Econometric modelling of multiple self-reports of health states: The switch from EQ-5D-3L to EQ-5D-5L in evaluating drug therapies for rheumatoid arthritis

The natural course of health-related quality of life in patients with clinically suspect arthralgia: a longitudinal study in progressors and non-progressors to rheumatoid arthritis

Individuals with clinically suspect arthralgia (CSA) are at risk of developing rheumatoid arthritis (RA). It is unknown whether CSA patients have a deprived health-related quality-of-life (HRQoL), how this develops over time, and whether it differs between those who develop RA and those who do not. Using three unique cohorts, we explored the course of HRQoL in CSA patients and after inflammatory arthritis (IA, in this case defined as being either undifferentiated arthritis (UA) or RA) diagnosis. Longitudinal cohort data were used from two CSA cohorts (n = 507) and an IA cohort (n = 282). HRQoL as measured with the EuroQol-5 Dimensions-5 levels (EQ-5D-5 L) questionnaire was compared between CSA patients who develop IA and who do not. We estimated the course of EQ-5D-5 L scores with linear mixed models. In addition, autoantibody-positive and -negative patients were compared. As patients developed IA, their mean EQ-5D-5 L scores deteriorated with 0.12 points (0.03-0.22) over two years, with mobility and usual activities most impacted. Self-care and pain/discomfort were already impacted longer before the diagnosis. Treatment initiation after IA diagnosis showcased an improvement of 0.13 (0.09-0.16) points within 4 months, particularly in the self-care and pain/discomfort dimensions, stabilizing thereafter. In CSA patients who did not develop IA, HRQoL remained stable with a minor improvement of 0.05 (0.02-0.08) points over 2 years. Autoantibody-status had no impact. HRQoL deteriorates before IA diagnosis but improves after treatment initiation. CSA patients who do not develop IA experience stable HRQoL. These findings suggest that early intervention in CSA could prevent deterioration in HRQoL, supporting the potential value of treatment in the CSA phase.

Potential Impact of EQ-5D-5L Mapping Function Recently Recommended by the National Institute for Health and Care Excellence on Utility Values and Decision Making

OBJECTIVES

In the absence of an accepted local EQ-5D-5L tariff, the National Institute for Health and Care Excellence (NICE) requires EQ-5D-5L responses to be mapped to the long-standing EQ-5D-3L UK value set. Their 2022 Manual recommends using the mapping function recently developed by the NICE Decision Support Unit (DSU), instead of the van Hout Crosswalk that was previously endorsed. Our aim was to compare utility values derived using these 2 mapping methods and assess the potential impact on decision making.

METHODS

For all 3125 unique EQ-5D-5L health states, utility values for both mapping functions were obtained and compared using numerical analysis and data visualization. Simulations in synthetic patient populations were conducted to evaluate the potential impact of the mapping functions on utility values derived from EQ-5D-5L clinical trial data.

RESULTS

For 1898 (61%) health states spread across the severity spectrum, the DSU mapping function generates a higher utility value than the van Hout Crosswalk. The mean difference was 0.062 (±0.139 SD), ranging from +0.619 to -0.198 for individual health states. The simulations suggest that mean utility values estimated with the DSU mapping function may lie higher than those obtained with the van Hout Crosswalk.

CONCLUSIONS

Not only the choice of EQ-5D instrument, but also the mapping approach can have an impact on utility values. The DSU mapping function may shift UK utility values further upward, potentially affecting NICE decision making. The use of various combinations of instruments, mapping functions, and tariffs may soon make it challenging to bring together historical 3L evidence and a growing body of 5L-based evidence.

A standard gamble study to determine health state utilities associated with seizures in glioma in the UK

BACKGROUND

Glioma are infiltrative primary brain tumours, which despite treatment, lead to a substantial reduction in life expectancy. Seizures are a common symptom of glioma, and have a serious impact on patient health related quality of life (HRQoL).

OBJECTIVE

The study aimed to estimate health state utility values for different types of seizures related to glioma, a serious type of brain tumour.

METHODS

Vignettes for the different health states were initially developed from the existing literature. The health states were then refined in collaboration with patients with previous experience of seizures and clinicians experienced in treating patients with seizures. The final vignettes represented three types of acute seizure: focal aware, focal impaired awareness and tonic clonic and several different health states which combined these acute seizures with other aspects of HRQoL. These vignettes were evaluated by a sample of the UK general public using an online survey and analysed descriptively using the mean and standard deviation.

RESULTS

302 participants, representative of the UK general population in terms of age, sex and geographical region, were included in the estimation sample. For the health states representing acute seizures, the focal aware seizure had the highest mean utility value (0.607), followed by the impaired awareness seizure (0.593) and the tonic clonic seizure (0.522). For the health states that also incorporated wider aspects of HRQoL, the health state utility values ranged from 0.504 (one focal aware seizure per year) to 0.337 (at least one focal impaired awareness seizure per week).

CONCLUSIONS

Seizures may have a major impact of the HRQoL of patients with glioma. The utility values obtained in the study may be used in future economic evaluations of interventions related to glioma where seizures are either a primary clinical outcome or an adverse event.

Health State Utility Values in Fabry Disease: Insights from the Pegunigalsidase Alfa Clinical Trials

INTRODUCTION

Fabry disease (FD) is a rare lysosomal storage disorder that is associated with pain and progressive damage to the renal, cardiac, and cerebrovascular systems. Enzyme replacement therapy (ERT) is one of the treatment options for FD and the most recently approved ERT agent, pegunigalsidase alfa, has shown clinical efficacy in three phase 3 clinical trials of adults with FD: BALANCE, BRIDGE, and BRIGHT. Recent published guidelines support the mapping of health utility state data to the EuroQol-5 Dimension-3 Level (EQ-5D-3L) index to align with the preferred methodology used by the National Institute for Health and Care Excellence (NICE). Therefore, the primary objective of this study was to estimate EQ-5D-3L values in clinical trials of pegunigalsidase alfa for FD for future cost-utility analyses.

METHODS

A mixed effects model was developed to predict values derived from EQ-5D-3L for the following health states used in cost-utility analyses: no Fabry clinical event (FCE)/no pain-related adverse event (AE), pain-related AE, cardiac FCE, cerebrovascular FCE, and renal FCE.

RESULTS

The baseline EQ-5D-3L utility value had a statistically significant (p < 0.0001) impact on utility values, whereas study, age, sex, disease type, treatment arm, kidney function, and serious AE were not statistically significant. Health state utility values with 95% confidence intervals (CI) for the final model were as follows: no FCE/no pain-related AE, 0.8005 (0.7675, 0.8334); pain-related AE, 0.7737 (0.7262, 0.8211); cardiac FCE, 0.7189 (0.6274, 0.8103); cerebrovascular FCE, 0.7923 (0.6633, 0.9212); and renal FCE, 0.6881 (0.3887, 0.9874).

CONCLUSIONS

The utility values generated by the present study are generally in line with EQ-5D values in the FD literature and can be used to inform both economic evaluations and our understanding of the impact that FD has on quality of life.

TRIAL REGISTRATION

NCT03018730, NCT02795676, NCT03180840.

Cost-Effectiveness of an Extended-Role General Practitioner Clinic for Persistent Physical Symptoms: Results From the Multiple Symptoms Study 3 Pragmatic Randomized Controlled Trial

OBJECTIVES

This study aimed to evaluate the cost-effectiveness of an extended-role general practitioner symptoms clinic (SC), added to usual care (UC) for patients with multiple persistent physical symptoms (sometimes known as medically unexplained symptoms).

METHODS

This was a 52-week within-trial cost-utility analysis of a pragmatic multicenter randomized controlled trial comparing SC + UC (n = 178) with UC alone (n = 176), conducted from the primary perspective of the UK National Health Service and personal and social services (PSS). Base-case quality-adjusted life-years (QALYs) were measured using EQ-5D-5L. Missing data were imputed using multiple imputation. Cost-effectiveness results were presented as incremental cost-effectiveness ratios and incremental net monetary benefits. Uncertainty was explored using cost-effectiveness acceptability curves (using 1000 nonparametric bootstrapped samples) and sensitivity analysis (including societal costs, using SF-6D and ICECAP-A capability measure for adults outcomes to estimate QALYs and years of full capability, respectively, varying intervention costs, missing data mechanism assumptions).

RESULTS

Multiple imputation analysis showed that compared with UC alone, SC + UC was more expensive (adjusted mean cost difference: 704; 95% CI £605-£807) and more effective (adjusted mean QALY difference: 0.0447; 95% CI 0.0067-0.0826), yielding an incremental cost-effectiveness ratio of £15 765/QALY, incremental net monetary benefit of £189.22 (95% CI -£573.62 to £948.28) and a 69% probability of the SC + UC intervention arm being cost-effective at a threshold of £20 000 per QALY. Results were robust to most sensitivity analyses but sensitive to missing data assumptions (2 of the 8 scenarios investigated), SF-6D, and ICECAP_A capability measure for adults quality-of-life outcomes.

CONCLUSIONS

A symptoms clinic is likely to be a potentially cost-effective treatment for patients with persistent physical symptoms.

The clinical and cost effectiveness of internet-delivered self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): Study protocol for a randomised controlled trial with ethnically diverse family carers

BACKGROUND

Following the successful completion of feasibility and acceptability studies of internet-delivered self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS), a full-scale randomised controlled trial (RCT) evaluating its clinical and cost effectiveness will be conducted. This paper describes the design and protocol for a multi-site, parallel, single-blind, 2-arm RCT evaluating the clinical and cost effectiveness of iACT4CARERS plus treatment-as-usual (TAU) in comparison to TAU alone for reducing anxiety in family carers of people with dementia.

METHODS

496 family carers aged ≥18 years, who are caring for a person with dementia, will be recruited from national healthcare services, general practices and community groups in England. Participants randomised to the intervention arm will receive iACT4CARERS over 12 weeks. Participants will complete outcome measures at baseline (0 weeks) and at 12-weeks and 24-weeks post-randomisation. The primary outcome and timepoint will be anxiety at 12 weeks. Secondary outcomes will include psychological flexibility, depression, and cost-effectiveness (cost per quality adjusted life years). Primary analyses will be by intention-to-treat and data will be analysed using linear mixed models. Fidelity and quality of implementation will be assessed and contextual factors associated with variation in outcomes identified in a process evaluation.

CONCLUSION

If iACT4CARERS is found to be effective and affordable, this self-help intervention, including minimal contact with minimally trained therapists, has the potential to be rolled out widely within healthcare services in the UK, reducing inequality in access to psychological services among this population.

CLINICAL TRIALS REGISTRATION

ISRCTN registry identifier ISRCTN45995725.

Psychometric Performance of the EQ Health and Wellbeing Short in a United Kingdom Population Sample

OBJECTIVES

This study assessed the psychometric performance and construct validity of the EQ Health and Wellbeing Short (EQ-HWB-S), using a validated measure, the EQ-5D-5L, as a comparator.

METHODS

The experimental version of the EQ-HWB-S was compared with the EQ-5D-5L to assess the psychometric performance of the measures. Data were drawn from the valuation stages of the Extending the Quality-Adjusted Life-Year project (UK general population, n = 429) and the EQ-5D-5L UK valuation pilot study (UK general population, n = 248). Construct validity was assessed based on convergent validity, using Spearman correlations and Pearson correlations. Known-group validity was assessed by estimating effect sizes to assess the ability of the EQ-HWB-S and EQ-5D-5L to discriminate between known groups based on "healthy" status, presence of a long-term condition, health and life satisfaction, age, and employment status. The degree of agreement in utility values across instruments was also evaluated using Bland-Altman plots.

RESULTS

Strong associations (rs ≥ 0.5, P < .001) were found between conceptually overlapping dimensions and the utility scores of the EQ-HWB-S and EQ-5D-5L. The instruments performed comparably in discriminating between known groups including healthy versus unhealthy groups (based on the visual analog scale ≥ 80), long-term condition (vs no long-term condition), and above versus below average health and life satisfaction and employed (vs unemployed and long-term sick).

CONCLUSIONS

The EQ-HWB-S performs favorably with utility values successfully discriminating between groups in which differences are expected. Convergence between the EQ-HWB-S and EQ-5D-5L is evident, especially between conceptually overlapping dimensions.

Health-related quality of life across disease stages in patients with amyotrophic lateral sclerosis: results from a real-world survey

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is characterized by a rapid disease course, with disease severity being associated with declining health-related quality of life (HRQoL) in persons living with ALS (pALS). The main objective of this study was to assess the impact of disease progression on HRQoL across King's, Milano-Torino Staging (MiToS), and physician-judgement clinical staging. Additionally, we evaluated the impact of the disease on the HRQoL of care partners (cALS).

METHODS

Data were sourced from the Adelphi ALS Disease Specific Programme (DSP)™, a cross-sectional survey of neurologists, pALS and cALS presenting in a real-world clinical setting between July 2020 and March 2021 in Europe and the United States.

RESULTS

Neurologists (n = 142) provided data for 880 pALS. There were significant negative correlations between all three clinical staging systems and EuroQol (European Quality of Life) Five Dimension Five Level Scale (EQ-5D-5L) utility scores and visual analogue scale (VAS) ratings. Although not all differences were significant, 5-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5) scores showed a stepwise increase in HRQoL impairment at each stage of the disease regardless of the staging system. At later stages, high levels of fatigue and substantial activity impairment were reported. As pALS disease states progressed, cALS also experienced a decline in HRQoL and increased burden.

CONCLUSIONS

Across outcomes, pALS and cALS generally reported worse outcomes at later stages of the disease, highlighting an unmet need in this population for strategies to maximise QoL despite disease progression. Recognition and treatment of symptoms such as pain and fatigue may lead to improved outcomes for pALS and cALS.

Use of removable support boot versus cast for early mobilisation after ankle fracture surgery: cost-effectiveness analysis and qualitative findings of the Ankle Recovery Trial (ART)

OBJECTIVES

To estimate the cost-effectiveness of using a removable boot versus a cast following ankle fracture from the National Health Service and Personal Social Services (NHS+PSS) payer and societal perspectives and explore the impact of both treatments on participants' activities of daily living.

DESIGN

Cost-effectiveness analyses and qualitative interviews performed alongside a pragmatic multicentre randomised controlled trial.

SETTING

Eight UK NHS secondary care trusts.

PARTICIPANTS

243 participants (60.5% female, on average 48.2 years of age (SD 16.4)) with ankle fracture. Qualitative interviews with 16 participants. Interventions removable air boot versus plaster cast 2 weeks after surgery weight bearing as able with group-specific exercises.

PRIMARY AND SECONDARY OUTCOME MEASURES

Quality-adjusted life years (QALYs) estimated from the EQ-5D-5L questionnaire, costs and incremental net monetary benefit statistics measured 12 weeks after surgery, for a society willing-to-pay £20 000 per QALY.

RESULTS

Care in the boot group cost, on average, £88 (95% CI £22 to £155) per patient more than in the plaster group from the NHS+PSS perspective. When including all societal costs, the boot saved, on average, £676 per patient (95% CI -£337 to £1689). Although there was no evidence of a QALY difference between the groups (-0.0020 (95% CI -0.0067 to 0.0026)), the qualitative findings suggest participants felt the boot enhanced their quality of life. Patients in the boot felt more independent and empowered to take on family responsibilities and social activities.

CONCLUSIONS

While the removable boot is slightly more expensive than plaster cast for the NHS+PSS payer at 12 weeks after surgery, it reduces productivity losses and the need for informal care while empowering patients. Given that differences in QALYs and costs to the NHS are small, the decision to use a boot or plaster following ankle surgery could be left to patients' and clinicians' preferences.

TRIAL REGISTRATION NUMBER

ISRCTN15497399, South Central-Hampshire A Research Ethics Committee (reference 14/SC/1409).

To what extent does the use of crosswalks instead of EQ-5D value sets impact reimbursement decisions?: a simulation study

PURPOSE

Inconsistent results have been found on the impact of using crosswalks versus EQ-5D value sets on reimbursement decisions. We sought to further investigate this issue in a simulation study.

METHODS

Trial-based economic evaluation data were simulated for different conditions (depression, low back pain, osteoarthritis, cancer), severity levels (mild, moderate, severe), and effect sizes (small, medium, large). For all 36 scenarios, utilities were calculated using 3L and 5L value sets and crosswalks (3L to 5L and 5L to 3L crosswalks) for the Netherlands, the United States, and Japan. Utilities, quality-adjusted life years (QALYs), incremental QALYs, incremental cost-effectiveness ratios (ICERs), and probabilities of cost-effectiveness (pCE) obtained from values sets and crosswalks were compared.

RESULTS

Differences between value sets and crosswalks ranged from -0.33 to 0.13 for utilities, from -0.18 to 0.13 for QALYs, and from -0.01 to 0.08 for incremental QALYs, resulting in different ICERs. For small effect sizes, at a willingness-to-pay of €20,000/QALY, the largest pCE difference was found for moderate cancer between the Japanese 5L value set and 5L to 3L crosswalk (difference = 0.63). For medium effect sizes, the largest difference was found for mild cancer between the Japanese 3L value set and 3L to 5L crosswalk (difference = 0.06). For large effect sizes, the largest difference was found for mild osteoarthritis between the Japanese 3L value set and 3L to 5L crosswalk (difference = 0.08).

CONCLUSION

The use of crosswalks instead of EQ-5D value sets can impact cost-utility outcomes to such an extent that this may influence reimbursement decisions.

The effectiveness and cost-effectiveness of a group domestic abuse perpetrator programme: protocol for a randomised controlled trial

BACKGROUND

In contrast to evidence for interventions supporting victim/survivors of domestic violence and abuse (DVA), the effectiveness of perpetrator programmes for reduction of abuse is uncertain. This study aims to estimate the effectiveness and cost-effectiveness of a perpetrator programme for men.

METHODS

Pragmatic two-group individually randomised controlled trial (RCT) with embedded process and economic evaluation. Five centres in southwest England and South Wales aim to recruit 316 (reduced from original target of 366) male domestic abuse perpetrators. These will be randomised 2:1 to a community-based domestic abuse perpetrator programme (DAPP) or usual care comparator with 12-month follow-up. Female partners/ex-partners will be invited to join the study. The intervention for men comprises 23 weekly sessions of a group programme delivered in voluntary sector domestic abuse services. The intervention for female partners/ex-partners is one-to-one support from a safety worker. Men allocated to usual care receive no intervention; however, they are free to access other services. Their partners/ex-partners will be signposted to support services. Data is collected at baseline, and 4, 8 and 12 months' follow-up. The primary outcome is men's self-reported abusive behaviour measured by the Abusive Behaviour Inventory (ABI-29) at 12 months. Secondary measures include physical and mental health status and resource use alongside the abuse measure ABI (ABI-R) for partners/ex-partners and criminal justice contact for men. A mixed methods process evaluation and qualitative study will explore mechanisms of effectiveness, judge fidelity to the intervention model using interviews and group observations. The economic evaluation, over a 1-year time horizon from three perspectives (health and social care, public sector and society), will employ a cost-consequences framework reporting costs alongside economic outcomes (Quality-Adjusted Life Years derived from EQ-5D-5L, SF-12 and CHU-9D, and ICECAP-A) as well as the primary and other secondary outcomes.

DISCUSSION

This trial will provide evidence of the (cost)effectiveness of a DAPP. The embedded process evaluation will further insights in the experiences and contexts of participants and their journey through a perpetrator programme, and the study will seek to address the omission in other studies of economic evaluations.

TRIAL REGISTRATION

ISRCTN15804282, April 1, 2019.

Cost Effectiveness of Difelikefalin Compared to Standard Care for Treating Chronic Kidney Disease Associated Pruritus (CKD-aP) in People with Kidney Failure Receiving Haemodialysis

BACKGROUND

Chronic kidney disease-associated pruritus (CKD-aP) is associated with an increased risk of depression, poor sleep and reduced health-related quality of life. Two phase III studies (KALM-1 and KALM-2) of difelikefalin showed reduced CKD-aP severity and improved itch-related health-related quality of life in patients with moderate and severe CKD-aP receiving haemodialysis for kidney failure.

OBJECTIVE

We aimed to estimate the cost effectiveness of difelikefalin for patients with CKD-aP receiving haemodialysis for kidney failure compared to standard care from a UK National Health Service perspective.

METHODS

A cohort model was developed with four health states representing levels of pruritus intensity over time, based on the KALM trials augmented with longer term CKD-aP severity data from another haemodialysis trial (SHAREHD) for standard care. Utilities were estimated from a mapping study of 5-D Itch to EQ-5D-5L in 487 patients receiving haemodialysis, costs were estimated based on resource use alongside the SHAREHD and 2018 unit costs, and inflated to 2021 costs. Costs and quality-adjusted life-years were discounted at 3.5% per annum. A de novo economic model was developed in Microsoft Excel with scenario analyses performed using a range of assumptions.

RESULTS

In the base-case analysis over a time horizon of 64 weeks, using a placeholder cost of £75 per 28-days for difelikefalin, the incremental cost-effectiveness ratio of difelikefalin compared with standard care was £19,558/quality-adjusted life-year (QALY). Scenario analyses resulted in incremental cost-effectiveness ratios that ranged from £10,154/QALY (severe only) to £16,957/QALY (5-year horizon) for difelikefalin compared to standard care. Probabilistic sensitivity analyses suggested difelikefalin has a 48.6% probability of being cost effective at a threshold of £20,000/QALY and a 57.2% probability of being cost effective at a threshold of £30,000/QALY.

CONCLUSIONS

The cost effectiveness of difelikefalin in a range of scenarios could make it an important pharmacotherapy to address the high burden of disease and unmet need for treatments associated with CKD-aP in the UK.

Estimating the Relationship Between EQ-5D-5L and EQ-5D-3L: Results from a UK Population Study

OBJECTIVES

The aim of this study was to estimate the relationship between EQ-5D-3L and EQ-5D-5L, in both directions, using a single model.

METHODS

An online survey containing both variants of EQ-5D, with randomised ordering, was administered to a large UK sample in 2020. A joint statistical model of the ten EQ-5D responses (five at 5L, five at 3L), using a multi-equation ordinal regression framework was estimated. The joint model ensures mappings in either direction are fully consistent with the information in the sample and satisfy Bayes' rule. Three extensions enhance model flexibility: a copula specification allows differing degrees of correlation between the 3L and 5L responses at the upper and lower extremes of health; a normal mixture residual distribution gives flexibility in the distributional form of responses; and a common factor captures correlations in responses across the five dimensions.

RESULTS

Almost 50,000 responses were received. Thirty-five percent of respondents reported an existing medical condition. Ninety percent of possible 3L and 43% of possible 5L health states were observed. The preferred model specification includes age, sex and the responses to the EQ-5D instrument. Close alignment to the observed data was observed both in within-sample and out-of-sample comparisons.

CONCLUSION

The results from this study provide a means of translating evidence to or from EQ-5D-3L to or from 5L based on a large-scale UK population survey with randomised ordering. Mapping can be performed either using descriptive system responses, individual utility scores or summary statistics.

Generating EQ-5D-5L health utility scores from BASDAI and BASFI: a mapping study in patients with axial spondyloarthritis using longitudinal UK registry data

BACKGROUND

Preference-based health-state utility values (HSUVs), such as the EuroQol five-dimensional questionnaire (EQ-5D-5L), are needed to calculate quality-adjusted life-years (QALYs) for cost-effectiveness analyses. However, these are rarely used in clinical trials of interventions in axial spondyloarthritis (axSpA). In these cases, mapping can be used to predict HSUVs.

OBJECTIVE

To develop mapping algorithms to estimate EQ-5D-5L HSUVs from the Bath Ankylosing Disease Activity Index (BASDAI) and the Bath Ankylosing Spondylitis Functional Index (BASFI).

METHODS

Data from the British Society for Rheumatology Biologics Register in Ankylosing Spondylitis (BSRBR-AS) provided 5122 observations with complete BASDAI, BASFI, and EQ-5D-5L responses covering the full range of disease severity. We compared direct mapping using adjusted limited dependent variable mixture models (ALDVMMs) and optional inclusion of the gap between full health and the next feasible value with indirect response mapping using ordered probit (OPROBIT) and generalised ordered probit (GOPROBIT) models. Explanatory variables included BASDAI, BASFI, and age. Metrics to assess model goodness-of-fit and performance/accuracy included Akaike and Bayesian information criteria (AIC/BIC), mean absolute error (MAE) and root mean square error (RMSE), plotting predictive vs. observed estimates across the range of BASDAI/BASFI and comparing simulated data with the original data set for the preferred/best model.

RESULTS

Overall, the ALDVMM models that did not formally include the gap between full health and the next feasible value outperformed those that did. The four-component mixture models (with squared terms included) performed better than the three-component models. Response mapping using GOPROBIT (no squared terms included) or OPROBIT (with squared terms included) offered the next best performing models after the three-component ALDVMM (with squared terms). Simulated data of the preferred model (ALDVMM with four-components) did not significantly underestimate uncertainty across most of the range of EQ-5D-5L values, however the proportion of data at full health was underrepresented, likely due in part to model fitting on a small number of observations at this point in the actual data (4%).

CONCLUSIONS

The mapping algorithms developed in this study enabled the generation of EQ-5D-5L utilities from BASDAI/BASFI. The indirect mapping equations reported for the EQ-5D-5L facilitate the calculation of the EQ-5D-5L utility scores using other UK and country-specific value sets.

Assessing the psychometric performance of EQ-5D-5L in dementia: a systematic review

BACKGROUND

EQ-5D is widely used for valuing changes in quality of life for economic evaluation of interventions for people with dementia. There are concerns about EQ-5D-3L in terms of content validity, poor inter-rater agreement and reliability in the presence of cognitive impairment, but there is also evidence to support its use with this population. An evidence gap remains regarding the psychometric properties of EQ-5D-5L.

OBJECTIVES

To report psychometric evidence around EQ-5D-5L in people with dementia.

METHODS

A systematic review identified primary studies reporting psychometric properties of EQ-5D-5L in people with dementia. Searches were completed up to November 2020. Study selection, data extraction and quality assessment were undertaken independently by at least 2 researchers.

RESULTS

Evidence was extracted from 20 articles from 14 unique studies covering a range of dementia severity. Evidence of known group validity from 5 of 7 studies indicated that EQ-5D-5L distinguishes severity of disease measured by cognitive impairment, depression, level of dependence and pain. Convergent validity (9 studies) showed statistically significant correlations of weak and moderate strengths, between EQ-5D-5L scores and scores on other key measures. Statistically significant change was observed in only one of 6 papers that allowed this property to be examined. All seven studies showed a lack of inter-rater reliability between self and proxy reports with the former reporting higher EQ-5D-5L scores than those provided by proxies. Five of ten studies found EQ-5D-5L to be acceptable, assessed by whether the measure could be completed by the PwD and/or by the amount of missing data. As dementia severity increased, the feasibility of self-completing EQ-5D-5L decreased. Three papers reported on ceiling effects, two found some evidence in support of ceiling effects, and one did not.

CONCLUSIONS

EQ-5D-5L seems to capture the health of people with dementia on the basis of known-group validity and convergent validity, but evidence is inconclusive regarding the responsiveness of EQ-5D-5L. As disease progresses, the ability to self-complete EQ-5D-5L is diminished.

Prediction Aided Tapering In rheumatoid arthritis patients treated with biOlogicals (PATIO): protocol for a randomized controlled trial

BACKGROUND

Biological disease-modifying anti-rheumatic drugs (bDMARDs) are effective in the treatment of rheumatoid arthritis (RA) but are expensive and increase the risk of infection. Therefore, in patients with a stable low level of disease activity or remission, tapering bDMARDs should be considered. Although tapering does not seem to affect long-term disease control, (short-lived) flares are frequent during the tapering process. We have previously developed and externally validated a dynamic flare prediction model for use as a decision aid during stepwise tapering of bDMARDs to reduce the risk of a flare during this process.

METHODS

In this investigator-initiated, multicenter, open-label, randomized (1:1) controlled trial, we will assess the effect of incorporating flare risk predictions into a bDMARD tapering strategy. One hundred sixty RA patients treated with a bDMARD with stable low disease activity will be recruited. In the control group, the bDMARD will be tapered according to "disease activity guided dose optimization" (DGDO). In the intervention group, the bDMARD will be tapered according to a strategy that combines DGDO with the dynamic flare prediction model, where the next bDMARD tapering step is not taken in case of a high risk of flare. Patients will be randomized 1:1 to the control or intervention group. The primary outcome is the number of flares per patient (DAS28-CRP increase > 1.2, or DAS28-CRP increase > 0.6 with a current DAS28-CRP ≥ 2.9) during the 18-month follow-up period. Secondary outcomes include the number of patients with a major flare (flare duration ≥ 12 weeks), bDMARD dose reduction, adverse events, disease activity (DAS28-CRP) and patient-reported outcomes such as quality of life and functional disability. Health Care Utilization and Work Productivity will also be assessed.

DISCUSSION

This will be the first clinical trial to evaluate the benefit of applying a dynamic flare prediction model as a decision aid during bDMARD tapering. Reducing the risk of flaring during tapering may enhance the safety and (cost)effectiveness of bDMARD treatment. Furthermore, this study pioneers the field of implementing predictive algorithms in clinical practice.

TRIAL REGISTRATION

Dutch Trial Register number NL9798, registered 18 October 2021, https://www.trialregister.nl/trial/9798 . The study has received ethical review board approval (number NL74537.041.20).

Mapping between EQ-5D-3L and EQ-5D-5L: A survey experiment on the validity of multi-instrument data

EQ-5D is a 5-item questionnaire instrument designed to measure health-related quality of life. It is extremely important, since it is used to measure health benefits in many studies providing evidence for reimbursement decisions by the National Institute for Health and Care Excellence in England and similar policy bodies in other countries. EQ-5D has been redesigned in a more detailed form (EQ-5D-5L), but much existing cost-effectiveness evidence is based on the older version (EQ-5D-3L). Statistical mapping from one version to another is widely used, exploiting data from multi-instrument surveys incorporating both variants. However, little is known about the robustness of data from such multi-instrument surveys. We design a randomized experiment to investigate whether inclusion of both versions at different stages in a single interview gives a reliable picture of the relationship between health measures from the two instruments and embed it in individual interviews from the UK Understanding Society household panel. We find that sequencing of the two versions of EQ-5D within an interview has a significant impact not only on the resulting data but also on the estimated mapping models. We illustrate the non-negligible effects in two real-world cost-effectiveness examples and discuss the implications for future multi-instrument survey design.

Health utilities and costs for neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, neurological disease that places a significant burden on patients, their carers, and healthcare systems.

OBJECTIVES

To estimate patient and carer health utilities and costs of NMOSD within the UK setting.

METHODS

Patients with NMOSD and their carers, recruited via a regional specialist treatment centre, completed a postal questionnaire that included a resource use measure, the EuroQoL (EQ)-5D-5L, EQ-5D-VAS, Vision and Quality of Life Index (VisQoL), Carer Experience Survey (CES) and the Expanded Disability Status Scale (EDSS). The questionnaire asked about respondents' use of health and community care services, non-medical costs, informal care and work capacity. Data were analysed descriptively. Uncertainties in costs and utilities were assessed using bootstrap analysis.

RESULTS

117 patients and 74 informal carers responded to the survey. Patients' mean EQ-5D-5L and VisQoL health utilities (95% central range) were 0.54 (- 0.29, 1.00) and 0.79 (0.11, 0.99), respectively. EQ-5D-5L utility decreased with increasing EDSS score bandings, from 0.80 (0.75, 0.85) for EDSS ≤ 4.0, to 0.20 (- 0.29, 0.56) for EDSS 8.0 to 9.5. Mean, 3-month total costs were £5623 (£2096, £12,156), but ranged from £562 (£381, £812) to £32,717 (£2888, £98,568) for these EDSS bandings. Carer-reported EQ-5D-5L utility and CES index scores were 0.85 (0.82, 0.89) and 57.67 (52.69, 62.66). Mean, 3-month costs of informal care were £13,150 to £24,560.

CONCLUSIONS

NMOSD has significant impacts on health utilities and NHS and carer costs. These data can be used as inputs to cost-effectiveness analyses of new medicines for NMOSD.

A Comparison of Generic and Condition-Specific Preference-Based Measures Using Data From Nivolumab Trials: EQ-5D-3L, Mapping to the EQ-5D-5L, and European Organisation for Research and Treatment of Cancer Quality of Life Utility Measure-Core 10 Dimensions

OBJECTIVES

There is growing interest in condition-specific preference measures, including the European Organisation for Research and Treatment of Cancer Quality of Life Utility Measure-Core 10 Dimensions (QLU-C10D). This research assessed the implications of using utility indices on the basis of the EQ-5D-3L, a mapping of EQ-5D-3L to the EQ-5D-5L, and the QLU-C10D, and compared their psychometric properties.

METHODS

Data were taken from 8 phase 3 randomized controlled trials of nivolumab with or without ipilimumab for the treatment of solid tumors. Utilities for progression-related states were calculated using the UK and English value sets and incremental quality-adjusted life-years (QALYs) derived from established UK cost-effectiveness models. The psychometric properties of the utility indices were assessed using pooled trial data.

RESULTS

Compared with the EQ-5D-3L index, the mapped EQ-5D-5L index yielded an average of 6% more and the QLU-C10D index an average of 2% fewer incremental QALYs for nivolumab versus comparators. All indices could differentiate between groups defined by performance status, cancer stage, or self-reported health status at baseline and detect meaningful changes in performance status, tumor response, health status, and quality of life over approximately 12 weeks of treatment.

CONCLUSIONS

The lower QALY yield of the QLU-C10D was balanced by evidence of greater validity and responsiveness. Benefits gained from using the QLU-C10D may be apparent when treatments affect targeted symptoms and functional aspects, including sleep, bowel function, appetite, nausea, and fatigue. The observed differences in QALYs may not be sufficiently large to affect health technology assessment decisions.

Dose Correlation of Panax ginseng and Atractylodes macrocephala Koidz. Drug Pairs in the Chinese Medicine Prescription Based on the Copula Function

Objective

Panax ginseng and Atractylodes macrocephala Koidz. (AMK) are widely used in treating various diseases; however, research is insufficient on measuring the relationship that exists by combining this drug pair using the copula function.

Methods

In this study, 279 traditional Chinese medicine prescriptions containing the Panax ginseng and AMK drug pair were extracted from the prescription database for three types of screened indications, namely, diabetes mellitus, diarrhea, and insomnia. Following the principle of dose conversion, each dynasty unit was uniformly converted into a modern unit. Then, the kernel density distribution of Panax ginseng and AMK was fitted with their empirical distribution functions. Finally, the optimal copula function was selected from the copula function family as a t-copula function.

Results

The empirical distribution and probability density functions of Panax ginseng and AMK were obtained. From the results, their Kendall rank correlation coefficients with indications of diabetes mellitus, insomnia, and diarrhea were 0.8689, 0.7858, and 0.7403, whereas their Spearman rank correlation coefficients were 0.9563, 0.9276, and 0.8958. Results also indicated that the use of the t-copula function can better reflect the correlation between Panax ginseng and AMK doses.

Conclusion

From the three indications, the dose between Panax ginseng and AMK was positively correlated. This study, therefore, confirms the medicinal principle of Chinese medicine “combining” from the perspective of mathematical statistics. Results from this study are practical to evaluate the correlation between the drug pair doses, Panax ginseng and AMK, using the copula function model, which provides a new model for the scientific explanation of compatibility for Chinese medicines. This study also provides a methodological basis for more drug measurement studies and clinical medications.

Mapping EQ-5D-3L to EQ-5D-5L

OBJECTIVES

The original 3-level EQ-5D (EQ-5D-3L) includes 5 dimensions with 3 levels of problems per dimension. Since 2010, a more sensitive version with 5 levels of problems per dimension (EQ-5D-5L) has become available. Population value sets have been developed for both versions of the questionnaire. The objective of this research was to develop a mapping function to link EQ-5D-3L responses to value sets for the EQ-5D-5L.

METHODS

Various algorithms were developed to link EQ-5D-3L and EQ-5D-5L responses using data from an observational study including members of 10 subgroups (N = 3580) who completed both versions of the questionnaire. Nonparametric and ordinal logistic regression models were fit to the data and compared using Akaike's information criterion (AIC) as well as the mean absolute error and root mean squared error of predictions. Results were contrasted qualitatively and quantitatively with those of an alternative copula-based approach.

RESULTS

Including indicants of problems for other EQ-5D-3L dimensions as regressors in the modeling yielded the greatest improvement in prediction accuracy. Adding age and gender lowered the AIC without improving predictions, while including a latent factor lowered the AIC further and slightly improved predictive accuracy. Models that conditioned on problems in other EQ-5D-3L dimensions yielded more accurate predictions than the alternative copula-based approach in subgroups defined by age and gender.

CONCLUSION

We present novel algorithms to map EQ-5D-3L responses to EQ-5D-5L value sets. The recommended approach is based on an ordinal logistic regression that disregards age and gender and accounts for unobserved heterogeneity using a latent factor.

Health-Related Quality of Life in Patients with Health Conditions in Lebanese Community Setting

Background: The measurement of health-related quality of life (HRQoL) provides utility scores that could be used for health economics assessment. The aim of this study was to measure HRQoL in Lebanese patients with certain medical conditions, and to determine demographic and medical factors affecting such health utility scores. Method: This was a prospective cross-sectional pilot study conducted to gather information on the socioeconomic status, health condition and quality of life of participants with common diseases during their community pharmacy visit. The EuroQol-5-Dimension instrument was used to measure utility scores and SPSS v26 was used to perform the statistical analysis. Results: Participants (n = 102) gave an average of 6.8 and 7.4 out of 10 for their current health and for their satisfaction with their treatment, respectively. The mean utility score was 0.762 (SD 0.202). The number of prescribed medications per respondent indicated a significant impact on HRQoL (p = 0.002). On average, the utility scores were low for participants who were 75 years or older (0.15, p < 0.001), and those who were hospitalized in the past 12 months (0.111, p < 0.001). For every unit increase in treatment satisfaction, the quality-of-life score increased by 0.036 unit (p = 0.001). Conclusion: This pilot study measured health utility scores and factors influencing HRQoL in the Lebanese population. Further studies are needed to confirm our findings and to develop and validate tools helping to measure health related quality of life in the population in Lebanon.

Intensive therapy for moderate established rheumatoid arthritis: the TITRATE research programme

Background

Rheumatoid arthritis is a major inflammatory disorder and causes substantial disability. Treatment goals span minimising disease activity, achieving remission and decreasing disability. In active rheumatoid arthritis, intensive management achieves these goals. As many patients with established rheumatoid arthritis have moderate disease activity, the TITRATE (Treatment Intensities and Targets in Rheumatoid Arthritis ThErapy) programme assessed the benefits of intensive management.

Objectives

To (1) define how to deliver intensive therapy in moderate established rheumatoid arthritis; (2) establish its clinical effectiveness and cost-effectiveness in a trial; and (3) evaluate evidence supporting intensive management in observational studies and completed trials.

Design

Observational studies, secondary analyses of completed trials and systematic reviews assessed existing evidence about intensive management. Qualitative research, patient workshops and systematic reviews defined how to deliver it. The trial assessed its clinical effectiveness and cost-effectiveness in moderate established rheumatoid arthritis.

Setting

Observational studies (in three London centres) involved 3167 patients. These were supplemented by secondary analyses of three previously completed trials (in centres across all English regions), involving 668 patients. Qualitative studies assessed expectations (nine patients in four London centres) and experiences of intensive management (15 patients in 10 centres across England). The main clinical trial enrolled 335 patients with diverse socioeconomic deprivation and ethnicity (in 39 centres across all English regions).

Participants

Patients with established moderately active rheumatoid arthritis receiving conventional disease-modifying drugs.

Interventions

Intensive management used combinations of conventional disease-modifying drugs, biologics (particularly tumour necrosis factor inhibitors) and depot steroid injections; nurses saw patients monthly, adjusted treatment and provided supportive person-centred psychoeducation. Control patients received standard care.

Main outcome measures

Disease Activity Score for 28 joints based on the erythrocyte sedimentation rate (DAS28-ESR)-categorised patients (active to remission). Remission (DAS28-ESR < 2.60) was the treatment target. Other outcomes included fatigue (measured on a 100-mm visual analogue scale), disability (as measured on the Health Assessment Questionnaire), harms and resource use for economic assessments.

Results

Evaluation of existing evidence for intensive rheumatoid arthritis management showed the following. First, in observational studies, DAS28-ESR scores decreased over 10–20 years, whereas remissions and treatment intensities increased. Second, in systematic reviews of published trials, all intensive management strategies increased remissions. Finally, patients with high disability scores had fewer remissions. Qualitative studies of rheumatoid arthritis patients, workshops and systematic reviews helped develop an intensive management pathway. A 2-day training session for rheumatology practitioners explained its use, including motivational interviewing techniques and patient handbooks. The trial screened 459 patients and randomised 335 patients (168 patients received intensive management and 167 patients received standard care). A total of 303 patients provided 12-month outcome data. Intention-to-treat analysis showed intensive management increased DAS28-ESR 12-month remissions, compared with standard care (32% vs. 18%, odds ratio 2.17, 95% confidence interval 1.28 to 3.68; p = 0.004), and reduced fatigue [mean difference –18, 95% confidence interval –24 to –11 (scale 0–100); p < 0.001]. Disability (as measured on the Health Assessment Questionnaire) decreased when intensive management patients achieved remission (difference –0.40, 95% confidence interval –0.57 to –0.22) and these differences were considered clinically relevant. However, in all intensive management patients reductions in the Health Assessment Questionnaire scores were less marked (difference –0.1, 95% confidence interval –0.2 to 0.0). The numbers of serious adverse events (intensive management n = 15 vs. standard care n = 11) and other adverse events (intensive management n = 114 vs. standard care n = 151) were similar. Economic analysis showed that the base-case incremental cost-effectiveness ratio was £43,972 from NHS and Personal Social Services cost perspectives. The probability of meeting a willingness-to-pay threshold of £30,000 was 17%. The incremental cost-effectiveness ratio decreased to £29,363 after including patients’ personal costs and lost working time, corresponding to a 50% probability that intensive management is cost-effective at English willingness-to-pay thresholds. Analysing trial baseline predictors showed that remission predictors comprised baseline DAS28-ESR, disability scores and body mass index. A 6-month extension study (involving 95 intensive management patients) showed fewer remissions by 18 months, although more sustained remissions were more likley to persist. Qualitative research in trial completers showed that intensive management was acceptable and treatment support from specialist nurses was beneficial.

Limitations

The main limitations comprised (1) using single time point remissions rather than sustained responses, (2) uncertainty about benefits of different aspects of intensive management and differences in its delivery across centres, (3) doubts about optimal treatment of patients unresponsive to intensive management and (4) the lack of formal international definitions of ‘intensive management’.

Conclusion

The benefits of intensive management need to be set against its additional costs. These were relatively high. Not all patients benefited. Patients with high pretreatment physical disability or who were substantially overweight usually did not achieve remission.

Future work

Further research should (1) identify the most effective components of the intervention, (2) consider its most cost-effective delivery and (3) identify alternative strategies for patients not responding to intensive management.

Trial registration

Current Controlled Trials ISRCTN70160382.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 8. See the NIHR Journals Library website for further project information.

A feasibility trial of an intervention in alcohol dependence for structured preparation before detoxification versus usual care: the SPADe trial results

BACKGROUND

Individuals who are 'moderately' or 'severely' dependent consume alcohol at levels that are likely to have a severe impact on their own health and mortality, the health and behaviours of others (family members) and to have economic and social implications. Treatment guidelines suggest that treatment needs to be planned with medically assisted withdrawal (also referred to as detoxification), and aftercare support but outcomes are poor with low proportions engaging in after care and high relapse rates. An approach of structured preparation before alcohol detoxification (SPADe) puts an emphasis on introducing lifestyle changes, development of coping strategies for cravings, stress and emotions as well as introducing changes to the immediate family and social environment in advance of alcohol cessation. Such a pre-habilitation paradigm compliments the established treatment approach. The key research question was: can we design a large scale, randomised controlled trial (RCT) that will answer whether such an approach is more effective than usual care in helping individuals to maintain longer periods of alcohol abstinence?

METHODS

This is a pragmatic, parallel, two-arm, feasibility RCT comparing SPADe and usual care against usual care only in maintaining alcohol abstinence in adults with alcohol dependence receiving care in two community addiction services in London. Feasibility outcomes, exploration of primary and secondary clinical outcomes and health economic outcomes are analysed. The trial follows the guidelines of phase 2 of the Medical Research Council (MRC) for complex interventions.

RESULTS

We were able to recruit 48/50 participants during a period of 9 months. Retention in the trial for the whole period of the 12 months was 75%. Treatment compliance was overall 44%. Data completion for the primary outcome was 65%, 50% and 63% at 3, 6 and 12 months, respectively. The intervention group had more days abstinent in the previous 90 days at the 12 months (n = 54.5) versus control (n = 41.5).

CONCLUSIONS

The results of this feasibility trial indicate that with the appropriate modifications, a full multicentred trial would be possible to test the effectiveness and cost-effectiveness of a pre-habilitation approach such as the SPADe group intervention in addition to usual care against usual care only.

TRIAL REGISTRATION

Name of registry: ISRCTN; Trial Registration Number: 14621127 ; Date of Registration: 22/02/2017.

An International Comparison of EQ-5D-5L and EQ-5D-3L for Use in Cost-Effectiveness Analysis

OBJECTIVES

To estimate the impact of using EQ5D-5L (5L) compared with EQ5D-3L (3L) in cost-effectiveness analyses in 6 countries with 3L and 5L values: Germany, Japan, Korea, The Netherlands, China, and Spain.

METHODS

Eight cost-effectiveness analyses based on clinical studies with 3L provided 11 pairwise comparisons. We estimated cost-effectiveness by applying the appropriate country values for 3L to observed responses. We re-estimated cost-effectiveness for each country by predicting the 5L tariff score for each respondent, for each country, using a previously published mapping method. We compared results in terms of impact on estimated incremental quality-adjusted life-year (QALY) gain and cost-effectiveness ratios.

RESULTS

For most countries the impact of moving from 3L to 5L is to lower the incremental QALY gain in the majority of comparisons. The only exception to this was Japan, where 4 out of 11 cases (37%) saw lower QALYs gained when using 5L. The mean and median reductions in health gain, in those case studies where 5L does lead to lower health gain, are largest in The Netherlands (84% mean reduction, 41% median reduction), Germany (68% and 27%), and Spain (30% and 31%). For most countries, those studies where 5L leads to lower health gain see larger reductions than the gains in studies showing the opposite tendency.

CONCLUSIONS

Overall, 3L and 5L are not interchangeable in these countries. Differences between results are large, but the direction of change can be unpredictable. These findings should prompt further investigation into the reasons for differences.

The Use of Oral Analgesics and Pain Self-Efficacy Are Independent Predictors of the Quality of Life of Individuals with Rheumatoid Arthritis

Objectives

This study investigated the relationship between quality of life (QOL) and several factors, including pain assessments, in patients with rheumatoid arthritis (RA).

Methods

This cross-sectional, single-center study enrolled 85 patients with RA. The variables investigated included demographic characteristics, the 28-joint disease activity score with C-reactive protein (DAS28-CRP), painDETECT questionnaire (PDQ), pain self-efficacy questionnaire (PSEQ), and pain catastrophizing scale (PCS). QOL was measured using the Japanese validated version of the European Quality of Life questionnaire with five dimensions and five levels (EQ-5D-5L).

Results

The use of oral steroids and oral analgesics was significantly associated with low EQ-5D-5L scores (P < 0.05). EQ-5D-5L score had a significant positive association with PSEQ (r = 0.414) and significant negative association with age, disease duration, DAS28-CRP, PDQ, and PCS (r = −0.217, −0.343, −0.217, −0.277, and −0.384, respectively). Multiple regression analysis showed that the use of oral analgesics and PSEQ were independent predictors of EQ-5D-5L score (β = -0.248, P < 0.05 and β = 0.233, P < 0.05).

Conclusions

The use of oral analgesics by RA patients may influence their QOL, which, in turn, may affect their feelings of self-efficacy. Various pain management strategies, including surgical treatment, may be explored for the treatment of RA. Furthermore, the PSEQ may be a prominent part of the patient's overall assessment.

Disability and multidimensional quality of life: A capability approach to health status assessment

This paper offers an approach to assessing quality of life, based on Sen's (1985) theory, which it uses to understand loss in quality of life due to mobility impairment. Specifically, it provides a novel theoretical analysis that is able to account for the possibility that some functionings may increase when a person's capabilities decrease, if substitution effects are large enough. We then develop new data consistent with our theoretical framework that permits comparison of quality of life between those with a disability (mobility impairment) and those without. Empirical results show that mobility impairment has widespread rather than concentrated impacts on capabilities and is associated with high psychological costs. We also find evidence that a small number of functionings are higher for those with a disability, as our theory allows. The paper concludes by discussing possible implications for policy and health assessment methods.

Mapping clinical outcomes to generic preference-based outcome measures: development and comparison of methods

BACKGROUND

Cost-effectiveness analysis using quality-adjusted life-years as the measure of health benefit is commonly used to aid decision-makers. Clinical studies often do not include preference-based measures that allow the calculation of quality-adjusted life-years, or the data are insufficient. 'Mapping' can bridge this evidence gap; it entails estimating the relationship between outcomes measured in clinical studies and the required preference-based measures using a different data set. However, many methods for mapping yield biased results, distorting cost-effectiveness estimates.

OBJECTIVES

Develop existing and new methods for mapping; test their performance in case studies spanning different preference-based measures; and develop methods for mapping between preference-based measures.

DATA SOURCES

Fifteen data sets for mapping from non-preference-based measures to preference-based measures for patients with head injury, breast cancer, asthma, heart disease, knee surgery and varicose veins were used. Four preference-based measures were covered: the EuroQoL-5 Dimensions, three-level version (n = 11), EuroQoL-5 Dimensions, five-level version (n = 2), Short Form questionnaire-6 Dimensions (n = 1) and Health Utility Index Mark 3 (n = 1). Sample sizes ranged from 852 to 136,327. For mapping between generic preference-based measures, data from FORWARD, the National Databank for Rheumatic Diseases (which includes the EuroQoL-5 Dimensions, three-level version, and EuroQoL-5 Dimensions, five-level version, in its 2011 wave), were used.

MAIN METHODS DEVELOPED

Mixture-model-based approaches for direct mapping, in which the dependent variable is the health utility value, including adaptations of methods developed to model the EuroQoL-5 Dimensions, three-level version, and beta regression mixtures, were developed, as were indirect methods, in which responses to the descriptive systems are modelled, for consistent multidirectional mapping between preference-based measures. A highly flexible approach was designed, using copulas to specify the bivariate distribution of each pair of EuroQoL-5 Dimensions, three-level version, and EuroQoL-5 Dimensions, five-level version, responses.

RESULTS

A range of criteria for assessing model performance is proposed. Theoretically, linear regression is inappropriate for mapping. Case studies confirm this. Flexible, direct mapping methods, based on different variants of mixture models with appropriate underlying distributions, perform very well for all preference-based measures. The precise form is important. Case studies show that a minimum of three components are required. Covariates representing disease severity are required as predictors of component membership. Beta-based mixtures perform similarly to the bespoke mixture approaches but necessitate detailed consideration of the number and location of probability masses. The flexible, bi-directional indirect approach performs well for testing differences between preference-based measures.

LIMITATIONS

Case studies drew heavily on EuroQoL-5 Dimensions. Indirect methods could not be undertaken for several case studies because of a lack of coverage. These methods will often be unfeasible for preference-based measures with complex descriptive systems.

CONCLUSIONS

Mapping requires appropriate methods to yield reliable results. Evidence shows that widely used methods such as linear regression are inappropriate. More flexible methods developed specifically for mapping show that close-fitting results can be achieved. Approaches based on mixture models are appropriate for all preference-based measures. Some features are universally required (such as the minimum number of components) but others must be assessed on a case-by-case basis (such as the location and number of probability mass points).

FUTURE RESEARCH PRIORITIES

Further research is recommended on (1) the use of the monotonicity concept, (2) the mismatch of trial and mapping distributions and measurement error and (3) the development of indirect methods drawing on methods developed for mapping between preference-based measures.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 34. See the NIHR Journals Library website for further project information. This project was also funded by a Medical Research Council grant (MR/L022575/1).

Multivariate multilevel modeling of quality of life dynamics of HIV infected patients

BACKGROUND

Longitudinal quality of life (QoL) is an important outcome in many chronic illness studies aiming to evaluate the efficiency of care both at the patient and health system level. Although many QoL studies involve multiple correlated hierarchical outcome measures, very few of them use multivariate modeling. In this work, we modeled the long-term dynamics of QoL scores accounting for the correlation between the QoL scores in a multilevel multivariate framework and to compare the effects of covariates across the outcomes.

METHODS

The data is from an ongoing prospective cohort study conducted amongst adult women who were HIV-infected and on the treatment in Kwazulu-Natal, South Africa. Independent and related QoL outcome multivariate multilevel models were presented and compared.

RESULTS

The analysis showed that related outcome multivariate multilevel models fit better for our data used. Our analyses also revealed that higher educational levels, middle age, stable sex partners and higher weights had a significant effect on better improvements in the rate of change of QoL scores of HIV infected patients. Similarly, patients without TB co-infection, without thrombocytopenia, with lower viral load, with higher CD4 cell count levels, with higher electrolytes component score, with higher red blood cell (RBC) component score and with lower liver abnormality component score, were associated with significantly improved the rate of change of QoL, amongst HIV infected patients.

CONCLUSION

It is hoped that the article will help applied researchers to familiarize themselves with the models and including interpretation of results. Furthermore, three issues are highlighted: model building of multivariate multilevel outcomes, how this model can be used to assess multivariate assumptions, involving fixed effects (for example, to examine the size of the covariate effect varying across QoL domain scores) and random effects (for example, to examine the rate of change in one response variable associated to changes in the other).

More Unnecessary Imaginary Worlds - Part 1: The Institute for Clinical and Economic Review's Evidence Report on Janus Kinase (JAK) Inhibitors in Rheumatoid Arthritis

Previous commentaries in the Formulary Evaluation section of INNOVATIONS in Pharmacy have pointed to the lack of credibility in modeled claims for cost-effectiveness and associated recommendations for pricing by the Institute for Clinical and Economic Review (ICER). The principal objection to ICER reports has been that their modeled claims fail the standards of normal science: they are best seen as pseudoscience. The purpose of this latest commentary is to consider the recently released ICER evidence report for Janus Kinase (JAK) Inhibitors. As ICER continues, in the case of JAK Inhibitors, to apply its modeled cost utility framework with consequent recommendations for pricing adjustments, these recommendations also lack credibility. In contrast with previous ICER evidence reports, the present report adopts only a 12-month timeframe, one due, in large part, to ICER being unable to justify assumptions to drive its construction of imaginary worlds beyond 12 months. This commentary emphasizesagain, why the ICER methodology fails to meet the standards of normal science. Claims made by ICER for the competing JAK Inhibitor therapies lack credibility, are impossible to evaluate, let alone replicate across treatment settings. Even so, it is important to examine a number of key elements in the ICER invention of the 12-month JAK Inhibitor imaginary world. While this does not imply any degree of acceptance of the ICER methodology, one element that merits particular attention is thefailure of the ICER modeling to meet logically defensible measurement standards in its application of generic health related quality of life (HRQoL) ordinal metrics to create its QALY claims. The failure to meet the required standards of fundamental measurement means that the cost-per-QALY claims are invalid. This raises the issue of the application of Rasch Measurement Theory (RMT) in instrument development and the potential role of patient centric outcome (PCO) instruments that represent the patient voice in value claims. The case made here is that the ICER approach should be abandoned as an unnecessary distraction. If we are to meet standards for the discovery of new facts in therapy response then our focus must be on proposing credible, evaluable and replicable claims within disease states. Instruments, such as the Rheumatoid Arthritis Quality of Life (RAQoL)questionnaire that build on the common construct that QoL is the extent to which human needs are fulfilled should be the basis for value claims. HRQoL Instruments that are clinically focused and reflect the value calculus of providers and not patients in measuring response by symptoms and activity limitations are irrelevant. This puts to one side the belief that incremental cost-per-QALY models, the construction of imaginary worlds are, in any sense, a 'gold standard'; a meme embraced by the health technology assessment profession. Claims for incremental cost per QALY outcomes and recommendations for pricing and access driven by willingness to pay thresholds are irrelevant to formulary decisions.

Yet another Ersatz World: The ICER Final Evidence Report for Additive Cardiovascular Therapies

Previous commentaries in the Formulary Evaluation section of INNOVATIONS in Pharmacy have pointed to the lack of credibility in modeled claims for cost-effectiveness and associated recommendations for pricing by the Institute for Clinical and Economic Review (ICER). The principal objection to ICER reports has been that their modeled claims fail the standards of normal science: they are best seen as pseudoscience. The purpose of this latest commentary is to consider the recently released ICER report for Additive Cardiovascular Disease therapies. This report should not be taken seriously in its claims for cost-effectiveness and pricing in cardiovascular disease (CVD). The analytical framework applied by ICER fails to meet the standards of normal science in demarcating science from pseudoscience. Irrespective of the value judgements and recommendations of an ICER report, these lack credibility. They were never intended to be evaluable and replicable across treatment settings. The claims made are constructed, driven by assumption, and should be put to one side by health system decision makers. In this review the focus is on to the ICER modeled estimates of utility scores in CVD, the insistence on utilizing a generic utility algorithm (the EQ-5D-3L) and the consequent quality adjusted life year (QALY) estimates. Two issues are raised that will be the subject of future commentaries: the lack of appreciation of fundamental measurement and (ii) the importance of the patient voice in benefit claims. Given the importance in the ICER methodology of QALYS, the ad hoc nature of the ordinal utilities introduced to the cardiovascular model must raise concerns over the role the ICER evidence report may play in health care decision-making. These concerns extend to the claim by ICER that, on ICER's own affordability threshold for individual new molecular entities, the anticipated uptake of these therapies may raise questions of overall affordability. Again, we are dealing with an arbitraryconstruct that may adversely impact patient access.

Severity-Adjusted Probability of Being Cost Effective

BACKGROUND

In the context of priority setting, a differential cost-effectiveness threshold can be used to reflect a higher societal willingness to pay for quality-adjusted life-year gains in the worse off. However, uncertainty in the estimate of severity can lead to problems when evaluating the outcomes of cost-effectiveness analyses.

OBJECTIVES

This study standardizes the assessment of severity, integrates its uncertainty with the uncertainty in cost-effectiveness results and provides decision makers with a new estimate: the severity-adjusted probability of being cost effective.

METHODS

Severity is expressed in proportional and absolute shortfall and estimated using life tables and country-specific EQ-5D values. We use the three severity-based cost-effectiveness thresholds (€20.000, €50.000 and €80.000, per QALY) adopted in The Netherlands. We exemplify procedures of integrating uncertainty with a stylized example of a hypothetical oncology treatment.

RESULTS

Applying our methods, taking into account the uncertainty in the cost-effectiveness results and in the estimation of severity identifies the likelihood of an intervention being cost effective when there is uncertainty about the appropriate severity-based cost-effectiveness threshold.

CONCLUSIONS

Higher willingness-to-pay thresholds for severe diseases are implemented in countries to reflect societal concerns for an equitable distribution of resources. However, the estimates of severity are uncertain, patient populations are heterogeneous, and this can be accounted for with the severity-adjusted probability of being cost effective proposed in this study. The application to the Netherlands suggests that not adopting the new method could result in incorrect decisions in the reimbursement of new health technologies.

Parallel Valuation: A Direct Comparison of EQ-5D-3L and EQ-5D-5L Societal Value Sets

OBJECTIVE

To compare and contrast EQ-5D-5L (5L) and EQ-5D-3L (3L) health state values derived from a common sample.

METHODS

Data from the 2017 US EQ-5D valuation study were analyzed. Value sets were estimated with random-effects linear regression based on composite time trade-off (cTTO) valuations for 3L and 5L health states with 2 approaches to model specification: main effects only and additional N3/N45 terms. Properties of the descriptive system and value set characteristics were compared by examining distributions of predicted index scores, ceiling effects, and single-level transition values from adjacent corner health states. Mean transition values were calculated for all predicted 3L and 5L health states and plotted against baseline index scores.

RESULTS

A total of 1062 respondents were included in the analysis. The observed mean cTTO values for the worst possible 3L and 5L health states were -0.423 and -0.343, respectively. The range of scale was larger with the 3L, compared to the 5L, for both main effects and N term models. Values for the mildest 5L health states (range, 0.857-0.924) were similar to 11111 for the 3L. Parameter estimates for matched dimension levels differed by <|0.07| except for the most severe level of Mobility. For the main effects model, 3L mean transition values were greater for more severe baseline 3L index scores, whereas 5L mean transition values remained constant irrespective of the baseline index score.

CONCLUSIONS

Compared to the 3L, the 5L exhibited a lower ceiling effect and improved measurement properties. There was a larger range of scale for the 3L compared to 5L; however, this difference was driven by differences in preference for the most severe level of problems in Mobility.

Disease progression of alpha-mannosidosis and impact on patients and carers - A UK natural history survey

Introduction

Alpha-mannosidosis is an ultra-rare lysosomal storage disorder resulting from the deficient activity of lysosomal alpha-mannosidase. Alpha-mannosidosis presents as a highly heterogenous condition with large variations in symptom severity and disease progression rates. Quantitative and qualitative data for alpha-mannosidosis patients and their caregivers provide important insights into their daily experiences.

Methods

A survey of nine alpha-mannosidosis patients was carried out in the UK between August 2017 and January 2018. Patient demographics, health-related quality of life (HRQoL), and qualitative data from patients and carers relating to clinical characteristics and impact of the disease and treatment were analysed.

Results

At the time of survey completion, patient age ranged from 7 to 37 years. Five patients were described as 'walking unassisted', one as 'walking with assistance', one as 'wheelchair-dependent', and two as 'severely immobile'. In addition to best supportive care, three patients had received haematopoietic stem cell transplantation (HSCT) and one had received velmanase alfa enzyme replacement therapy (ERT). Patient HRQoL results for the EQ-5D-5 L questionnaire and the Health Utilities Index-3 showed that patients with more severe ambulatory health states reported lower utility values than patients who were more mobile. Patients who received HSCT or ERT experienced improved HRQoL. Carer HRQoL results for the Hospital Anxiety and Depression Scale and Caregiver Strain Index demonstrated that carers experience high levels of stress and anxiety from their caregiving responsibilities.

Conclusions

This survey confirmed the heterogeneity of alpha-mannosidosis and the large impact of the disease and treatment on patients, carers, and families. Early diagnosis and access to treatment offers the best chance of slowing the disease progression and may provide some relief to patients and carers.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

The Impact of Moving from EQ-5D-3L to -5L in NICE Technology Appraisals

BACKGROUND

The EuroQol-5 Dimension (EQ-5D) instrument is the National Institute for Health and Care Excellence (NICE)'s preferred measure of health-related quality of life (QoL) in adults. The three-level (3L) value set is currently recommended for use, but the five-level (5L) set is increasingly being used in practice.

OBJECTIVE

We aimed to explore the impact of moving from 3L to 5L in NICE appraisals.

METHODS

We adapted our existing mapping for use with health state utility values derived from a population where the original distribution of utilities was unknown. We used this mapping to estimate 5L utilities for 21 comparisons of interventions from models used in NICE technology appraisal decision making, covering a range of disease areas.

RESULTS

All utilities increased using 5L, and the differences between highest and lowest utilities decreased. In ten oncology comparisons, using 5L generally increased the incremental quality-adjusted life-years (QALYs) as the benefit from improving survival increased. In four non-oncology comparisons where the intervention improved QoL only, the incremental QALYs decreased as the benefit of improving QoL was reduced. In seven non-oncology comparisons where interventions improved survival and QoL, there was a trade-off between increasing the benefit from survival and decreasing the benefit from improving QoL.

CONCLUSION

3L and 5L lead to substantially different estimates of incremental QALYs and cost effectiveness. The direction and magnitude of the change is not consistent across case studies. Using 5L instead of 3L may lead to different reimbursement decisions. NICE will face inconsistencies in decision making if it uses 3L and 5L concurrently.

Obstetric brachial plexus injuries (OBPIs): health-related quality of life in affected adults and parents

Background

Obstetric brachial plexus injuries (OBPIs) are rare but can have significant implications for those affected, their caregivers and the health system. Symptoms can range from restricted movement to complete paralysis of the arm. We investigated health-related quality of life in adults with OBPIs and parents of children with permanent OBPIs, compared these with population norms, and investigated whether certain socio-demographic or clinical factors were associated with the quality of life in these cohorts.

Methods

A cross-sectional study examined 50 affected adults and 78 parents. Participants completed EQ-5D-5 L and characteristics questionnaires. EQ-5D-5 L responses were mapped onto an EQ-5D-3 L value set to generate utility scores. Mean utility scores were compared with English population norms. Univariable and multivariable linear regression models were conducted to assess for associations between participant characteristics and the utility scores.

Results

The overall mean utility scores for affected adults and parents were 0.56 (SD 0.28) and 0.80 (SD 0.19) respectively. Affected adults (95% CI (− 0.38, − 0.22), p < 0.001) and parents of children with permanent OBPIs (95% CI (− 0.10, − 0.02), p = 0.007) had lower mean utility scores, and therefore quality of life, compared to English population norms. For affected adults, previous OBPI surgery (95% CI (0.01, 0.25), p = 0.040), employment in non-manual work (95% CI (0.06, 0.30), p = 0.005) and having a partner (95% CI (0.04, 0.25), p = 0.009) appeared to be positively associated with the utility score. Affected adults receiving disability benefits related to OBPIs appeared to have worse utility scores than those not receiving any disability benefits (95% CI (− 0.31, − 0.06), p = 0.005). For parents, employment was associated with better utility scores (95% CI (0.02, 0.20), p = 0.024) but the presence of one or more medical condition appeared to be associated with worse utility scores (95% CI (− 0.16, − 0.04), p = 0.001).

Conclusions

Adults with OBPIs and parents of children with permanent OBPIs reported worse utility scores, and therefore quality of life, compared to the English general population. We also identified certain characteristics as possible factors to consider when dealing with utility scores in these cohorts. The utility scores in this study can be used in future economic evaluations related to OBPIs.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-1039-z) contains supplementary material, which is available to authorized users.

EQ-5D-5L versus EQ-5D-3L: The Impact on Cost Effectiveness in the United Kingdom

OBJECTIVES

To model the relationship between the three-level (3L) and the five-level (5L) EuroQol five-dimensional questionnaire and examine how differences have an impact on cost effectiveness in case studies.

METHODS

We used two data sets that included the 3L and 5L versions from the same respondents. The EuroQol Group data set (n = 3551) included patients with different diseases and a healthy cohort. The National Data Bank data set included patients with rheumatoid disease (n = 5205). We estimated a system of ordinal regressions in each data set using copula models to link responses of the 3L instrument to those of the 5L instrument and its UK tariff, and vice versa. Results were applied to nine cost-effectiveness studies.

RESULTS

Best-fitting models differed between the EuroQol Group and the National Data Bank data sets in terms of the explanatory variables, copulas, and coefficients. In both cases, the coefficients of the covariates and latent factors between the 3L and the 5L instruments were significantly different, indicating that moving between instruments is not simply a uniform re-alignment of the response levels for most dimensions. In the case studies, moving from the 3L to the 5L caused a decrease of up to 87% in incremental quality-adjusted life-years gained from effective technologies in almost all cases. Incremental cost-effectiveness ratios increased, often substantially. Conversely, one technology with a significant mortality gain saw increased incremental quality-adjusted life-years.

CONCLUSIONS

The 5L shifts mean utility scores up the utility scale toward full health and compresses them into a smaller range, compared with the 3L. Improvements in quality of life are valued less using the 5L than using the 3L. The 3L and the 5L can produce substantially different estimates of cost effectiveness. There is no simple proportional adjustment that can be made to reconcile these differences.