Integrating preferences into health status assessment for amyotrophic lateral sclerosis: the ALS Utility Index

Cost-utility analysis for sublingual versus intravenous edaravone in the treatment of amyotrophic lateral sclerosis

BACKGROUND

Edaravone has been widely used in amyotrophic lateral sclerosis (ALS) treatment, and a sublingual (SL) tablet has been developed to offer a more convenient alternative for injection. We present a cost-utility analysis to comprehensively evaluate the costs and health outcomes of oral and intravenous edaravone for the treatment of ALS in Chinese medical context.

METHODS

Cost-utility analysis of SL tablets of edaravone versus intravenous edaravone at home was performed by constructing a 20-year Markov model of ALS stage 1-4 and death. The data were extracted from the literature with model assumptions. Typical sensitivity analysis and scenario analysis for administering SL tablets at home versus intravenous tablets at the hospital were performed.

RESULTS

In the base case analysis, with SL tablets and intravenous injections both at home, the model estimated an additional cost of ¥12,670.04 and an additional 0.034 QALYs over 20 years (life time) of modeling analysis, and the ICER was ¥372,648.24 per QALY. However, in the scenario of intravenous administration at the hospital, SL tablet was demonstrated dominance to intravenous injection.

CONCLUSIONS

Using 3 times the GDP per capita of China in 2023 as the threshold, the SL tablet edaravone was not cost-effective in the context of home treatment for both formulationst, but was dominance to intravenous injection in hospital treatment. The results highlighted the importance of treatment context for health economic analysis.

Consideration of quality of life in the health technology assessments of rare disease treatments

OBJECTIVES

Challenges with patient-reported outcome (PRO) evidence and health state utility values (HSUVs) in rare diseases exist due to small, heterogeneous populations, lack of disease knowledge and early onset. To better incorporate quality of life (QoL) into Health Technology Assessment, a clearer understanding of these challenges is needed.

METHODS

NICE appraisals of non-oncology treatments with an EMA orphan designation (n = 24), and corresponding appraisals in the Netherlands, France, and Germany were included. Document analysis of appraisal reports investigated how PROs/HSUVs influenced decision-making and was representative of QoL impact of condition and treatment.

RESULTS

PRO evidence was not included in 6/24 NICE appraisals. When included, it either failed to demonstrate change, capture domains important for patients, or was uncertain. In the other countries, little information was reported and evidence largely did not demonstrate change. In NICE appraisals, HSUVs were derived through the collection of EQ-5D data (7/24 cases), mapping (6/24), vignettes (5/24), and published literature or other techniques (6/24). The majority did not use data collected alongside clinical trials. Few measures demonstrated significant change due to lack of sensitivity or face validity, short-term data, or implausible health states. In 8/24 NICE appraisals, patient surveys or input during appraisal committee meetings supported the interpretation of uncertainty or provided evidence about QoL.

CONCLUSIONS

This study sheds light on the nature of PRO evidence in rare diseases and associated challenges. Results emphasise the need for improved development and use of PRO/HSUVs. Other forms of evidence and expert input are crucial to support better appraisal of uncertain or missing evidence.

Estimation of an EORTC QLU-C10 Value Set for Spain Using a Discrete Choice Experiment

BACKGROUND

The EORTC QLU-C10D is a preference-based measure derived from the EORTC QLQ-C30. For use in economic evaluations, country-specific value sets are needed. This study aimed to generate an EORTC QLU-C10 value set for Spain.

METHODS

A sample of the Spanish general population completed an online discrete choice experiment. An attribute-balanced incomplete block design was used to select 960 choice tasks, with a total of 1920 health states. Each participant was randomly assigned 16 choice sets without replacement. Data were modelled using generalized estimating equations and mixed logistic regressions.

RESULTS

A total of 1625 panel members were invited to participate, 1010 of whom were included in the study. Dimension decrements were generally monotonic with larger disutilities at increased severity levels. Dimensions associated with larger decrements were physical functioning and pain, while the dimension with the smallest decrement was sleep disturbances. The PITS state (i.e. worst attainable health) for the Spanish population is - 0.043.

CONCLUSIONS

This study generated the first Spanish value set for the QLU-C10D. This can facilitate cost-utility analyses when applied to data collected with the EORTC QLQ-C30.

Dimensions Used in Instruments for QALY Calculation: A Systematic Review

Economic assessment is of utmost importance in the healthcare decision-making process. The quality-adjusted life-year (QALY) concept provides a rare opportunity to combine two crucial aspects of health, i.e., mortality and morbidity, into a single index to perform cost-utility comparison. Today, many tools are available to measure morbidity in terms of health-related quality of life (HRQoL) and a large literature describes how to use them. Knowing their characteristics and development process is a key point for elaborating, adapting, or selecting the most well-suited instrument for further needs. In this aim, we conducted a systematic review on instruments used for QALY calculation, and 46 studies were selected after searches in four databases: Medline EBSCO, Scopus, ScienceDirect, and PubMed. The search procedure was done to identify all relevant publications up to 18 June 2020. We mainly focused on the type of instrument developed (i.e., generic or specific), the number and the nature of dimensions and levels used, the elicitation method and the model selected to determine utility scores, and the instrument and algorithm validation methods. Results show that studies dealing with the development of specific instruments were mostly motivated by the inappropriateness of generic instruments in their field. For the dimensions' and levels' selection, item response theory, Rasch analysis, and literature review were mostly used. Dimensions and levels were validated by methods like the Loevinger H, the standardised response mean, or discussions with experts in the field. The time trade-off method was the most widely used elicitation method, followed by the visual analogue scale. Random effects regression models were frequently used in determining utility scores.

Preference-based measurement of mobility-related quality of life: developing the MobQoL-7D health state classification system

PURPOSE

Generic preference-based measures often lack validity in states of impaired mobility. Our aim was to derive a novel health state classification system from the MobQoL tool, for the purpose of preference-based measurement of states of impaired mobility.

MATERIALS AND METHODS

Data were collected through online and postal surveys. Respondents were recruited through the NHS, charitable organisations and HealthWise Wales. Statistical and psychometric analyses were used to assess the validity and reliability of the MobQoL tool. Exploratory factor analysis and Rasch analysis were used to determine dimensional structure and to select items for the MobQoL health state classification system.

RESULTS

Three hundred and forty-two respondents completed the survey. Respondents had a wide range of different mobility impairments. Nine of the MobQoL items demonstrated adequate validity and reliability. Exploratory factor analysis and Rasch analysis confirmed two sub-scales within the item structure: 1) physical and role functioning, and 2) mental wellbeing. Seven items were found to have adequate model fit and were retained in the final health state classification system, called the MobQoL-7D.

CONCLUSIONS

The MobQoL-7D contains seven dimensions of mobility-related quality of life: accessibility, contribution, pain/discomfort, independence, self-esteem, mood/emotions and anxiety. Population level preference weights are now needed for different states of mobility impairment.IMPLICATIONS FOR REHABILITATIONMobility impairment has distinct impacts on mental wellbeing and physical/role functioning.The MobQoL-7D will facilitate accurate preference-based outcome measurement in populations with impaired mobility, which in turn will promote methods of economic evaluation in this context.MobQoL-7D offers a concise and valid tool for rehabilitation professionals to measure and monitor mobility-related quality of life as part of routine clinical practice.

'Mapping' Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

BACKGROUND

The use of patient-reported outcome measures (PROMs) to monitor the effects of disease and treatment on patient symptomatology and daily life is increasing in rare diseases (RDs) (i.e. those affecting less than one in 2000 people); however, these instruments seldom yield health state utility values (HSUVs) for cost-utility analyses. In such a context, 'mapping' allows HSUVs to be obtained by establishing a statistical relationship between a 'source' (e.g. a disease-specific PROM) and a 'target' preference-based measure [e.g. the EuroQol-5 Dimension (EQ-5D) tool].

OBJECTIVE

This study aimed to systematically review all published studies using 'mapping' to derive HSUVs from non-preference-based measures in RDs, and identify any critical issues related to the main features of RDs, which are characterised by small, heterogeneous, and geographically dispersed patient populations.

METHODS

The following databases were searched during the first half of 2019 without time, study design, or language restrictions: MEDLINE (via PubMed), the School of Health and Related Research Health Utility Database (ScHARRHUD), and the Health Economics Research Centre (HERC) database of mapping studies (version 7.0). The keywords combined terms related to 'mapping' with Orphanet's list of RD indications (e.g. 'acromegaly') in addition to 'rare' and 'orphan'. 'Very rare' diseases (i.e. those with fewer than 1000 cases or families documented in the medical literature) were excluded from the searches. A predefined, pilot-tested extraction template (in Excel^®) was used to collect structured information from the studies.

RESULTS

Two groups of studies were identified in the review. The first group (n = 19) developed novel mapping algorithms in 13 different RDs. As a target measure, the majority used EQ-5D, and the others used the Short-Form Six-Dimension (SF-6D) and 15D; most studies adopted ordinary least squares (OLS) regression. The second group of studies (n = 9) applied previously published algorithms in non-RDs to comparable RDs, mainly in the field of cancer. The critical issues relating to 'mapping' in RDs included the availability of very few studies, the relatively high number of cancer studies, and the absence of research in paediatric RDs. Moreover, the reviewed studies recruited small samples, showed a limited overlap between RD-specific and generic PROMs, and highlighted the presence of cultural and linguistic factors influencing results in multi-country studies. Lastly, the application of existing algorithms developed in non-RDs tended to produce inaccuracies at the bottom of the EQ-5D scale, due to the greater severity of RDs.

CONCLUSIONS

More research is encouraged to develop algorithms for a broader spectrum of RDs (including those affecting young children), improve mapping study quality, test the generalisability of algorithms developed in non-RDs (e.g. HIV) to rare variants or evolutions of the same condition (e.g. AIDS wasting syndrome), and verify the robustness of results when mapped HSUVs are used in cost-utility models.

Health Utilities and Costs for Motor Neurone Disease

BACKGROUND

Motor neurone disease (MND) places a significant burden on patients, their carers, and healthcare systems.

OBJECTIVES

To estimate health utilities and costs of MND within the UK setting.

METHODS

Patients with MND, recruited via 22 regional clinics, completed a postal questionnaire of a cost and quality-of-life survey. Health outcome assessment included the EuroQoL (EQ)-5D-5L, EQ-5D-visual analogue scale, Amyotrophic Lateral Sclerosis Utility Index, and the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised. Clinical staging was based on the Kings and Milano-Torino (MiToS) systems. The questionnaire asked about patients' use of primary, secondary, and community care services in the previous 3 months. Variability in total costs was examined using regression models.

RESULTS

595 patients were included in the health utility analysis, of whom 584 patients also completed a resource use questionnaire. Mean health utility decreased and costs increased between consecutive Kings stages, from 0.76 (95% CI 0.71-0.80) and £1096 (£757-£1240) in Kings stage 1, to 0.50 (0.45-0.54) and £3311 (£2666-£4151) in stage 4, respectively. The changes by MiToS stages were from 0.71 (0.69-0.73) and £1115 (£937-£1130) in MiToS stage 0, to 0.25 (0.07-0.42) and £2899 (£2190-£3840) in stage 2. Kings stages 3 and 4 and MiToS stages 1 and 2, respectively, were significant in explaining variability in total costs.

CONCLUSIONS

The impact of MND on health utilities and costs differs by disease severity. The data provided here can be used in cost-effectiveness analyses and to inform decision-making regarding healthcare provision for people with MND.

Mapping ALSFRS-R and ALSUI to EQ-5D in Patients with Motor Neuron Disease

BACKGROUND

The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) is the preferred measure of health outcome in clinical trials in motor neuron disease (MND). It, however, does not provide a preference-based health utility score required for estimating quality-adjusted life-years in economic evaluations for health technology assessments.

OBJECTIVES

To develop algorithms for mapping from measures used in MND clinical studies to allow for future prediction of the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) utility in populations of patients with MND when utility data have not been collected.

METHODS

Direct mapping models were developed using ordinary least squares and Tobit regression analyses to estimate EQ-5D-5L utilities (based on English tariffs), with ALSFRS-R total, domain, and item scores used as explanatory variables, using patient-level data from a UK cohort study. Indirect mapping models were also used to map EQ-5D-5L domains, using the same variables, along with the Neuropathic Pain Scale and the Hospital and Anxiety Depression Scale for MND using multinomial logistic regression analysis. Goodness of fit was assessed along with predicted values for each mapping model.

RESULTS

The best-performing model predicting EQ-5D-5L utilities used five items of the ALSFRS-R items as explanatory variables in a stepwise ordinary least squares regression. The mean squared error was 0.0228, and the mean absolute error was 0.1173. Prediction was good, with 55.4% of estimated values within 0.1 and 91.4% within 0.25 of the observed EQ-5D-5L utility value. Indirect mapping using the Neuropathic Pain Scale and the Hospital and Anxiety Depression Scale for MND provided less predictive power than direct mapping models.

CONCLUSIONS

This is the first study to present mapping algorithms to crosswalk between ALSFRS-R and EQ-5D-5L. This analysis demonstrates that the ALSFRS-R can be used to estimate EQ-5D-5L utilities when they have not been collected directly within a trial.

The Role of Condition-Specific Preference-Based Measures in Health Technology Assessment

A condition-specific preference-based measure (CSPBM) is a measure of health-related quality of life (HRQOL) that is specific to a certain condition or disease and that can be used to obtain the quality adjustment weight of the quality-adjusted life-year (QALY) for use in economic models. This article provides an overview of the role and the development of CSPBMs, and presents a description of existing CSPBMs in the literature. The article also provides an overview of the psychometric properties of CSPBMs in comparison with generic preference-based measures (generic PBMs), and considers the advantages and disadvantages of CSPBMs in comparison with generic PBMs. CSPBMs typically include dimensions that are important for that condition but may not be important across all patient groups. There are a large number of CSPBMs across a wide range of conditions, and these vary from covering a wide range of dimensions to more symptomatic or uni-dimensional measures. Psychometric evidence is limited but suggests that CSPBMs offer an advantage in more accurate measurement of milder health states. The mean change and standard deviation can differ for CSPBMs and generic PBMs, and this may impact on incremental cost-effectiveness ratios. CSPBMs have a useful role in HTA where a generic PBM is not appropriate, sensitive or responsive. However, due to issues of comparability across different patient groups and interventions, their usage in health technology assessment is often limited to conditions where it is inappropriate to use a generic PBM or sensitivity analyses.

Economic Studies in Motor Neurone Disease: A Systematic Methodological Review

BACKGROUND

Motor neurone disease (MND) is a devastating condition which greatly diminishes patients' quality of life and limits life expectancy. Health technology appraisals of future interventions in MND need robust data on costs and utilities. Existing economic evaluations have been noted to be limited and fraught with challenges.

OBJECTIVE

The aim of this study was to identify and critique methodological aspects of all published economic evaluations, cost studies, and utility studies in MND.

METHODS

We systematically reviewed all relevant published studies in English from 1946 until January 2016, searching the databases of Medline, EMBASE, Econlit, NHS Economic Evaluation Database (NHS EED) and the Health Economics Evaluation Database (HEED). Key data were extracted and synthesised narratively.

RESULTS

A total of 1830 articles were identified, of which 15 economic evaluations, 23 cost and 3 utility studies were included. Most economic studies focused on riluzole (n = 9). Six studies modelled the progressive decline in motor function using a Markov design but did not include mutually exclusive health states. Cost estimates for a number of evaluations were based on expert opinion and were hampered by high variability and location-specific characteristics. Few cost studies reported disease-stage-specific costs (n = 3) or fully captured indirect costs. Utilities in three studies of MND patients used the EuroQol EQ-5D questionnaire or standard gamble, but included potentially unrepresentative cohorts and did not consider any health impacts on caregivers.

CONCLUSION

Economic evaluations in MND suffer from significant methodological issues such as a lack of data, uncertainty with the disease course and use of inappropriate modelling framework. Limitations may be addressed through the collection of detailed and representative data from large cohorts of patients.

A Systematic Review of the Literature on the Development of Condition-Specific Preference-Based Measures of Health

BACKGROUND

Health state utility values (HSUVs) are required to calculate quality-adjusted life-years (QALYs). They are frequently derived from generic preference-based measures of health. However, such generic measures may not capture health attributes of relevance to specific conditions. In such cases, a condition-specific preference-based measure (CSPBM) may be more appropriate.

OBJECTIVE

This systematic review aimed to identify all published accounts of developing CSPBMs to describe and appraise the methods used.

METHOD

We undertook a systematic search (of Embase, MEDLINE, PsycINFO, Web of Science, the Cochrane Library, CINAHL, EconLit, ASSIA and the Health Management Information Consortium database) to identify published accounts of CSPBM development up to July 2015. Studies were reviewed to investigate the methods used to design classification systems, estimate HSUVs, and validate the measures.

RESULTS

A total of 86 publications were identified, describing 51 CSPBMs. Around two-thirds of these were QALY measures; the remainder were designed for clinical decision making only. Classification systems for 33 CSPBMs were derived from existing instruments; 18 were developed de novo. HSUVs for 34 instruments were estimated using a 'composite' approach, involving statistical modelling; the remainder used a 'decomposed' approach based on multi-attribute utility theory. Half of the papers that described the estimation of HSUVs did not report validating their measures.

CONCLUSION

Various methods have been used at all stages of CSPBM development. The choice between developing a classification system de novo or from an existing instrument may depend on the availability of a suitable existing measure, while the choice between a decomposed or composite approach appears to be determined primarily by the purpose for which the instrument is designed. The validation of CSPBMs remains an area for further development.

Estimation of a valuation function for a diabetes mellitus-specific preference-based measure of health: the Diabetes Utility Index

Preference-based measures of health (PBMH) provide 'preference' or 'utility' weights that enable the calculation of QALYs for the economic evaluations of interventions. The Diabetes Utility Index (DUI) was developed as a brief, self-administered, diabetes mellitus-specific PBMH that can efficiently estimate patient-derived health state utilities. To describe the development of the valuation function for the DUI, and to report the validation results of the valuation function. Multi-Attribute Utility Theory (MAUT) was used as the framework to develop a valuation function for the DUI. Twenty of 768 possible health states of the DUI classified as anchor states, single-attribute level states including corner states, and marker states were selected and described for preference elicitation interviews. Visual analogue scale and standard gamble (SG) exercises were used to measure preferences from individuals with diabetes recruited from primary care and community settings in and around Morgantown, WV, USA for the 20 health states defined by combinations of DUI attributes and severity levels. Data collected in the interviews were used to develop a valuation function that calculates utilities for the DUI health states and calculates attribute-level utilities. A validation survey of the valuation function was conducted in collaboration with the West Virginia University (WVU) Diabetes Institute. A total of 100 individuals with diabetes were interviewed and their preferences for various DUI health states measured. From data generated in the interviews, a DUI valuation function was developed on a scale where 1.00 = perfect health (PH) and 0.00 = the all worse 'pits' state, and adjusted to yield utilities on the conventional scale 1.00 = PH and 0.00 = dead. A total of 396 patients with diabetes who received care at WVU clinics completed a DUI mail validation survey (response rate = 33%). Clinical data consisting of International Classification of Diseases, 9th edition, diagnosis codes and glycosylated haemoglobin (HbA(1c)) values for the respondents were merged with their responses to the DUI. The utilities calculated by the scoring function of the DUI compared favourably to cardinal SG utilities for three DUI health states for which both assessments were available. The DUI utility function slightly underestimated actual SG utilities for mild and moderate health states (mean absolute difference = 0.05). There was a small but significant correlation between DUI utility scores and average past year HbA(1c) values (r = -0.30; p < 0.001). Respondents with two or more complications had significantly lower DUI utilities than those with no complications (p < 0.001) or one complication (p = 0.015). Insulin users had significantly lower DUI utilities than non-users (p < 0.001), and those with HbA(1c) values <7% had significantly higher DUI utilities than those with HbA(1c) values of >or=7% (p < 0.001). No significant association was found between DUI scores and age or sex. These results show evidence of the feasibility and validity of the DUI. Further research is suggested to demonstrate the generalizability of these findings, to study the responsiveness of the DUI, and to examine the clinical meaningfulness of DUI change scores.