Economic Evaluations of Obesity-Targeted Sugar-Sweetened Beverage (SSB) Taxes-A Review to Identify Methodological Issues.

INTRODUCTION: Economic evaluations of public health interventions like sugar-sweetened beverage (SSB) taxes face difficulties similar to those previously identified in other public health areas. This stems from challenges in accurately attributing effects, capturing outcomes and costs beyond health, and integrating equity effects. This review examines how these challenges were addressed in economic evaluations of SSB taxes. METHODS: A systematic review was conducted to identify economic evaluations of SSB taxes focused on addressing obesity in adults, published up to February 2021. The methodological challenges examined include measuring effects, valuing outcomes, assessing costs, and incorporating equity. RESULTS: Fourteen economic evaluations of SSB taxes were identified. Across these evaluations, estimating SSB tax effects was uncertain due to a reliance on indirect evidence that was less robust than evidence from randomised controlled trials. Health outcomes, like quality-adjusted life years, along with a healthcare system perspective for costs, dominated the evaluations of SSB taxes, with a limited focus on broader non-health consequences. Equity analyses were common but employed significantly different approaches and exhibited varying degrees of quality. CONCLUSION: Addressing the methodological challenges remains an issue for economic evaluations of public health interventions like SSB taxes, suggesting the need for increased attention on those issues in future studies. Dedicated methodological guidelines, in particular addressing the measurement of effect and incorporation of equity impacts, are warranted.

Cost-utility analysis of adjuvant imatinib treatment in patients with high risk of recurrence after gastrointestinal stromal tumour (GIST) resection in Thailand.

BACKGROUND: Many patients develop tumour recurrence within a few years after undergoing surgical resection of gastrointestinal stromal tumours (GIST). Adjuvant imatinib treatment is recommended for patients with high risk of GIST recurrence as it can improve recurrence-free survival and overall survival of patients. This study aims to assess the cost-utility of adjuvant imatinib in patients with high risk of GIST recurrence after surgery compared with no adjuvant therapy in Thailand. METHODS: A Markov model was developed to estimate lifetime costs and outcomes of using adjuvant imatinib treatment and other treatment alternatives if recurrence occurred compared with the current situation of no adjuvant therapy in high-risk patients after surgery. A 1-month cycle length was deployed in the model. Transition probabilities were derived from literature review. Costs were collected and calculated for the year 2014 from a societal perspective. Future costs and outcomes were discounted at 3% per year. One-way and probabilistic sensitivity analyses were conducted to assess parameter uncertainties. RESULTS: Three years of adjuvant imatinib treatment followed by imatinib treatment and best supportive care if recurrence occurred after or during adjuvant therapy, respectively, was the best option as it produced more health outcomes (1.23 life years (LYs) and 1.16 quality-adjusted life years (QALYs)) compared to no adjuvant therapy while yielding the lowest incremental cost-effectiveness ratio (ICER) of 1,648,801 Thai Baht (THB) per QALY gained. Three years of adjuvant imatinib treatment followed by sunitinib treatment if recurrence occurred had an ICER of 2,608,264 THB per QALY gained compared to the best option, while other options were dominated. A one-way sensitivity analysis showed that the utility of patients receiving adjuvant imatinib had the greatest effect on the model, followed by the discount rate and probability of GIST recurrence. CONCLUSIONS: Adjuvant imatinib treatment improved the health benefits of patients with high risk of GIST recurrence. However, in the Thai context, it was not cost-effective at the current price.

An economic analysis of chromosome testing in couples with children who have structural chromosome abnormalities.

BACKGROUND: Structural chromosome abnormalities can cause significant negative reproductive outcomes as they typically result in morbidity and mortality of newborns. The prevalence of structural chromosomal abnormalities in live births is at least 0.05%, of which many of them have parental origins. It is uncommon to predict structural chromosome abnormalities at birth in the first child but it is possible to prevent repeated abnormalities through screening and diagnostic programmes. This study will provide an economic analysis of the prenatal detection of these abnormalities. METHODS: A cost-benefit analysis using a decision analytic model was employed to compare the status quo (doing nothing) with two interventional strategies. The first strategy (Strategy I) is preconceptional screening plus amniocentesis, and the second strategy (Strategy II) is amniocentesis alone. The monetary values in Thai baht (THB) were adjusted to international dollars (I$) using purchasing power parity (PPP) (I$1 = THB 17.60 for the year 2013). The robustness of the results was tested by applying a probabilistic sensitivity analysis. RESULTS: Both diagnostic strategies can reduce approximately 10.7-11.1 births with abnormal chromosomes per 1,000 diagnosed couples. The benefit cost ratios were 1.62 for Strategy I and 1.24 for Strategy II. Net present values per 1,000 diagnoses in couples were I$464,000 for Strategy I and I$267,000 for Strategy II. The probabilistic sensitivity analysis suggested that the cost-benefit analysis was sufficiently robust, confirming that both strategies provided higher benefits than costs. CONCLUSIONS: Since the benefits of both diagnostic strategies exceeded their costs, both strategies are economical-with Strategy I being more economically attractive. Strategy I is superior to Strategy II because it decreases the risk of normal children potentially dying from the amniocentesis process.

A Systematic Review of Economic Evaluation Methodologies Between Resource-Limited and Resource-Rich Countries: A Case of Rotavirus Vaccines.

BACKGROUND: For more than three decades, the number and influence of economic evaluations of healthcare interventions have been increasing and gaining attention from a policy level. However, concerns about the credibility of these studies exist, particularly in studies from low- and middle- income countries (LMICs). This analysis was performed to explore economic evaluations conducted in LMICs in terms of methodological variations, quality of reporting and evidence used for the analyses. These results were compared with those studies conducted in high-income countries (HICs). METHODS: Rotavirus vaccine was selected as a case study, as it is one of the interventions that many studies in both settings have explored. The search to identify individual studies on rotavirus vaccines was performed in March 2014 using MEDLINE and the National Health Service Economic Evaluation Database. Only full economic evaluations, comparing cost and outcomes of at least two alternatives, were included for review. Selected criteria were applied to assess methodological variation, quality of reporting and quality of evidence used. RESULTS: Eighty-five studies were included, consisting of 45 studies in HICs and 40 studies in LMICs. Seventy-five percent of the studies in LMICs were published by researchers from HICs. Compared with studies in HICs, the LMIC studies showed less methodological variety. In terms of the quality of reporting, LMICs had a high adherence to technical criteria, but HICs ultimately proved to be better. The same trend applied for the quality of evidence used. CONCLUSION: Although the quality of economic evaluations in LMICs was not as high as those from HICs, it is of an acceptable level given several limitations that exist in these settings. However, the results of this study may not reflect the fact that LMICs have developed a better research capacity in the domain of health economics, given that most of the studies were in theory led by researchers from HICs. Putting more effort into fostering the development of both research infrastructure and capacity building as well as encouraging local engagement in LMICs is thus necessary.

An Economic Evaluation of Neonatal Screening for Inborn Errors of Metabolism Using Tandem Mass Spectrometry in Thailand.

BACKGROUND: Inborn errors of metabolism (IEM) are a rare group of genetic diseases which can lead to several serious long-term complications in newborns. In order to address these issues as early as possible, a process called tandem mass spectrometry (MS/MS) can be used as it allows for rapid and simultaneous detection of the diseases. This analysis was performed to determine whether newborn screening by MS/MS is cost-effective in Thailand. METHOD: A cost-utility analysis comprising a decision-tree and Markov model was used to estimate the cost in Thai baht (THB) and health outcomes in life-years (LYs) and quality-adjusted life year (QALYs) presented as an incremental cost-effectiveness ratio (ICER). The results were also adjusted to international dollars (I$) using purchasing power parities (PPP) (1 I$ = 17.79 THB for the year 2013). The comparisons were between 1) an expanded neonatal screening programme using MS/MS screening for six prioritised diseases: phenylketonuria (PKU); isovaleric acidemia (IVA); methylmalonic acidemia (MMA); propionic acidemia (PA); maple syrup urine disease (MSUD); and multiple carboxylase deficiency (MCD); and 2) the current practice that is existing PKU screening. A comparison of the outcome and cost of treatment before and after clinical presentations were also analysed to illustrate the potential benefit of early treatment for affected children. A budget impact analysis was conducted to illustrate the cost of implementing the programme for 10 years. RESULTS: The ICER of neonatal screening using MS/MS amounted to 1,043,331 THB per QALY gained (58,647 I$ per QALY gained). The potential benefits of early detection compared with late detection yielded significant results for PKU, IVA, MSUD, and MCD patients. The budget impact analysis indicated that the implementation cost of the programme was expected at approximately 2,700 million THB (152 million I$) over 10 years. CONCLUSION: At the current ceiling threshold, neonatal screening using MS/MS in the Thai context is not cost-effective. However, the treatment of patients who were detected early for PKU, IVA, MSUD, and MCD, are considered favourable. The budget impact analysis suggests that the implementation of the programme will incur considerable expenses under limited resources. A long-term epidemiological study on the incidence of IEM in Thailand is strongly recommended to ascertain the magnitude of problem.

Methodological variation in economic evaluations conducted in low- and middle-income countries: information for reference case development.

Information generated from economic evaluation is increasingly being used to inform health resource allocation decisions globally, including in low- and middle- income countries. However, a crucial consideration for users of the information at a policy level, e.g. funding agencies, is whether the studies are comparable, provide sufficient detail to inform policy decision making, and incorporate inputs from data sources that are reliable and relevant to the context. This review was conducted to inform a methodological standardisation workstream at the Bill and Melinda Gates Foundation (BMGF) and assesses BMGF-funded cost-per-DALY economic evaluations in four programme areas (malaria, tuberculosis, HIV/AIDS and vaccines) in terms of variation in methodology, use of evidence, and quality of reporting. The findings suggest that there is room for improvement in the three areas of assessment, and support the case for the introduction of a standardised methodology or reference case by the BMGF. The findings are also instructive for all institutions that fund economic evaluations in LMICs and who have a desire to improve the ability of economic evaluations to inform resource allocation decisions.