Health utility scores in Alzheimer's disease: differences based on calculation with American and Canadian preference weights

Model-Based Economic Evaluations of Interventions for Dementia: An Updated Systematic Review and Quality Assessment

BACKGROUND

There has been an increase in model-based economic evaluations of interventions for dementia. The most recent systematic review of economic evaluations for dementia highlighted weaknesses in studies, including lack of justification for model assumptions and data inputs.

OBJECTIVE

This study aimed to update the last published systematic review of model-based economic evaluations of interventions for dementia, including Alzheimer's disease, with a focus on any methodological improvements and quality assessment of the studies.

METHODS

Systematic searches in eight databases, including PubMed, Cochrane, Embase, CINAHL, PsycINFO, EconLit, international HTA database, and the Tufts Cost-Effectiveness Analysis Registry were undertaken from February 2018 until August 2022. The quality of the included studies was assessed using the Philips checklist and the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 checklist. The findings were summarized through narrative analysis.

RESULTS

This review included 23 studies, comprising cost-utility analyses (87%), cost-benefit analyses (9%) and cost-effectiveness analyses (4%). The studies covered various interventions, including pharmacological (n = 10, 43%), non-pharmacological (n = 4, 17%), prevention (n = 4, 17%), diagnostic (n = 4, 17%) and integrated (n = 1, 4%) [diagnostics-pharmacologic] strategies. Markov transition models were commonly employed (65%), followed by decision trees (13%) and discrete-event simulation (9%). Several interventions from all categories were reported as being cost effective. The quality of reporting was suboptimal for the Methods and Results sections in almost all studies, although the majority of studies adequately addressed the decision problem, scope, and model-type selection in their economic evaluations. Regarding the quality of methodology, only a minority of studies addressed competing theories or clearly explained the rationale for model structure. Furthermore, few studies systematically identified key parameters or assessed data quality, and uncertainty was mostly addressed partially.

CONCLUSIONS

This review informs future research and resource allocation by providing insights into model-based economic evaluations for dementia interventions and highlighting areas for improvement.

Valuing health-related quality of life among the Indian population: a protocol for the Development of an EQ-5D Value set for India using an Extended design (DEVINE) Study

INTRODUCTION

Quality-adjusted life year (QALY) has been recommended by the government as preferred outcome measure for Health Technology Assessment (HTA) in India. As country-specific health-related quality of life tariff values are essential for accurate measurement of QALYs, the government of India has commissioned the present study. The aim of this paper is to describe the methods for the Development of an EQ-5D Value set for India using an Extended design (DEVINE) Study. Additionally, this study aspires to establish if the design of 10-time trade-off (TTO) blocks is enough to generate valid value sets.

METHODS AND ANALYSIS

A cross-sectional survey using the EuroQol Group's Valuation Technology (EQ-VT) will be undertaken in a sample of 2700 respondents selected from six different states of India using a multistage stratified random sampling technique. The participants will be interviewed using computer-assisted personal interviewing technique. The TTO valuation will be done using 10 composite TTO (c-TTO) tasks and 7 discrete choice experiment (DCE) tasks. Hybrid modelling approach using both c-TTO and DCE data to estimate the potential value set will be applied. Values of all 3125 health states will be predicted using both the conventional EQ-VT design of 10 blocks of 10 TTO tasks, and an extended design of 18 blocks of 10 TTO tasks. The potential added value of the eight additional blocks in overall validity will be tested. The study will deliver value set for India and assess the adequacy of existing 10-blocks design to be able to correctly predict the values of all 3125 health states.

ETHICS AND DISSEMINATION

The ethical approval has been obtained from Institutional Ethics Committee of PGIMER, Chandigarh, India. The anonymised EQ-5D-5L value set will be available for general use and in the HTAs commissioned by India's central HTA Agency.

Health Utility Weighting of the Modified Rankin Scale: A Systematic Review and Meta-analysis

IMPORTANCE

The utility-weighted modified Rankin Scale (UW-mRS) has been proposed as a patient-centered alternative primary outcome for stroke clinical trials. However, to date, there is no clear consensus on an approach to weighting the mRS.

OBJECTIVE

To characterize the between-study variability in utility weighting of the mRS in a population of patients who experienced stroke and its implications when applied to the results of a clinical trial.

DATA SOURCES

In this systematic review and meta-analysis, MEDLINE, Embase, and PsycINFO were searched from January 1987 through May 2019 using major search terms for stroke, health utility, and mRS.

STUDY SELECTION

Original research articles published in English were reviewed. Included were studies with participants 18 years or older with ischemic or hemorrhagic stroke, transient ischemic attack, or subarachnoid hemorrhage, with mRS scores and utility weights evaluated concurrently. A total of 5725 unique articles were identified. Of these, 283 met criteria for full-text review, and 24 were included in the meta-analysis.

DATA EXTRACTION AND SYNTHESIS

PRISMA guidelines for systematic review were followed. Data extraction was performed independently by multiple researchers. Data were pooled using mixed models.

MAIN OUTCOMES AND MEASURES

The mean utility weights and 95% CIs were calculated for each mRS score and health utility scale. Geographic differences in weighting for the EuroQoL 5-dimension (EQ-5D) and Stroke Impact Scale-based UW-mRS were explored using inverse variance-weighted linear models. The results of 18 major acute stroke trials cited in current guidelines were then reanalyzed using the UW-mRS weighting scales identified in the systematic review.

RESULTS

The meta-analysis included 22 389 individuals; the mean (SD) age of participants was 65.9 (4.0) years, and the mean (SD) proportion of male participants was 58.2% (7.5%). For all health utility scales evaluated, statistically significant differences were observed between the mean utility weights by mRS score. For studies using an EQ-5D-weighted mRS, between-study variance was higher for worse (mRS 2-5) compared with better (mRS 0-1) scores. Of the 18 major acute stroke trials with reanalyzed results, 3 had an unstable outcome when using different UW-mRSs.

CONCLUSIONS AND RELEVANCE

Multiple factors, including cohort-specific characteristics and health utility scale selection, can influence mRS utility weighting. If the UW-mRS is selected as a primary outcome, the approach to weighting may alter the results of a clinical trial. Researchers using the UW-mRS should prospectively and concurrently obtain mRS scores and utility weights to characterize study-specific outcomes.

Cost-effectiveness analysis of the treatment of mild and moderate Alzheimer’s disease in Brazil

Objective:

To perform a cost-effectiveness analysis of donepezil and rivastigmine therapy for mild and moderate Alzheimer’s disease (AD) from the perspective of the Brazilian Unified Health System.

Method:

A hypothetical cohort of 1,000 individuals of both sexes, aged >65 years, and diagnosed with AD was simulated using a Markov model. The time horizon was 10 years, with 1-year cycles. A deterministic and probabilistic sensitivity analysis was performed.

Results:

For mild AD, the study showed an increase in quality-adjusted life years (QALYs) of 0.61 QALY/21,907.38 Brazilian reais (BRL) for patients treated with donepezil and 0.58 QALY/BRL 24,683.33 for patients treated with rivastigmine. In the moderate AD group, QALY increases of 0.05/BRL 27,414.96 were observed for patients treated with donepezil and 0.06/BRL 34,222.96 for patients treated with rivastigmine.

Conclusions:

The findings of this study contradict the standard of care for mild and moderate AD in Brazil, which is based on rivastigmine. A pharmacological treatment option based on current Brazilian clinical practice guidelines for AD suggests that rivastigmine is less cost-effective (0.39 QALY/BRL 32,685.77) than donepezil. Probabilistic analysis indicates that donepezil is the most cost-effective treatment for mild and moderate AD.

Spillover Effects on Caregivers' and Family Members' Utility: A Systematic Review of the Literature

BACKGROUND

A growing body of research has identified health-related quality-of-life effects for caregivers and family members of ill patients (i.e. 'spillover effects'), yet these are rarely considered in cost-effectiveness analyses (CEAs).

OBJECTIVE

The objective of this study was to catalog spillover-related health utilities to facilitate their consideration in CEAs.

METHODS

We systematically reviewed the medical and economic literatures (MEDLINE, EMBASE, and EconLit, from inception through 3 April 2018) to identify articles that reported preference-based measures of spillover effects. We used keywords for utility measures combined with caregivers, family members, and burden.

RESULTS

Of 3695 articles identified, 80 remained after screening: 8 (10%) reported spillover utility per se, as utility or disutility (i.e. utility loss); 25 (30%) reported a comparison group, either population values (n = 9) or matched, non-caregiver/family member or unaffected individuals' utilities (n = 16; 3 reported both spillover and a comparison group); and 50 (63%) reported caregiver/family member utilities only. Alzheimer's disease/dementia was the most commonly studied disease/condition, and the EQ-5D was the most commonly used measurement instrument.

CONCLUSIONS

This comprehensive catalog of utilities showcases the spectrum of diseases and conditions for which caregiver and family members' spillover effects have been measured, and the variation in measurement methods used. In general, utilities indicated a loss in quality of life associated with being a caregiver or family member of an ill relative. Most studies reported caregiver/family member utility without any comparator, limiting the ability to infer spillover effects. Nevertheless, these values provide a starting point for considering spillover effects in the context of CEA, opening the door for more comprehensive analyses.

Use of Checklists in Reviews of Health Economic Evaluations, 2010 to 2018

OBJECTIVE

It is useful for reviewers of economic evaluations to assess quality in a manner that is consistent and comprehensive. Checklists can allow this, but there are concerns about their reliability and how they are used in practice. We aimed to describe how checklists have been used in systematic reviews of health economic evaluations.

METHODS

Meta-review with snowball sampling. We compiled a list of checklists for health economic evaluations and searched for the checklists' use in systematic reviews from January 2010 to February 2018. We extracted data regarding checklists used, stated checklist function, subject area, number of reviewers, and issues expressed about checklists.

RESULTS

We found 346 systematic reviews since 2010 that used checklists to assess economic evaluations. The most common checklist in use was developed in 1996 by Drummond and Jefferson, and the most common stated use of a checklist was quality assessment. Checklists and their use varied within subject areas; 223 reviews had more than one reviewer who used the checklist.

CONCLUSIONS

Use of checklists is inconsistent. Eighteen individual checklists have been used since 2010, many of which have been used in ways different from those originally intended, often without justification. Different systematic reviews in the same subject areas would benefit from using one checklist exclusively, using checklists as intended, and having 2 reviewers complete the checklist. This would increase the likelihood that results are transparent and comparable over time.

A pharmacoeconomic evaluation of cholinesterase inhibitors and memantine for the treatment of Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) results in progressively worsening cognitive decline, leading to loss of functional ability, behavior/mood disturbances, institutionalization, and death. Current pharmaceutical therapies only treat the symptoms of cognitive decline yet can be expensive for payers. Areas covered: The authors undertook a systematic review of economic evaluations of pharmaceutical therapies for AD. The literature search encompassed English-language studies indexed in PubMed (Medline), Cochrane Library Current, and Web of Science. The search included articles published between 1 January 1995 and 10 February 2018. The literature suggested AD medications generally dominated comparator treatments (e.g. placebo). Expert opinion: The authors noted several limitations of the included economic evaluations. These limitations suggest the results of the economic evaluations should be interpreted with caution. Many economic models were not transparent with respect to sources of probabilities and cost data, and data collected in certain jurisdictions were applied to other jurisdictions without considering the validity of such applications. Measuring health utilities in cognitively impaired populations raises questions about the validity of quality-adjusted life years, but this issue was unaddressed in the included studies. Most included studies were sponsored by industry and the results tended to overwhelmingly support the manufacturer's product.

Associations between the Drug Burden Index, Potentially Inappropriate Medications and Quality of Life in Residential Aged Care

BACKGROUND

Inappropriate polypharmacy may negatively impact the quality of life of residents in aged care facilities, but it remains unclear which medications may influence this reduced quality of life.

OBJECTIVE

The objective of this study was to examine whether the Drug Burden Index and potentially inappropriate medications were associated with quality of life in older adults living in residential care with a high prevalence of cognitive impairment and dementia.

METHODS

We conducted cross-sectional analyses of 541 individuals recruited from 17 residential aged care facilities in Australia in the Investigating Services Provided in the Residential Environment for Dementia (INSPIRED) study. Quality of life was measured using the EuroQol Five Dimensions Questionnaire (a measure of generic quality of life) and the Dementia Quality of Life Questionnaire completed by the participant or a proxy.

RESULTS

In the 100 days prior to recruitment, 83.1% of the participants received at least one anticholinergic or sedative medication included in the Drug Burden Index and 73.0% received at least one potentially inappropriate medication according to the Beers Criteria. Multi-level linear models showed there was a significant association between a higher Drug Burden Index and lower quality of life according to the EuroQol Five Dimensions Questionnaire [β (standard error): - 0.034 (0.012), p = 0.006] after adjustment for potential confounding factors. Increasing numbers of potentially inappropriate medications were also associated with lower EuroQol Five Dimensions Questionnaire scores [- 0.030 (0.010), p = 0.003] and Dementia Quality of Life Questionnaire-Self-Report-Utility scores [- 0.020 (0.009), p = 0.029]. Exposure to both Drug Burden Index-associated medications and potentially inappropriate medications was associated with lower Dementia Quality of Life Questionnaire-Self-Report-Utility scores [- 0.034 (0.017), p = 0.049].

CONCLUSION

Exposure to anticholinergic and sedative medications and potentially inappropriate medications occurred in over three-quarters of a population of older adults in residential care and was associated with a lower quality of life.

An empirical comparison of the measurement properties of the EQ-5D-5L, DEMQOL-U and DEMQOL-Proxy-U for older people in residential care

PURPOSE

This study aimed to empirically compare the measurement properties of self-reported and proxy-reported (in cases of severe cognitive impairment) generic (EQ-5D-5L) and condition-specific (DEMQOL-U and DEMQOL-Proxy-U) preference-based HRQoL instruments in residential care, where the population is characterised by older people with high rates of cognitive impairment, dementia and disability.

METHODS

Participants were recruited from seventeen residential care facilities across four Australian states. One hundred and forty-three participants self-completed the EQ-5D-5L and the DEMQOL-U while three hundred and eight-seven proxy completed (due to the presence of severe dementia) the EQ-5D-5L and DEMQOL-Proxy-U. The convergent validity of the outcome measures and known group validity relative to a series of clinical outcome measures were assessed.

RESULTS

Results satisfy convergent validity among the outcome measures. EQ-5D-5L and DEMQOL-U utilities were found to be significantly correlated with each other (p < 0.01) as were EQ-5D-5L and DEMQOL-Proxy-U utilities (p < 0.01). Both self-reported and proxy-reported EQ-5D-5L utilities demonstrated strong known group validity in relation to clinically recognised thresholds of cognition and physical functioning, while in contrast neither DEMQOL-U nor DEMQOL-Proxy-U demonstrated this association.

CONCLUSIONS

The findings suggest that the EQ-5D-5L, DEMQOL-U and DEMQOL-Proxy-U capture distinct aspects of HRQoL for this population. The measurement and valuation of HRQoL form an essential component of economic evaluation in residential care. However, high levels of cognitive impairment may preclude self-completion for a majority. Further research is needed to determine cognition thresholds beyond which an individual is unable to reliably self-report their own health-related quality of life.

Impact of reconceptualization response shift on rating of quality of life over time among people with advanced cancer

BACKGROUND

People with cancer may experience change in what constitutes quality of life (QOL) over time as a result of the cancer progression (true change) or adaptation to the experience, considered as a response shift phenomenon. As individualized measures are ideally suited to explore response shift, this study aimed to estimate the extent to which reconceptualization response shift occurred over time in a cancer population and the impact of this response shift on estimates of change on QOL measures.

METHODS

Ninety-seven people with advanced cancer completed the study measures including the Patient-Generated Index (PGI) at diagnosis (T0) and 1 year later (T1). The response shift indicator was the change in the number of areas nominated (range - 4 to + 3). Multivariate linear regression was used to estimate the effect of changing areas on change in the PGI score, single indicators of global QOL, and the EQ-5D_index adjusted for age and sex.

RESULTS

Approximately 72% of people in this sample either added or dropped areas over time. People who dropped more than two areas had higher PGI scores at T1 than T0 while people who added areas showed low PGI score.

CONCLUSION

The results are consistent with the PGI framework as areas nominated tend to focus on negative aspects of QOL.

A comparison of health utility scores calculated using United Kingdom and Canadian preference weights in persons with alzheimer's disease and their caregivers

Background

The use of the EQ-5D to asses the economic benefits of health technologies has led to questions about the cross-population transferability of preference weights to calculate health utility scores. The aim of this study is to investigate whether the use of UK and Canadian preference weights will lead to the calculation of different health utility scores in a sample of persons with Alzheimer’s disease (AD) and their primary informal caregivers.

Methods

We recruited 216 patient-caregiver dyads from nine geriatric and memory clinics across Canada. Participants used the EQ-5D-3L to rate their health-related quality-of-life (HRQoL). EQ-5D-3L responses were transformed into health utility scores using UK and Canadian preference weights. The levels of agreement between the two sets of scores were assessed using intraclass correlation coefficients (ICCs). Bland-Altman plots depicted individual-level differences between the two sets of scores. Differences in health utility scores were tested using the Wilcoxon signed rank sum test. A generalized linear model with a gamma distribution was used to examine whether participants’ socio-demographic characteristics were associated with their health utility scores.

Results

The distributions of health utility scores derived from both the UK and Canadian preference weights were skewed to the left. The intraclass correlation coefficient was 0.94 (95 % CI: 0.92, 0.95) for persons with AD and 0.92 (95 % CI: 0.88, 0.94) for the caregivers. The Canadian weights yielded slightly higher median health utility scores than the UK weights for caregivers (median difference: 0.009; 95 % confidence interval: 0.007, 0.013). This finding persisted after stratifying by disease severity. Few socio-demographic characteristics were associated with the two sets of health utility scores.

Conclusions

Health utility scores exhibited small and clinically unimportant differences when calculated with UK versus Canadian preference weights in persons with AD and their caregivers. The original UK and Canadian population samples used to obtain the preference weights valued health states similarly.

EQ-5D-derived health utilities and minimally important differences for chronic health conditions: 2011 Commonwealth Fund Survey of Sicker Adults in Canada

PURPOSE

The purpose of the study is to estimate the EQ-5D-derived health utilities associated with selected chronic conditions (hypertension, heart disease, arthritis, asthma or COPD, cancer, diabetes, chronic back pain, and anxiety or depression) and to estimate minimally important differences (MID) based on the Commonwealth Fund Survey of Sicker Adults in Canada.

METHODS

We used a cross-sectional survey of 3765 sick adults in Canada conducted in 2011 by the Commonwealth Fund. Health utilities were calculated for the entire sample and for each of the eight chronic health conditions. An ordinary least squares regression was used to estimate the utility decrement associated with these conditions with and without adjustment for socio-demographic factors. The MIDs were estimated using the anchor- and distribution-based methods.

RESULTS

The adjusted utility decrement varied from 0.028 (95 % confidence interval (CI) -0.049, -0.008) for diabetes to 0.124 (95 % CI -0.142, -0.105) for anxiety or depression. The anchor-based MID for the entire group was 0.044 (95 % CI 0.025, 0.062), and the distribution-based MID for the entire group was 0.091. The condition-specific MIDs using the distribution-based method ranged from 0.089 for cancer to 0.108 for asthma or COPD.

CONCLUSIONS

The MID estimated by the distribution-based method was larger than the MID estimated by the anchor-based method, indicating that the choice of method matters. The impact of arthritis, anxiety or depression, and chronic back pain on health utility was substantial, all exceeding or approximating the MID estimated using either anchor- or distribution-based methods.

A systematic review of instruments for measuring outcomes in economic evaluation within aged care

BACKGROUND

This paper describes the methods and results of a systematic review to identify instruments used to measure quality of life outcomes in older people. The primary focus of the review was to identify instruments suitable for application with older people within economic evaluations conducted in the aged care sector.

METHODS

Online databases searched were PubMed, Medline, Scopus, and Web of Science, PsycInfo, CINAHL, Embase and Informit. Studies that met the following criteria were included: 1) study population exclusively above 65 years of age 2) measured health status, health related quality of life or quality of life outcomes more broadly through use of an instrument developed for this purpose, 3) used a generic preference based instrument or an older person specific preference based or non-preference based instrument or both, and 4) published in journals in the English language after 2000.

RESULTS

The most commonly applied generic preference based instrument in both the community and residential aged care context was the EuroQol - 5 Dimensions (EQ-5D), followed by the Adult Social Care Outcomes Toolkit (ASCOT) and the Health Utilities Index (HUI2/3). The most widely applied older person specific instrument was the ICEpop CAPability measure for Older people (ICECAP-O) in both community and residential aged care.

CONCLUSION

In the absence of an ideal instrument for incorporating into economic evaluations in the aged care sector, this review recommends the use of a generic preference based measure of health related quality of life such as the EQ-5D to obtain quality adjusted life years, in combination with an instrument that has a broader quality of life focus like the ASCOT, which was designed specifically for evaluating interventions in social care or the ICECAP-O, a capability measure for older people.

Does the choice of EQ-5D tariff matter? A comparison of the Swedish EQ-5D-3L index score with UK, US, Germany and Denmark among type 2 diabetes patients

Objective

To compare the performance of the recently developed Swedish experience-based time trade-off (TTO) valuation of the EuroQol-5D-3L (EQ-5D-3L) against the hypothetical-based TTO valuations from UK, US, Germany and Denmark.

Methods

Type 2 diabetes patients from the Swedish National Diabetes Register (N = 1 757) responded to EQ-5D-3L questionnaire in 2008. Health utilities were compared using a range of parametric and nonparametric tests. Absolute agreement and consistency were investigated using intra-class correlations coefficients (ICCs) and Bland-Altman plots. Differences in health utilities between known-groups were evaluated. Transition scores for pairs of observed EQ-5D-3L health states were calculated and compared.

Results

The Swedish tariff (SWT) resulted in substantially higher health utilities and differences were more profound for more severe health problems. ICC ranged 0.6 to 0.8 and Bland-Altman plots showed wide limits of agreement. While all tariffs discriminate between known-groups, the effect sizes were generally small. The SWT had higher (lower) known-group validity for macrovascular (microvascular) complications. The SWT and UK tariff were associated with the lowest and the highest mean absolute transition scores, respectively, for 2775 observed pairs of the EQ-5D-3L health states.

Conclusion

There were systematic differences between the SWT and tariffs from other countries meaning that the choice of tariff might have substantial impact on funding decisions. The Swedish experienced-based TTO valuation will give higher priority to life-extending interventions than those which improve quality of life. We suggest that economic evaluations in Sweden include both Swedish experience-based and non-Swedish hypothetical-based valuations through a sensitivity analysis.