Cefiderocol for treating severe aerobic Gram-negative bacterial infections: technology evaluation to inform a novel subscription-style payment model.

Background: To limit the use of antimicrobials without disincentivising the development of novel antimicrobials, there is interest in establishing innovative models that fund antimicrobials based on an evaluation of their value as opposed to the volumes used. The aim of this project was to evaluate the population-level health benefit of cefiderocol in the NHS in England, for the treatment of severe aerobic Gram-negative bacterial infections when used within its licensed indications. The results were used to inform the National Institute for Health and Care Excellence guidance in support of commercial discussions regarding contract value between the manufacturer and NHS England. Methods: The health benefit of cefiderocol was first derived for a series of high-value clinical scenarios. These represented uses that were expected to have a significant impact on patients' mortality risks and health-related quality of life. The clinical effectiveness of cefiderocol relative to its comparators was estimated by synthesising evidence on susceptibility of the pathogens of interest to the antimicrobials in a network meta-analysis. Patient-level costs and health outcomes of cefiderocol under various usage scenarios compared with alternative management strategies were quantified using decision modelling. Results were reported as incremental net health effects expressed in quality-adjusted life-years, which were scaled to 20-year population values using infection number forecasts based on data from Public Health England. The outcomes estimated for the high-value clinical scenarios were extrapolated to other expected uses for cefiderocol. Results: Among Enterobacterales isolates with the metallo-beta-lactamase resistance mechanism, the base-case network meta-analysis found that cefiderocol was associated with a lower susceptibility relative to colistin (odds ratio 0.32, 95% credible intervals 0.04 to 2.47), but the result was not statistically significant. The other treatments were also associated with lower susceptibility than colistin, but the results were not statistically significant. In the metallo-beta-lactamase Pseudomonas aeruginosa base-case network meta-analysis, cefiderocol was associated with a lower susceptibility relative to colistin (odds ratio 0.44, 95% credible intervals 0.03 to 3.94), but the result was not statistically significant. The other treatments were associated with no susceptibility. In the base case, patient-level benefit of cefiderocol was between 0.02 and 0.15 quality-adjusted life-years, depending on the site of infection, the pathogen and the usage scenario. There was a high degree of uncertainty surrounding the benefits of cefiderocol across all subgroups. There was substantial uncertainty in the number of infections that are suitable for treatment with cefiderocol, so population-level results are presented for a range of scenarios for the current infection numbers, the expected increases in infections over time and rates of emergence of resistance. The population-level benefits varied substantially across the base-case scenarios, from 896 to 3559 quality-adjusted life-years over 20 years. Conclusion: This work has provided quantitative estimates of the value of cefiderocol within its areas of expected usage within the NHS. Limitations: Given existing evidence, the estimates of the value of cefiderocol are highly uncertain. Future work: Future evaluations of antimicrobials would benefit from improvements to NHS data linkages; research to support appropriate synthesis of susceptibility studies; and application of routine data and decision modelling to assess enablement value. Study registration: No registration of this study was undertaken. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment Policy Research Programme (NIHR award ref: NIHR135591), conducted through the Policy Research Unit in Economic Methods of Evaluation in Health and Social Care Interventions, PR-PRU-1217-20401, and is published in full in Health Technology Assessment; Vol. 28, No. 28. See the NIHR Funding and Awards website for further award information.

This project tested new methods for estimating the value to the NHS of an antimicrobial, cefiderocol, so its manufacturer could be paid fairly even if very little drug is used in order to reduce the risk of bacteria becoming resistant to the product. Clinicians said that the greatest benefit of cefiderocol is when used for complicated urinary tract infections and pneumonia acquired within hospitals caused by two types of bacteria (called Enterobacterales and Pseudomonas aeruginosa), with a resistance mechanism called metallo-beta-lactamase. Because there were no relevant clinical trial data, we estimated how effective cefiderocol and alternative treatments were by doing a systematic literature review of studies that grew bacteria from infections in the laboratory and tested the drugs on them. We linked this to data estimating the long-term health and survival of patients. Some evidence was obtained by asking clinicians detailed questions about what they thought the effects would be based on their experience and the available evidence. We included the side effects of the alternative treatments, some of which can cause kidney damage. We estimated how many infections there would be in the UK, whether they would increase over time and how resistance to treatments may change over time. Clinicians told us that they would also use cefiderocol to treat intra-abdominal and bloodstream infections, and some infections caused by another bacteria called Stenotrophomonas. We estimated how many of these infections there would be, and assumed the same health benefits as for other types of infections. The total value to the NHS was calculated using these estimates. We also considered whether we had missed any additional elements of value. We estimated that the value to the NHS was £18­71 million over 20 years. This reflects the maximum the NHS could pay for use of cefiderocol if the health lost as a result of making these payments rather than funding other NHS services is not to exceed the health benefits of using this antimicrobial. However, these estimates are uncertain due to limitations with the evidence used to produce them and assumptions that had to be made.

Anti-Vascular Endothelial Growth Factor Drugs Compared With Panretinal Photocoagulation for the Treatment of Proliferative Diabetic Retinopathy: A Cost-Effectiveness Analysis.

OBJECTIVES: This study aimed to evaluate the cost-effectiveness of anti-vascular endothelial growth factor drugs (anti-VEGFs) compared with panretinal photocoagulation (PRP) for treating proliferative diabetic retinopathy (PDR) in the United Kingdom. METHODS: A discrete event simulation model was developed, informed by individual participant data meta-analysis. The model captures treatment effects on best corrected visual acuity in both eyes, and the occurrence of diabetic macular edema and vitreous hemorrhage. The model also estimates the value of undertaking further research to resolve decision uncertainty. RESULTS: Anti-VEGFs are unlikely to generate clinically meaningful benefits over PRP. The model predicted anti-VEGFs be more costly and similarly effective as PRP, generating 0.029 fewer quality-adjusted life-years at an additional cost of £3688, with a net health benefit of -0.214 at a £20 000 willingness-to-pay threshold. Scenario analysis results suggest that only under very select conditions may anti-VEGFs offer potential for cost-effective treatment of PDR. The consequences of loss to follow-up were an important driver of model outcomes. CONCLUSIONS: Anti-VEGFs are unlikely to be a cost-effective treatment for early PDR compared with PRP. Anti-VEGFs are generally associated with higher costs and similar health outcomes across various scenarios. Although anti-VEGFs were associated with lower diabetic macular edema rates, the number of cases avoided is insufficient to offset the additional treatment costs. Key uncertainties relate to the long-term comparative effectiveness of anti-VEGFs, particularly considering the real-world rates and consequences of treatment nonadherence. Further research on long-term visual acuity and rates of vision-threatening complications may be beneficial in resolving uncertainties.

Priorities for research to support local authority action on health and climate change: a study in England.

BACKGROUND: Evidence is needed to support local action to reduce the adverse health impacts of climate change and maximise the health co-benefits of climate action. Focused on England, the study identifies priority areas for research to inform local decision making. METHODS: Firstly, potential priority areas for research were identified from a brief review of UK policy documents, and feedback invited from public and policy stakeholders. This included a survey of Directors of Public Health (DsPH) in England, the local government officers responsible for public health. Secondly, rapid reviews of research evidence examined whether there was UK evidence relating to the priorities identified in the survey. RESULTS: The brief policy review pointed to the importance of evidence in two broad areas: (i) community engagement in local level action on the health impacts of climate change and (ii) the economic (cost) implications of such action. The DsPH survey (n = 57) confirmed these priorities. With respect to community engagement, public understanding of climate change's health impacts and the public acceptability of local climate actions were identified as key evidence gaps. With respect to economic implications, the gaps related to evidence on the health and non-health-related costs and benefits of climate action and the short, medium and longer-term budgetary implications of such action, particularly with respect to investments in the built environment. Across both areas, the need for evidence relating to impacts across income groups was highlighted, a point also emphasised by the public involvement panel. The rapid reviews confirmed these evidence gaps (relating to public understanding, public acceptability, economic evaluation and social inequalities). In addition, public and policy stakeholders pointed to other barriers to action, including financial pressures, noting that better evidence is insufficient to enable effective local action. CONCLUSIONS: There is limited evidence to inform health-centred local action on climate change. More evidence is required on public perspectives on, and the economic dimensions of, local climate action. Investment in locally focused research is urgently needed if local governments are to develop and implement evidence-based policies to protect public health from climate change and maximise the health co-benefits of local action.

Reflecting Parameter Uncertainty in Addition to Variability in Constrained Healthcare Resource Discrete Event Simulations: Worth Going the Extra Mile or a Road to Nowhere?

OBJECTIVES: Probabilistic sensitivity analysis (PSA) has been shown to reduce bias in outcomes of health economic models. However, only 1 existing study has been identified that incorporates PSA within a resource-constrained discrete event simulation (DES) model. This article aims to assess whether it is feasible and appropriate to use PSA to characterize parameter uncertainty in DES models that are primarily constructed to explore the impact of constrained resources. METHODS: PSA is incorporated into a new case study of an Emergency Department DES. Structured expert elicitation is used to derive the variability and uncertainty input distributions associated with length of time taken to complete key activities within the Emergency Department. Potential challenges of implementation and analysis are explored. RESULTS: The results of a trial of the model, which used the best estimates of the elicited means and variability around the time taken to complete activities, provided a reasonable fit to the data for length of time within the Emergency Department. However, there was substantial and skewed uncertainty around the activity times estimated from the elicitation exercise. This led to patients taking almost 3 weeks to leave the Emergency Department in some PSA runs, which would not occur in practice. CONCLUSIONS: Structured expert elicitation can be used to derive plausible estimates of activity times and their variability, but experts' uncertainty can be substantial. For parameters that have an impact on interactions within a resource-constrained simulation model, PSA can lead to implausible model outputs; hence, other methods may be needed.

Study Protocol. Evaluating the life-course health impact of a city-wide system approach to improve air quality in Bradford, UK: A quasi-experimental study with implementation and process evaluation.

BACKGROUND: Air quality is a major public health threat linked to poor birth outcomes, respiratory and cardiovascular disease, and premature mortality. Deprived groups and children are disproportionately affected. Bradford will implement a Clean Air Zone (CAZ) as part of the Bradford Clean Air Plan (B-CAP) in 2022 to reduce pollution, providing a natural experiment. The aim of the current study is to evaluate the impact of the B-CAP on health outcomes and air quality, inequalities and explore value for money. An embedded process and implementation evaluation will also explore barriers and facilitators to implementation, impact on attitudes and behaviours, and any adverse consequences. METHODS: The study is split into 4 work packages (WP). WP1A: 20 interviews with decision makers, 20 interviews with key stakeholders; 10 public focus groups and documentary analysis of key reports will assess implementation barriers, acceptability and adverse or unanticipated consequences at 1 year post-implementation (defined as point at which charging CAZ goes 'live'). WP1B: A population survey (n = 2000) will assess travel behaviour and attitudes at baseline and change at 1 year post-implementation). WP2: Routine air quality measurements will be supplemented with data from mobile pollution sensors in 12 schools collected by N = 240 pupil citizen scientists (4 within, 4 bordering and 4 distal to CAZ boundary). Pupils will carry sensors over four monitoring periods over a 12 month period (two pre, and two post-implementation). We will explore whether reductions in pollution vary by CAZ proximity. WP3A: We will conduct a quasi-experimental interrupted time series analysis using a longitudinal routine health dataset of > 530,000 Bradford residents comparing trends (3 years prior vs 3 years post) in respiratory health (assessed via emergency/GP attendances. WP3B: We will use the richly-characterised Born in Bradford cohort (13,500 children) to explore health inequalities in respiratory health using detailed socio-economic data. WP4: will entail a multi-sectoral health economic evaluation to determine value for money of the B-CAP. DISCUSSION: This will be first comprehensive quasi-experimental evaluation of a city-wide policy intervention to improve air quality. The findings will be of value for other areas implementing this type of approach. TRIAL REGISTRATION: ISRCTN67530835 https://doi.org/10.1186/ISRCTN67530835.

Eliciting uncertainty for complex parameters in model-based economic evaluations: quantifying a temporal change in the treatment effect.

BACKGROUND: In model-based economic evaluations, the effectiveness parameter is often informed by studies with a limited duration of follow-up, requiring extrapolation of the treatment effect over a longer time horizon. Extrapolation from short-term data alone may not adequately capture uncertainty in that extrapolation. This study aimed to use structured expert elicitation to quantify uncertainty associated with extrapolation of the treatment effect observed in a clinical trial. METHODS: A structured expert elicitation exercise was conducted for an applied study of a podiatry intervention designed to reduce the rate of falls and fractures in the elderly. A bespoke web application was used to elicit experts' beliefs about two outcomes (rate of falls and odds of fracture) as probability distributions (priors), for two treatment options (intervention and treatment as usual) at multiple time points. These priors were used to derive the temporal change in the treatment effect of the intervention, to extrapolate outcomes observed in a trial. The results were compared with extrapolation without experts' priors. RESULTS: The study recruited thirty-eight experts (geriatricians, general practitioners, physiotherapists, nurses, and academics) from England and Wales. The majority of experts (32/38) believed that the treatment effect would depreciate over time and expressed greater uncertainty than that extrapolated from a trial-based outcome alone. The between-expert variation in predicted outcomes was relatively small. CONCLUSIONS: This study suggests that uncertainty in extrapolation can be informed using structured expert elicitation methods. Using structured elicitation to attach values to complex parameters requires key assumptions and simplifications to be considered.

Does providing everyone with free-of-charge organised exercise opportunities work in public health?

BACKGROUND AND PURPOSE: Population-level initiatives of free-of-charge organised exercise have been implemented to encourage residents to take up regular physical activity. However, there exists a paucity of evidence on the ability of these interventions to attract and engage residents, especially targeted subgroups. Seeking to contribute to this evidence base, we evaluated a proportionate universal programme providing free exercise sessions, Leeds Let's Get Active. METHODS: Descriptive statistics were used to summarise the programme data and participants. Time to event, count and logistic regression models examined how different population subgroups engaged with the programme in terms of number of entries, weekly participation rates and drop-off patterns. RESULTS: 51,874 adult residents registered to the programme and provided baseline data (2013-2016). A small proportion (1.6%) attended the free sessions on a weekly basis. Higher participation rates were estimated for the groups of males, retired and non-inactive participants. A neighbourhood-level deprivation status was found to have no marginal effect on the level and frequency of participation, but to be negatively associated with participation drop-off (HR 0.93, 95% CI 0.89-0.97, p = 0.001). CONCLUSIONS: Providing everyone with free-of-charge organised exercise opportunities in public leisure centres located in deprived areas can attract large volumes of residents, but may not sufficiently encourage adults, especially inactive residents and those living in disadvantaged neighbourhoods, to take up regular exercise.

Digital interventions in mental health: evidence syntheses and economic modelling.

BACKGROUND: Economic evaluations provide evidence on whether or not digital interventions offer value for money, based on their costs and outcomes relative to the costs and outcomes of alternatives. OBJECTIVES: (1) Evaluate and summarise published economic studies about digital interventions across different technologies, therapies, comparators and mental health conditions; (2) synthesise clinical evidence about digital interventions for an exemplar mental health condition; (3) construct an economic model for the same exemplar mental health condition using the previously synthesised clinical evidence; and (4) consult with stakeholders about how they understand and assess the value of digital interventions. METHODS: We completed four work packages: (1) a systematic review and quality assessment of economic studies about digital interventions; (2) a systematic review and network meta-analysis of randomised controlled trials on digital interventions for generalised anxiety disorder; (3) an economic model and value-of-information analysis on digital interventions for generalised anxiety disorder; and (4) a series of knowledge exchange face-to-face and digital seminars with stakeholders. RESULTS: In work package 1, we reviewed 76 economic evaluations: 11 economic models and 65 within-trial analyses. Although the results of the studies are not directly comparable because they used different methods, the overall picture suggests that digital interventions are likely to be cost-effective, compared with no intervention and non-therapeutic controls, whereas the value of digital interventions compared with face-to-face therapy or printed manuals is unclear. In work package 2, we carried out two network meta-analyses of 20 randomised controlled trials of digital interventions for generalised anxiety disorder with a total of 2350 participants. The results were used to inform our economic model, but when considered on their own they were inconclusive because of the very wide confidence intervals. In work package 3, our decision-analytic model found that digital interventions for generalised anxiety disorder were associated with lower net monetary benefit than medication and face-to-face therapy, but greater net monetary benefit than non-therapeutic controls and no intervention. Value for money was driven by clinical outcomes rather than by intervention costs, and a value-of-information analysis suggested that uncertainty in the treatment effect had the greatest value (£12.9B). In work package 4, stakeholders identified several areas of benefits and costs of digital interventions that are important to them, including safety, sustainability and reducing waiting times. Four factors may influence their decisions to use digital interventions, other than costs and outcomes: increasing patient choice, reaching underserved populations, enabling continuous care and accepting the 'inevitability of going digital'. LIMITATIONS: There was substantial uncertainty around effect estimates of digital interventions compared with alternatives. This uncertainty was driven by the small number of studies informing most comparisons, the small samples in some of these studies and the studies' high risk of bias. CONCLUSIONS: Digital interventions may offer good value for money as an alternative to 'doing nothing' or 'doing something non-therapeutic' (e.g. monitoring or having a general discussion), but their added value compared with medication, face-to-face therapy and printed manuals is uncertain. Clinical outcomes rather than intervention costs drive 'value for money'. FUTURE WORK: There is a need to develop digital interventions that are more effective, rather than just cheaper, than their alternatives. STUDY REGISTRATION: This study is registered as PROSPERO CRD42018105837. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 1. See the NIHR Journals Library website for further project information.

Digital interventions are activities accessed via technology platforms (e.g. computers, smartphones and virtual reality) that can improve users' mental health and reduce addiction problems. To assess whether or not digital interventions offer 'value for money', we needed to compare their costs and outcomes with the costs and outcomes of alternatives, such as face-to-face therapy and medication. This was done through economic evaluations. This project consisted of four work packages. In work package 1, we reviewed 76 published economic evaluations of digital interventions for different mental health and addiction problems. We could not directly compare their results because of differences in the methods that were used, but the overall picture suggested that digital interventions could offer good value for money as an alternative to 'doing nothing' or simply monitoring someone or giving them general information. The picture was unclear when digital interventions were compared with face-to-face therapy. In work package 2, we pooled research studies that evaluated the outcomes of digital interventions in reducing anxiety and worry; the results were inconclusive because we were uncertain about the differences in outcomes between digital interventions and alternatives. In work package 3, an economic model suggested that value for money in digital interventions is driven by how good they are and not by how much they cost. In work package 4, we presented our methods and results to service users, mental health professionals and researchers who wanted to know more about the value of digital interventions for specific groups (e.g. children and older adults) and for outcomes other than reducing symptoms (e.g. reducing waiting times for treatment and improving attendance for therapy). Finally, the stakeholders highlighted four factors that may influence their decisions to use digital interventions, other than costs and outcomes: increasing choice, reaching underserved populations, enabling continuous care and accepting the 'inevitability of going digital'.

Cost Effectiveness of Digital Interventions for Generalised Anxiety Disorder: A Model-Based Analysis.

BACKGROUND: Digital interventions (DIs) are increasingly being used in mental health care, despite limited evidence regarding their value for money. This study aimed to evaluate the cost effectiveness of DIs for generalised anxiety disorder (GAD), in comparison with alternative care options, from the perspective of the UK health care system. METHODS: An open-source decision analytic cohort model was used to extrapolate the results of a network meta-analysis over a patient's lifetime and estimate the costs and outcomes (quality-adjusted life-years) of DIs and their comparators. The net monetary benefit (NMB) and probability of cost effectiveness was estimated for each comparator, and we conducted a Value of Information analysis to evaluate the scale and drivers of uncertainty. RESULTS: DIs were associated with lower NMB compared with medication and with group therapy, but greater NMB compared with non-therapeutic controls and with usual care. DIs that were supported by a clinician, an assistant or a lay person had higher delivery costs than purely patient-self-directed DIs, yielding a greater NMB when opportunity cost was above £3000/QALY. There was considerable uncertainty in the findings driven largely by uncertainty in the estimated treatment effects. The value of further research to establish the effectiveness of DIs for GAD was substantial, at least £12.9 billion. CONCLUSIONS: The high uncertainty about these results does not allow for recommendations based on the cost effectiveness of DIs. However, the analysis highlights areas for future research, and demonstrates that apparent cost savings associated with DIs can be offset by reduced effectiveness.

Reference Case Methods for Expert Elicitation in Health Care Decision Making.

BACKGROUND: The evidence used to inform health care decision making (HCDM) is typically uncertain. In these situations, the experience of experts is essential to help decision makers reach a decision. Structured expert elicitation (referred to as elicitation) is a quantitative process to capture experts' beliefs. There is heterogeneity in the existing elicitation methodology used in HCDM, and it is not clear if existing guidelines are appropriate for use in this context. In this article, we seek to establish reference case methods for elicitation to inform HCDM. METHODS: We collated the methods available for elicitation using reviews and critique. In addition, we conducted controlled experiments to test the accuracy of alternative methods. We determined the suitability of the methods choices for use in HCDM according to a predefined set of principles for elicitation in HCDM, which we have also generated. We determined reference case methods for elicitation in HCDM for health technology assessment (HTA). RESULTS: In almost all methods choices available for elicitation, we found a lack of empirical evidence supporting recommendations. Despite this, it is possible to define reference case methods for HTA. The reference methods include a focus on gathering experts with substantive knowledge of the quantities being elicited as opposed to those trained in probability and statistics, eliciting quantities that the expert might observe directly, and individual elicitation of beliefs, rather than solely consensus methods. It is likely that there are additional considerations for decision makers in health care outside of HTA. CONCLUSIONS: The reference case developed here allows the use of different methods, depending on the decision-making setting. Further applied examples of elicitation methods would be useful. Experimental evidence comparing methods should be generated.

Modelling decay in effectiveness for evaluation of behaviour change interventions: a tutorial for public health economists.

BACKGROUND AND PURPOSE: Recent methodological reviews of evaluations of behaviour change interventions in public health have highlighted that the decay in effectiveness over time has been mostly overlooked, potentially leading to suboptimal decision-making. While, in principle, discrete-time Markov chains-the most commonly used modelling approach-can be adapted to account for decay in effectiveness, this framework inherently lends itself to strong model simplifications. The application of formal and more appropriate modelling approaches has been supported, but limited progress has been made to date. The purpose of this paper is to encourage this shift by offering a practical guide on how to model decay in effectiveness using a continuous-time Markov chain (CTMC)-based approach. METHODS: A CTMC approach is demonstrated, with a contextualized tutorial being presented to facilitate learning and uptake. A worked example based on the stylized case study in physical activity promotion is illustrated with accompanying R code. DISCUSSION: The proposed framework presents a relatively small incremental change from the current modelling practice. CTMC represents a technical solution which, in absence of relevant data, allows for formally testing the sensitivity of results to assumptions regarding the long-term sustainability of intervention effects and improving model transparency. CONCLUSIONS: The use of CTMC should be considered in evaluations where decay in effectiveness is likely to be a key factor to consider. This would enable more robust model-based evaluations of population-level programmes to promote behaviour change and reduce the uncertainty surrounding the decision to invest in these public health interventions.

Digital Interventions for Generalized Anxiety Disorder (GAD): Systematic Review and Network Meta-Analysis.

Background: Generalized anxiety disorder is the most common mental health condition based on weekly prevalence. Digital interventions have been used as alternatives or as supplements to conventional therapies to improve access, patient choice, and clinical outcomes. Little is known about their comparative effectiveness for generalized anxiety disorder. Methods: We conducted a systematic review and network meta-analysis of randomized controlled trials comparing digital interventions with medication, non-digital interventions, non-therapeutic controls, and no intervention. Results: We included 21 randomized controlled trials with a total of 2,350 participants from generalized anxiety disorder populations. Pooled outcomes using analysis of Covariance and rankograms based on the surface under the cumulative ranking curves indicated that antidepressant medication and group therapy had a higher probability than digital interventions of being the "best" intervention. Supported digital interventions were not necessarily "better" than unsupported (pure self-help) ones. Conclusions: Due to very wide confidence intervals, network meta-analysis results were inconclusive as to whether digital interventions are better than no intervention and non-therapeutic active controls, or whether they confer an additional benefit to standard therapy. Future research needs to compare digital interventions with one-to-one therapy and with manualized non-digital self-help and to include antidepressant medication as a treatment comparator and effect modifier.

The Cost Effectiveness of Ecotherapy as a Healthcare Intervention, Separating the Wood from the Trees.

Internationally, shifts to more urbanised populations, and resultant reductions in engagements with nature, have been a contributing factor to the mental health crisis facing many developed and developing countries. While the COVID-19 pandemic reinforced recent trends in many countries to give access to green spaces more weight in political decision making, nature-based activities as a form of intervention for those with mental health problems constitute a very small part of patient pathways of care. Nature-based interventions, such as ecotherapy, are increasingly used as therapeutic solutions for people with common mental health problems. However, there is little data about the potential costs and benefits of ecotherapy, making it difficult to offer robust assessments of its cost-effectiveness. This paper explores the capacity for ecotherapy to be cost-effective as a healthcare intervention. Using a pragmatic scoping review of the literature to understand where the potential costs and health benefit lie, we applied value of information methodology to identify what research is needed to inform future cost-effectiveness assessments. We show that there is the potential for ecotherapy for people with mild to moderate common mental health problems to be cost-effective but significant further research is required. Furthermore, nature-based interventions such as ecotherapy also confer potential social and wider returns on investment, strengthening the case for further research to better inform robust commissioning.

Developing a reference protocol for structured expert elicitation in health-care decision-making: a mixed-methods study.

BACKGROUND: Many decisions in health care aim to maximise health, requiring judgements about interventions that may have higher health effects but potentially incur additional costs (cost-effectiveness framework). The evidence used to establish cost-effectiveness is typically uncertain and it is important that this uncertainty is characterised. In situations in which evidence is uncertain, the experience of experts is essential. The process by which the beliefs of experts can be formally collected in a quantitative manner is structured expert elicitation. There is heterogeneity in the existing methodology used in health-care decision-making. A number of guidelines are available for structured expert elicitation; however, it is not clear if any of these are appropriate for health-care decision-making. OBJECTIVES: The overall aim was to establish a protocol for structured expert elicitation to inform health-care decision-making. The objectives are to (1) provide clarity on methods for collecting and using experts' judgements, (2) consider when alternative methodology may be required in particular contexts, (3) establish preferred approaches for elicitation on a range of parameters, (4) determine which elicitation methods allow experts to express uncertainty and (5) determine the usefulness of the reference protocol developed. METHODS: A mixed-methods approach was used: systemic review, targeted searches, experimental work and narrative synthesis. A review of the existing guidelines for structured expert elicitation was conducted. This identified the approaches used in existing guidelines (the 'choices') and determined if dominant approaches exist. Targeted review searches were conducted for selection of experts, level of elicitation, fitting and aggregation, assessing accuracy of judgements and heuristics and biases. To sift through the available choices, a set of principles that underpin the use of structured expert elicitation in health-care decision-making was defined using evidence generated from the targeted searches, quantities to elicit experimental evidence and consideration of constraints in health-care decision-making. These principles, including fitness for purpose and reflecting individual expert uncertainty, were applied to the set of choices to establish a reference protocol. An applied evaluation of the developed reference protocol was also undertaken. RESULTS: For many elements of structured expert elicitation, there was a lack of consistency across the existing guidelines. In almost all choices, there was a lack of empirical evidence supporting recommendations, and in some circumstances the principles are unable to provide sufficient justification for discounting particular choices. It is possible to define reference methods for health technology assessment. These include a focus on gathering experts with substantive skills, eliciting observable quantities and individual elicitation of beliefs. Additional considerations are required for decision-makers outside health technology assessment, for example at a local level, or for early technologies. Access to experts may be limited and in some circumstances group discussion may be needed to generate a distribution. LIMITATIONS: The major limitation of the work conducted here lies not in the methods employed in the current work but in the evidence available from the wider literature relating to how appropriate particular methodological choices are. CONCLUSIONS: The reference protocol is flexible in many choices. This may be a useful characteristic, as it is possible to apply this reference protocol across different settings. Further applied studies, which use the choices specified in this reference protocol, are required. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 37. See the NIHR Journals Library website for further project information. This work was also funded by the Medical Research Council (reference MR/N028511/1).

BACKGROUND: Decisions in health care aim to maximise health, requiring judgements about treatments. The evidence used to make these judgements is typically uncertain. In these situations, the experience of experts is essential. Structured expert elicitation collects beliefs from experts. There are different guidelines available for structured expert elicitation; however, it is not clear if any of these be can be used in health-care decision-making, for example in considering if a treatment should be made available in the NHS. This project aimed to develop a guidance for structured expert elicitation to inform health-care decision-making. METHODS: Reviews and experimental techniques were used to gather a list of methods to conduct structured expert elicitation. The suitability of these choices in health-care decision-making was then determined by comparing these with a set of standards that support the use of structured expert elicitation in health-care decision-making. RESULTS: Different guidelines prefer different approaches to conduct structured expert elicitation. There is a lack of evidence available to determine which of these methods is most appropriate across the whole of health-care decision-making. It is possible to define reference protocol methods that could be used in a particular type of health-care decision-making, health technology assessment. This includes gathering experts with knowledge of the clinical area, asking experts about things that they observe in clinical practice and asking experts individually for their beliefs. For decision-makers working outside health technology assessment, for example at a local level, or for treatments that are not yet available to patients, these choices may not be appropriate. CONCLUSIONS: This flexibility of this guidance is a useful feature. It is possible for different decision-makers in health care to interpret the reference protocol for their own circumstances.

Taking a local government perspective for economic evaluation of a population-level programme to promote exercise.

BACKGROUND: In order to tackle the issue of physical inactivity, local governments have implemented population-level programmes to promote exercise. While evidence is accumulating on the cost-effectiveness of these interventions, studies have typically adopted a health sector perspective for economic evaluation. This approach has been challenged as it does not allow for key concerns by local governments, which are primary stakeholders, to be addressed. OBJECTIVES: To show how taking a local government perspective for economic evaluation can be implemented in practice and this may affect the economic conclusions. METHODS: Based on data from a case study, the health equity impact of the intervention and its opportunity cost from a service provider viewpoint were assessed. The cost-effectiveness implications of a change in perspective were subsequently estimated by means of scenario analysis. FINDINGS: The intervention was found to provide adult residents living in the most deprived city areas with greater health benefits compared with the rest of the population. However, a negative net equity impact was found in the short-term. The opportunity cost of the intervention was estimated to be substantially lower than its financial cost (£2.77 per person/year), with significant implications for decision-making. CONCLUSIONS: Taking a local government perspective can affect the conclusions drawn from the economic evaluation of population-level programmes to promote exercise, and therefore influence decision making.

Delayed transfers of care for older people: a wider perspective.

Delayed transfers of care (DTOC), often unhelpfully referred to as 'bed blocking', has become a byword for waste and inefficiency in healthcare systems throughout the world. An estimated 2.7 million bed days are occupied each year in England by older people no longer in need of acute treatment, estimated to cost £820 million (2014/15) in inpatient care. Policy and media attention have often been drawn to this narrative of financial waste, resulting in policy setting that directly targets the level of DTOC, but has done little to put patient health first. These figures and policies portray a misleading image of the delays as primarily of concern in terms of their financial burden on acute hospital care, with little consideration given to the quantification on patient health or wider societal impacts. In spite of the multi-factorial decision-making process that occurs for each patient discharge, current evaluation frameworks and national policy setting fail to reflect the complexity of the process. In this commentary, we interrogate the current approach to the quantification of the DTOC impact and explore how policies and evaluation methods can do more to reflect the true impact of the delays.

Model to Determine the Cost-Effectiveness of Screening Psoriasis Patients for Psoriatic Arthritis.

OBJECTIVE: Screening psoriasis patients for psoriatic arthritis (PsA) is intended to identify patients at earlier stages of the disease. Early treatment is expected to slow disease progression and delay the need for biologic therapy. Our objective was to determine the cost-effectiveness of screening for PsA in patients with psoriasis in Canada. METHODS: A Markov model was built to estimate the costs and quality-adjusted life years (QALYs) of screening tools for PsA in psoriasis patients. The screening tools included the Toronto Psoriatic Arthritis Screen, Psoriasis Epidemiology Screening Tool, Psoriatic Arthritis Screening and Evaluation, and Early Psoriatic Arthritis Screening Questionnaire (EARP) questionnaires. States of health were defined by disability levels as measured by the Health Assessment Questionnaire. State transitions were modeled based on annual disease progression. Incremental cost-effectiveness ratios and incremental net monetary benefits were estimated. Sensitivity analyses were undertaken to account for parameter uncertainty and to test model assumptions. RESULTS: Screening was cost-effective compared to no screening. The EARP tool had the lowest total cost ($2,000 per patient per year saved compared to no screening) and the highest total QALYs (additional 0.18 per patient compared to no screening). The results were most sensitive to test accuracy and the efficacy of disease-modifying antirheumatic drugs (DMARDs). No screening was cost-effective (at $50,000 per QALY) relative to screening when DMARDs failed to slow disease progression. CONCLUSION: If early therapy with DMARDs delays biologic treatment, implementing screening in patients with psoriasis in Canada is expected to represent a cost savings of $220 million per year and improve the quality of life.

Systematic Review and Critique of Methods for Economic Evaluation of Digital Mental Health Interventions.

OBJECTIVES: Investment in digital interventions for mental health conditions is growing rapidly, offering the potential to elevate systems that are currently overstretched. Despite a growing literature on economic evaluation of digital mental health interventions (DMHIs), including several systematic reviews, there is no conclusive evidence regarding their cost-effectiveness. This paper reviews the methodology used to determine their cost-effectiveness and assesses whether this meets the requirements for decision-making. In doing so we consider the challenges specific to the economic evaluation of DMHIs, and identify where consensus and possible further research is warranted. METHODS: A systematic review was conducted to identify all economic evaluations of DMHIs published between 1997 and December 2018. The searches included databases of published and unpublished research, reference lists and citations of all included studies, forward citations on all identified protocols and conference abstracts, and contacting authors researchers in the field. The identified studies were critiqued against a published set of requirements for decision-making in healthcare, identifying methodological challenges and areas where consensus is required. RESULTS: The review identified 67 papers evaluating DMHIs. The majority of the evaluations were conducted alongside trials, failing to capture all relevant available evidence and comparators, and long-term impact of mental health disorders. The identified interventions are complex and heterogeneous. As a result, there are a number of challenges specific to their evaluation, including estimation of all costs and outcomes, conditional on analysis viewpoint, and identification of relevant comparators. A taxonomy for DMHIs may be required to inform what interventions can reasonably be pooled and compared. CONCLUSIONS: This study represents the first attempt to understand the appropriateness of the methodologies used to evaluate the value for money of DMHIs, helping work towards consensus and methods' harmonisation on these complex interventions.

Cost-effectiveness of a proportionate universal offer of free exercise: Leeds Let's Get Active.

BACKGROUND: The purpose of this paper is to assess the cost-effectiveness of a proportionate universal programme to reduce physical inactivity (Leeds Let us Get Active (LLGA)) in adults. METHODS: A continuous-time Markov chain model was developed to assess the cost implications and QALY gains associated with increases in physical activity levels across the adult population. A parametric survival analysis approach was applied to estimate the decay of intervention effect over time. Baseline model data were obtained from previous economic models, population-based surveys and other published literature. A cost-utility analysis was conducted from a health care sector perspective over the programme duration (39 months). Scenario and probabilistic sensitivity analyses were performed to test the robustness of cost-effectiveness results. RESULTS: In total, 51 874 adult residents registered to the programme and provided baseline data,19.5% of which were living in deprived areas. Under base case assumptions, LLGA was found to be likely to be cost-effective. However, variations in key structural assumptions showed sensitivity of the results. CONCLUSIONS: Results from this study suggest a non-negligible level of uncertainty regarding the effectiveness, and therefore, cost-effectiveness of a universal offer of free leisure centre-based exercise that targets hard to reach groups. Further data collection and a shift towards prospective evaluations are needed.

Antimicrobial-impregnated central venous catheters for preventing neonatal bloodstream infection: the PREVAIL RCT.

BACKGROUND: Clinical trials show that antimicrobial-impregnated central venous catheters reduce catheter-related bloodstream infection in adults and children receiving intensive care, but there is insufficient evidence for use in newborn babies. OBJECTIVES: The objectives were (1) to determine clinical effectiveness by conducting a randomised controlled trial comparing antimicrobial-impregnated peripherally inserted central venous catheters with standard peripherally inserted central venous catheters for reducing bloodstream or cerebrospinal fluid infections (referred to as bloodstream infections); (2) to conduct an economic evaluation of the costs, cost-effectiveness and value of conducting additional research; and (3) to conduct a generalisability analysis of trial findings to neonatal care in the NHS. DESIGN: Three separate studies were undertaken, each addressing one of the three objectives. (1) This was a multicentre, open-label, pragmatic randomised controlled trial; (2) an analysis was undertaken of hospital care costs, lifetime cost-effectiveness and value of information from an NHS perspective; and (3) this was a retrospective cohort study of bloodstream infection rates in neonatal units in England. SETTING: The randomised controlled trial was conducted in 18 neonatal intensive care units in England. PARTICIPANTS: Participants were babies who required a peripherally inserted central venous catheter (of 1 French gauge in size). INTERVENTIONS: The interventions were an antimicrobial-impregnated peripherally inserted central venous catheter (coated with rifampicin-miconazole) or a standard peripherally inserted central venous catheter, allocated randomly (1 : 1) using web randomisation. MAIN OUTCOME MEASURE: Study 1 - time to first bloodstream infection, sampled between 24 hours after randomisation and 48 hours after peripherally inserted central venous catheter removal. Study 2 - cost-effectiveness of the antimicrobial-impregnated peripherally inserted central venous catheter compared with the standard peripherally inserted central venous catheters. Study 3 - risk-adjusted bloodstream rates in the trial compared with those in neonatal units in England. For study 3, the data used were as follows: (1) case report forms and linked death registrations; (2) case report forms and linked death registrations linked to administrative health records with 6-month follow-up; and (3) neonatal health records linked to infection surveillance data. RESULTS: Study 1, clinical effectiveness - 861 babies were randomised (antimicrobial-impregnated peripherally inserted central venous catheter, n = 430; standard peripherally inserted central venous catheter, n = 431). Bloodstream infections occurred in 46 babies (10.7%) randomised to antimicrobial-impregnated peripherally inserted central venous catheters and in 44 (10.2%) babies randomised to standard peripherally inserted central venous catheters. No difference in time to bloodstream infection was detected (hazard ratio 1.11, 95% confidence interval 0.73 to 1.67; p = 0.63). Secondary outcomes of rifampicin resistance in positive blood/cerebrospinal fluid cultures, mortality, clinical outcomes at neonatal unit discharge and time to peripherally inserted central venous catheter removal were similar in both groups. Rifampicin resistance in positive peripherally inserted central venous catheter tip cultures was higher in the antimicrobial-impregnated peripherally inserted central venous catheter group (relative risk 3.51, 95% confidence interval 1.16 to 10.57; p = 0.02) than in the standard peripherally inserted central venous catheter group. Adverse events were similar in both groups. Study 2, economic evaluation - the mean cost of babies' hospital care was £83,473. Antimicrobial-impregnated peripherally inserted central venous catheters were not cost-effective. Given the increased price, compared with standard peripherally inserted central venous catheters, the minimum reduction in risk of bloodstream infection for antimicrobial-impregnated peripherally inserted central venous catheters to be cost-effective was 3% and 15% for babies born at 23-27 and 28-32 weeks' gestation, respectively. Study 3, generalisability analysis - risk-adjusted bloodstream infection rates per 1000 peripherally inserted central venous catheter days were similar among babies in the trial and in all neonatal units. Of all bloodstream infections in babies receiving intensive or high-dependency care in neonatal units, 46% occurred during peripherally inserted central venous catheter days. LIMITATIONS: The trial was open label as antimicrobial-impregnated and standard peripherally inserted central venous catheters are different colours. There was insufficient power to determine differences in rifampicin resistance. CONCLUSIONS: No evidence of benefit or harm was found of peripherally inserted central venous catheters impregnated with rifampicin-miconazole during neonatal care. Interventions with small effects on bloodstream infections could be cost-effective over a child's life course. Findings were generalisable to neonatal units in England. Future research should focus on other types of antimicrobial impregnation of peripherally inserted central venous catheters and alternative approaches for preventing bloodstream infections in neonatal care. TRIAL REGISTRATION: Current Controlled Trials ISRCTN81931394. FUNDING: This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 57. See the NIHR Journals Library website for further project information.

Babies who are born too early or who are very sick require intensive care after birth and during early life. Most will have a long, narrow, plastic tube, called a catheter, inserted into a vein. The catheter is used to give babies fluids containing medicines and nutrition to keep them well and help them grow. The catheter can remain in place for several days or weeks. But the presence of plastic tubing in the vein increases the risk of infection. This study aimed to find out whether or not catheters coated with antimicrobial medicines, called rifampicin and miconazole, could reduce the risk of infection. These medicines act by stopping germs from growing on the catheter, but do not harm the baby or interfere with other treatments. A randomised controlled trial was carried out in 18 neonatal units in England. Whenever a baby needed a catheter, their parents were asked for consent to participate in the trial. The baby was then randomised, similar to tossing a coin, to receive either the antimicrobial catheter or a standard one. A total of 861 babies participated. We followed up all babies in the same way until after the catheter was removed to compare how often babies in each group had an infection. It was found that antimicrobial catheters were no better or worse at preventing infection than standard catheters. Antimicrobial catheters cost more and we found no evidence of benefit; these results suggest that their use in neonatal intensive care is not justified. It was calculated that further research on ways to reduce infection may be good value for money, depending on the costs of this research. The babies who took part in this study were typical of babies in England receiving catheters, meaning that the results can be applied across the NHS. Future research should focus on catheters that contain other types of antimicrobials and alternative ways of preventing infection.