Systematic Review of Health State Utility Values Used in European Pharmacoeconomic Evaluations for Chronic Hepatitis C: Impact on Cost-Effectiveness Results

Health-related quality of life among people who inject drugs in Australia

PURPOSE

There is limited research on health-related quality of life (HRQoL) among people who inject drugs (PWID). We aimed to evaluate factors associated with HRQoL among a cohort of PWID in Australia.

METHODS

Participants were enrolled in an observational cohort study (the LiveRLife Study) between 2014 and 2018 at 15 sites in Australia. They provided fingerstick whole-blood samples for point-of-care HCV RNA testing and underwent transient elastography to assess liver disease. Participants completed the EQ-5D-3L survey at enrolment. Regression models were used to assess the impact of clinical and socioeconomic characteristics on the EQ-5D-3L scores.

RESULTS

Among 751 participants (median age, 43 years; 67% male), 63% reported injection drug use in the past month, 43% had current HCV infection, and 68% had no/mild liver fibrosis (F0/F1). The mean EQ-5D-3L and EQ-VAS scores were 0.67 and 62, respectively, for the overall study population. There was no significant difference in the EQ-5D-3L scores among people with and without recent injecting drug use (mean: 0.66 vs. 0.68, median: 0.73 vs. 0.78, P = 0.405), and among people receiving and not receiving opioid agonist therapy (mean: 0.66 vs. 0.68, median: 0.73 vs. 0.76, P = 0.215). Participants who were employed were found to have the highest mean EQ-5D-3L (0.83) and EQ-VAS scores (77). The presence of current HCV infection, liver fibrosis stage, and high-risk alcohol consumption had little impact on HRQoL.

CONCLUSIONS

The study findings provide important HRQoL data for economic evaluations, useful for guiding the allocation of resources for HCV elimination strategies and interventions among PWID.

Evaluation of EuroQol Valuation Technology (EQ-VT) Designs to Generate National Value Sets: Learnings from the Development of an EQ-5D Value Set for India Using an Extended Design (DEVINE) Study

INTRODUCTION

Countries develop their EQ-5D-5L value sets using the EuroQol Valuation Technology (EQ-VT) protocol. This study aims to assess if extension in the conventional EQ-VT design can lead to development of value sets with improved precision.

METHODS

A cross-sectional survey was undertaken in a representative sample of 3,548 adult respondents, selected from 5 different states of India using a multistage stratified random sampling technique. A novel extended EQ-VT design was created that included 18 blocks of 10 health states, comprising 150 unique health states and 135 observations per health state. In addition to the standard EQ-VT design, which is based on 86 health states and 100 observations per health state, 3 extended designs were assessed for their predictive performance. The extended designs were created by 1) increasing the number of observations per health state in the design, 2) increasing the number of health states in the design, and 3) implementing both 1) and 2) at the same time. Subsamples of the data set were created for separate designs. The root mean squared error (RMSE) and mean absolute error (MAE) were used to measure the predictive accuracy of the conventional and extended designs.

RESULTS

The average RMSE and MAE for the standard EQ-VT design were 0.055 and 0.041, respectively, for the 150 health states. All 3 types of design extensions showed lower RMSE and MAE values as compared with the standard design and hence yielded better predictive performance. RMSE and MAE were lowest (0.051 and 0.039, respectively) for the designs that use a greater number of health states. Extending the design with inclusion of more health states was shown to improve the predictive performance even when the sample size was fixed at 1,000.

CONCLUSION

Although the standard EQ-VT design performs well, its prediction accuracy can be further improved by extending its design. The addition of more health states in EQ-VT is more beneficial than increasing the number of observations per health state.

HIGHLIGHTS

The EQ-5D-5L value sets are developed using the standardized EuroQol Valuation Technology (EQ-VT) protocol. This is the first study to empirically assess how much can be gained from extending the standard EQ-VT design in terms of sample size and/or health states. It not only presents useful insights into the performance of the standard design of the EQ-VT but also tests the potential extensions in the standard EQ-VT design in terms of increasing the health states to be directly valued as well as the number of observations recorded to predict the utility value of each of these health states.The study demonstrates that the standard EQ-VT design performs good, and an extension in the design of the standard EQ-VT can lead to further improvement in its performance. The addition of more health states in EQ-VT is more beneficial than increasing the number of observations per health state. Extending the design with inclusion of more health states marginally improves the predictive performance even when the sample size was fixed at 1,000.The findings of the study will streamline the systematic process for generating precise EQ-5D-5L value sets, thus facilitating the conduct of credible, transparent, and robust outcome valuation in health technology assessments.

The impact of age on health utility values for older women with early-stage breast cancer: a systematic review and meta-regression

INTRODUCTION

An increasing number of postmenopausal women are diagnosed with breast cancer at an older age (≥ 70 years). There is a lack of synthesised health utility data to support decision-making for managing breast cancer in this older population. This study aimed to identify the availability of, and the subsequent impact of age on, health state utility values (HSUVs) measured by the EQ-5D for older women with early-stage breast cancer.

METHOD

This systematic review identified EQ-5D (3L or 5L version) HSUVs for postmenopausal women with early-stage breast cancer. Studies were identified from a previous systematic review (inception to 2009) and an electronic database search (Medline and Embase; 2009 to September 2021). Mean HSUVs were summarised by health state. Quality appraisal was performed on studies reporting HSUVs for older ages (≥ 70 years). Multivariable meta-regression assessed the association between HSUVs and age, health state, treatments received, and time of measuring the utility values (greater or less than one year post-treatment).

RESULTS

Fifty EQ-5D HSUVs were identified from 13 studies. Mean HSUVs decreased as health state worsened: from the stable (mean=0.83) to progression (mean=0.79) and advanced (mean=0.68) states. Two studies reported six HSUVs estimated from the sample of women with a mean age ≥ 70. Meta-regression model fit improved by including age as an independent variable and attenuated the estimated utility decrements associated with worse health states. Utility decrements for the progression and advanced states were -0.052 (95%CI: -0.097, -0.007) and -0.143 (95%CI: -0.264, -0.022) respectively. The breast cancer-specific utility decrement associated with a one-year increase in age was -0.001 (95%CI: -0.004, 0.002).

CONCLUSION

Relevant and accurate HSUVs are essential to help support decision-making about the most effective and cost-effective ways to manage early-stage breast cancer in older women. Age has a vital role in determining health utility values in this population. This study provides analysts and decision-makers with HSUVs and utility decrements that reflect the disease process in this older population.

Quality appraisal for systematic literature reviews of health state utility values: a descriptive analysis

BACKGROUND

Health state utility values (HSUVs) are an essential input parameter to cost-utility analysis (CUA). Systematic literature reviews (SLRs) provide summarized information for selecting utility values from an increasing number of primary studies eliciting HSUVs. Quality appraisal (QA) of such SLRs is an important process towards the credibility of HSUVs estimates; yet, authors often overlook this crucial process. A scientifically developed and widely accepted QA tool for this purpose is lacking and warranted.

OBJECTIVES

To comprehensively describe the nature of QA in published SRLs of studies eliciting HSUVs and generate a list of commonly used items.

METHODS

A comprehensive literature search was conducted in PubMed and Embase from 01.01.2015 to 15.05.2021. SLRs of empirical studies eliciting HSUVs that were published in English were included. We extracted descriptive data, which included QA tools checklists or good practice recommendations used or cited, items used, and the methods of incorporating QA results into study findings. Descriptive statistics (frequencies of use and occurrences of items, acceptance and counterfactual acceptance rates) were computed and a comprehensive list of QA items was generated.

RESULTS

A total of 73 SLRs were included, comprising 93 items and 35 QA tools and good recommendation practices. The prevalence of QA was 55% (40/73). Recommendations by NICE and ISPOR guidelines appeared in 42% (16/40) of the SLRs that appraised quality. The most commonly used QA items in SLRs were response rates (27/40), statistical analysis (22/40), sample size (21/40) and loss of follow up (21/40). Yet, the most commonly featured items in QA tools and GPRs were statistical analysis (23/35), confounding or baseline equivalency (20/35), and blinding (14/35). Only 5% of the SLRS used QA to inform the data analysis, with acceptance rates of 100% (in two studies) 67%, 53% and 33%. The mean counterfactual acceptance rate was 55% (median 53% and IQR 56%).

CONCLUSIONS

There is a considerably low prevalence of QA in the SLRs of HSUVs. Also, there is a wide variation in the QA dimensions and items included in both SLRs and extracted tools. This underscores the need for a scientifically developed QA tool for multi-variable primary studies of HSUVs.

Cost effectiveness of simplified HCV screening-and-treatment interventions for people who inject drugs in Dar-es-Salaam, Tanzania

BACKGROUND

Compared to other countries in sub-Saharan Africa, Tanzania has a relatively progressive illicit drug harm reduction (HR) policy, through a predominantly opioid substitution therapy-based programme. However, access to hepatitis C virus (HCV) diagnosis and curative direct acting antiviral therapy remains elusive. We developed a cost-effectiveness model to evaluate a simplified HCV screening-and-treatment intervention amongst PWID in Dar-es-Salaam, Tanzania.

METHODS

A decision tree and Markov state transition model compared existing practice (no access to HCV viral confirmation and treatment) with the integration of point-of-care HCV screening and treatment within (1) existing HR services and (2) expansion to include PWID not currently engaged in HR. Outcome measures were screening, treatment, HR and disease-related costs per PWID, quality-adjusted life years (QALY) and disability adjusted life years (DALY). Cost-effectiveness was evaluated from a healthcare payer's perspective over a 30-year time horizon over a range of willingness-to-pay thresholds (USD$273 to USD$1,050). Both deterministic and probabilistic sensitivity analyses have been conducted.

RESULTS

Assuming a chronic HCV prevalence of 18.8%, screening-and-treatment in existing HR settings resulted in an ICER per QALY-gained and DALY averted of USD$633 and USD$1,161, respectively. Expanding to include an outreach programme for unengaged PWID yielded an ICER per QALY-gained and DALY-averted of USD$4,091 and USD$10,288. Factors affecting the sensitivity of the ICER value included the cost of HR and the health utility of non-cirrhotic disease states.

CONCLUSION

Simplified HCV screening and treatment of PWID has the potential to be cost-effective in Dar-es-Salaam, Tanzania. In practice, synergism of human and financial resources with established health programmes may offer a pragmatic solution to minimise operational costs.

Differences in the Selection of Health State Utility Values by Sponsorship in Published Cost-Effectiveness Analyses

BACKGROUND

Health state utility values (HSUVs) are among the most influential attributes of cost-effectiveness analyses (CEAs). Our objective was to evaluate whether industry-funded studies select systematically different HSUVs as compared with studies without industry funding.

METHODS

Among 10 diseases with high disease burden in the United States, we further identified 31 progressive health states. We then searched the Tufts Medical Center's CEA Registry to identify studies that included HSUVs and were submitted to the registry between 2002 and 2019. Two reviewers mapped the free-text descriptions of health states onto the 31 predefined health states. We analyzed the effect of industry funding on the point estimates of these HSUVs with a beta regression. We also analyzed the difference between related health states within studies by funding source with a linear regression.

RESULTS

After identifying 26,222 HSUVs from 4198 CEAs, we matched 2573 HSUVs to the 31 predefined health states. We observed large variations within each health state: 12 of 31 health states included a range of HSUVs greater than 0.5. The point estimate model showed 1 statistically significant difference of 31 comparisons between studies with any industry funding and those without. The utility difference model found 3 significant differences out of 39 comparisons between CEAs with any industry funding and those without.

LIMITATIONS

Inclusion of unpublished CEAs may have affected our conclusions about the effect of industry funding on selection of HSUVs. We also relied on free-text descriptions of health states available in the CEA Registry and did not include adjustment for multiple comparisons.

CONCLUSION

Limited evidence exists that industry-funded studies select different HSUVs compared to non-industry-funded studies for the health states we considered.