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Conference proceeding

Estimating the Health Economic Benefits of Physical Activity for People with Limited Mobility in the UK

YHEC authors: Matthew Taylor
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: The level of an individual's physical activity has a clear and strong association with physical and mental health status. Those with sedentary lifestyles or with low levels of physical activity are at a higher risk of many conditions including coronary heart disease, stroke, cancer and depression. We aimed to estimate the health economic impact associated with different levels of increases in physical activity for people with limited mobility.

METHODS: We used national health survey data to estimate the current level of physical activity in people with limited mobility (n=1113), and how these levels changed after an intervention was introduced. Limited mobility was defined as having either 'Some problems in walking about' or 'Confined to bed' on the mobility component of the EQ-5D questionnaire. The level of physical activity was measured using metabolic equivalent time (MET) minutes, a measure that combines the time spent exercising with the level of vigour involved. We used information from published studies to estimate the risk of developing five health conditions (breast and colon cancer, diabetes, stroke and coronary heart disease), depending on MET level. Costs, utilities and mortality rates were assigned to each of these conditions, to estimate the lifetime costs and quality-adjusted life years for a range of scenarios.

RESULTS: Interventions that cost £25, £100 and £250 per person would need to increase physical activity by approximately 4, 16 and 41 MET minutes per week respectively to be deemed cost effective. Sensitivity analysis showed that changes to cost, utility and mortality input parameters had minimal impact on these results.

CONCLUSIONS: Even small increases in physical activity can generate substantial health gains in a population with limited mobility. Whilst the benefits need to be weighed against the implementation costs, it is likely that most public health strategies to facilitate activity in this population will be cost effective.

Conference proceeding

Evaluating the Impact of Implementing Nitrous Oxide Destruction Technology in NHS Labour Wards

YHEC authors: Barbara Uzdzinska, Will Green, Amy Dymond, Daniela Afonso, Melissa Pegg
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: The UK NHS is committed to achieving net zero direct carbon emissions by 2040. Nitrous oxide (N2O) is a greenhouse gas used for pain relief during contractions in labor. Destruction technology (DT) can help the NHS achieve its target by breaking N2O down into nitrogen and oxygen. This study evaluated the impact of introducing N2O DT in labou=r wards on NHS emissions and costs.

METHODS: A cost-consequence model was developed to estimate the per delivery incremental cost, and NHS cost impact, of implementing DT. A pragmatic literature search was conducted to identify all model inputs. N2O emissions were monetized by converting into CO2 equivalents (CO2e) and using the 2022 marginal abatement CO2e costs. Scenario analysis explored the impact with varying rates of N2O use and one-way deterministic sensitivity analysis was used to identify the main drivers of results.

RESULTS: N2O DT is estimated to be cost saving to the NHS when valuing emissions monetarily. Per-delivery savings vary from £14.09 to £135.20 for emergency caesarean section labors (which use less N2O) and labors using N2O for every contraction, respectively. The per-delivery cost of mobile DT units is £5.57, and £10.10 for central units. It would cost the NHS £22,512,210 and £40,765,953 to purchase and maintain mobile and central DT units, respectively, for all UK consultant-led labor wards. Sensitivity analysis shows the amount of N2O used, the carbon value, and the effectiveness of DT impact results most, though DT remains cost saving in all scenarios.

CONCLUSIONS: The reduction in emissions offsets the cost increase of DT when these emissions are monetized. This raises the wider question of whether the environmental impact of technologies should be formally quantified in cost-effectiveness analyses because it may be a key driver of the conclusions. This study also adds to evidence from European studies to support DT implementation.

Conference proceeding

Evaluating the Impact of Matching-Adjusted Indirect Comparisons on Propagated Uncertainty on Economic Outcomes

YHEC authors: Tom Bromilow, Neil Hansell, Karin Butler, Heather Riley
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: Single-arm trials (SATs) are becoming more common in an era of precision medicines. SATs typically lack trial randomization due to small sample sizes and limited statistical power, but health technology assessment bodies like The National Institute for Health and Care Excellence (NICE) require comparative effectiveness estimates for reimbursement decision making. Matching-adjusted indirect comparisons (MAICs) are one statistical method used to indirectly compare single-arm evidence to relevant comparators. This research aims to quantify the impact of MAIC parameter inclusion and sample size on propagated economic model uncertainty.

METHODS: We used a NICE technology appraisal (TA781) and supporting publications to create a simulated individual participant data (SIPD) set, conduct MAICs using the published comparator data, calculate parametric survival analysis and populate a partitioned-survival model. Two cuts of the SIPD were selected, the 'full' sample size (n=174) and an arbitrarily selected smaller subset ('small', n=30). For both cuts, MAICs were conducted using all variables (ALL) and high priority variables (HP) only.

RESULTS: For the full [small] samples, the effective sample size (ESS) reduced by 40% [46%] (ALL) and 25% [18%] (HP). The full sample MAICs displayed similar levels of uncertainty in the probabilistic economic model. The HP small sample MAIC displayed more uncertainty than both full sample MAICs. The small sample ALL MAIC displayed the most uncertainty, with probabilistic iterations spread across all four quadrants of the cost-effectiveness plane.

CONCLUSIONS: Where uncertainty is driven by low ESS, we recommend consideration of whether a MAIC is truly informative. If a MAIC is deemed necessary, we recommend preserving ESS by only including HP variables whilst transparently outlining the impact this could have on the MAIC quality and supplementing with analyses, such as naïve comparison and qualitative discussion. We suggest these analyses are presented to decision makers so the original shape of iterations is known.

Conference proceeding

Generalised Gamma in Economic Models: A Persistent Issue with Regression Analysis and the Proposed Solution

YHEC authors: Sam Harper, Harriet Fewster, Neil Hansell, Karin Butler
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: Generalised gamma (GG) is one of six probability distributions recommended by the National Institute for Health and Care Excellence (NICE) Decision Support Unit (DSU) for survival analysis. A persistent issue was investigated, where some survival models fitted using the GG distribution would produce deterministic results that functioned appropriately, however, the mean survival would be overestimated in the probabilistic sensitivity analysis (PSA). The objective of this analysis was to identify the cause of this overestimation.

METHODS: The reconstructed individual participant data (IPD) were used to provide example survival analysis inputs. The GG parametric survival models were fitted using the R package 'flexsurv'. Extrapolation and PSA were performed in both Microsoft Excel and R to control for any differences between the two.

RESULTS: The formulae used in Excel and R for extrapolation were found to be identical. The cause of the overestimation was identified as PSA samples where extrapolated survival was constant at 100% due to high parameter variance and covariance (particularly of the shape parameter 'Q') in the GG model. This is statistically and clinically implausible. The potential for survival overestimation in the PSA is not observable unless the survival analysis coefficients are applied probabilistically. The erroneous PSA samples only occurred when the GG distribution was used. This issue was observed in both Excel and R, and in raw and reconstructed IPD.

CONCLUSIONS: When reporting a GG model, it is recommended to check for: high variance and covariance in the survival model parameters; PSA samples with 100% survival; incongruence between mean survival in the PSA and deterministic estimates. If these elements are present, the GG model is inappropriate due to the inadvertent inclusion of statistically and clinically implausible survival probabilities in the PSA and the high levels of overall uncertainty this represents.

Conference proceeding

Home Sweet Hospital: Evaluating Evidence Gaps and Future Research Priorities for Hospital at Home

YHEC authors: Charlotte Graham, Robert Malcolm, Lavinia Ferrante di Ruffano, Hayden Holmes, Rachael MacDonald, Nick Hex, Rachael McCool
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: Healthcare systems face significant strain due to growing demand, with urgent and emergency care centers particularly affected. 'Hospital at Home' (HaH) has been identified as a potential solution, allowing patients to receive acute care at home or in community settings. HaH facilitates early hospital discharge (step-down care) or prevents hospital admission (step-up care). This research examines the challenges in generating evidence for technology-enabled HaH initiatives and highlights factors for future evaluation.

METHODS: A pragmatic literature review was conducted to assess safety, clinical effectiveness, and cost effectiveness of HaH initiatives. Gap analysis identified priority areas for future research and issues in evidence generation. The authors leveraged their experience from an early value assessment for NICE on virtual wards for acute respiratory infection to inform the review and gap analysis.

RESULTS: Evidence, though limited, suggests HaH is potentially safe and effective. Clinical effectiveness varies by patient cohort and virtual ward model (step-up, step-down, mixed). Most studies were non-comparative or underpowered. Case studies of HaH initiatives in the NHS lacked peer review, involved small samples, and were not transparent about costs. Key issues in evaluation include variability in features between technology-enabled HaH initiatives, population and subgroup differences, and potential distortions in comparison with standard care. Future research should focus on prospective cohort studies to understand clinical and resource outcomes, impacts of different technological features, and true resource use.

CONCLUSIONS: Technology-enabled HaH initiatives are complex interventions. Preliminary evidence suggests that they may benefit healthcare system resources, but comprehensive evaluations are crucial to understand their clinical efficacy, safety, risks and costs. Comprehensive evaluations are vital as HaH initiatives are rapidly implemented across global healthcare systems. Future studies should determine the effectiveness of HaH initiatives across different clinical areas, identify effective features, and be used to determine the optimal implementation and management of HaH in different settings.

Conference proceeding

Inequity in Vaccine Access: Variation in Vaccine Decision-Making Processes Across Five Countries

YHEC authors: Emily Gregg, Charlotte Graham, Karina Watts, Karin Butler, Stuart Mealing
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: Quick and equitable vaccine access is a global priority. However, the vaccine assessment is complex, meaning there is variation in vaccine schedules between countries and limited opportunities to develop a centralized framework. This heterogeneity further contributes to inequity of vaccine access. This work aims to increase awareness of the key vaccine assessment elements in EU and non-EU countries.

METHODS: Pragmatic desk-based research was conducted in June 2024 to explore the key stages involved in vaccine market access and how these differ across England, Italy, Germany, France and the United States (US). Where available, data were extracted about the stakeholders involved in vaccine appraisal, the key assessment factors and value framework considered, and the number and type of vaccines included in the national vaccination schedule.

RESULTS: National Immunization Technical Advisory Groups (NITAGs) are key stakeholders in all five countries but play different roles. In some countries the NITAG is solely responsible for vaccine appraisal (England, Germany, US), but in other countries the vaccine appraisal is conducted by the health technology assessment (HTA) body (Italy) or both the NITAG and HTA body in parallel (France). There are key differences in the vaccine assessment by NITAGs and HTA bodies. For example, NITAGs consider public health impact, which is not considered by HTA bodies. There are also differences in the value framework between NITAGs in different countries. For example, only England's NITAG formally considers the disease impact on quality of life of carers. Consequently, the key vaccine assessment factors differ between countries, resulting in a different number of vaccines in each country's vaccination schedule.

CONCLUSIONS: Several between-country differences in vaccine market access are identified; for example, the role of NITAGs, vaccine assessment factors, and value frameworks. Vaccine developers should consider these results when planning market access strategies to ensure rapid and equitable vaccine access across countries.

Conference proceeding

Inferiority Complex: Challenges in Clinical Equivalence and Non-Inferiority Trials in Health Technology Assessment

YHEC authors: Matthew Taylor, Joe Goldbacher, Charlotte Graham
Publication date: November 2024
Conference: ISPOR EU, Barcelona
Type of conference proceeding: Poster

Abstract

OBJECTIVES: Non-inferiority and clinical equivalence clinical trials can be used to determine whether a health technology is, at least, no worse than an existing treatment. There is a large body of literature and guidance on this topic, with substantial variation in definitions and practice, which can make it challenging to robustly demonstrate or assess claims of non-inferiority or clinical equivalence. This study aimed to provide actionable recommendations in the appraisal of claims of non-inferiority and clinical equivalence.

METHODS: International guidelines and published literature were reviewed to identify approaches for the conduct and reporting of non-inferiority or clinical equivalence studies. Guidelines from health technology assessment (HTA) and regulatory bodies were considered, and literature reviews from 2010 to 2023 were identified. The results of the reviews were supplemented with findings from an expert panel and synthesized to form a series of recommendations, using case studies from the National Institute for Health and Care Excellence (NICE).

RESULTS: The majority of guidelines (13/14) discussed, to varying extents, methods to determine the non-inferiority margin and how the analysis should be conducted. Despite this, the rationale for the margin was not reported in over 50% of 273 blinded randomized controlled trials between 1966 and 2015. Evidence of non-inferiority or clinical equivalence presented in NICE Medical Technology Evaluation Program appraisals (for health technologies) is often of lower quality than in Technology Appraisal appraisals (for pharmaceuticals), increasingly concluding that further evidence generation is required.

CONCLUSIONS: Despite clear guidance, the quality of reporting in non-inferiority and clinical equivalence trials is consistently poor. Prior to presentation of trial evidence, HTA submissions that claim non-inferiority or equivalence should present the technical, biological and/or pharmacokinetic reasonings that support the claim. HTA bodies should introduce more precise definitions of non-inferiority and clinical equivalence so that evidence standards are more likely to be met.

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