Cross-model validation of public health microsimulation models; comparing two models on estimated effects of a weight management intervention.

BACKGROUND: Health economic modelling indicates that referral to a behavioural weight management programme is cost saving and generates QALY gains compared with a brief intervention. The aim of this study was to conduct a cross-model validation comparing outcomes from this cost-effectiveness analysis to those of a comparator model, to understand how differences in model structure contribute to outcomes. METHODS: The outcomes produced by two models, the School for Public Health Research diabetes prevention (SPHR) and Health Checks (HC) models, were compared for three weight-management programme strategies; Weight Watchers (WW) for 12 weeks, WW for 52 weeks, and a brief intervention, and a simulated no intervention scenario. Model inputs were standardised, and iterative adjustments were made to each model to identify drivers of differences in key outcomes. RESULTS: The total QALYs estimated by the HC model were higher in all treatment groups than those estimated by the SPHR model, and there was a large difference in incremental QALYs between the models. SPHR simulated greater QALY gains for 12-week WW and 52-week WW relative to the Brief Intervention. Comparisons across socioeconomic groups found a stronger socioeconomic gradient in the SPHR model. Removing the impact of treatment on HbA1c from the SPHR model, running both models only with the conditions that the models have in common and, to a lesser extent, changing the data used to estimate risk factor trajectories, resulted in more consistent model outcomes. CONCLUSIONS: The key driver of difference between the models was the inclusion of extra evidence-based detail in SPHR on the impacts of treatments on HbA1c. The conclusions were less sensitive to the dataset used to inform the risk factor trajectories. These findings strengthen the original cost-effectiveness analyses of the weight management interventions and provide an increased understanding of what is structurally important in the models.

Identification of tax options for high fat, sugar, salt foods for the HEALTHEI Project: a mixed-methods study.

BACKGROUND: The health economic analysis incorporating effects on labour outcomes, households, environment, and inequalities (HEALTHEI) explores which food taxes would have greatest benefits to health, labour, and work outcomes; household expenditure; environmental sustainability; and inequalities within the UK food system. Work package 1 includes a rapid review and workshops, aiming to explore the effects of price increases in food and non-alcoholic beverages to facilitate the specification of food taxes and research design. METHODS: In this mixed-methods study, we first did a rapid review to examine relevant published evidence. A preplanned framework ensured a systematic approach, in which we searched PubMed, HMIC, Scopus, Google, Mintel/Mintel Food and Drink, and Business Source Ultimate for papers published in English from Jan 1, 2010, to Nov 2, 2022. This review was followed by three online workshops (in March, 2023), which used interactive padlets to explore food systems, food taxation policy, tax rationales, and a rapid review infographic. 14 stakeholders from non-governmental organisations (n=10), academia (n=2), the Civil Service (n=1), and a local authority (n=1) took part (gender or ethnicity were not recorded). A stakeholder recruitment grid was developed to ensure representation across public sectors and disciplines of public health, nutrition, environment, and economics. FINDINGS: The rapid review identified six tax options with a broadly positive impact on consumption and health (high fat, high sugar, high salt, "junk food", sugar-sweetened-beverages, and meats plus sugar-sweetened beverages). It generated five core rationales for a food tax: change consumption, reduce or prevent harm, change product affordability, raise revenue, and industry impact. Using the workshop feedback, health inequalities, economics, ease of implementation and animal welfare were additional key areas for a so-called real-world application of tax. Stakeholders questioned the taxes in the current economic and political climate. INTERPRETATION: The work highlights the need to develop an impactful food tax option that encompasses the five core rationales identified in the findings. The workshops identified key areas to explore further to understand the feasibility, impact, and logistics of implementing future food taxes. Being unable to deliver workshops in person due to difficulties of participants travelling to London was a limitation. However, switching online allowed for varied and well attended workshops. FUNDING: National Institute of Health Research (Ref: NIHR133927).

Estimation of HbA1c after weight loss using a beta-regression for an economic evaluation of a behavioural weight management programme from the GLoW trial: a methodological study.

BACKGROUND: In economic evaluations, average intervention effects are usually applied to a population. However, this fails to reflect the change in the distribution of HbA1c due to heterogeneous responses to weight loss. We aimed to investigate whether allowing heterogeneous treatment effects using a beta regression better represented the distribution of HbA1c after a weight-loss intervention, and how this affected cost effectiveness. METHODS: The Glucose Lowering through Weight Management (GLoW) trial evaluated the effectiveness of a diabetes education and weight-loss intervention against a standard diabetes education programme. Adults diagnosed with type 2 diabetes within 3 years were recruited from Clinical Commissioning Groups across 159 sites in England from July 20, 2018, to July 22, 2018. Ethics approval (18/ES/0048) and participant informed consent were obtained. Considering the between-treatment-arm difference in HbA1c after 12 months, we compared a mean-effect estimated from a mixed-effects regression to a heterogeneous effect estimated from a beta regression performed on 12-month HbA1c conditional on baseline HbA1c, gender, diabetes duration and intervention group. We used the School of Public Health Research (SPHR) Diabetes Treatment model to apply these treatment effects and evaluate the lifetime NHS costs and quality-adjusted life-years (QALYs), discounted at 3·5%. The microsimulation model estimated diabetes-related health outcomes using the UK Prospective Diabetes Study Outcomes Model 2 risk equations and risk factor trajectory equations, alongside estimating diabetes remission, osteoarthritis, and cancer. We calculated the incremental net benefit (INB) of the intervention using a £20 000 per QALY valuation, by deterministic analysis. The GLoW trial is registered with the ISRCTN Registry, ISRCTN18399564. FINDINGS: The trial recruited 577 participants (mean age 60 years; 278 [53%] female, 247 [47%] male; 474 [91%] white ethnic background). Applying heterogeneous HbA1c changes better reproduced the skewness in post-intervention HbA1c than applying a mean-effect (Kolmogorov-Smirnov test p=0·02 compared with p=0·0000007). The beta-regression method suggested the intervention was more cost-effective, estimating an INB of £736 per person, compared with £584 when applying the mean-effect. INTERPRETATION: Alternative regression specification methods should be considered when evaluating the cost-effectiveness of interventions if the key intervention outcomes are not normally distributed. However, this alternative method requires further investigation to conclude its appropriateness in evaluating cost-effectiveness in different contexts. FUNDING: National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research Programme (Reference Number RP-PG0216-20010).

Understanding the use of media analysis in public health research through food tax debates (HEALTHEI Project): a scoping review.

BACKGROUND: Poor diet is a major public health concern. In 2021, 63·8% of adults and 22·2% of reception-age children were either overweight or obese in England. Fiscal interventions have become a popular policy measure to reduce obesity and encourage healthy eating. Such measures are highly controversial, leading to media debate promoting pro-tax and anti-tax arguments. To better understand food tax debates and the use of media analysis in public health research, we conducted a scoping review of media analyses using food taxes as a case study. METHODS: In this scoping review, we searched SCOPUS, PubMed, and EBSCOhost databases on Feb 14-22, 2023, using keyword variations for "food", "tax", and "media analysis". Results were restricted to English-only, peer-reviewed journal articles. The initial results were manually screened through an iterative process to exclude articles that did not analyse a food tax, were non-English language, were not peer-reviewed, or did not use media analysis as the primary method. Modelled on Arksey and O'Malley's (2005) five-stage review protocol, two researchers used a coding framework to independently code all articles and checked result quality through regular discussion. Extracted data included article title, author, year, country, tax type, media sources used, identified media frames, and research aims, methods, results, and conclusions. Results are reported according to PRISMA guidelines and data files submitted to FigShare Repository (non-accessible). FINDINGS: Of 1087 articles reviewed, 19 were eligible to be included in the study. Articles were published between 2013 and 2023, with 2021 having the highest concentration of studies carried out mainly in UK and USA. Despite search terms encompassing a range of food products, the retrieved media analyses focused on three types of food product taxes: sugar-sweetened beverages, meat, and groceries. Most articles explored arguments for and against policy implementation, with some investigating stakeholder representation. Results demonstrate that stakeholders' arguments, both positive and negative, are consistent across countries and food products. INTERPRETATION: The consistency of how both pro-tax and anti-tax arguments are presented in the media demonstrates the importance of coordination between stakeholder groups to influence policy adoption. To our knowledge, this is the first study to investigate media analysis across a diverse range of food products. FUNDING: National Institute for Health and Care Research (NIHR).

Guidance on the use of complex systems models for economic evaluations of public health interventions.

To help health economic modelers respond to demands for greater use of complex systems models in public health. To propose identifiable features of such models and support researchers to plan public health modeling projects using these models. A working group of experts in complex systems modeling and economic evaluation was brought together to develop and jointly write guidance for the use of complex systems models for health economic analysis. The content of workshops was informed by a scoping review. A public health complex systems model for economic evaluation is defined as a quantitative, dynamic, non-linear model that incorporates feedback and interactions among model elements, in order to capture emergent outcomes and estimate health, economic and potentially other consequences to inform public policies. The guidance covers: when complex systems modeling is needed; principles for designing a complex systems model; and how to choose an appropriate modeling technique. This paper provides a definition to identify and characterize complex systems models for economic evaluations and proposes guidance on key aspects of the process for health economics analysis. This document will support the development of complex systems models, with impact on public health systems policy and decision making.

Effectiveness and cost-effectiveness of referral to a commercial open group behavioural weight management programme in adults with overweight and obesity: 5-year follow-up of the WRAP randomised controlled trial.

BACKGROUND: There is evidence that commercially available behavioural weight management programmes can lead to short-term weight loss and reductions in glycaemia. Here, we aimed to provide the 5-year impact and cost-effectiveness of these interventions compared with a brief intervention. METHODS: WRAP was a non-blinded, parallel-group randomised controlled trial (RCT). We recruited from primary care practices in England and randomly assigned participants to one of three interventions (brief intervention, 12-week open-group behavioural programme [WW, formerly Weight Watchers], or a 52-week open-group WW behavioural programme) in an uneven (2:5:5) allocation. Participants were followed up 5 years after randomisation using data from measurement visits at primary care practices or a research centre, review of primary care electronic medical notes, and self-report questionnaires. The primary outcome was change in weight at 5 years follow-up, assessed using analysis of covariance. We also estimated cost-effectiveness of the intervention. This study is registered at Current Controlled Trials, ISRCTN64986150. FINDINGS: Between Oct 18, 2012, and Feb 10, 2014, we recruited 1269 eligible participants (two participants were randomly assigned but not eligible and therefore excluded) and 1040 (82%) consented to be approached about additional follow-up and to have their medical notes reviewed at 5 years. The primary outcome (weight) was ascertained for 871 (69%) of 1267 eligible participants. Mean duration of follow-up was 5·1 (SD 0·3) years. Mean weight change from baseline to 5 years was -0·46 (SD 8·31) kg in the brief intervention group, -1·95 (9·55) kg in the 12-week programme group, and -2·67 (9·81) kg in the 52-week programme. The adjusted difference in weight change was -1·76 (95% CI -3·68 to 0·17) kg between the 52-week programme and the brief intervention; -0·80 (-2·13 to 0·54) kg between the 52-week and the 12-week programme; and -0·96 (-2·90 to 0·97) kg between the 12-week programme and the brief intervention. During the trial, the 12-week programme incurred the lowest cost and produced the highest quality-adjusted life-years (QALY). Simulations beyond 5 years suggested that the 52-week programme would deliver the highest QALYs at the lowest cost and would be the most cost-effective. No participants reported adverse events related to the intervention. INTERPRETATION: Although the difference in weight change between groups was not statistically significant, some weight loss was maintained at 5 years after an open-group behavioural weight management programme. Health economic modelling suggests that this could have important implications to reduce the incidence of weight-related disease and these interventions might be cost-saving. FUNDING: The UK National Institute for Health and Care Research Programme Grants for Applied Research and the Medical Research Council.

The health, cost and equity impacts of restrictions on the advertisement of high fat, salt and sugar products across the transport for London network: a health economic modelling study.

BACKGROUND: Policies aimed at restricting the marketing of high fat, salt and sugar products have been proposed as one way of improving population diet and reducing obesity. In 2019, Transport for London implemented advertising restrictions on high fat, salt and sugar products. A controlled interrupted time-series analysis comparing London with a north of England control, suggested that the advertising restrictions had resulted in a reduction in household energy purchases. The aim of the study presented here was to estimate the health benefits, cost savings and equity impacts of the Transport for London policy using a health economic modelling approach, from an English National Health Service and personal social services perspective. METHODS: A diabetes prevention microsimulation model was modified to incorporate the London population and Transport for London advertising intervention. Conversion of calorie to body mass index reduction was mediated through an approximation of a mathematical model estimating weight loss. Outcomes gathered included incremental obesity, long-term diabetes and cardiovascular disease events, quality-adjusted life years, healthcare costs saved and net monetary benefit. Slope index of inequality was calculated for proportion of people with obesity across socioeconomic groups to assess equity impacts. RESULTS: The results show that the Transport for London policy was estimated to have resulted in 94,867 (4.8%) fewer individuals with obesity, and to reduce incidence of diabetes and cardiovascular disease by 2,857 and 1,915 cases respectively within three years post intervention. The policy would produce an estimated 16,394 additional quality-adjusted life-years and save £218 m in NHS and social care costs over the lifetime of the current population. Greater benefits (e.g. a 37% higher gain in quality-adjusted life-years) were expected to accrue to individuals from the most socioeconomically deprived groups compared to the least deprived. CONCLUSIONS: This analysis suggests that there are considerable potential health and economic gains from restricting the advertisement of high fat, salt and sugar products. The population health and economic impacts of the Transport for London advertising restrictions are likely to have reduced health inequalities in London.

Estimating the impact of changes in weight and BMI on EQ-5D-3L: a longitudinal analysis of a behavioural group-based weight loss intervention.

PURPOSE: To estimate the association between changes in BMI and changes in Health-Related Quality of Life (EQ-5D-3L). METHODS: The WRAP trial was a multicentre, randomised controlled trial with parallel design and recruited 1267 adults (BMI ≥ 28 kg/m2). Participants were allocated to Brief Intervention, a Commercial weight management Programme (WW, formerly Weight Watchers) for 12 weeks, or the same Programme for 52 weeks. Participants were assessed at 0, 3, 12, 24, and 60 months. We analysed the relationship between BMI and EQ-5D-3L, adjusting for age and comorbidities, using a fixed effects model. Test for attrition, model specification and missing data were conducted. Secondary analyses investigated a non-symmetric gradient for weight loss vs. regain. RESULTS: A unit increase in BMI was associated with a - 0.011 (95% CI - 0.01546, - 0.00877) change in EQ-5D-3L. A unit change in BMI between periods of observation was associated with - 0.016 017 (95% CI - 0.0077009, - 0.025086) change in EQ-5D-3L. The negative association was reduced during weight loss, as opposed to weight gain, but the difference was not statistically significant. CONCLUSIONS: We have identified a strong and statistically significant negative relationship between BMI changes and HRQoL. These estimates could be used in economic evaluations of weight loss interventions to inform policymaking. CLINICAL TRIAL REGISTRATION: This trial was registered with Current Controlled Trials, number ISRCTN82857232.

Using health economic modelling to inform the design and development of an intervention: estimating the justifiable cost of weight loss maintenance in the UK.

BACKGROUND: There is a need to develop cost-effective weight loss maintenance interventions to prolong the positive impact of weight loss on health outcomes. Conducting pre-trial health economic modelling is recommended to inform the design and development of behavioural interventions. We aimed to use health economic modelling to estimate the maximum cost per-person (justifiable cost) of a cost-effective behavioural weight loss maintenance intervention, given an estimated intervention effect for individuals with: i) a Body Mass Index (BMI) of 28 kg/m2 or above without diabetes and ii) a diagnosis of type 2 diabetes prescribed a single non-insulin diabetes medication. METHODS: The School for Public Health Research Diabetes prevention model was used to estimate the lifetime Quality-adjusted life year (QALY) gains, healthcare costs, and maximum justifiable cost associated with a weight loss maintenance intervention. Based on a meta-analysis, the estimated effect of a weight loss maintenance intervention following a 9 kg weight loss, was a regain of 1.33 kg and 4.38 kg in years one and two respectively compared to greater regain of 2.84 kg and 5.6 kg in the control group. Sensitivity analysis was conducted around the rate of regain, duration of effect and initial weight loss. RESULTS: The justifiable cost for a weight loss maintenance intervention at an ICER of £20,000 per QALY was £104.64 for an individual with a BMI of 28 or over and £88.14 for an individual with type 2 diabetes. Within sensitivity analysis, this varied from £36.42 to £203.77 for the former, and between £29.98 and £173.05 for the latter. CONCLUSIONS: Researchers developing a weight loss maintenance intervention should consider these maximum justifiable cost estimates and the potential impact of the duration of effect and initial weight loss when designing intervention content and deciding target populations. Future research should consider using the methods demonstrated in this study to use health economic modelling to inform the design and budgetary decisions in the development of a behavioural interventions.

What are the cost-savings and health benefits of improving detection and management for six high cardiovascular risk conditions in England? An economic evaluation.

OBJECTIVES: To estimate the cost savings and health benefits of improving detection of individuals at high risk of cardiovascular disease (CVD) in England, to determine to which patient subgroups these benefits arise, and to compare different strategies for subsequent management. DESIGN: An economic analysis using the School for Public Health Research CVD Prevention Model. SETTING: England 2018. PARTICIPANTS: Adults aged 16 and older with one or more high cardiovascular risk conditions, including hypertension, diabetes, non-diabetic hyperglycaemia, atrial fibrillation, chronic kidney disease and high cholesterol. INTERVENTIONS: Detection of 100% of individuals with CVD high risk conditions compared with current levels of detection in England. Detected individuals are assumed to be managed either according to current levels of care or National Institute of Health and Care Excellence (NICE) guidelines. MAIN OUTCOME MEASURES: Incremental and cumulative costs, savings, quality adjusted life years (QALYs), CVD cases, and net monetary benefit, from a UK NHS and Personal Social Services perspective. RESULTS: £68 billion could be saved, 4.9 million QALYs gained and 3.4 million cases of CVD prevented over 25 years if all individuals in England with the six CVD high risk conditions were diagnosed and subsequently managed at current levels. Additionally, if all detected individuals were managed according to NICE guidelines, total savings would be £61 billion, 8.1 million QALYs would be gained and 5.2 million CVD cases prevented. Most benefits come from detection of high cholesterol in the short term and diabetes in the long term. CONCLUSIONS: Substantial cost savings and health benefits would accrue if all individuals with conditions that increase CVD risk could be diagnosed, with detection of undiagnosed diabetes producing greatest benefits. Ensuring all conditions are managed according to NICE guidelines would further increase health benefits. Projected cost-savings could be invested in developing acceptable and cost-effective solutions for improving detection and management.

The Impact of Including Costs and Outcomes of Dementia in a Health Economic Model to Evaluate Lifestyle Interventions to Prevent Diabetes and Cardiovascular Disease.

OBJECTIVES: Economic evaluations of lifestyle interventions, which aim to prevent diabetes/cardiovascular disease (CVD), have not included dementia. Lifestyle interventions decrease dementia risk and extend life expectancy, leading to competing effects on health care costs. We aim to demonstrate the feasibility of including dementia in a public health cost-effectiveness analysis and quantify the overall impacts accounting for these competing effects. METHODS: The School for Public Health Research (SPHR) diabetes prevention model describes individuals' risk of type 2 diabetes, microvascular outcomes, CVD, congestive heart failure, cancer, osteoarthritis, depression, and mortality in England. In version 3.1, we adapted the model to include dementia using published data from primary care databases, health surveys, and trials of dementia to describe dementia incidence, diagnosis, and disease progression. We estimate the impact of dementia on lifetime costs and quality-adjusted life years (QALYs) gained of the National Health Service diabetes prevention program (NHS DPP) from an NHS/personal social services perspective with 3 scenarios: 1) no dementia, 2) dementia only, and 3) reduced dementia risk. Subgroup, parameter, and probabilistic sensitivity analyses were conducted. RESULTS: The lifetime cost savings of the NHS DPP per patient were £145 in the no-dementia scenario, £121 in the dementia-only scenario, and £167 in the reduced dementia risk scenario. The QALY gains increased by 0.0006 in dementia only and 0.0134 in reduced dementia risk. Dementia did not alter the recommendation that the NHS/DPP is cost-effective. CONCLUSIONS: Including dementia into a model of lifestyle interventions was feasible but did not change policy recommendations or modify health economic outcomes. The impact on health economic outcomes was largest where a direct impact on dementia incidence was assumed, particularly in elderly populations.

A Systematic Review of Methods to Predict Weight Trajectories in Health Economic Models of Behavioral Weight-Management Programs: The Potential Role of Psychosocial Factors.

Objectives. There is limited evidence on the long-term effectiveness of behavioral weight-management interventions, and thus, when conducting health economic modeling, assumptions are made about weight trajectories. The aims of this review were to examine these assumptions made about weight trajectories, the evidence sources used to justify them, and the impact of assumptions on estimated cost-effectiveness. Given the evidence that some psychosocial variables are associated with weight-loss trajectories, we also aimed to examine the extent to which psychosocial variables have been used to estimate weight trajectories and whether psychosocial variables were measured within cited evidence sources. Methods. A search of databases (Medline, PubMed, Cochrane, NHS Economic Evaluation, Embase, PSYCinfo, CINAHL, EconLit) was conducted using keywords related to overweight, weight-management, and economic evaluation. Economic evaluations of weight-management interventions that included modeling beyond trial data were included. Results. Within the 38 eligible articles, 6 types of assumptions were reported (weight loss maintained, weight loss regained immediately, linear weight regain, subgroup-specific trajectories, exponential decay of effect, maintenance followed by regain). Fifteen articles cited at least 1 evidence source to support the assumption reported. The assumption used affected the assessment of cost-effectiveness in 9 of the 19 studies that tested this in sensitivity analyses. None of the articles reported using psychosocial factors to estimate weight trajectories. However, psychosocial factors were measured in evidence sources cited by 11 health economic models. Conclusions. Given the range of weight trajectories reported and the potential impact on funding decisions, further research is warranted to investigate how psychosocial variables measured in trials can be used within health economic models to simulate heterogeneous weight trajectories and potentially improve the accuracy of cost-effectiveness estimates.

Computer Modeling of Diabetes and Its Transparency: A Report on the Eighth Mount Hood Challenge.

OBJECTIVES: The Eighth Mount Hood Challenge (held in St. Gallen, Switzerland, in September 2016) evaluated the transparency of model input documentation from two published health economics studies and developed guidelines for improving transparency in the reporting of input data underlying model-based economic analyses in diabetes. METHODS: Participating modeling groups were asked to reproduce the results of two published studies using the input data described in those articles. Gaps in input data were filled with assumptions reported by the modeling groups. Goodness of fit between the results reported in the target studies and the groups' replicated outputs was evaluated using the slope of linear regression line and the coefficient of determination (R2). After a general discussion of the results, a diabetes-specific checklist for the transparency of model input was developed. RESULTS: Seven groups participated in the transparency challenge. The reporting of key model input parameters in the two studies, including the baseline characteristics of simulated patients, treatment effect and treatment intensification threshold assumptions, treatment effect evolution, prediction of complications and costs data, was inadequately transparent (and often missing altogether). Not surprisingly, goodness of fit was better for the study that reported its input data with more transparency. To improve the transparency in diabetes modeling, the Diabetes Modeling Input Checklist listing the minimal input data required for reproducibility in most diabetes modeling applications was developed. CONCLUSIONS: Transparency of diabetes model inputs is important to the reproducibility and credibility of simulation results. In the Eighth Mount Hood Challenge, the Diabetes Modeling Input Checklist was developed with the goal of improving the transparency of input data reporting and reproducibility of diabetes simulation model results.

The impact of a local sugar sweetened beverage health promotion and price increase on sales in public leisure centre facilities.

BACKGROUND: We aimed to evaluate the impact of a local sugar sweetened beverages (SSB) health promotion and 20p price increase in leisure centre venues and estimate the impact on consumption. METHOD: Monthly cold drinks sales data and attendance at leisure centres across the city of Sheffield were analysed over the period January 2015-July 2017. Interrupted time-series methods were employed to estimate changes in consumption per attendance of SSB and non-SSB cold drinks following the introduction of the SSB policy from August 2016 adjusting for seasonal variation and autocorrelation. SSB price elasticities were estimated with fixed effects log-log models by SSB product type (soda can, soda bottle, soda post mix, energy drinks, juice from concentrate). FINDINGS: We estimated a 31% (95% CI 4%, 59%) reduction in units of SSB sold per attendance in the year since the policy was introduced. We did not observe substitution effects to fruit juice or water but found sales of other artificially sweetened non-SSB products increased by 27% (95% CI 6%, 47%) after the introduction of the tax. Price elasticity analysis identified that a 1% increase in price alongside health promotion leads to a 3.8% (95% CI 3.1% 4.4%) decrease in demand for SSB's. Price elasticity of demand was highest for child friendly and high caffeine energy drinks. INTERPRETATION: Demand for SSB drinks at leisure centre venues is highly responsive to the policy, particularly for child-friendly and high caffeine energy drinks, compared with other SSB tax policy evaluations. The policy also increased purchases of carbonated non-SSB.

Assessing the potential return on investment of the proposed UK NHS diabetes prevention programme in different population subgroups: an economic evaluation.

OBJECTIVES: To evaluate potential return on investment of the National Health Service Diabetes Prevention Programme (NHS DPP) in England and estimate which population subgroups are likely to benefit most in terms of cost-effectiveness, cost-savings and health benefits. DESIGN: Economic analysis using the School for Public Health Research Diabetes Prevention Model. SETTING: England 2015-2016. POPULATION: Adults aged ≥16 with high risk of type 2 diabetes (HbA1c 6%-6.4%). Population subgroups defined by age, sex, ethnicity, socioeconomic deprivation, baseline body mass index, baseline HbA1c and working status. INTERVENTIONS: The proposed NHS DPP: an intensive lifestyle intervention focusing on dietary advice, physical activity and weight loss. Comparator: no diabetes prevention intervention. MAIN OUTCOME MEASURES: Incremental costs, savings and return on investment, quality-adjusted life-years (QALYs), diabetes cases, cardiovascular cases and net monetary benefit from an NHS perspective. RESULTS: Intervention costs will be recouped through NHS savings within 12 years, with net NHS saving of £1.28 over 20 years for each £1 invested. Per 100 000 DPP interventions given, 3552 QALYs are gained. The DPP is most cost-effective and cost-saving in obese individuals, those with baseline HbA1c 6.2%-6.4% and those aged 40-74. QALY gains are lower in minority ethnic and low socioeconomic status subgroups. Probabilistic sensitivity analysis suggests that there is 97% probability that the DPP will be cost-effective within 20 years. NHS savings are highly sensitive to intervention cost, effectiveness and duration of effect. CONCLUSIONS: The DPP is likely to be cost-effective and cost-saving under current assumptions. Prioritising obese individuals could create the most value for money and obtain the greatest health benefits per individual targeted. Low socioeconomic status or ethnic minority groups may gain fewer QALYs per intervention, so targeting strategies should ensure the DPP does not contribute to widening health inequalities. Further evidence is needed around the differential responsiveness of population subgroups to the DPP.

Sipuleucel-T for the Treatment of Metastatic Hormone-Relapsed Prostate Cancer: A NICE Single Technology Appraisal; An Evidence Review Group Perspective.

The National Institute for Health and Care Excellence (NICE) invited Dendreon, the company manufacturing sipuleucel-T, to submit evidence for the clinical and cost effectiveness of sipuleucel-T for asymptomatic or minimally symptomatic, metastatic, non-visceral hormone-relapsed prostate cancer patients in whom chemotherapy is not yet clinically indicated, as part of NICE's single technology appraisal process. The comparator was abiraterone acetate (AA) or best supportive care (BSC). The School of Health and Related Research at the University of Sheffield was commissioned to act as the Evidence Review Group (ERG). This paper describes the company submission (CS), ERG review, and subsequent decision of the NICE Appraisal Committee (AC). The ERG produced a critical review of the clinical and cost-effectiveness evidence of sipuleucel-T based upon the CS. Clinical-effectiveness data relevant to the decision problem were taken from three randomised controlled trials (RCTs) of sipuleucel-T and a placebo (PBO) comparator of antigen-presenting cells (APC) being re-infused (APC-PBO) (D9901, D9902A and D9902B), and one RCT (COU-AA-302) of AA plus prednisone vs. PBO plus prednisone. Two trials reported a significant advantage for sipuleucel-T in median overall survival compared with APC-PBO: for trial D9901, an adjusted hazard ratio (HR) 0.47; (95 % confidence interval [CI] 0.29, 0.76) p < 0.002; for D9902B, adjusted HR 0.78 (95 % CI 0.61, 0.98) p = 0.03. There was no significant difference between groups in D9902A, unadjusted HR 0.79 (95 % CI 0.48, 1.28) p = 0.331. Sipuleucel-T and APC-PBO groups did not differ significantly in time to disease progression, in any of the three RCTs. Most adverse events developed within 1 day of the infusion, and resolved within 2 days. The CS included an indirect comparison of sipuleucel-T (D9902B) and AA plus prednisone (COU-AA-302). As trials differed in prior use of chemotherapy, an analysis of only chemotherapy-naïve patients was included, in which the overall survival for sipuleucel-T and AA was not significantly different, HR 0.94 (95 % CI 0.69, 1.28) p = 0.699. The ERG had several concerns regarding the data and assumptions incorporated within the company's cost-effectiveness analyses and conducted exploratory analyses to quantify the impact of making alternative assumptions or using alternative data inputs. The deterministic incremental cost-effectiveness ratio (ICER) for sipuleucel-T vs. BSC when using the ERG's preferred data and assumptions was £ 108,585 per quality-adjusted life-year (QALY) in the whole licensed population and £ 61,204/QALY in the subgroup with low prostate-specific antigen at baseline. The ERG also conducted an incremental analysis comparing sipuleucel-T with both AA and BSC in the chemotherapy-naïve subgroup. Sipuleucel-T had a deterministic ICER of £ 111,682/QALY in this subgroup, when using the ERG's preferred assumptions, and AA was extendedly dominated. The ERG also concluded that estimates of costs and benefits for AA should be interpreted with caution given the limitations of the indirect comparison. The AC noted that the ICER for sipuleucel-T was well above the range usually considered cost effective, and did not recommend sipuleucel-T for the treatment of asymptomatic or minimally symptomatic, metastatic, non-visceral hormone-relapsed prostate cancer.

Estimating the Expected Value of Sample Information Using the Probabilistic Sensitivity Analysis Sample: A Fast, Nonparametric Regression-Based Method.

Health economic decision-analytic models are used to estimate the expected net benefits of competing decision options. The true values of the input parameters of such models are rarely known with certainty, and it is often useful to quantify the value to the decision maker of reducing uncertainty through collecting new data. In the context of a particular decision problem, the value of a proposed research design can be quantified by its expected value of sample information (EVSI). EVSI is commonly estimated via a 2-level Monte Carlo procedure in which plausible data sets are generated in an outer loop, and then, conditional on these, the parameters of the decision model are updated via Bayes rule and sampled in an inner loop. At each iteration of the inner loop, the decision model is evaluated. This is computationally demanding and may be difficult if the posterior distribution of the model parameters conditional on sampled data is hard to sample from. We describe a fast nonparametric regression-based method for estimating per-patient EVSI that requires only the probabilistic sensitivity analysis sample (i.e., the set of samples drawn from the joint distribution of the parameters and the corresponding net benefits). The method avoids the need to sample from the posterior distributions of the parameters and avoids the need to rerun the model. The only requirement is that sample data sets can be generated. The method is applicable with a model of any complexity and with any specification of model parameter distribution. We demonstrate in a case study the superior efficiency of the regression method over the 2-level Monte Carlo method.

Valuing Trial Designs from a Pharmaceutical Perspective Using Value-Based Pricing.

Our aim was to adapt the traditional framework for expected net benefit of sampling (ENBS) to be more compatible with drug development trials from the pharmaceutical perspective. We modify the traditional framework for conducting ENBS and assume that the price of the drug is conditional on the trial outcomes. We use a value-based pricing (VBP) criterion to determine price conditional on trial data using Bayesian updating of cost-effectiveness (CE) model parameters. We assume that there is a threshold price below which the company would not market the new intervention. We present a case study in which a phase III trial sample size and trial duration are varied. For each trial design, we sampled 10,000 trial outcomes and estimated VBP using a CE model. The expected commercial net benefit is calculated as the expected profits minus the trial costs. A clinical trial with shorter follow-up, and larger sample size, generated the greatest expected commercial net benefit. Increasing the duration of follow-up had a modest impact on profit forecasts. Expected net benefit of sampling can be adapted to value clinical trials in the pharmaceutical industry to optimise the expected commercial net benefit. However, the analyses can be very time consuming for complex CE models.