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This thesis seeks to explore how economic evaluations of rehabilitation services are carried out in the 'real world'. To consider whether the multifaceted components of the rehabilitation process can be, or are, meaningfully evaluated within the existing framework of economic evaluation. Attention will focus on three areas: • The theory and methodology underpinning economic evaluation of health interventions; elements that make up an 'ideal' or high quality economic evaluation • How current and past economic evaluations of rehabilitation services have been carried out, the differences and similarities and how far these evaluations conform to the 'ideal'. • A case study to identify the limitations placed upon economic evaluations of these types of service will explore how constraints shape the evaluation, influence the results and thus the conclusions that may be drawn from the study Chapters One to Five of the thesis look at existing work undertaken in this field. It begins by giving the rationale and context of the study in the current political and health care environment. It goes on to consider the rehabilitation process, the theory and methodology underpinning economic evaluation in health care and to identify essential elements of an economic evaluation. A literature review is carried out to identify trends in the evaluation of rehabilitation services and to explore how actual evaluations fit with the ideals of economic evaluation in this field. Chapter Six to Ten present a case study that explores different scenarios when carrying out an economic evaluation of a rehabilitation service; the constraints and limitations incurred in the evaluation design and process, how these may be overcome, how they are reflected in the results and changes in parameters within the evaluation. Chapter Eleven draws together the evidence presented to address the study question; can rehabilitation services be meaningfully evaluated within the existing framework of economic evaluation?

Background: Many factors can introduce uncertainty into medical laboratory test measurements, and this uncertainty can affect downstream clinical and health-economic outcomes. Currently, however, the impact of measurement uncertainty on outcomes is rarely considered, either within laboratory medicine or Health Technology Assessment (HTA) practices. Aim: To develop a framework for assessing the impact of test measurement uncertainty on clinical and health-economic outcomes. Methods: Five hypotheses were addressed in this thesis. Hypothesis A – that measurement uncertainty has not been routinely addressed within HTAs – was assessed via a systematic review of HTAs. Hypothesis B – that methods for assessing the impact of measurement uncertainty on outcomes have been used in the broader literature – was assessed via a methodology literature review. The remaining hypotheses – that methods from the literature could be used/adapted to: [C] evaluate the impact of measurement uncertainty on clinical performance, utility and cost-effectiveness; [D] derive outcome-based analytical performance specifications (APS); and [E] accommodate real world evidence on measurement performance – were assessed via a case study analysis, exploring the role of faecal calprotectin for the diagnosis of Inflammatory Bowel Disease (IBD). Results: The HTA review confirmed that, to date, HTAs have rarely assessed the impact of measurement uncertainty on outcomes. The methodology review, meanwhile, identified various relevant methods from the broader literature (mostly from the laboratory medicine field). Of those, iterative simulation and decision modelling were selected for further exploration based on their ability to be integrated into existing HTA methodology. The subsequent case study demonstrated a framework of analysis building on these methods. Using both hypothetical and real world evidence simulations, the robustness of faecal calprotectin clinical pathway outcomes to increasing measurement uncertainty was assessed, and regions of acceptable measurement uncertainty (i.e. outcome-based APS) were identified. Conclusions: The presented framework can help to improve HTA-decision making and inform outcome-based laboratory practices.

This study explored the association between transport accessibility to healthcare facilities and health outcomes for patients in England with Arthritis. The aim was to provide evidence on the impacts on patient health from changing where patients attend hospital and a method for evaluating who would be affected under a range of scenarios. The study had three main stages: 1. Systematic review to consider the current evidence. This review focused on studies that had considered the associations between travel time/ distance and health outcomes in global north countries. Out of 108 identified studies 77% reported evidence that patients who live further from where their healthcare is provided have poorer health outcomes. 2. Exploring the association. The study used two datasets to explore the association between transport accessibility and health outcomes. These were the linked Hospital Episode Statistics and Patient Reported Outcomes Measures dataset (using West Yorkshire patient data) and the English Longitudinal Study of Ageing (using a national sample). These were used to assess whether travelling further to the hospital or the GP was associated with poorer health. The results include some evidence of a decline for those travelling the furthest, but importantly that the key association with health outcomes was ease of travel. The burden of travel to healthcare was exacerbated for individuals without access to a car, living alone and with mobility issues. 3. Assessing the impact of changes to healthcare provision. Using mapping techniques (including location-allocation methods), the study has assessed the impact on patient travel and inequalities within groups for a number of service provision scenarios. Modelling was used to predict changes in health outcomes from these changes. These findings can help inform future planning decisions concerning where patients attend healthcare services to minimise the impact on patient travel and health inequalities.

The UK population is ageing, with the proportion of the population aged over 65 continuing to rise. Old age is associated with increasing prevalence of frailty, characterised by a slow and steady decline in health and functioning. Older adults experiencing frailty often have complex needs, requiring complicated combinations of health and social care services over the long-term. This has led to a push for integration between health and social care services. Traditionally, the economic evaluation of health services has focussed on health-related quality of life (QoL) as the unit of benefit. However, current health measures may not be appropriate to evaluate the outcomes of social care or integrated health and social care interventions. Outcome measurement methods may need to be adapted to include broader assessment of QoL or wellbeing. This thesis aims to examine the psychometric performance of existing measures of health, QoL and wellbeing in older adults. First, the existing evidence of the psychometric performance of the EQ-5D-5L, SF-12v2, ASCOT, WEMWBS and ONS-4 was systematically reviewed. Then, item response theory (IRT) was used to examine the construct and structural validity and internal consistency of these measures in older adults aged 65+. Differential item functioning (DiF) analyses assessed whether older and younger adults with the same underlying health, QoL or wellbeing had different expected scores, indicating bias due to age. Lastly, the content validity of the EQ-5D-5L, SF-12v2, WEMWBS and ONS-4 was explored using cognitive interviews in older adults. This thesis identified some key findings which can inform the choice of measure in the evaluation of health and social care interventions aimed at older adults. In the IRT study, the ASCOT and EQ-5D-5L displayed ceiling effects, while the SF-12v2 and EQ-5D-5L exhibited DiF, both of which can bias the estimates of effectiveness obtained from these measures in an economic evaluation. The cognitive interviewing study provided insight into the way older adults conceptualise QoL and how this impacts the way they respond to items. Issues with response shift were broadly identified, which are the likely cause of DiF. Participants found the functional focused EQ-5D-5L items easier to answer and mostly relevant to their situation. The relevance of broader subjective wellbeing items on the WEMWBS and ONS-4 and negatively phrased mental health items across the measures were commonly questioned as these concepts were not prioritised in older adults' conceptualisation of QoL. However, the coverage of any of the measures would need to be extended to include broader elements of QoL identified as important to older adults. This may be through adaptations to the EQ-5D-5L, such as bolt ons, or the development of a new measure, possibly based on the style of the EQ-5D-5L.

Adult obesity remains a public health crisis with little sign of abating. Interventions to tackle obesity are many, and funding choices should be supported by evidence on value for money. A key issue with the economic assessment of weight-management programmes is that effectiveness should be extrapolated into the future, and therefore predictions should be made regarding long-term weight-change. However, as these weight-trajectories are often unknown, assumptions must be made within the model. In previous models, weight-trajectory assumptions are often basic and comprehensive sensitivity analysis of these weight-trajectories is rare. This PhD aims to improve the best practice of cost-effectiveness modelling for weight management programmes and test various scenarios regarding weight-trajectories following these programmes. Economic and behavioural economic theories of weight-management were identified and used to build a framework to explain decision making regarding weight-management, and predict weight-change. A meta-regression model to predict weight-regain following weight-management programmes was then built. Following this, a longitudinal dataset of a sample of the UK population was analysed to predict a background weight trajectory. The cost-effectiveness model used the Slimming World programme as a case-study, and combined the previous workstreams to inform weight-trajectories of the participants, parameters, and various sensitivity analysis, including scenarios used in economic evaluations from the literature. The research found that assumptions regarding weight-regain were the key driver of cost-effectiveness, and that assumptions used by previous economic models may have caused large inaccuracies in estimations of cost-effectiveness. This PhD provides guidance to future projects estimating long-term cost-effectiveness of weight-management programmes. Policymakers will also gain an improved understanding of the potential weight-trajectories following weight-management programmes, and the impact than these long-term trajectories can have on the overall cost-effectiveness of the programme. This should lead to more accurate estimates of the value of interventions, and greater confidence in preventative healthcare spending decisions.

Background: Diseases such as stroke and heart disease are chiefly caused by unhealthy behaviours and are a major societal burden. User financial incentives are being explored as a way to encourage healthier lifestyles. This research developed a framework to provide information on pricing and cost-effectiveness of incentives and guide design of future incentive schemes. Methods: The workstreams were: a) structured, configurative literature review to identify neo-classical/behavioural economic explanations for behaviour change and incentives; b) contingent valuation survey to identify willingness to accept (WTA) and incentive pricing; c) systematic review and meta-analysis of incentives for weight loss; d) development of decision-analytic model to estimate cost-effectiveness of incentives for weight loss. Results: The reviews identified a number of factors important for understanding the effect of incentives including internal motivation, self-control and time preference. A theoretical framework of incentive impact was developed to facilitate WTA survey design. The WTA survey was completed by 112 people (n=56 at 3 months). 57% strongly disagreed with incentive use. The mean incentive required per month depended on behaviour, ranging £103.69 for smoking cessation to £45.43 for reducing alcohol intake. The most important predictors of WTA were self-control, perceived difficulty of change and attitudes to incentives. There was some evidence that WTA incentives increased over time. Review and meta-regression provided efficacy parameters for the decision-analytic model which comprised the following health states: healthy, type II diabetes, stroke, myocardial infarction and dead. Analyses from NHS and employer perspectives indicated incentives for weight loss are cost-effective over a lifetime as they dominated usual care. Discussion: Incentives may be most powerful if they are personalised to account for individual factors and attitudes and are dynamic in response to these. Incentives may be cost-effective in a number of scenarios. Further research is required on the long term outcomes of incentives and financing models.

Rising global healthcare expenditures, the fallout from the global financial crisis and a commitment to improving patient outcomes have increased pressure on the budget of the National Health Service (NHS) in England to unprecedented levels. Therefore, ensuring services are delivered efficiently is key both politically and economically. In the context of the NHS, the large share of spending in secondary care means that this area is well analysed in the literature. However, the scale of the savings needed requires that both (a) more research is needed to identify further possible gains; and (b) the potential for improvement that has been identified by these studies is captured. To these ends, there are two specific aims of this thesis. The first is to examine the regulation of NHS hospital efficiency. Drawing from health care and other sectors of the economy, a number of lessons for regulators to promote hospital efficiency in the NHS and beyond are proposed. The second is to look to areas of hospital activity for which empirical evidence on efficiency is limited to identify further available gains. Many studies in the UK and beyond have sought to measure efficiency in health: the so-called “supply” of efficiency analysis is booming. However, despite their potential, the use of these studies has been limited in the NHS. In response to this, this thesis seeks to answer some of the methodological and practical issues raised around efficiency measurement and its application to the setting of NHS hospital efficiency targets. How these findings are useful more widely to health care systems around the world is also discussed.

Rates of obesity are predicted to increase, which is worrying given the association with adverse health outcomes. Cost of food or diet is one proposed contributor to an ‘obesogenic environment’. The “food price-obesity hypothesis” supposes that, with limited purchasing power, consumers may purchase energy-dense foods to obtain the maximum calories, resulting in excess energy intake. This thesis attempts to gauge whether obesity may be attributed to food prices. Firstly, the published literature was synthesised. Secondly, the study examined how income and cost of diet are implicated in excess energy intake, as implied by the body mass index (BMI) and dietary energy density (DED), of adults in the National Diet and Nutrition Survey (NDNS). The literature review revealed a heterogeneous body of studies that was generally supportive of the food price-obesity theory, but not conclusive. Studies of diet costs and DED overwhelmingly report a negative association. A limited number of studies investigating diet costs and BMI reported contradictory findings. The evidence linking income and DED was not strong. In the NDNS sample, income was found to be negatively associated with DED, BMI, and overweight/obesity. In addition, a negative association was observed between diet costs and DED. There was no association between whole diet costs and BMI. In contrast, using proportional food group costs revealed some significant associations. This suggests that measuring how people apportion their food budget, rather than how much the whole diet is worth, may be insightful. The thesis also addresses some methodological issues. Firstly, analyses demonstrate how equivalizing household income to take into account household composition can impact on findings. Secondly, a comparison of diet costing methods is presented. Despite methodological challenges, the findings presented in the thesis suggest there is merit in pursuing research into diet costs, with many unexplored opportunities in this emerging field.

Obesity, particularly in the younger population, is a major public health concern. Because of this, numerous public health initiatives and specialised weight management interventions are available for this population. Economic evaluations of weight management interventions can be utilised to inform resource allocation decision making. But in order to provide fully informed economic evaluations of weight management interventions, a valid and reliable tool to a) measure weight specific quality of life (QoL) and b) assign preference values to different aspects of weight specific QoL is necessary. Currently no existing tools meet these crucial requirements, and this thesis aims to fill this gap. The thesis utilised a multiple methodological approach in the development of a new weight specific instrument. The development of the tool comprised of four distinct studies. The first was informed by the existing literature and aimed to identify items through a) qualitative interviews with adolescents and b) discussion with specialists in the field of adolescent obesity. A long list of potential items for inclusion in the new instrument was crafted in the first study. The aim of the second study was the identification of a reduced item set by performing psychometric assessments and Rasch analysis. At the end of the first two studies the new instrument was created. The third study aimed to assess its measurement properties through psychometric analyses. The final feasibility valuation study addressed the derivation of preference values for the states described by the instrument. The results of the empirical studies taken together demonstrated that it is feasible to identify the impact of weight status on QoL using adolescents’ views. It has been possible to create the Weight-specific Adolescent Instrument for Economic-evaluation (WAItE), consisting of seven items each associated with five response options. It was not possible to obtain a scoring algorithm for the states described by the WAItE when three variants of discrete choice experiments were implemented. The WAItE can be used to investigate the benefits associated with alternative weight management interventions.