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Biomedical subjects

Mark Sculpher

Publications and source records attributed to Mark Sculpher.

At least 19 recordsLinked to original sources
PubMed2007

Implications of chronic obstructive pulmonary disease (COPD) on patients' health status: a western view.

AIM: To assess and compare health status among chronic obstructive pulmonary disease (COPD) patients presenting for treatment in six countries and in two healthcare settings using a generic health status instrument. METHODS: A population based cross-sectional survey was conducted among 2703 patients and their physicians (1381 in primary and 1322 in specialty care) in five EU countries and the USA. Information was collected on demographic and clinical characteristics, exacerbations and health status estimated using EQ-5D. RESULTS: The mean EQ-5D score for COPD patients was similar between primary and specialty settings in all countries except Italy. Approximately, half of the patients indicated some impairment in health status on mobility, usual activities, pain/discomfort and anxiety/depression domains of EQ-5D. Approximately, 5% of patients in EU countries except UK had health status valued as worse than death based on valuations of the general population. Patients suffering from severe breathlessness, experiencing > or =3 exacerbations in the previous year, categorised as severe according to GOLD criteria, and experiencing day-time and night-time symptoms had significantly impaired health status. CONCLUSION: COPD patients classified as moderate/severe in clinical practice have worse health status compared to mild patients. This impairment is similar in primary and specialty setting across western countries.

Age Distribution↗
PubMed2006

Cost effectiveness of perindopril in reducing cardiovascular events in patients with stable coronary artery disease using data from the EUROPA study.

BACKGROUND: The EUropean trial on Reduction Of cardiac events with Perindopril in stable coronary Artery disease (EUROPA) trial has recently reported. OBJECTIVE: To assess the cost effectiveness of perindopril in stable coronary heart disease in the UK. METHODS: Clinical and resource use data were taken from the EUROPA trial. Costs included drugs and hospitalisations. Health-related quality of life values were taken from published sources. A cost-effectiveness analysis is presented as a function of the risk of a primary event (non-fatal myocardial infarction, cardiac arrest or cardiovascular death) in order to identify people for whom treatment offers greatest value for money. RESULTS: The median incremental cost of perindopril for each quality-adjusted life year (QALY) gained across the heterogeneous population of EUROPA was estimated as 9700 pounds(interquartile range 6400-14,200 pounds). Overall, 88% of the EUROPA population had an estimated cost per QALY below 20,000 pounds and 97% below 30,000 pounds. For a threshold value of cost effectiveness of 30,000 pounds per QALY gained, treatment of people representing the 25th, 50th (median) and 75th centiles of the cost effectiveness distribution for perindopril has a probability of 0.999, 0.99 and 0.93 of being cost effective, respectively. Cost effectiveness was strongly related to higher risk of a primary event under standard care. CONCLUSIONS: Whether the use of perindopril can be considered cost effective depends on the threshold value of cost effectiveness of healthcare systems. For the large majority of patients included in EUROPA, the incremental cost per QALY gained was lower than the apparent threshold used by the National Institute for Health and Clinical Excellence in the UK.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2006

Evidence synthesis, parameter correlation and probabilistic sensitivity analysis.

Over the last decade or so, there have been many developments in methods to handle uncertainty in cost-effectiveness studies. In decision modelling, it is widely accepted that there needs to be an assessment of how sensitive the decision is to uncertainty in parameter values. The rationale for probabilistic sensitivity analysis (PSA) is primarily based on a consideration of the needs of decision makers in assessing the consequences of decision uncertainty. In this paper, we highlight some further compelling reasons for adopting probabilistic methods for decision modelling and sensitivity analysis, and specifically for adopting simulation from a Bayesian posterior distribution. Our reasoning is as follows. Firstly, cost-effectiveness analyses need to be based on all the available evidence, not a selected subset, and the uncertainties in the data need to be propagated through the model in order to provide a correct analysis of the uncertainties in the decision. In many--perhaps most--cases the evidence structure requires a statistical analysis that inevitably induces correlations between parameters. Deterministic sensitivity analysis requires that models are run with parameters fixed at 'extreme' values, but where parameter correlation exists it is not possible to identify sets of parameter values that can be considered 'extreme' in a meaningful sense. However, a correct probabilistic analysis can be readily achieved by Monte Carlo sampling from the joint posterior distribution of parameters. In this paper, we review some evidence structures commonly occurring in decision models, where analyses that correctly reflect the uncertainty in the data induce correlations between parameters. Frequently, this is because the evidence base includes information on functions of several parameters. It follows that, if health technology assessments are to be based on a correct analysis of all available data, then probabilistic methods must be used both for sensitivity analysis and for estimation of expected costs and benefits.

Bayes Theorem↗
PubMed2006

Discounting and cost-effectiveness in NICE - stepping back to sort out a confusion.

Brouwer and colleagues [1] argue that the reasons for specifying an equal discount rate for health outcomes and costs in the recent guidance on methods of technology appraisal issued by the National Institute for Clinical Excellence (NICE) [2] is both opaque and wrong. They argue that a lower rate should apply to health outcomes like QALYs. It is also claimed that the guidance on discounting represents a step backwards, that is both inconsistent with current theoretical insights and will prejudice the outcome of cost-effectiveness studies of preventive interventions.The reasoning behind the use of equal discount rates for costs and health outcomes is indeed not well developed in the published guidance. Nor does it reflect the debate that underpinned the guidance. We therefore welcome the opportunity to explain more completely the rationale in the minds of the principal authors of the current guidance.

Academies and Institutes↗
PubMed2006

Is self-care a cost-effective use of resources? Evidence from a randomized trial in inflammatory bowel disease.

OBJECTIVES: To determine if a whole-system approach to self-management in inflammatory bowel disease (IBD), using a guidebook developed with patients and physicians trained in patient-centred care, leads to cost-effective use of health system resources. METHODS: Cost-effectiveness analysis over a one-year time horizon comparing the whole systems self-management approach to treatment with usual treatment. Nineteen hospitals in the northwest England were randomized to the intervention or to be controls; 651 patients (285 at intervention sites and 366 at control sites) with established IBD were included. The economic evaluation related differential health service costs, from a UK NHS perspective, to differences in quality-adjusted life years (QALYs) based on patients' responses to the EQ-5D. RESULTS: The intervention was associated with a mean reduction in costs of 148 pounds sterling per patient and a small mean reduction in QALYs of 0.00022 per patient compared with the control group. This resulted in an incremental cost per QALY gained of 676,417 pounds sterling for treatment as usual and a probability of around 63% that the whole-system approach to self-management is cost-effective, assuming a willingness to pay up to 30,000 pounds sterling for an additional QALY. CONCLUSIONS: Although there is uncertainty associated with these estimates, more widespread use of this method in chronic disease management seems likely to reduce health care costs without evidence of adverse effect on patient outcomes.

Cost-Benefit Analysis↗
PubMed2006

Bayesian methods for evidence synthesis in cost-effectiveness analysis.

Recently, health systems internationally have begun to use cost-effectiveness research as formal inputs into decisions about which interventions and programmes should be funded from collective resources. This process has raised some important methodological questions for this area of research. This paper considers one set of issues related to the synthesis of effectiveness evidence for use in decision-analytic cost-effectiveness (CE) models, namely the need for the synthesis of all sources of available evidence, although these may not 'fit neatly' into a CE model. Commonly encountered problems include the absence of head-to-head trial evidence comparing all options under comparison, the presence of multiple endpoints from trials and different follow-up periods. Full evidence synthesis for CE analysis also needs to consider treatment effects between patient subpopulations and the use of nonrandomised evidence. Bayesian statistical methods represent a valuable set of analytical tools to utilise indirect evidence and can make a powerful contribution to the decision-analytic approach to CE analysis. This paper provides a worked example and a general overview of these methods with particular emphasis on their use in economic evaluation.

Bayes Theorem↗
PubMed2006

Good practice guidelines for decision-analytic modelling in health technology assessment: a review and consolidation of quality assessment.

The use of decision-analytic modelling for the purpose of health technology assessment (HTA) has increased dramatically in recent years. Several guidelines for best practice have emerged in the literature; however, there is no agreed standard for what constitutes a 'good model' or how models should be formally assessed. The objective of this paper is to identify, review and consolidate existing guidelines on the use of decision-analytic modelling for the purpose of HTA and to develop a consistent framework against which the quality of models may be assessed. The review and resultant framework are summarised under the three key themes of Structure, Data and Consistency. 'Structural' aspects relate to the scope and mathematical structure of the model including the strategies under evaluation. Issues covered under the general heading of 'Data' include data identification methods and how uncertainty should be addressed. 'Consistency' relates to the overall quality of the model. The review of existing guidelines showed that although authors may provide a consistent message regarding some aspects of modelling, such as the need for transparency, they are contradictory in other areas. Particular areas of disagreement are how data should be incorporated into models and how uncertainty should be assessed. For the purpose of evaluation, the resultant framework is applied to a decision-analytic model developed as part of an appraisal for the National Institute for Health and Clinical Excellence (NICE) in the UK. As a further assessment, the review based on the framework is compared with an assessment provided by an independent experienced modeller not using the framework. It is hoped that the framework developed here may form part of the appraisals process for assessment bodies such as NICE and decision models submitted to peer review journals. However, given the speed with which decision-modelling methodology advances, there is a need for its continual update.

Cost-Benefit Analysis↗
PubMed2006

Cost effectiveness of increasing the dose intensity of chemotherapy with granulocyte colony-stimulating factor in small-cell lung cancer: based on data from the Medical Research Council LU19 trial.

BACKGROUND: The use of granulocyte colony-stimulating factor (G-CSF) can enable dose intensification of chemotherapy in small-cell lung cancer (SCLC). However, given its acquisition cost, it is important to assess its cost effectiveness within a resource-constrained health service. OBJECTIVE: To assess the cost effectiveness, from the UK NHS perspective, of G-CSF given in addition to doxorubicin, cyclophosphamide and etoposide (ACE) versus ACE alone in the management of SCLC. METHODS: Using data from a UK Medical Research Council trial (LU19) to assess chemotherapy dose intensification in patients with previously untreated SCLC of any disease extent, a retrospective cost-effectiveness analysis was undertaken. Resource use data, including hospitalisations and non-protocol cancer treatments, were collected during the first 6-month treatment phase of the trial. Mean costs ( pound, 2003 values) of managing patients in the two arms of the trial were calculated. Mean survival duration was calculated for the two groups using patient-specific follow-up data collected in the trial. Incremental cost-effectiveness analysis was undertaken, and uncertainty in cost effectiveness was expressed using cost-effectiveness acceptability curves. RESULTS: The use of G-CSF in addition to ACE chemotherapy is more costly ( 4647 pounds) but results in longer mean survival duration (0.20 years; 0.18 years when discounted). This generates an incremental cost per additional life-year of 25,816 pounds for ACE + G-CSF therapy. The probability of the addition of G-CSF being cost effective, if decision makers are willing to pay 30,000 pounds for an additional life-year, is 0.57. Secondary analysis suggests that cost effectiveness is likely to be sensitive to assumptions about the health-related quality of life (HR-QOL) experienced by patients. CONCLUSION: Based on data collected in the LU19 trial, chemotherapy dose intensification using G-CSF in SCLC adds to health service costs but increases survival duration. Its overall cost effectiveness is likely to be finely balanced.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Determining the cost effectiveness of a smoke alarm give-away program using data from a randomized controlled trial.

BACKGROUND: In 2001, 486 deaths and 17,300 injuries occurred in domestic fires in the UK. Domestic fires represent a significant cost to the UK economy, with the value of property loss alone estimated at pounds 375 million in 1999. In 2001 in the US, there were 383 500 home fires, resulting in 3110 deaths, 15,200 injuries and dollar 5.5 billion in direct property damage. METHODS: A cluster RCT was conducted to determine whether a smoke alarm give-away program, directed to an inner-city UK population, is effective and cost-effective in reducing the risk of fire-related deaths/injuries. Forty areas were randomized to the give-away or control group. The number of injuries/deaths and the number of fires in each ward were collected prospectively. Cost-effectiveness analysis was undertaken to relate the number of deaths/injuries to resource use (damage, fire service, healthcare and give-away costs). Analytical methods were used which reflected the characteristics of the trial data including the cluster design of the trial and a large number of zero costs and effects. RESULTS: The mean cost for a household in a give-away ward, including the cost of the program, was pounds 12.76, compared to pounds 10.74 for the control ward. The total mean number of deaths and injuries was greater in the intervention wards then the control wards, 6.45 and 5.17. When an injury/death avoided is valued at pounds 1000, a smoke alarm give-away has a probability of being cost effective of 0.15. CONCLUSIONS: A smoke alarm give-away program, as administered in the trial, is unlikely to represent a cost-effective use of resources.

Cluster Analysis↗
PubMed2005

Management of non-ST-elevation acute coronary syndromes: how cost-effective are glycoprotein IIb/IIIA antagonists in the UK National Health Service?

BACKGROUND: The glycoprotein IIb/IIIa antagonists (GPAs) represent a new class of drugs to prevent platelet aggregation in the acute treatment of non-ST-elevation acute coronary syndromes (NSTE-ACS). Systematic reviews have identified serious limitations in published cost-effectiveness analyses, including a lack of UK-specific studies and an absence of studies comparing different protocols for the use of GPAs. METHODS: A model was developed to assess the cost effectiveness of a variety of protocols employing GPAs for patients presenting with NSTE-ACS in the UK. The perspective of the UK National Health Service was adopted, with outcomes in terms of quality-adjusted life-years (QALYs). Four treatment strategies were evaluated: GPAs as part of initial medical management (Strategy 1); GPAs in patients with planned percutaneous coronary interventions (PCIs; Strategy 2); GPAs as an adjunct to the PCI procedure (Strategy 3); and no GPAs (Strategy 4). Baseline event rates and costs were taken from a UK observational study of ACS patients and relative risk reductions from GPAs were taken from a meta analysis of trials. Long-term costs and QALYs were estimated using data from a UK longitudinal study. RESULTS: The most cost-effective use of GPAs is likely to be Strategy 1, with an incremental cost per QALY gained of between pound4605 to pound10,343. Focusing this use of GPAs only on the subgroup of patients at high risk appears to represent the most cost-effective use of NHS resources. CONCLUSIONS: Medical management of patients with NSTE-ACS using GPAs is the most cost-effective use of resources, particularly if targeted to higher risk subgroups.

Coronary Disease↗
PubMed2005

Probabilistic sensitivity analysis for NICE technology assessment: not an optional extra.

Recently the National Institute for Clinical Excellence (NICE) updated its methods guidance for technology assessment. One aspect of the new guidance is to require the use of probabilistic sensitivity analysis with all cost-effectiveness models submitted to the Institute. The purpose of this paper is to place the NICE guidance on dealing with uncertainty into a broader context of the requirements for decision making; to explain the general approach that was taken in its development; and to address each of the issues which have been raised in the debate about the role of probabilistic sensitivity analysis in general. The most appropriate starting point for developing guidance is to establish what is required for decision making. On the basis of these requirements, the methods and framework of analysis which can best meet these needs can then be identified. It will be argued that the guidance on dealing with uncertainty and, in particular, the requirement for probabilistic sensitivity analysis, is justified by the requirements of the type of decisions that NICE is asked to make. Given this foundation, the main issues and criticisms raised during and after the consultation process are reviewed. Finally, some of the methodological challenges posed by the need fully to characterise decision uncertainty and to inform the research agenda will be identified and discussed.

Cost-Benefit Analysis↗
PubMed2005

Estimating utility data from clinical indicators for patients with stable angina.

This study estimated a model from which data routinely collected in clinical trials of angina patients can be mapped to a utility scale and used to estimate quality-adjusted life years (QALYs). Patients with stable angina attending four cardiac out-patient clinics in the UK were included in the study. Data collected included information on patients' health-related quality of life (HRQL) using the EQ-5D, and severity of angina symptoms using two cardiac-specific measures [Breathlessness Grade and Canadian Cardiovascular Society (CCS) classification of angina]. Regression analysis was used to predict EQ-5D index values from the data. Data were obtained from 510 patients. For CCS grades, mean EQ-5D scores ranged from 0.36 (95% confidence interval 0.25-0.48) for grade 4 to 0.81 (0.77-0.85) for grade 0, and for breathlessness grades, EQ-5D scores ranged from 0.31 (0.06-0.55) for grade 0 to 0.84 (0.79-0.88) for grade 5. The final model used data on CCS grades, breathlessness grades, and patients' current medications to predict EQ-5D scores. The model had an R2 value of 0.37, and predictions for less severe angina were considered more reliable than the estimates for severe angina. In the absence of utility data collected as part of a clinical trial it is possible to map HRQL utility data from samples of patients with similar characteristics to those in the original trial. The uncertainty surrounding the estimates should be considered when using the results to estimate QALYs for purposes of economic evaluation.

Adult↗
PubMed2005

Common methodological flaws in economic evaluations.

Economic evaluations are increasingly being used by those bodies such as government agencies and managed care groups that make decisions about the reimbursement of health technologies. However, several reviews of economic evaluations point to numerous deficiencies in the methodology of studies or the failure to follow published methodological guidelines. This article, written for healthcare decision-makers and other users of economic evaluations, outlines the common methodological flaws in studies, focussing on those issues that are likely to be most important when deciding on the reimbursement, or guidance for use, of health technologies. The main flaws discussed are: (i) omission of important costs or benefits; (ii) inappropriate selection of alternatives for comparison; (iii) problems in making indirect comparisons; (iv) inadequate representation of the effectiveness data; (v) inappropriate extrapolation beyond the period observed in clinical studies; (vi) excessive use of assumptions rather than data; (vii) inadequate characterization of uncertainty; (viii) problems in aggregation of results; (ix) reporting of average cost-effectiveness ratios; (x) lack of consideration of generalizability issues; and (xi) selective reporting of findings. In each case examples are given from the literature and guidance is offered on how to detect flaws in economic evaluations.

Cost-Benefit Analysis↗
PubMed2005

Incorporation of uncertainty in health economic modelling studies.

In a recent leading article in PharmacoEconomics, Nuijten described some methods for incorporating uncertainty into health economic models and for utilising the information on uncertainty regarding the cost effectiveness of a therapy in resource allocation decision-making. His proposals are found to suffer from serious flaws in statistical and health economic reasoning.Nuijten's suggestions for incorporating uncertainty: (a) wrongly interpret the p-value as the probability that the null hypothesis is true; (b) represent this probability wrongly by truncating the input distribution; and (c) in the specific example of an antiparkinsonian drug uses a completely inappropriate p-value of 0.05 when the null hypothesis would, in reality, be emphatically disproved by the data.His suggestions regarding minimum important differences in cost effectiveness: (a) introduce areas of indifference that suggest inappropriate reliance on cost minimisation while failing to recognise that decisions should be based on expected costs versus benefits; and (b) offer no guidance on how the probabilities associated with these areas could be used in decision-making. Furthermore, Nuijten's model for Parkinson's disease is over-simplified to the point of providing a bad example of modelling practice, which may mislead the readers of PharmacoEconomics. The rationale for this paper is to ensure that readers do not apply inappropriate analyses as a result of following the proposals contained in Nuijten's paper. In addition to a detailed critique of Nuijten's proposals, we provide brief summaries of the currently accepted best practice in cost-effectiveness decision-making under uncertainty.

Antiparkinson Agents↗
PubMed2005

Should patients have a greater role in valuing health states?

Currently, health state values are usually obtained from members of the general public trying to imagine what the state would be like rather than by patients who are actually in the various states of health. Valuations of a health state by patients tend to vary from those of the general population, and this seems to be due to a range of factors including errors in the descriptive system, adaptation to the state and changes in internal standards. The question of whose values are used in cost-effectiveness analysis is ultimately a normative one, but the decision should be informed by evidence on the reasons for the differences. There is a case for obtaining better informed general population preferences by providing more information on what it is like for patients (including the process of adaptation).

Adaptation, Psychological↗
PubMed2005

Increasing the generalizability of economic evaluations: recommendations for the design, analysis, and reporting of studies.

OBJECTIVES: Health technology assessment (HTA) is increasingly an international activity, and HTA agencies collaborate to avoid unnecessary duplication of effort. However, the sharing of the results from HTAs raises questions about their generalizability; namely, are the results of an HTA undertaken in one country relevant to another? METHODS: This study presents recommendations for increasing the generalizability of economic evaluations. They represent an important component of HTAs and are commonly thought to have limited generalizability. RESULTS: Recommendations are given for studies using patient-level data (i.e., evaluations conducted alongside clinical trials) and for studies using decision analytic modeling. CONCLUSIONS: If implemented, the recommendations would increase the value for investments in HTA.

Cooperative Behavior↗