. Per protocol analysis yielded 2 tendon ruptures in the RME plus orthoses and 1 in the dynamic WHFO. There were no differences in health system and societal cost, or quality-adjusted life years.

DISCUSSION

RME plus orthosis wearers had greater injury complexity than those in dynamic WHFOs, with overall rupture rate for both groups comparatively more than reported by others; however, percentage %TAM was comparable. The number of participants needed was underestimated, so risk of chance findings should be considered.

CONCLUSIONS

RME plus management of finger zones V-VI extensor tendon repairs is non-inferior to dynamic WHFO in %TAM, therapy and orthotic satisfaction, QuickDASH, and %Grip. Major costs associated with this injury are related to lost work time.

An Organizational Model of Online Learning in the Pandemic Period: Comparison with Traditional Face-to-Face Learning

The COVID-19 pandemic has led to a paradigm shift in educational systems. During the lockdown, higher education became digital. This caused a change in communication within the educational ecosystem. Relational coordination (RC) is a communication and relationship model associated with the improvement of organizational results. Therefore, the objective of this research is to build an organizational model of online learning applied during the pandemic period and compare it with the previous face-to-face learning. A sample of 2774 students from two Ecuadorian universities was selected. A two-stage methodology was applied: First, an organizational model of online learning was built using multivariate methods. The RC model was linked to student satisfaction using generalized linear models (GLM). In the second stage, the organizational differences between the 2018 face-to-face and the 2020 online learning were identified. Finally, the online learning model was validated with external data. The components associated with a higher level of RC were institutional cooperation, institutional problem-solving, and administrative communication. Administrative communication lost importance in the online model. Significant differences between the satisfaction of the two models were not found. Nevertheless, since online learning was not associated with an improvement in satisfaction, the creation of a third educational model that combines the best practices of online and face-to-face learning in a hybrid system could be an alternative that improves the satisfaction of students.

Assessment of health state utilities in dermatology: an experimental time trade-off value set for the dermatology life quality index

Background

Dermatology Life Quality Index (DLQI) scores are used in many countries as access and reimbursement criteria for costly dermatological treatments. In this study we examined how time trade-off (TTO) utility valuations made by individuals from the general population are related to combinations of DLQI severity levels characterizing dermatologically relevant health states, with the ultimate purpose of developing a value set for the DLQI.

Methods

We used data from an online cross-sectional survey conducted in Hungary in 2020 (n = 842 after sample exclusions). Respondents were assigned to one of 18 random blocks and were asked to provide 10-year TTO valuations for the corresponding five hypothetical health states. To analyze the relationship between DLQI severity levels and utility valuations, we estimated linear, censored, ordinal, and beta regression models, complemented by two-part scalable models accommodating heterogeneity effects in respondents’ valuation scale usage. Successive severity levels (0–3) of each DLQI item were represented by dummy variables. We used cross-validation methods to reduce the initial set of 30 dummy variables and improve model robustness.

Results

Our final, censored linear regression model with 13 dummy variables had R² = 0.136, thus accounting for 36.9% of the incremental explanatory power of a maximal (full-information) benchmark model (R² = 0.148) over the uni-dimensional model (R² = 0.129). Each DLQI item was found to have a negative effect on the valuation of health states, yet this effect was largely heterogeneous across DLQI items, and the relative contribution of distinctive severity levels also varied substantially. Overall, we found that the social/interpersonal consequences of skin conditions (in the areas of social and leisure activities, work and school, close personal relationships, and sexuality) had roughly twice as large disutility impact as the physical/practical aspects.

Conclusions

We have developed an experimental value set for the DLQI, which could prospectively be used for quantifying the quality-adjusted life years impact of dermatological treatments and serve as a basis for cost-effectiveness analyses. We suggest that, after validation of our main results through confirmatory studies, population-specific DLQI value sets could be developed and used for conducting cost-effectiveness analyses and developing financing guidelines in dermatological care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01995-x.

Quantitative Comparison between Traditional and Intensive Face-to-Face Education through an Organizational Model

Face-to-face education continues to present benefits in terms of student motivation, even though in COVID-19 scenario, online education has been the model of choice. In addition to the traditional face-to-face style, the intensive face-to-face style remains, which allows greater flexibility for the student. The objective of this study was to compare both educational styles and build an organizational model to improve student satisfaction. Two-way general linear model (GLM) with educational styles and satisfaction as fixed factors and discriminant analysis was applied. The selection of the most discriminant variables was made applying the F of Snedecor, Wilks’-Lambda, and the 1-Tolerance. A discriminant model was built. The four variables with the highest discriminant power were problem-solving communication with students’ representatives and shared knowledge and goals with lectures in the intensive style and frequent communication with administrative officers in the traditional style. In addition, it was found that greater face-to-face attendance did not imply greater coordination and that intensive style students show greater satisfaction. The appropriate duration of face-to-face education can contribute to the design of an innovative hybrid system in the future.

Are manual therapy or booster sessions worthwhile in addition to exercise therapy for knee osteoarthritis: Economic evaluation and 2-year follow-up of a randomized controlled trial

BACKGROUND

Exercise therapy is known to be an effective intervention for patients with osteoarthritis, however the evidence is limited as to whether adding manual therapy or booster sessions are cost-effective strategies to extend the duration of benefits.

OBJECTIVE

To investigate the cost-effectiveness, at 2-year follow-up, of adding manual therapy and/or booster sessions to exercise therapy.

DESIGN

2-by-2 factorial randomized controlled trial.

METHODS

Participants with knee osteoarthritis were randomly allocated (1:1:1:1) to: exercise therapy delivered in consecutive sessions within 9 weeks (control group), exercise therapy distributed over 1 year using booster sessions, exercise therapy plus manual therapy delivered within 9 weeks, and exercise therapy plus manual therapy with booster sessions. The primary outcome was incremental cost-effectiveness from health system and societal perspectives interpreted as incremental net monetary benefit (INMB).

RESULTS

Of 75 participants, 66 (88 %) were retained at 1-year and 40 (53 %) at 2-year follow-up. All three interventions were cost-effective from both the health system and societal perspectives (INMBs, at 0.5 × GDP/capita willingness to pay (WTP) threshold: $3278 (95%CI -3244 to 9800) and $3904 (95%CI -2823 to 10,632) respectively for booster sessions; $2941 (95%CI -3686 to 9568) and $2618 (95%CI -4005 to 9241) for manual therapy; $270 (95%CI -6139 to 6679) and $404 (95%CI -6097 to 6905) for manual therapy with booster sessions).

CONCLUSION

Manual therapy or booster sessions in addition to exercise therapy are cost-effective at 2-year follow-up. The evidence did not support combining both booster sessions and manual therapy in addition to exercise therapy.

New Zealand Population Norms for the EQ-5D-5L Constructed From the Personal Value Sets of Participants in a National Survey

OBJECTIVES

To derive New Zealand (NZ) population norms for the EQ-5D-5L and to examine the association between participants' sociodemographic characteristics and their health-related quality of life.

METHODS

Data from the 2018 NZ EQ-5D-5L valuation study (n = 2468) were used. Each participant's 5-digit profile was converted to a single utility value using their personal value set. The profiles, mean utility values, and mean EuroQol visual analog scale (EQ-VAS) scores were summarized by dimension and disaggregated by age group and gender. Multivariable logistic and Tobit regressions were used to investigate the association between participants' sociodemographic characteristics and the EQ-5D-5L dimensions, utility values, and EQ-VAS scores.

RESULTS

The mean utility value was 0.847 and the mean EQ-VAS score was 74.8. Of the 3125 possible EQ-5D-5L profiles, 25 profiles represented the current health status of the majority of participants (78%). The odds of having problems with anxiety or depression was greatest for people aged 18 to 24 years and decreased with age. People with a long-term disability or chronic illness had greater odds of problems on all dimensions and lower (poorer) utility values and EQ-VAS scores. Age, ethnicity, employment status, long-term disability, and chronic illness were associated with utility.

CONCLUSION

EQ-5D-5L population norms were derived for the NZ population using the personal value sets of 2468 participants. Consistent with other countries' population norms, EQ-5D-5L utility values and EQ-VAS scores were associated with age, employment status, long-term disability, and chronic illness. These norms will support resource allocation decision making and help in understanding the health-related quality of life of the NZ population.

Three Versus Six Months of Adjuvant Doublet Chemotherapy for Patients With Colorectal Cancer: A Multi-Country Cost-Effectiveness and Budget Impact Analysis

BACKGROUND

The Short Course Oncology Treatment (SCOT) trial demonstrated non-inferiority, less toxicity, and cost-effectiveness from a UK perspective of 3 versus 6 months of oxaliplatin-based chemotherapy for patients with colorectal cancer. This study assessed the cost-effectiveness of shorter treatment and the budget impact of implementing trial findings from the perspectives of all countries recruited to SCOT: Australia, Denmark, New Zealand, Spain, Sweden, and the United Kingdom.

PATIENTS AND METHODS

Individual cost-utility analyses were performed from the perspective of each country. Resource, quality of life, and survival estimates from the SCOT trial (N = 6065) were used. Probabilistic sensitivity analysis and subgroup analyses were undertaken. Using undiscounted costs from these cost-utility analyses, the impact on country-specific healthcare budgets of implementing the SCOT trial findings was calculated over a 5-year period. The currency used was US dollars (US$), and 2019 was the base year. One-way and scenario sensitivity analysis addressed uncertainty within the budget impact analysis.

RESULTS

Three months of treatment were cost saving and cost-effective compared to 6 months from the perspective of all countries. The incremental net monetary benefit per patient ranged from US$8972 (Spain) to US$13,884 (Denmark). The healthcare budget impact over 5 years for the base-case scenario ranged from US$3.6 million (New Zealand) to US$61.4 million (UK) and totaled over US$150 million across all countries.

CONCLUSION

This study has widened the transferability of results from the SCOT trial, showing that shorter treatment is cost-effective from a multi-country perspective. The vast savings from implementation could fully justify the investment in conducting the SCOT trial.

Patients' preferences for delaying metastatic castration-resistant prostate cancer: Combining health state and treatment valuation

PURPOSE

Men with castration-resistant prostate cancer (CRPC) experience disease progression at different rates. The purpose of this study was to quantify the strength of patient preferences for delaying prostate cancer progression utilizing a discrete choice experiment (DCE) and valuing 3 health states in the continuum of CRPC.

PATIENTS AND METHODS

Men with CRPC, recruited from US patient panels, completed a cross-sectional web-based survey. The survey consisted of vignette-based time trade-off and a DCE designed to quantify patients' willingness to pay to delay metastatic CRPC. Three health states were presented: (1) living with non-metastatic castration-resistant prostate cancer (nmCRPC) (2) living with metastatic CRPC (mCRPC) before chemotherapy, and (3) living with mCRPC either on or after chemotherapy. The DCE consisted of 15 hypothetical choices with attributes characterizing CRPC (pain, fatigue, out of pocket cost, dosing, and time until cancer metastasizes). Patients' willingness to pay for changes in each attribute were derived.

RESULTS

A total of 176 patients with CRPC were surveyed (mean age: 64.2 years; 74% nmCRPC). Patients valued the nmCRPC health state (0.865) significantly higher than mCRPC before chemotherapy (0.743) or mCRPC on or after chemotherapy (0.476), both P < 0.001. In the DCE, patient treatment valuation was most affected by increasing the number of months until cancer metastasized; patients were willing to pay an additional $682 per month to delay time to metastases from 6 to 24 months (95% Confidence Interval: $387-$977) and additional $1,041 per month to delay time to metastasis to 48 months (95% Confidence Interval: $591-$1,490).

CONCLUSIONS

The results of this study demonstrated men with CRPC place significant value on delaying metastases. This study represents the first time 2 stated preference methods, time trade-off and DCE, were used together to understand patients' preferences and valuation of health states in CRPC.

Comparison of online and face-to-face valuation of the EQ-5D-5L using composite time trade-off

OBJECTIVE

The aim of this study was to compare online, unsupervised and face-to-face (F2F), supervised valuation of EQ-5D-5L health states using composite time trade-off (cTTO) tasks.

METHODS

The official EuroQol experimental design and valuation protocol for the EQ-5D-5L of 86 health states were implemented in interviewer-assisted, F2F and unsupervised, online studies. Validity of preferences was assessed using prevalence of inconsistent valuations and expected patterns of TTO values. Respondent task engagement was measured using number of trade-offs and time per task. Trading patterns such as better-than-dead only was compared between modes. Value sets were generated using linear regression with a random intercept (RILR). Value set characteristics such as range of scale and dimension ranking were evaluated between modes.

RESULTS

Five hundred one online and 1,134 F2F respondents completed the surveys. Mean elicited TTO values were higher online than F2F when compared by health state severity. Compared to F2F, a larger proportion of online respondents did not assign the poorest EQ-5D-5L health state (i.e., 55555) the lowest TTO value ([Online] 41.3% [F2F] 12.2%) (p < 0.001). A higher percentage of online cTTO tasks were completed in 3 trade-offs or fewer ([Online] 15.8% [F2F] 3.7%), (p < 0.001). When modeled using the RILR, the F2F range of scale was larger than online ([Online] 0.600 [F2F] 1.307) and the respective dimension rankings differed.

CONCLUSIONS

Compared to F2F data, TTO tasks conducted online had more inconsistencies and decreased engagement, which contributed to compromised data quality. This study illustrates the challenges of conducting online valuation studies using the TTO approach.

Design and sample size considerations for valuation studies of multi-attribute utility instruments

The EQ-5D, a widely used multiattribute utility instrument, is commonly used in health economic evaluations where the goal is to decide on which treatments to reimburse. Like other instruments, value sets of the EQ-5D are constructed using valuation studies typically valuing a subset of the health states and using predicted values from a regression model for the unvalued health states. In current practice the prediction errors associated with the value sets are substantial. The goal of this work is 2-fold. First, derive a formula of the mean squared error (MSE) of a value set assuming that the value set is estimated using a linear mixed model with either an independent or a Gaussian spatial correlation on the model misspecification error. Second, explore the effect of the number of health states directly valued, the number of participants and the correlation structure on the MSE. Keeping the total number of participants and the total number of valuations fixed, valuing all 242 health states of the EQ-5D-3L was found to reduce the MSE considerably compared with the common practice of valuing only 42 health states. Furthermore, an independent correlation structure with 3773 participants valuing 42 health states produced the MSE that can be achieved with less than 600 participants valuing all 242 health states under a Gaussian spatial correlation structure. Based on the comparison of the MSE values of some of the well-known designs our suggestion is to value more health states and to use a model with spatially correlated misspecification errors.

Does Device or Connection Type Affect Health Preferences in Online Surveys?

BACKGROUND AND OBJECTIVE

Recent evidence has shown that online surveys can reliably collect preference data, which markedly decrease the cost of health preference studies and expand their representativeness. As the use of mobile technology continues to grow, we wanted to examine its potential impact on health preferences.

METHODS

Two recently completed discrete choice experiments using members of the US general population (n = 15,292) included information on respondent device (cell phone, tablet, Mac, PC) and internet connection (business, cellular, college, government, residential). In this analysis, we tested for differences in respondent characteristics, participation, response quality, and utility values for the 5-level EQ-5D (EQ-5D-5L) by device and connection.

RESULTS

Compared to Mac and PC users, respondents using a cell phone or tablet had longer completion times and were significantly more likely to drop out during the surveys (p < 0.001). Tablet users also demonstrated more logical inconsistencies (p = 0.05). Likewise, respondents using a cellular internet connection exhibit significantly less consistency in their health preferences. However, matched samples for tablets and cell phones produced similar EQ-5D-5L utility values (mean differences < 0.06 on a quality-adjusted life-year [QALY] scale for all potential health states).

CONCLUSION

Allowing respondents to complete online surveys using a cell phone or tablet or over a cellular connection substantially increases the diversity of respondents and the likelihood of obtaining a representative sample, as many individuals have cell phones but not a computer. While the results showed systematic variability in participation and response quality by device and connection type, this study did not show any meaningful changes in utility values.

A new tool for creating personal and social EQ-5D-5L value sets, including valuing 'dead'

The EuroQol Group's health descriptive systems, the EQ-5D-3L and its successor introduced in 2009, the EQ-5D-5L, are widely used worldwide for valuing health-related quality of life for cost-utility analysis and patient-reported health outcome measures. A new online tool for creating personal and social EQ-5D-5L value sets was recently developed and trialled in New Zealand (NZ). The tool, which includes extensive checks of the quality of participants' data, implements the PAPRIKA method - a novel type of adaptive discrete choice experiment in the present context - and a binary search algorithm to identify any health states worse than dead. After development and testing, the tool was distributed in an online survey in February and March 2018 to a representative sample of NZ adults (N = 5112), whose personal value sets were created. The tool's extensive data quality checks resulted in a 'high-quality' sub-sample of 2468 participants whose personal value sets were, in effect, averaged to create a social value set for NZ. These results overall as well as feedback from participants indicates that the new valuation tool is feasible and acceptable to participants, enabling valuation data to be relatively easily and cheaply collected. The tool could also be used in other countries, tested against other methods for creating EQ-5D-5L value sets, applied in personalised medicine and adapted to create value sets for other health descriptive systems.

Exclusion Criteria as Measurements I: Identifying Invalid Responses

Background. In a systematic review, Engel et al. found large variation in the exclusion criteria used to remove responses held not to represent genuine preferences in health state valuation studies. We offer an empirical approach to characterizing the similarities and differences among such criteria. Setting. Our analyses use data from an online survey that elicited preferences for health states defined by domains from the Patient-Reported Outcomes Measurement Information System (PROMIS^®), with a U.S. nationally representative sample (N = 1164). Methods. We use multidimensional scaling to investigate how 10 commonly used exclusion criteria classify participants and their responses. Results. We find that the effects of exclusion criteria do not always match the reasons advanced for applying them. For example, excluding very high and very low values has been justified as removing aberrant responses. However, people who give very high and very low values prove to be systematically different in ways suggesting that such responses may reflect different processes. Conclusions. Exclusion criteria intended to remove low-quality responses from health state valuation studies may actually remove deliberate but unusual ones. A companion article examines the effects of the exclusion criteria on societal utility estimates.

Exclusion Criteria as Measurements II: Effects on Utility Functions

Background. Researchers often justify excluding some responses in studies eliciting valuations of health states as not representing respondents' true preferences. Here, we examine the effects of applying 8 common exclusion criteria on societal utility estimates. Setting. An online survey of a US nationally representative sample (N = 1164) used the standard gamble method to elicit preferences for health states defined by 7 health domains from the Patient-Reported Outcomes Measurement Information System (PROMIS^®). Methods. We estimate the impacts of applying 8 commonly used exclusion criteria on mean utility values for each domain, using beta regression, a form of analysis suited to double-bounded scales, such as utility. Results. Exclusion criteria have varied effects on the utility functions for the different PROMIS health domains. As a result, applying those criteria would have varied effects on the value of treatments (and side effects) that change health status on those domains. Limitations. Although our method could be applied to any health utility judgments, the present estimates reflect the features of the study that produced them. Those features include the selected health domains, standard gamble method, and an online format that excluded some groups (e.g., visually impaired and illiterate individuals). We also examined only a subset of all possible exclusion criteria, selected to represent the space of possibilities, as characterized in a companion article. Conclusions. Exclusion criteria can affect estimates of the societal utility of health states. We use those effects, in conjunction with the results of the companion article, to make suggestions for selecting exclusion criteria in future studies.

A General Population Utility Valuation Study for Metastatic Epidural Spinal Cord Compression Health States

STUDY DESIGN

General population utility valuation study.

OBJECTIVE

This study obtained utility valuations from a Canadian general population perspective for 31 unique metastatic epidural spinal cord compression (MESCC) health states and determined the relative importance of MESCC-related consequences on quality-of-life.

SUMMARY OF BACKGROUND DATA

Few prospective studies on the treatment of MESCC have collected quality-adjusted-life-year weights (termed "utilities"). Utilities are an important summative measure which distills health outcomes to a single number that can assist healthcare providers, patients, and policy makers in decision making.

METHODS

We recruited a sample of 1138 adult Canadians using a market research company. Quota sampling was used to ensure that the participants were representative of the Canadian population in terms of age, sex, and province of residence. Using the validated MESCC module for the "Self-administered Online Assessment of Preferences" (SOAP) tool, participants were asked to rate six of the 31 MESCC health states, each of which presented varying severities of five MESCC-related dysfunctions (dependent; non-ambulatory; incontinent; pain; other symptoms).

RESULTS

Participants equally valued all MESCC-related dysfunctions which followed a pattern of diminishing marginal disutility (each additional consequence resulted in a smaller incremental decrease in utility than the previous). These results demonstrate that the general population values physical function equal to other facets of quality-of-life.

CONCLUSION

We provide a comprehensive set of ex ante utility estimates for MESCC health states that can be used to help inform decision making. This is the first study reporting direct utility valuation for a spinal disorder. Our methodology offers a feasible solution for obtaining quality-of-life data without collecting generic health status questionnaire responses from patients.

LEVEL OF EVIDENCE

4.

A hybrid modelling approach for eliciting health state preferences: the Portuguese EQ-5D-5L value set

BACKGROUND

The EQ-5D is a generic preference-based quality of life measure considered useful for supporting clinical and policy decisions by providing utility values that can easily be converted into quality-adjusted life years to be integrated in cost-utility economic evaluations. Although the three-level classification system of the EuroQol questionnaire (EQ-5D-3L) is still the most popular preference-based instrument used worldwide, several studies reported a ceiling effect on this version, especially in healthy and/or young individuals. In 2009, the EuroQol Group introduced a five-level EQ-5D, which expands the descriptive system from three to five levels within the same five dimensions. For this version to be used in health economic evaluation, societal values need to be assigned to the 3125 health states generated by this instrument.

OBJECTIVES

The aims of this study were to elicit the EQ-5D-5L health state preferences from the general Portuguese population and to derive the Portuguese value set for the EQ-5D-5L.

METHODS

A representative sample of the Portuguese general population aged above 18 years was stratified by age and gender (n = 1451). Between October 2015 and July 2016, 28 interviewers carried out a series of 1-h-long computer-assisted personal interviews following the EuroQol Valuation Technology protocol. Each interview included the valuation of ten health states using the composite time trade-off (cTTO) and seven pairs of discrete choice experiments (DCEs). A standardized tool for quality control was used to assess the quality of the data as well as direct supervision and cross-examination of 10% of the global sample size. Data from both cTTO and DCE valuation tasks were modelled using a censored heteroskedastic hybrid model.

RESULTS

Interviewers complied with the quality control protocol in providing high-quality valuation data. The hybrid econometric model had consistent and significant parameters. The derived societal values for the Portuguese population ranged from - 0.603 to 1.

CONCLUSION

This study provided the Portuguese value set for the EQ-5D-5L on the basis of a hybrid econometric model using cTTO and DCE data. These results represent the preferences of the Portuguese population and are recommended to inform health decision-making in Portugal.

The Psychometric Properties of a Self-Administered, Open-Source Module for Valuing Metastatic Epidural Spinal Cord Compression Utilities

INTRODUCTION

Web surveys are often used for utility valuation. Typically, custom utility valuation tools that have not undergone psychometric evaluation are used.

OBJECTIVES

This study aimed to determine the psychometric properties of a metastatic epidural spinal cord compression (MESCC) module run on a customizable open-source, internet-based, self-directed utility valuation platform (Self-directed Online Assessment of Preferences [SOAP]).

METHODS

Individuals accompanying patients to the emergency department waiting room in Ottawa, Canada, were recruited. Participants made SOAP MESCC health state valuations in the waiting room and 48 h later at home. Validity, agreement reliability, and responsiveness were measured by logical consistency of responses, smallest detectable change, the interclass correlation coefficient, and Guyatt's responsiveness index, respectively.

RESULTS

Of 285 participants who completed utility valuations, only 113 (39.6%) completed the re-test. Of these 113 participants, 92 (81.4%) provided valid responses on the first test and 75 (66.4%) provided valid responses on the test and re-test. Agreement for all groups of health states was adequate, since their smallest detectable change was less than the minimal clinically important difference. The mean interclass correlation coefficients for all health states were > 0.8, indicating at least substantial reliability. Guyatt's responsiveness indices all exceeded 0.80, indicating a high level of responsiveness.

CONCLUSIONS

To our knowledge, this is the first validated open-source, web-based, self-directed utility valuation module. We have demonstrated the SOAP MESCC module is valid, reproducible, and responsive for obtaining ex ante utilities. Considering the successful psychometric validation of the SOAP MESCC module, other investigators can consider developing modules for other diseases where direct utility valuation is needed.

Validation of a novel diabetic retinopathy utility index using discrete choice experiments

BACKGROUND/AIMS

To validate a preference-based Diabetic Retinopathy Utility Index (DRU-I) using discrete choice experiment (DCE) methods and assess disutilities associated with vision-threatening DR (VTDR: severe non-proliferative DR, proliferative DR and clinically significant macular oedema) and associated vision impairment.

METHODS

The DRU-I comprises five quality-of-life dimensions, including Visual symptoms, Activity limitation/mobility, Lighting and glare, Socio-emotional well-being and Inconvenience, each rated as no, some, or a lot of difficulty. The DRU-I was developed using a DCE comprising six blocks of nine choice sets which, alongside the EuroQoL-5D (EQ-5D-3L) and Vision and Quality of Life (VisQoL) utility instruments, were interviewer-administered to participants. To ensure the DRU-I was sensitive to severe disease, we oversampled patients with VTDR. Data were analysed using conditional logit regression.

RESULTS

Of the 220 participants (mean±SD age 60.1±11.3 years; 70.9% men), 57 (29.1%) and 139 (70.9%) had non-VTDR and VTDR, respectively, while 157 (71.4%), 20 (9.4%) and 37 (17.3%) had no, mild or moderate/severe vision impairment, respectively. Regression coefficients for all dimensions were ordered as expected, with worsening levels in each dimension being less preferred (theoretical validity). DRU-I utilities decreased as DR severity (non-VTDR=0.87; VTDR=0.80; p=0.021) and better eye vision impairment (none=0.84; mild=0.78; moderate/severe=0.72; p=0.012) increased. DRU-I utilities had low (r=0.39) and moderate (r=0.58) correlation with EQ-5D and VisQoL utilities, respectively (convergent validity).

DISCUSSION

The DRU-I can estimate utilities associated with vision-threatening DR and associated vision impairment. It has the potential to assess the cost-effectiveness of DR interventions from a patient perspective and inform policies on resource allocation relating to DR.

Valuation of Quality Weights for EuroQol 5-Dimensional Health States With the Time Trade-Off Method in the Capital of Iran

BACKGROUND

The EuroQol 5-dimension (EQ-5D) is a standard instrument that is widely used for measuring health-related quality of life and quality-adjusted life years in economic evaluation of healthcare interventions.

OBJECTIVE

To estimate a preference valuation set for EQ-5D 3-level (3L) health states from the perspective of the general population in the capital of Iran.

METHODS

Eight hundred seventy adults aged ≥18 years were interviewed in Tehran (Iran's capital) from July to November 2013. The participants were selected by a stratified random sampling method and were interviewed face-to-face at their usual residence. Forty-two health states were selected and valued from the 243 states derived from the EQ-5D-3L instrument. Each respondent valued 11 health states using the time trade-off method. Generalized least squares regression with random effect was used to predict values for health states.

RESULTS

The analysis was performed for 846 respondents. The final model yielded the best fit for the time trade-off value at the individual level with an overall R² of 0.45 and a mean absolute error of 0.214. The mean values for the 42 health states ranged from 0.934 for state 11121 to -0.142 for state 33333.

CONCLUSIONS

This study provided for the first time a value set for calculating quality-adjusted life years from the EQ-5D instrument in Iran. The Iranian EQ-5D-3L value set slightly differs from the value sets of the UK and the United States.

A new method for valuing health: directly eliciting personal utility functions

BACKGROUND

Standard methods for eliciting the preference data upon which 'value sets' are based generally have in common an aim to 'uncover' people's preferences by asking them to evaluate a subset of health states, then using their responses to infer their preferences over all dimensions and levels. An alternative approach is to ask people directly about the relative importance to them of the dimensions, levels and interactions between them. This paper describes a new stated preference approach for directly eliciting personal utility functions (PUFs), and reports a pilot study to test its feasibility for valuing the EQ-5D.

METHODS

A questionnaire was developed, designed to directly elicit PUFs from general public respondents via computer-assisted personal interviews, with a focus on helping respondents to reflect and deliberate on their preferences. The questionnaire was piloted in England.

RESULTS

Seventy-six interviews were conducted in December 2015. Overall, pain/discomfort and mobility were found to be the most important of the EQ-5D dimensions. The ratings for intermediate improvements in each dimension show heterogeneity, both within and between respondents. Almost a quarter of respondents indicated that no EQ-5D health states are worse than dead.

DISCUSSION

The PUF approach appears to be feasible, and has the potential to yield meaningful, well-informed preference data from respondents that can be aggregated to yield a value set for the EQ-5D. A deliberative approach to health state valuation also has the potential to complement and develop existing valuation methods. Further refinement of some elements of the approach is required.

Cytisine versus varenicline for smoking cessation for Māori (the indigenous people of New Zealand) and their extended family: protocol for a randomized non-inferiority trial

BACKGROUND AND AIMS

Cytisine, a nicotinic acetylcholine receptor partial agonist (like varenicline) found in some plants, is a low-cost, effective smoking cessation medication that may appeal to Māori [the indigenous people of New Zealand (NZ)]. The RAUORA trial aims to determine the effectiveness, safety and cost-effectiveness of cytisine (Tabex^® ) versus varenicline (Champix^® ) for smoking cessation in Māori and the whānau (extended family) of Māori.

DESIGN

Pragmatic, community-based, open-label randomized non-inferiority trial.

SETTING

Lakes District Health Board region, NZ.

PARTICIPANTS

Daily smokers (n = 2140) who self-identify as Māori or whānau of Māori, and are: aged ≥ 18 years, motivated to quit smoking in the next 2 weeks, eligible for subsidized varenicline, able to provide verbal consent and have daily access to a mobile phone/internet. Recruitment uses multi-media advertising.

INTERVENTION AND COMPARATOR

Participants are randomized (1 : 1 ratio) to receive a prescription for 12 weeks of cytisine tablets [following the manufacturer's dosing regimen for 25 days, then one 1.5-mg tablet every 6 hours (two per day) until 12 weeks] or varenicline tablets (following the manufacturer's dosing regimen). Both groups receive brief stop-smoking advice from the prescribing doctor and withdrawal-orientated behavioural support via community-based stop-smoking counselling services (frequency, duration and mode of delivery tailored for participants) or a research assistant (six weekly 10-15-minute calls). Participants are advised to reduce their smoking over the first 4 days of treatment, with day 5 as their designated quit-date.

MEASUREMENTS

The primary outcome is carbon monoxide-verified continuous abstinence at 6 months post-quit date. Secondary outcomes at 1, 3, 6 and 12 months post-quit date include: self-reported continuous abstinence, 7-day point prevalence abstinence, cigarettes per day, time to (re)lapse, adverse events, treatment adherence/compliance, treatment acceptability, nicotine withdrawal/urge to smoke and health-care utilization/health-related quality of life.

COMMENTS

This trial compares cytisine and varenicline when used by the indigenous people of NZ and their extended family for smoking cessation.

How Significant Are "High" Correlations Between EQ-5D Value Sets?

The calculation of quality-adjusted life years, as used for cost-utility analysis, depends on the availability of value sets representing people's preferences with respect to health-related quality of life (HRQoL). A value set consists of HRQoL index values for all health states representable by the particular descriptive system used, of which the EQ-5D (EuroQoL, 5 Dimensions) is by far the most widely used. High correlation coefficients for EQ-5D value sets derived from different samples-across countries and/or using different valuation techniques-are conventionally interpreted as evidence that the people in the respective samples have similar HRQoL preferences. However, EQ-5D value sets-for both versions of the system (EQ-5D-3L and EQ-5D-5L)-contain many inherent rankings of health state values by design. By calculating correlation coefficients for value sets created from random data, we demonstrate that "high" coefficients are artifacts of these inherent rankings, such as median Pearson's r = 0.783 for the EQ-5D-3L and 0.850 for the EQ-5D-5L instead of zero. Therefore, high correlation coefficients do not necessarily constitute evidence of meaningful associations in terms of similar HRQoL preferences. After calculating significance levels based on our simulations-available as an online resource for other researchers-we find that many high coefficients are not as significant as conventionally interpreted, whereas other coefficients are not significant. These "high" but insignificant correlations are in fact spurious.

The effectiveness and safety of combining varenicline with nicotine e-cigarettes for smoking cessation in people with mental illnesses and addictions: study protocol for a randomised-controlled trial

Background

Smoking rates are higher in New Zealand (NZ) adults with mental illnesses and alcohol and other drug (AOD) addictions, compared to the overall population. Quit attempts using “gold standard” smoking cessation treatments often fail in people with these conditions, so more flexible treatment regimens that adapt to a person’s responsiveness to treatment are worth investigating. The STATUS trial aims to evaluate the effectiveness and safety of combining varenicline with nicotine e-cigarettes for smoking cessation among varenicline non-responders in treatment for mental health illnesses and/or AOD addictions.

Methods

This is a pragmatic two-arm, open-label, randomised trial. Participants will be daily smokers using mental health and/or addiction services in Auckland, aged ≥18 years, motivated to quit smoking, and eligible to access varenicline through the NZ special authority process. After 2 weeks of using varenicline plus behavioural support, participants who have not reduced their daily smoking by ≥50% will be randomised (1:1) to either 10 weeks of continued varenicline use or 10 weeks of varenicline plus an 18 mg/mL nicotine e-cigarette. All participants will receive weekly withdrawal-orientated behavioural support calls for 6 weeks post-randomisation. The primary outcome is self-reported biochemically-verified (exhaled carbon monoxide) continuous abstinence at 24 weeks post-randomisation. Secondary outcomes, measured at six, 12 and 24 weeks post-randomisation include: self-reported continuous abstinence, 7-day point prevalence abstinence, smoking reduction, time to relapse, cross-over, use of other smoking cessation support, serious adverse events, treatment adherence, compliance, acceptability, dual use, continuation of treatment use, mental illness symptoms and AOD use, health-related quality of life, and cost-analysis. A sample size of 338 will confer 80% power (p = 0.05) to detect a 15% absolute difference between the varenicline alone and varenicline plus e-cigarette groups.

Discussion

People with mental illness and/or AOD addictions are just as motivated as others to quit smoking, but are less likely to succeed. Adapting smoking cessation medication after a lack of responsiveness in the first 2 weeks of initial treatment in this priority population by adding a nicotine e-cigarette may be one way to increase long-term quit rates.

Trial Registration

Australian NZ Clinical Trial Registry: ACTRN12616001355460 (29 September 2016).

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5351-7) contains supplementary material, which is available to authorized users.

Development and validation of a new population-based simulation model of osteoarthritis in New Zealand

OBJECTIVE

To describe the construction and preliminary validation of a new population-based microsimulation model developed to analyse the health and economic burden and cost-effectiveness of treatments for knee osteoarthritis (OA) in New Zealand (NZ).

METHOD

We developed the New Zealand Management of Osteoarthritis (NZ-MOA) model, a discrete-time state-transition microsimulation model of the natural history of radiographic knee OA. In this article, we report on the model structure, derivation of input data, validation of baseline model parameters against external data sources, and validation of model outputs by comparison of the predicted population health loss with previous estimates.

RESULTS

The NZ-MOA model simulates both the structural progression of radiographic knee OA and the stochastic development of multiple disease symptoms. Input parameters were sourced from NZ population-based data where possible, and from international sources where NZ-specific data were not available. The predicted distributions of structural OA severity and health utility detriments associated with OA were externally validated against other sources of evidence, and uncertainty resulting from key input parameters was quantified. The resulting lifetime and current population health-loss burden was consistent with estimates of previous studies.

CONCLUSION

The new NZ-MOA model provides reliable estimates of the health loss associated with knee OA in the NZ population. The model structure is suitable for analysis of the effects of a range of potential treatments, and will be used in future work to evaluate the cost-effectiveness of recommended interventions within the NZ healthcare system.

New methods for modelling EQ-5D-5L value sets: An application to English data

Value sets for the EQ-5D-5L are required to facilitate its use in estimating quality-adjusted life years. An international protocol has been developed to guide the collection of stated preference data for this purpose and has been used to generate EQ-5D-5L valuation data for England. The aim of this paper is report the innovative methods used for modelling those data to obtain a value set. Nine hundred and ninety-six members of the English general public completed time trade-off (TTO) and discrete choice experiment (DCE) tasks. We estimate models, with and without interactions, using DCE data only, TTO data only, and TTO/DCE data combined. TTO data are interpreted as both left and right censored. Heteroskedasticity and preference heterogeneity between individuals are accounted for. We use Bayesian methods in the econometric analysis. The final model is chosen based on the deviance information criterion (DIC). Censoring and taking account of heteroskedasticity have important effects on parameter estimation. For DCE data only, TTO data only, and DCE/TTO data combined, models with parameters for all dimensions and levels perform best, as judged by the DIC. Taking account of heterogeneity improves fit, and the multinomial model reports the lowest DIC. This paper presents approaches that suit observed characteristics of EQ-5D-5L valuation data and recognise respondents' preference heterogeneity. The methods described are potentially relevant to other value set studies.

Logical inconsistencies in time trade-off valuation of EQ-5D-5L health states: Whose fault is it?

INTRODUCTION

Inconsistency in the time trade-off (TTO) task in EQ-5D-5L occurs when a respondent gives a higher value to a logically worse health state, the occurrence of inconsistency compromises the quality of the data. It is not yet clear which factors are associated with individual level inconsistency. Relating inconsistency to the characteristics of the respondent, interviewer, and the interview process could be helpful in understanding the causes of inconsistency. The objective of this paper is to discover the factors associated with individual level inconsistencies.

METHODS

Twenty interviewers interviewed 1,296 respondents and each respondent valued 10 health states using the EQ-VT platform in 5 cities in China. At the respondent level, inconsistency was identified in terms of severity and quantity and related to the respondent's background characteristics, the time and iterations spent on the wheelchair example task, and the formal TTO tasks, using multilevel multinomial regression analyses. Interviewers' impact on inconsistencies was analyzed using single level multinomial regression analyses.

RESULTS

In the full dataset, slight inconsistency was more related to the interview process (Time spent on TTO task: RRR = 1.246 with 95%CI: 1.076,1.441; time spent on Wheelchair example: RRR = 0.815 with 95%CI:0.699,0.952) while severe inconsistency was more related to respondent's gender (Gender: RRR = 2.347 with 95%CI:1.429,3.855). One Interviewer (Interviewer 7: RRR = 7.335 with 95%CI:1.908,28.195) and interviewer's experience (Sequence: RRR = 0.511 with 95%CI:0.385,0.678) in general showed strong influence over inconsistency in the TTO task.

CONCLUSION

In conclusion, logical inconsistency in the valuation of EQ-5D-5L health states is associated not only with respondents' characteristics but also with interviewers' performance and the interview process. The role of interviewers and the importance of interviewer training may be more crucial than hitherto believed. This finding could be generalizable to other interviewer-administered health-state valuation study.

Sample size determination for EQ-5D-5L value set studies

PURPOSE

The EuroQol 5-Dimension (EQ-5D) is a widely used health status instrument for cost-utility analysis of healthcare interventions. Recently, its 5-Level version (EQ-5D-5L) and a protocol for conducting valuation of its health states were developed. We propose four approaches for estimating the sample size for EQ-5D-5L valuation according to the standardized procedures of the protocol.

METHODS

The first approach is for estimating mean health state utility values with a desired precision level using a regression model. The second approach, empirical in nature, determines a sample size based on mean absolute error in predicting health state values using a large-scale reference study. The last two approaches are for assessing the significance of regression coefficients of health state descriptors and to estimate the regression coefficients with a desired precision for predicting health state utility values.

RESULTS

Using data from a Singaporean study, we estimated parameters that are useful for sample size determination, including the design effect. Each of the approaches was illustrated with examples and pragmatic recommendations were provided.

CONCLUSIONS

Capitalizing on the EQ-5D-5L valuation protocol, we proposed four sample size estimation approaches which can help to decide an appropriate sample size for a value set study.

Choice Blindness and Health-State Choices among Adolescents and Adults

OBJECTIVE

To assess the feasibility and validity of using a discrete choice experiment format to elicit health preferences in adolescents by comparing illogical choices and choice-blindness rates between adults and adolescents; and to explore the relationship between personality traits and health-state choices.

METHODS

A convenience sample of adults and adolescents (12 to 17 y old) were recruited from around Chicago, USA. A personality inventory was administered, followed by pairwise comparisons of 6 health-state scenarios which asked each candidate to select their preferred choice. Health-state descriptions were based on a simplified 3-dimension version of the EQ-5D (mobility, pain, depression, each with 3 levels). For 2 scenarios, the respondent's preferred choice was switched; if the respondent did not notice the switch they were considered "choice blind". Logistic regression evaluated the association of personality, gender, and age with choice blindness and health-state choice.

RESULTS

Ninety-nine respondents were recruited (44% adults). Comparing adolescents to adults, there was no significant difference in the rate of illogical preferences (9% v. 12%) or in preferring dead to the worst health state (56% v. 64%) ( P > 0.05). Choice-blindness rates were significantly higher in adolescents (35%) than adults (9%) ( P < 0.01). The adjusted odds of choice blindness in adolescents was 6.6 (95% CI = 1.8 to 23.8; P = 0.004). Conscientiousness was significantly associated with health-state choice in 3 of the 6 models predicting health-state choice (using P < 0.1 as a threshold).

CONCLUSIONS

The results of this exploratory study suggest it is feasible to conduct choice experiments in adolescents; however, adolescents are significantly more likely to demonstrate choice blindness. Psychological traits may be noteworthy predictors of health-state choices, with conscientiousness independently associated with several health-state choices.

Health literacy and logical inconsistencies in valuations of hypothetical health states: results from the Canadian EQ-5D-5L valuation study

OBJECTIVES

To examine the association of health literacy with logical inconsistencies in time trade-off valuations of hypothetical health states described by the EQ-5D-5L classification system.

METHODS

Data from the EQ-5D-5L Canadian Valuation study were used. Health literacy was assessed using the Brief Health Literacy Screen. A health state valuation was considered logically inconsistent if a respondent gave the same or lower value for a very mild health state compared to the value given to 55555, or gave the same or lower value for a very mild health state compared to value assigned to the majority of the health states that are dominated by the very mild health state.

RESULTS

Average age of respondents (N = 1209) was 48 (SD = 17) years, 45% were male, 7% reported inadequate health literacy, and 11% had a logical inconsistency. In adjusted analysis, participants with inadequate health literacy were 2.2 (95%CI: 1.2, 4.0; p = 0.014) times more likely to provide an inconsistent valuation compared to those with adequate health literacy. More specifically, those who had problems in "understanding written information" and "reading health information" were more likely to have a logical inconsistency compared to those who did not. However, lacking "confidence in completing medical forms" was not associated with logical inconsistencies.

CONCLUSIONS

Health literacy was associated with logical inconsistencies in valuations of hypothetical health states described by the EQ-5D-5L classification system. Valuations studies should consider assessing health literacy, and explore better ways to introduce the valuation tasks or use simpler approaches of health preferences elicitation for individuals with inadequate health literacy.

The quality-of-life burden of knee osteoarthritis in New Zealand adults: A model-based evaluation

BACKGROUND

Knee osteoarthritis is a leading global cause of health-related quality of life loss. The aim of this project was to quantify health losses arising from knee osteoarthritis in New Zealand (NZ) in terms of quality-adjusted life years (QALYs) lost.

METHODS

The Osteoarthritis Policy Model (OAPol), a validated Monte Carlo computer simulation model, was used to estimate QALYs lost due to knee osteoarthritis in the NZ adult population aged 40-84 over their lifetimes from the base year of 2006 until death. Data were from the NZ Health Survey, NZ Burden of Diseases, NZ Census, and relevant literature. QALYs were derived from NZ EQ-5D value set 2. Sensitivity to health state valuation, disease and pain prevalence were assessed in secondary analyses.

RESULTS

Based on NZ EQ-5D health state valuations, mean health losses due to knee osteoarthritis over people's lifetimes in NZ are 3.44 QALYs per person, corresponding to 467,240 QALYs across the adult population. Average estimated per person QALY losses are higher for non-Māori females (3.55) than Māori females (3.38), and higher for non-Māori males (3.34) than Māori males (2.60). The proportion of QALYs lost out of the total quality-adjusted life expectancy for those without knee osteoarthritis is similar across all subgroups, ranging from 20 to 23 percent.

CONCLUSIONS

At both the individual and population levels, knee osteoarthritis is responsible for large lifetime QALY losses. QALY losses are higher for females than males due to greater prevalence of knee osteoarthritis and higher life expectancy, and lower for Māori than non-Māori due to lower life expectancy. Large health gains are potentially realisable from public health and policy measures aimed at decreasing incidence, progression, pain, and disability of osteoarthritis.

The DEP-6D, a new preference-based measure to assess health states of dependency

In medical literature there are numerous multidimensional scales to measure health states for dependence in activities of daily living. However, these scales are not preference-based and are not able to yield QALYs. On the contrary, the generic preference-based measures are not sensitive enough to measure changes in dependence states. The objective of this paper is to propose a new dependency health state classification system, called DEP-6D, and to estimate its value set in such a way that it can be used in QALY calculations. DEP-6D states are described as a combination of 6 attributes (eat, incontinence, personal care, mobility, housework and cognition problems), with 3-4 levels each. A sample of 312 Spanish citizens was surveyed in 2011 to estimate the DEP-6D preference-scoring algorithm. Each respondent valued six out of the 24 states using time trade-off questions. After excluding those respondents who made two or more inconsistencies (6% out of the sample), each state was valued between 66 and 77 times. The responses present a high internal and external consistency. A random effect model accounting for main effects was the preferred model to estimate the scoring algorithm. The DEP-6D describes, in general, more severe problems than those usually described by means of generic preference-based measures. The minimum score predicted by the DEP-6D algorithm is -0.84, which is considerably lower than the minimum value predicted by the EQ-5D and SF-6D algorithms. The DEP-6D value set is based on community preferences. Therefore it is consistent with the so-called 'societal perspective'. Moreover, DEP-6D preference weights can be used in QALY calculations and cost-utility analysis.

Population-Based Preference Weights for the EQ-5D Health States Using the Visual Analogue Scale (VAS) in Iran

Background

Health-related quality of life (HRQoL) is used as a measure to valuate healthcare interventions and guide policy making. The EuroQol EQ-5D is a widely used generic preference-based instrument to measure Health-related quality of life.

Objectives

The objective of this study was to develop a value set of the EQ-5D health states for an Iranian population.

Patients and Methods

This study is a cross-sectional study of Iranian populations. Our sample from Iranian populations consists out of 869 participants, who were selected for this study using a stratified probability sampling method. The sample was taken from individuals living in the city of Tehran and was stratified by age and gender from July to November 2013. Respondents valued 13 health states using the visual analogue scale (VAS) of the EQ-5D. Several fixed effects regression models were tested to predict the full set of health states. We selected the final model based on the logical consistency of the estimates, the sign and magnitude of the regression coefficients, goodness of fit, and parsimony. We also compared predicted values with a value set from similar studies in the UK and other countries.

Results

Our results show that the HRQoL does not vary among socioeconomic groups. Models at the individual level resulted in an additive model with all coefficients being statistically significant, R² = 0.55, a value of 0.75 for the best health state (11112), and a value of -0.074 for the worst health state (33333). The value set obtained for the study sample remarkably differs from those elicited in developed countries.

Conclusions

This study is the first estimate for the EQ-5D value set based on the VAS in Iran. Given the importance of locally adapted value set the use of this value set can be recommended for future studies in Iran and In the EMRO regions.

An Empirical Study of Two Alternative Comparators for Use in Time Trade-Off Studies

BACKGROUND

Studies to produce value sets for preference-based measures of health require definition of a full health upper anchor if the values are to be used to calculate quality-adjusted life years. Recent value sets derived for the EQ-5D-5L instrument have described the upper anchor as "full health," whereas older valuation studies for the EQ-5D used "best health state" in the descriptive system (11111). It is unclear whether this change could have led to differences in the values obtained. The objective of this study was to assess differences in time trade-off (TTO) valuations using two different comparators (full health and 11111).

METHODS

Preferences for EQ-5D-5L health states were elicited from a broadly representative sample of the UK general public. TTO data were collected by using computer-assisted personal interviews. Respondents were randomly allocated to one of two arms, each using a different comparator health state. Respondents completed 10 or 11 TTO valuations and a series of follow-up questions examining their interpretations of the term "full health."

RESULTS

Interviews with 443 respondents were completed in 2014. The differences in mean values across arms are mostly small and nonsignificant. The two arms produced data of similar quality. There is evidence of interviewer effects. Health state 11111 was given a value of 1 by 98.2% of the respondents who valued it.

CONCLUSIONS

EQ-5D-5L values elicited by using the composite TTO approach are not greatly affected by the use of full health or 11111 as the comparator health state.

Logical Inconsistencies in 3 Preference Elicitation Methods for EQ-5D Health States: A Study in the Brazilian Population

BACKGROUND

. Logical inconsistency for health states preferences occurs when one logically worse health state, in terms of quality of life, is ranked higher than a logically better health state.

OBJECTIVE

. This study explores the presence of inconsistent responses for the EQ-5D health states valuations in a Brazilian population survey. It compares the level of inconsistency in 3 preference-based methods: ranking, visual analog scale (VAS), and time tradeoff (TTO). The influence of EQ-5D health state descriptions is explored by examining the distance between states using a city-block metric as an indicator of proximity. Moreover, it examines the association between formal education and the presence of inconsistencies, as well as the effect of removing inconsistent respondents on the estimation of social value sets from TTO and VAS.

METHODS

. Data came from a valuation study with 3362 literate individuals aged between 18 and 64 years living in urban areas of Minas Gerais state, Brazil. Logical inconsistency was assessed using the percentage of inconsistent respondents and inconsistency rate. A logistic model was estimated to assess the association between formal education and the logical inconsistency. Societal preferences were estimated excluding inconsistent respondents considering city-block metric.

RESULTS

. The percentage of inconsistent respondents and inconsistency rate are similar for TTO and ranking and lower for VAS. The probability of being inconsistent is higher among less educated groups in ranking and TTO. Inconsistency decreases with distance for all 3 methods. The removal of inconsistent individuals by considering city-block distance improves TTO estimation of social value sets.

CONCLUSION

. Findings suggest that removal of inconsistencies in TTO should consider city-block distance. For VAS, inconsistencies are not associated with formal education and do not affect social value set estimation.

Exclusion Criteria in National Health State Valuation Studies: A Systematic Review

BACKGROUND

Health state valuation data are often excluded from studies that aim to provide a nationally representative set of values for preference-based health-related quality of life (HRQoL) instruments. The purpose was to provide a systematic examination of exclusion criteria used in the derivation of societal scoring algorithms for preference-based HRQoL instruments.

METHODS

Data sources included MEDLINE, official instrument websites, and publication reference lists. Analyses that used data from national valuation studies and reported a scoring algorithm for a generic preference-based HRQoL instrument were included. Data extraction included exclusion criteria and associated justifications, exclusion rates, the characteristics of excluded respondents, and analyses that explored consequential implications of exclusion criteria on the respective national tariff.

RESULTS

Seventy-six analyses (from 70 papers) met the inclusion criteria. In addition to being excluded for logical inconsistencies, respondents were often excluded if they valued fewer than 3 health states or if they gave the same value to all health states. Numerous other exclusion criteria were identified, with varying degrees of justification, often based on an assumption that respondents did not understand the task or as a consequence of the chosen statistical modeling techniques. Rates of exclusion ranged from 0% to 65%, with excluded respondents more likely to be older, less educated, and less healthy. Limitations included that the database search was confined to MEDLINE; study selection focused on national valuation studies that used standard gamble, time tradeoff, and/or visual analog scale techniques; and only English-language studies were included.

CONCLUSION

Exclusion criteria used in national valuation studies vary considerably. Further consideration is necessary in this important and influential area of research, from the design stage to the reporting of results.

Long-term air humidification therapy is cost-effective for patients with moderate or severe chronic obstructive pulmonary disease or bronchiectasis

OBJECTIVE

To establish the cost-effectiveness of long-term humidification therapy (LTHT) added to usual care for patients with moderate or severe chronic obstructive pulmonary disease or bronchiectasis.

METHODS

Resource usage in a 12-month clinical trial of LTHT was estimated from hospital records, patient diaries, and the equipment supplier. Health state utility values were derived from the St. Georges Respiratory Questionnaire (SGRQ) total score. All patients who remained in the trial for 12 months and who had at least 90 days of diary records were included (87 of 108).

RESULTS

Clinical costs were NZ $3973 (95% confidence interval [CI] $1614-$6332) for the control group and NZ $3331 (95% CI $948-$6920) for the intervention group. The mean health benefit per patient was -6.9 SGRQ units (95% CI -13.0 to -7.2; P < 0.05) or +0.0678 quality-adjusted life-years (95% CI 0.001-0.135). With the intervention costing NZ $2059 annually, the mean cost per quality-adjusted life-year was NZ $20,902 (US $18,907) and the bootstrap median was NZ $19,749 (2.5th percentile -$40,923, 97.5th percentile $221,275). At a willingness-to-pay (WTP) threshold of NZ $30,000, the probability of cost-effectiveness was 61%, ranging from 49% to 72% as the cost of LTHT was varied by ±30%. At a WTP of NZ $20,000, the probability was 49% (range 34%-61%).

CONCLUSIONS

LTHT is moderately cost-effective for patients with moderate to severe chronic obstructive pulmonary disease or bronchiectasis at a WTP threshold that is acceptable for public funding of medicines in New Zealand. These findings must be interpreted with caution because of the modest size of the clinical study, necessary lack of blinding in the clinical trial, and uncertainty in estimating health state utility from the SQRQ.

A comparison of injured patient and general population valuations of EQ-5D health states for New Zealand

Background

A near-universal finding internationally is that patient valuations of their own health, represented using the EQ-5D system, are mostly higher than general population valuations of the same EQ-5D states. This paper investigates whether this result also applies to New Zealand. Despite the EQ-5D’s widespread use for cost-utility analysis in New Zealand, in particular by the Pharmaceutical Management Agency (PHARMAC) for health technology assessments, no previous studies comparing patient and general population valuations have included data for New Zealand.

Methods

Valuations of 13 EQ-5D health states from a 1999 survey of the New Zealand general population (n = 396) are compared with injured New Zealanders’ (n = 2099) valuations of their own health (also represented on the EQ-5D) collected between 2007 and 2009 in the Prospective Outcomes of Injury Study. Which EQ-5D dimensions are most strongly associated with the population valuations is also investigated.

Results

Injured population valuations are higher (better-rated health) than general population valuations for all 13 health states considered except 11111 (no problems on any EQ-5D dimension). This difference, which tends to be larger the ‘worse’ the state, is statistically significant at the 10% level for most of the states. State 11111 is rated significantly lower by the injured population than the general population. Pain/discomfort is more important in determining valuations for the general population than for injured people, whereas problems with self-care are more important for the injured population; anxiety/depression is important in both general and injured population valuations.

Conclusions

Consistent with the international literature, injured people’s valuations of their own health are mostly higher than the general population’s hypothetical valuations of the same EQ-5D states for New Zealand. These differences are practically significant in the sense that they are larger than minimally important differences for the EQ-5D from the literature, and they appear capable of significantly affecting CUA results.

Visual impairment as a function of visual acuity in both eyes and its impact on patient reported preferences

Purpose

To assess the impact of VA loss on patient reported utilities taking both eyes into account compared to taking only the better or the worse eye into account.

Methods

In this cross-sectional study 1085 patients and 254 controls rated preferences with the generic health-related (EQ-5D; n = 868) and vision-specific (Vision and Quality of Life Index (VisQoL); n = 837) multi-attribute utility instruments (MAUIs). Utilities were calculated for three levels of VA in the better and worse eyes, as well as for 6 different vision states based on combinations of the better and worse eye VA.

Results

Using the VisQoL, utility scores decreased significantly with deteriorating vision in both the better and worse eyes when analysed separately. When stratified by the 6 vision states, VisQoL utilities decreased as VA declined in the worse eye despite stable VA in the better eye. Differences in VisQoL scores were statistically significant for cases where the better eye had no vision impairment and the worse seeing fellow eye had mild, moderate or severe vision impairment. In contrast, the EQ-5D failed to capture changes in better or worse eye VA, or any of the six vision states.

Conclusions

Calculating utilities based only on better eye VA or using a generic MAUI is likely to underestimate the impact of vision impairment, particularly when the better eye has no or little VA loss and the worse eye is moderately to severely visually impaired. These findings have considerable implications for the assessment of overall visual impairment as well as economic evaluations within eye health.

The valuation of the EQ-5D in Portugal

PURPOSE

The EQ-5D is a preference-based measure widely used in cost-utility analysis (CUA). Several countries have conducted surveys to derive value sets, but this was not the case for Portugal. The purpose of this study was to estimate a value set for the EQ-5D for Portugal using the time trade-off (TTO).

METHODS

A representative sample of the Portuguese general population (n = 450) stratified by age and gender valued 24 health states. Face-to-face interviews were conducted by trained interviewers. Each respondent ranked and valued seven health states using the TTO. Several models were estimated at both the individual and aggregated levels to predict health state valuations. Alternative functional forms were considered to account for the skewed distribution of these valuations.

RESULTS

The models were analyzed in terms of their coefficients, overall fit and the ability for predicting the TTO values. Random effects models were estimated using generalized least squares and were robust across model specification. The results are generally consistent with other value sets.

CONCLUSION

This research provides the Portuguese EQ-5D value set based on the preferences of the Portuguese general population as measured by the TTO. This value set is recommended for use in CUA conducted in Portugal.

Comparing EQ-5D valuation studies: a systematic review and methodological reporting checklist

BACKGROUND

There has been a growing interest around the world in developing country-specific scoring algorithms for the EQ-5D. This study systematically reviews all existing EQ-5D valuation studies to highlight their strengths and limitations, explores heterogeneity in observed utilities using meta-regression, and proposes a methodological checklist for reporting EQ-5D valuation studies.

METHODS

. We searched Medline, EMBASE, the National Health Service Economic Evaluation Database (NHS EED) via Wiley's Cochrane Library, and Wiley's Health Economic Evaluation Database from inception through November 2012, as well as bibliographies of key papers and the EuroQol Plenary Meeting Proceedings from 1991 to 2012 for English-language reports of EQ-5D valuation studies. Two reviewers independently screened the titles and abstracts for relevance. Three reviewers performed data extraction and compared the characteristics and scoring algorithms developed in the included valuation studies.

RESULTS

. Of the 31 studies included in the review, 19 used the time trade-off (TTO) technique, 10 used the visual analogue scale (VAS) technique, and 2 used both TTO and VAS. Most studies included respondents from the general population selected by random or quota sampling and used face-to-face interviews or postal surveys. Studies valued between 7 and 198 total states, with 1-23 states valued per respondent. Different model specifications have been proposed for scoring. Some sample or demographic factors, including gender, education, percentage urban population, and national health care expenditure, were associated with differences in observed utilities for moderate or severe health states.

CONCLUSIONS

. EQ-5D valuation studies conducted to date have varied widely in their design and in the resulting scoring algorithms. Therefore, we propose the Checklist for Reporting Valuation Studies of the EQ-5D (CREATE) for those conducting valuation studies.

Valuing EQ-5D using time trade-off in France

OBJECTIVES

While a French language version of the EQ-5D exists, to date, there has been no French value set to accompany it. The objective of our study was then to derive the French TTO value set of the EQ-5D.

METHODS

A total of 452 respondents aged over 18 were recruited who were representative of the French population with regard to age, gender, and socio-professional group. The direct valuation of 24 health states was first obtained by Time Trade-Off (TTO), and the negative TTO values were bounded using the monotonic transformation. Several alternative model specifications were investigated to estimate the values for all 243 states in the EQ-5D descriptive system. Only the best fitting model is presented in this paper. The analysis was conducted at an individual level to make the maximum use of the available data, and we estimated mixed models with random intercept. Models were compared through the Akaike information criterion (AIC), the mean absolute error (MAE), and the Pearson correlation coefficient between the observed and the predicted values of each model.

RESULTS

After exclusion, 443 respondents took part in the study. The best fitting model included the same variables as the N3-model used in UK.

CONCLUSION

This study provides the French value set of the EQ-5D based on the stated preferences of the French general public facilitating cost-effectiveness analysis.

Retrospective evaluation versus population norms for the measurement of baseline health status

Background

Patient recall or the application of population norms are commonly used methods to estimate (unobservable) health status prior to acute-onset illness or injury; however, both measures are potentially subject to bias. This article reports tests of the validity of both approaches, and discusses the implications for reporting changes in health-related quality of life following acute-onset illness or injury.

Methods

Recalled pre-injury health status and health status at 5- and 12-months post-injury were collected from participants in a prospective cohort study of people injured in New Zealand. Reported post-injury health status was compared with recalled pre-injury status and New Zealand norms for two groups: those who reported having fully recovered, and those who had not.

Results

There was a small but statistically significant difference between pre- and post-injury health state valuations for people who had fully recovered, with recalled pre-injury health status being higher than reported post-injury health. Perceived health status for those who had fully recovered was significantly higher than the population norm.

Conclusions

Retrospective evaluation of health status is more appropriate than the application of population norms to estimate health status prior to acute-onset injury or illness, although there may be a small upward bias in such measurements.

Time trade-off and attitudes toward euthanasia: implications of using 'death' as an anchor in health state valuation

PURPOSE

Health state values are by convention anchored to 'perfect health' and 'death.' Attitudes toward death may consequently influence the valuations. We used attitudes toward euthanasia (ATE) as a sub-construct for attitudes toward death. We compared the influence on values elicited with time trade-off (TTO), lead-time TTO (LT-TTO) and visual analogue scale (VAS).Since the 'death' anchor is most explicit in TTO, we hypothesized that TTO values would be most influenced by ATE.

METHODS

Respondents valued eight EQ-5D health states with VAS, then TTO (n = 328) or LT-TTO (n = 484). We measured ATE on a scale from -2 (fully disagree) to 2 (fully agree) and used multiple linear regressions to predict VAS, TTO, and LT-TTO values by ATE, sex, age, and education.

RESULTS

A one-point increase on the ATE scale predicted a mean TTO value change of -.113 and LT-TTO change of -.072. Demographic variables, but not ATE, predicted VAS values.

CONCLUSIONS

TTO appears to measure ATE in addition to preferences for health states. Different ways of incorporating death in the valuation may impact substantially on the resulting values. 'Death' is a metaphysically unknown concept, and implications of attitudes toward death should be investigated further to evaluate the appropriateness of using 'death' as an anchor.

Canadian valuation of EQ-5D health states: preliminary value set and considerations for future valuation studies

Background

The EQ-5D is a preference based instrument which provides a description of a respondent's health status, and an empirically derived value for that health state often from a representative sample of the general population. It is commonly used to derive Quality Adjusted Life Year calculations (QALY) in economic evaluations. However, values for health states have been found to differ between countries. The objective of this study was to develop a set of values for the EQ-5D health states for use in Canada.

Methods

Values for 48 different EQ-5D health states were elicited using the Time Trade Off (TTO) via a web survey in English. A random effect model was fitted to the data to estimate values for all 243 health states of the EQ-5D. Various model specifications were explored. Comparisons with EQ-5D values from the UK and US were made. Sensitivity analysis explored different transformations of values worse than dead, and exclusion criteria of subjects.

Results

The final model was estimated from the values of 1145 subjects with socio-demographics broadly representative of Canadian general population with the exception of Quebec. This yielded a good fit with observed TTO values, with an overall R2 of 0.403 and a mean absolute error of 0.044.

Conclusion

A preference-weight algorithm for Canadian studies that include the EQ-5D is developed. The primary limitations regarded the representativeness of the final sample, given the language used (English only), the method of recruitment, and the difficulty in the task. Insights into potential issues for conducting valuation studies in countries as large and diverse as Canada are gained.

Using a discrete choice experiment to estimate health state utility values

In this study we explored a novel application of the discrete choice experiment (DCE) that resembles the time trade off (TTO) task to estimate values on the health utility scale for the EQ-5D. The DCE was tested in a survey alongside the TTO in a sample of English-speaking Canadians recruited by a market research company. The study found that the DCE is able to derive logical and consistent values for health states valued on the full health - dead scale. The DCE overcame some issues identified in the version of TTO currently used to value EQ-5D, notably allowing for fewer data exclusions and incorporating values considered worse than dead without introducing a separate valuation procedure. This has important implications for providing robust values that represent the preferences of all respondents.

Estimating an EQ-5D value set for Malaysia using time trade-off and visual analogue scale methods

OBJECTIVES

To estimate a EQ-5D value set for Malaysia by using time trade-off (TTO) and visual analogue scale (VAS) valuation methods.

METHODS

TTO and VAS valuations were obtained from face-to-face surveys of a convenience sample of patients, caregivers, and health professionals conducted at nine government hospitals in 2004 and 2005. Forty-five EQ-5D questionnaire health states were valued, divided into five sets of 15 health states. Analysis was conducted by using linear additive regression models applying N3 and D1 specifications. Model selection was based on criteria of coefficient properties, statistical significance, and goodness of fit.

RESULTS

One hundred fifty-two respondents were interviewed, yielding 2174 TTO and 2265 VAS valuations. Respondents found TTO valuations to be more difficult than VAS valuations, and there were more inconsistencies in TTO valuations. All the independent variables in the models were statistically significant and consistent with expected signs and magnitude, except for the D1 specification modeled on TTO valuations. The N3 model provided the best fit for the VAS valuation data, with a mean absolute error of 0.032.

CONCLUSION

This study provides a Malaysian EQ-5D questionnaire value set that can be used for cost-utility studies despite survey limitations.

Estimating population-based values for EQ-5D health states in Thailand

OBJECTIVE

To derive EuroQol five-dimensional (EQ-5D) health states values from the Thai general population.

METHODS

Forty-eight trained individuals successfully conducted interviews with a representative sample of 1409 respondents in 2007. A total of 12 sets of health states were used with one set allocated to each respondent. A respondent was requested to assign values for 11 states using the ranking and visual analogue scale methods and 10 states using the time trade-off method. The variables from the three existing models were used in model specifications and the best model was chosen on the basis of the extent of logical inconsistency in the estimated scores, predictive performance, parsimony, and sensitivity to changes in health.

RESULTS

Eighty-six health states were valued. The mean age of respondents was 44.6 years old. The highly consistent respondents tend to give higher scores for mild states and lower scores for severe states, compared with those given by the highly inconsistent respondents. The best model used variables from the Dolan 1997 study and estimated from the scores given by the respondents with fewer than 11 inconsistencies. The estimated scores are completely consistent, R(2) is 0.448. The second highest score was 0.766 given to state 11112 and the lowest score was -0.454 for state 33333.

CONCLUSION

Values for EQ-5D health states were estimated from the Thai general population. This is the first Thai generic health state value results to be used in evaluating health interventions in Thailand.

Time trade-off derived EQ-5D weights for Australia

BACKGROUND

Cost-utility analyses (CUAs) are increasingly common in Australia. The EuroQol five-dimensional (EQ-5D) questionnaire is one of the most widely used generic preference-based instruments for measuring health-related quality of life for the estimation of quality-adjusted life years within a CUA. There is evidence that valuations of health states vary across countries, but Australian weights have not previously been developed.

METHODS

Conventionally, weights are derived by applying the time trade-off elicitation method to a subset of the EQ-5D health states. Using a larger set of directly valued health states than in previous studies, time trade-off valuations were collected from a representative sample of the Australian general population (n = 417). A range of models were estimated and compared as a basis for generating an Australian algorithm.

RESULTS

The Australia-specific EQ-5D values generated were similar to those previously produced for a range of other countries, but the number of directly valued states allowed inclusion of more interaction effects, which increased the divergence between Australia's algorithm and other algorithms in the literature.

CONCLUSION

This new algorithm will enable the Australian community values to be reflected in future economic evaluations.