Economic evaluation of minimal access surgery: The case of surgical treatment for menorrhagia

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The purpose of this thesis is to explore the methodological and empirical issues relating to the economic evaluation of minimal access surgery (MAS). Given the likely increase in the utilisation of economic analysis in this area, it is crucial to explore whether the methods of economic evaluation have limitations in the face of the particular characteristics of MAS. The comparison of abdominal hysterectomy (AH) and transcervical endometrial resection (TCRE), for the treatment of menorrhagia, is used as a vehicle to develop methods in relation to MAS. Having reviewed the literature and issues relating to the economic analysis of this group of technologies, the empirical starting point of the thesis is the assessment of the limitations of economic evaluations alongside clinical trials, using a trial comparing AH and TCRE. Three major areas of weakness are identified, and alternative ways of addressing these weaknesses are explored in the remainder of the thesis. The first area of methodological development relates to the measure of benefit used in economic evaluation of MAS. In this clinical context, it is argued that the trade-offs that exist between MAS and conventional surgery, in terms of process characteristics and outcomes, should result in an important role for patients' preferences in the construction of a benefit measure. A cost-utility analysis using the standard quality-adjusted life year (GALY) is undertaken, using trial data augmented with valuation data from a further study. The lack of consistency between individual preferences and standard QALYs suggests a major weakness with this measure of benefit. The strengths and weaknesses of an alternative measure of benefit in cost-utility analysis - the ex ante healthy years equivalent (HYE) - are assessed based on a further valuation study. It is shown that it is feasible to elicit ex ante HYEs from patients and that this measure of benefit exhibits some consistency with other expressions of patients' preferences. However, the HYE is likely to impose a greater measurement burden than the standard QALY. The second area of methodological development in the thesis is the analysis of the generalisability of trial-based economic evaluation, given the limitations that often exist with the external validity of trials. A framework is developed within which trial and observational data can be synthesised. This facilitates the use of sensitivity analysis to explore the robustness of base-case (trial-generated) results to alternative sources of data, which may be more representative of routine practice. The third area of methodological development stems from the importance of patients' preferences in relation to MAS. This element relates to the use of methods to model and to evaluate management strategies which use patients' preferences to determine treatment allocation. It is concluded that preference-based decision making has the potential to be cost effective in relation to TCRE and AH, and MAS applications more generally. The thesis demonstrates the importance of continued development in the detailed methods of economic evaluation.Funding was obtained from the Department of Healt

Coverage with evidence development, only in research, risk sharing or patient access scheme? : A framework for coverage decisions

Until recently, purchasers’ options regarding whether to pay for the use of technologies have been binary in nature: a treatment is covered or not covered. However, policies have emerged which expand the options - for example, linking coverage to evidence development, an option increasingly used for new treatments with limited/uncertain evidence. There has been little effort to reconcile the features of technologies with the available options in a way that reflects purchasers’ ranges of authorit

Rationale and design of the Clinical Evaluation of Magnetic Resonance Imaging in Coronary heart disease 2 trial (CE-MARC 2): a prospective, multicenter, randomized trial of diagnostic strategies in suspected coronary heart disease

Background: A number of investigative strategies exist for the diagnosis of coronary heart disease (CHD). Despite the widespread availability of noninvasive imaging, invasive angiography is commonly used early in the diagnostic pathway. Consequently, approximately 60% of angiograms reveal no evidence of obstructive coronary disease. Reducing unnecessary angiography has potential financial savings and avoids exposing the patient to unnecessary risk. There are no large-scale comparative effectiveness trials of the different diagnostic strategies recommended in international guidelines and none that have evaluated the safety and efficacy of cardiovascular magnetic resonance.<p></p> Trial Design: CE-MARC 2 is a prospective, multicenter, 3-arm parallel group, randomized controlled trial of patients with suspected CHD (pretest likelihood 10%-90%) requiring further investigation. A total of 1,200 patients will be randomized on a 2:2:1 basis to receive 3.0-T cardiovascular magnetic resonance–guided care, single-photon emission computed tomography–guided care (according to American College of Cardiology/American Heart Association appropriate-use criteria), or National Institute for Health and Care Excellence guidelines–based management. The primary (efficacy) end point is the occurrence of unnecessary angiography as defined by a normal (>0.8) invasive fractional flow reserve. Safety of each strategy will be assessed by 3-year major adverse cardiovascular event rates. Cost-effectiveness and health-related quality-of-life measures will be performed.<p></p> Conclusions: The CE-MARC 2 trial will provide comparative efficacy and safety evidence for 3 different strategies of investigating patients with suspected CHD, with the intension of reducing unnecessary invasive angiography rates. Evaluation of these management strategies has the potential to improve patient care, health-related quality of life, and the cost-effectiveness of CHD investigation

Striving for a societal perspective : a framework for economic evaluations when costs and effects fall on multiple sectors and decision-makers

In most societies, resources are distributed by individuals acting in markets and by governments through some form of collective decision-making process. Economic evaluation offers a set of tools to inform collective decisions by examining the resource requirements and outcomes of alternative policies. The ‘societal perspective’ has been advocated, but less consideration has been given to what this should include and its practical implementation. This paper presents a framework for economic evaluation of policies with costs and outcomes falling on different sectors (e.g. health, criminal justice, education) and involving different decision makers. It extends the ‘impact inventory’ developed by the Second Panel on Cost-Effectiveness in Health and Medicine by considering all affected individuals and reflecting how outcomes attributed to an intervention can be compared with outcomes forgone as a result of resources not being available for other purposes. The framework sets out the series of assessments to be made, distinguishing points at which value judgements feed into the evaluation, and the implications of alternative judgements. These assessments reflect the institutional arrangements of public bodies, for example, their funding, the outcomes they consider important and their relative valuations of these outcomes. By avoiding the use of an abstract ‘societal perspective’, the contribution of the framework is to inform multiple decision makers with different objectives and provide practical guidance on overall societal impact

The use of MCDA in HTA : great potential, but more effort needed

The potential for multi-criteria decision analysis (MCDA) to support health technology assessment (HTA) has been much discussed, and various HTA agencies are piloting or applying MCDA. Alongside these developments, good practice guidelines for the application of MCDA in health care have been developed. An assessment of current applications of MCDA to HTA in light of good practice guidelines reveals, however, that many have methodologic flaws that undermine their usefulness. Three challenges are considered: the use of additive models, a lack of connection between criteria scales and weights, and the use of MCDA in economic evaluation. More attention needs to be paid to MCDA good practice by researchers, journal editors, and decision makers and further methodologic developments are required if MCDA is to achieve its potential to support HTA

Long term health care use and costs in patients with stable coronary artery disease : a population based cohort using linked electronic health records (CALIBER)

Aims To examine long term health care utilisation and costs of patients with stable coronary artery disease (SCAD). Methods and results Linked cohort study of 94,966 patients with SCAD in England, 1st January 2001 to 31st March 2010, identified from primary care, secondary care, disease and death registries. Resource use and costs, and cost predictors by time and 5-year cardiovascular (CVD) risk profile were estimated using generalised linear models. Coronary heart disease hospitalisations were 20.5% in the first year and 66% in the year following a non-fatal (myocardial infarction, ischaemic or haemorrhagic stroke) event. Mean health care costs were £3,133 per patient in the first year and £10,377 in the year following a non-fatal event. First year predictors of cost included sex (mean cost £549 lower in females); SCAD diagnosis (NSTEMI cost £656 more than stable angina); and co-morbidities (heart failure cost £657 more per patient). Compared with lower risk patients (5-year CVD risk 3.5%), those of higher risk (5-year CVD risk 44.2%) had higher 5-year costs (£23,393 vs. £9,335) and lower lifetime costs (£43,020 vs. £116,888). Conclusion Patients with SCAD incur substantial health care utilisation and costs, which varies and may be predicted by 5-year CVD risk profile. Higher risk patients have higher initial but lower lifetime costs than lower risk patients as a result of shorter life expectancy. Improved cardiovascular survivorship among an ageing CVD population is likely to require stratified care in anticipation of the burgeoning demand

Supporting the development of an essential health package: principles and initial assessment for Malawi

Many health care systems in low income settings define essential health packages (EHP) to concentrate scarce resources on key health interventions to which their populations can have free access at the point of delivery. Malawi has used EHPs since 2004 but they have generally included unaffordable interventions that have not been fully delivered. To guide decisions about the 2016 EHP in Malawi, an analytical framework is proposed that identifies interventions which, based on currently available evidence, offer the most gains in population health. The framework uses existing estimates of what the Malawian health care system is currently able to afford to generate gains in health – a measure of health opportunity costs. This facilitates an initial quantification of an appropriate budget for the EHP, and of the interventions that might be included which can then be prioritised on the basis of their expected impact on population health assuming 100% implementation. In practice, lower levels of implementation will be achieved by interventions due to various constraints operating on the demand or supply side, and which apply to specific interventions or the system more generally. The framework provides an analytical basis to consider the implications for population health of these different types of constraints. It uses this as a basis of assessing how the underspend on the EHP due to the ‘implementation gap’ can be used. The framework estimates the potential impacts on health outcomes of intervention-specific implementation activities and system strengthening. These potential impacts are compared with the health outcomes offered by extending the package to include additional interventions. The analytical framework can also assess the implications for population health of the types of constraints that donors may impose on their funding schemes in health care. These constraints can include requiring that particular interventions are included in the EHP when the funding could have a bigger impact on health if spent elsewhere; offers to expand the package but restricted to particular interventions and forgoing greater health outcomes elsewhere; and offers to provide additional funding as long as these are matched by government. In negotiating with donors and communicating with relevant stakeholders, policy makers will benefit from understanding the implications for population health of such constraints

Methods for network meta-analysis of continuous outcomes using individual patient data : a case study in acupuncture for chronic pain

Background: Network meta-analysis methods, which are an extension of the standard pair-wise synthesis framework, allow for the simultaneous comparison of multiple interventions and consideration of the entire body of evidence in a single statistical model. There are well-established advantages to using individual patient data to perform network meta-analysis and methods for network meta-analysis of individual patient data have already been developed for dichotomous and time-to-event data. This paper describes appropriate methods for the network meta-analysis of individual patient data on continuous outcomes. Methods: This paper introduces and describes network meta-analysis of individual patient data models for continuous outcomes using the analysis of covariance framework. Comparisons are made between this approach and change score and final score only approaches, which are frequently used and have been proposed in the methodological literature. A motivating example on the effectiveness of acupuncture for chronic pain is used to demonstrate the methods. Individual patient data on 28 randomised controlled trials were synthesised. Consistency of endpoints across the evidence base was obtained through standardisation and mapping exercises. Results: Individual patient data availability avoided the use of non-baseline-adjusted models, allowing instead for analysis of covariance models to be applied and thus improving the precision of treatment effect estimates while adjusting for baseline imbalance. Conclusions: The network meta-analysis of individual patient data using the analysis of covariance approach is advocated to be the most appropriate modelling approach for network meta-analysis of continuous outcomes, particularly in the presence of baseline imbalance. Further methods developments are required to address the challenge of analysing aggregate level data in the presence of baseline imbalance