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M Buxton

Publications and source records attributed to M Buxton.

At least 19 recordsLinked to original sources
PubMed2001

Design and analytic considerations in determining the cost-effectiveness of early intervention in asthma from a multinational clinical trial.

Demand for economic and outcomes data in support of drug formulary listing in private and government-sponsored health programs has led to fundamental changes in drug development. In part as a response to these pressures, the pharmaceutical industry has begun to include economic and quality-of-life endpoints in clinical trials with the hope of providing information to answer health policy questions on the economic value of its products. Here, the design and health economic techniques that will be used to analyze the START (inhaled Steroid Treatment As Regular Therapy in early asthma) study-a multinational (31 countries), randomized, placebo-controlled trial of 7240 patients with mild asthma over 3 years-will be presented. START compares the effect of once-daily administration of an inhaled glucocorticosteroid (Pulmicort Turbuhaler to conventional therapy in the management of newly diagnosed asthma, for which the use of this therapy is currently not the standard. The START study will examine both clinical effectiveness (measured as symptom-free days) and asthma-related costs for both treatment arms, aggregated for all patients across all countries. We believe that presenting the analytical plan prior to disseminating the results is an important way of increasing the credibility of economic evaluations. However, using clinical trials for collecting economic data poses several challenges, and the methods for conducting such evaluations are being developed. This paper will present and discuss several methodological options and the current state of the art for conducting economic evaluations alongside multinational clinical trials.

Administration, Inhalation↗
PubMed2001

A model for analyzing the cost of the main clinical events after lung transplantation.

BACKGROUND: The aim of this project was to model clinically important events experienced by lung transplant patients (from the day after transplant to 5 years or death) and costs associated with these events, and to assess the economic impact of different immunosuppression therapies. METHODS: The population comprised 356 lung transplant patients (223 heart-lung, 102 single lung and 31 double lung) transplanted between April 1984 and December 1997. All patients received a cyclosporine-based triple-immunosuppression protocol. We designed a Markov model that included 3 time periods (0 to 6, 7 to 12, and 13 to 60 months), 5 clinical states (well, acute rejection, cytomegalovirus infection, non-cytomegalovirus infection and bronchiolitis obliterans syndrome), and death. For the well state, cost elements were immunosuppression, prophylaxis, and routine clinic visits. For all other states, cost elements were diagnosis, treatment, and bed days/visits. We excluded costs of the procedure. RESULTS: The monthly costs associated with the well state decreased over time, from pound sterlings 1,778 ($2,658) in the first 6 months to pound sterlings 503 ($752) in months 7 to 12 and pound sterlings 350 ($523) after the first 12 months. The cost per event of the acute states remained reasonably constant over the 3 periods: pound sterlings 1,850 ($2,766) for rejection, pound sterlings 3,380 ($5,053) for cytomegalovirus, and pound sterlings 2,790 ($4,171) for other infections. The average cost per patient, discounted at 6%, over 5 years was pound sterlings 35,429 ($52,966) (95% range, pound1,435 [$2,145] to pound67,079 [$100,283]). This estimate is most sensitive to changes in immunosuppression. Substituting tacrolimus for cyclosporine increased 5-year costs by 5%; substituting mycophenolate mofetil for azathioprine increased 5-year costs by 26%. CONCLUSIONS: This model is valuable in estimating the effect of new immunosuppression agents on the costs of follow-up care.

Adult↗
PubMed2001

A simulation modelling approach to evaluating alternative policies for the management of the waiting list for liver transplantation.

A shortage of donor liver grafts unfortunately results in approximately 10% of patients dying whilst listed for a liver transplant in Europe and the United States. Thus it is imperative that all available organs are used as efficiently as possible. This paper reports upon the application of a simulation modelling approach to assess the impact of several alternative allocation policies upon the cost effectiveness of this technology at one liver transplant centre in the UK. The impact of changes in allocation criteria on the estimated net life expectancy, average net costs and overall cost effectiveness of the transplantation programme were evaluated. The incremental cost effectiveness ratio (ICER) for the base case allocation policy, based upon the time spent on the waiting list (i.e., longest wait first) was 11,557 pounds sterling at 1999 prices. The ICERs associated with an allocation policy based upon age (lowest age first), and an allocation policy based upon the severity of the pre-transplant condition of the patient (with most severely ill patients given a lower priority) were lower than the base case at 10,424 pounds sterling and 9,077 pounds sterling, respectively. The results of this modelling study suggest that the overall cost effectiveness of the liver transplantation programme could be improved if the current allocation policy were modified to give more weight to the age of the patient and the reduced chances of success of the most severely ill patients.

Cost-Benefit Analysis↗
PubMed2000

Preference measurement using conjoint methods: an empirical investigation of reliability.

The application of conjoint measurement to the field of health economics is relatively new, although there is growing interest and there have been a number of studies undertaken recently. Wider acceptance of the technique requires methodological issues concerning both reliability and validity to be addressed. This paper reports an empirical investigation of the test-retest reliability of the discrete choice conjoint measurement approach in health care. This investigation of conjoint reliability was framed using the clinical context of investigation and treatment of knee injuries. A high level of reliability at both the input data and results levels was demonstrated.

Adolescent↗
PubMed2000

Estimating the impact of a diffuse technology on the running costs of a hospital. A case study of a picture archiving and communication system.

OBJECTIVES: This paper considers the methodological problems that arise in conducting cost analyses in economic evaluations where only observational (rather than experimental) data are available and where the technology being evaluated is diffuse, such that the unit of analysis has to be the institution rather than the patient. METHODS: A case study is reported that concerns the application of computer technology in radiology: picture archiving and communication systems (PACS). A range of different approaches were used to estimate changes in running costs, including time series analyses of routine data and direct observation of resource use. RESULTS: The analysis illustrates some of the difficulties involved in costing the introduction of a diffuse technology. Nevertheless, it provides a firm indication that, overall, the introduction of PACS was found to be associated with a significant increase in hospital costs, suggesting that the initial expectations of financial savings were unduly optimistic. CONCLUSIONS: The research demonstrates that, using multiple methods, it is possible to estimate cost changes within a single hospital. In addition, the paper discusses the nature of the uncertainties in such analyses and possible ways of representing such uncertainty in terms of confidence intervals.

Budgets↗
PubMed1999

Transmyocardial laser revascularisation in patients with refractory angina: a randomised controlled trial.

BACKGROUND: Transmyocardial laser revascularisation (TMLR) is used to treat patients with refractory angina due to severe coronary artery disease, not suitable for conventional revascularisation. We aimed in a randomised controlled trial to assess the effectiveness of TMLR compared with medical management. METHODS: 188 patients with refractory angina were randomly assigned TMLR plus normal medication or medical management alone. At 3 months, 6 months, and 12 months after surgery (TMLR) or initial assessment (medical management) we assessed exercise capacity with the treadmill test and the 12 min walk. FINDINGS: Mean treadmill exercise time, adjusted for baseline values, was 40 s (95% CI -15 to 94) longer in the TMLR group than in the medical-management group at 12 months (p=0.152). Mean 12 min walk distance was 33 m (-7 to 74) further in TMLR patients than medical-management patients (p=0.108) at 12 months. The differences were not significant or clinically important. Perioperative mortality was 5%. Survival at 12 months was 89% (83-96) in the TMLR group and 96% (92-100) in the medical-management group (p=0.14). Canadian Cardiovascular Society score for angina had decreased by at least two classes in 25% of TMLR and 4% of medical-management patients at 12 months (p<0.001). INTERPRETATION: Our findings show that the adoption of TMLR cannot be advocated. Further research may be appropriate to assess any potential benefit for sicker patients.

Angina Pectoris↗
PubMed1999

Evaluation of a hospital picture archiving and communication system.

OBJECTIVES: To establish the net costs to the hospital and the broad range of benefits associated with a hospital-wide picture archiving and communication system (PACS) that comprised digital acquisition, storage and transmission of radiological images via a hospital-wide network to 150 workstations. METHODS: 'Before and after' comparisons and time series analyses at Hammersmith Hospital (London, UK), and comparison with five other British hospitals where PACS was not being installed. The cost analysis considered implementation costs and changes in key elements of hospital running costs, including the impact of changes in the length of inpatient stays. A range of benefit measures were investigated, including image availability, avoidance of repeat imaging, avoidance of exposure to radiation, patient turn-round speed, time from examination to image availability in intensive care, avoidance of diagnostic 'errors' by casualty doctors, the additional diagnostic value of PACS-based images and clinician satisfaction. RESULTS: The annual equivalent capital cost of the PACS was 1.7 million Pounds (annual equivalent replacement cost: 0.8 million Pound). Overall, the PACS substantially increased running costs. No convincing evidence of a PACS-induced change in length of inpatient stay was found. PACS was associated with some improvements in the performance of the radiology department: improved image availability (97.7% versus 86.9%), lower repeat imaging rate (7.3% versus 9.9%) and 20% lower total radiation doses for examinations of the lateral lumbar spine. No improvements were identified in the quality of the radiology reporting service. Benefits outside radiology included shorter time from examination to image availability for routine uses in intensive care (19 versus 37 minutes), and a lower rate of diagnostic 'errors' in casualty (0.65% versus 1.51%). High levels of satisfaction with PACS were found amongst both providers and clinical users. CONCLUSIONS: PACS was almost universally preferred by users and brought many operational and clinical benefits. However, these advantages came at a significant capital and net running cost.

Cost-Benefit Analysis↗
PubMed1999

Patients' preferences regarding the process and outcomes of life-saving technology. An application of conjoint analysis to liver transplantation.

The economic technique of conjoint analysis was used to assess the relative importance of health outcome versus several process attributes (e.g., waiting time, continuity of contact with the same medical staff) in determining patients' preferences for liver transplantation services. The attributes were established by reference to the literature and through initial qualitative interviews with liver transplant recipients (n = 12). Following a pilot study of 40 patients, a sample of patients (n = 213) who have received a liver transplant at the Queen Elizabeth Hospital in Birmingham were surveyed. The technique of conjoint analysis was used to ascertain the relative importance of the attributes included in the exercise and to estimate the marginal rates of substitution (MRS) between different attributes. A useable response rate of 89% was achieved. Although a small proportion of respondents (15%) exhibited dominant preferences for the chance of success attribute, the majority of respondents indicated that they would be prepared to exchange a reduction in health outcome for an improvement in the process characteristics of the liver transplantation service. The results of this study have potentially important implications for the assessment of the benefits of medical technologies since they suggest that, even in the extreme case of life-saving interventions, the preferences of respondents may not be dependent solely upon health outcomes but may also be determined by attributes associated with the process of care.

Choice Behavior↗
PubMed1998

Magnetic resonance imaging for the investigation of knee injuries: an investigation of preferences.

The conventional approach to the diagnosis and treatment of severe knee injuries is arthroscopy, a minimally invasive surgical procedure. Since arthroscopy is an invasive technique that carries risks, magnetic resonance imaging (MRI) is increasingly being used for diagnosis. MRI is potentially associated with diagnostic and therapeutic 'impacts', in that arthroscopy can be avoided. This paper reports a discrete choice conjoint analysis exercise that assessed the value placed on such 'impacts' by potential patients and investigated the degree to which respondents were willing to trade between process and outcome. The marginal rates of substitution between attributes were estimated. The results suggest that the diagnostic and therapeutic 'impacts' of MRI were valued by many respondents. The study has highlighted a number of important issues for the design and analysis of future health-related conjoint studies, including the use of treatment cost as an attribute, dealing with data from lexicographic respondents, and distinguishing between points of indifference and missing data.

Adult↗
PubMed1998

The preliminary economic evaluation of health technologies for the prioritization of health technology assessments. A discussion.

This paper critically evaluates methods for the preliminary economic evaluation of health technologies and the prioritization of health technology assessment projects. It reports on the literature, and considers methods currently employed and the purposes of preliminary appraisal. It concludes that a preliminary economic appraisal needs to be applied to the two main stages of the prioritization process; to have transparent criteria; to allow for an appropriate range of potential outcomes; to be practicable, flexible, and efficient; and to be relevant to the assessment of different research projects.

Cost-Benefit Analysis↗
PubMed1998

The economic perspective.

The rationale for the economic perspective on screening is presented and the particular relevance of economic evaluation highlighted. The principles of economic evaluation are described in terms of measuring and valuing the costs and outcomes associated with screening. The different types of economic evaluation are described with discussion of data sources. The problematic issues associated with time preferences and discounting and with the measurement and valuation of outcomes other than true positives are discussed. Issues associated with antenatal screening, in particular the inclusion of averted costs due to the termination of an affected pregnancy and the inclusion and valuation of the unborn child's utility, are also raised.

Cost-Benefit Analysis↗
PubMed1997

Cost effectiveness scenario analysis for a proposed trial of hormone replacement therapy.

Whereas evaluation of resource implications and quality of life are often incorporated into assessments of health technology, the decision to undertake the assessment is still mostly driven by interests in the clinical outcomes alone. A systematic approach to evaluating expected returns to health technology assessment has not been readily taken up by research funders or assessors. This paper sets out a specific methodology for ex ante evaluation or triage and proposes a decision procedure, using alternative outcome scenarios and the associated policy changes and costs and benefits, against a background of likely clinical practice in the absence of the assessment. The methodology is used to consider implications of a proposed major clinical trial to assess the long term costs and benefits of hormone replacement therapy.

Clinical Trials as Topic↗
PubMed1997

The iterative use of economic evaluation as part of the process of health technology assessment.

The economic evaluation of health care technologies has a key role within the new National Health Service health technology assessment process. There has, however, been little discussion of the best way of combining economic and clinical research. Economic evaluation should be iterative, generating progressively firmer estimates of cost-effectiveness and helping to maximise the efficiency of health care R&D. Here, four stages of economic analysis are suggested, starting with stage I when the basic clinical science is complete, and finishing with stage IV analysis to generalise the results of earlier studies to routine clinical practice.

Clinical Trials as Topic↗