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Biomedical subjects

M Buxton

Publications and source records attributed to M Buxton.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1996

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

Using information from the Papworth Hospital heart transplant service, a model was developed to link the main clinical events after cardiac transplantation to survival and costs. On the basis of the clinical and survival experience of 387 patients treated with triple-drug immunosuppression between 1986 and 1993, together with protocols for patient management, resource use, and costs, a 5-year Markov model with three time periods was used to simulate survival and estimate costs. The model accurately mirrors observed actuarial survival; 1- and 5-year survival rates were 81% and 65%, respectively. An average cost per patient of 26,000 pounds over 5 years (discounted at a rate of 6%) was estimated. The expense of routine care for patients accounts for the majority of the costs; a patient who remains well throughout the 5-year period would incur costs of 23,000 pounds. The sensitivity of the estimates to alternative assumptions is presented, and the way in which the model can be used to compare alternative future scenarios is explored.

Adolescent↗
PubMed1996

Costs and cost effectiveness of cardiovascular screening and intervention: the British family heart study.

OBJECTIVE: To measure costs and cost effectiveness of the British family heart study cardiovascular screening and intervention programme. DESIGN: Cost effectiveness analysis of randomised controlled trial. Clinical and resource use data taken from trial and unit cost data from external estimates. SETTING: 13 general practices across Britain. SUBJECTS: 4185 men aged 40-59 and their 2827 partners. INTERVENTION: Nurse led programme using a family centered approach, with follow up according to degree of risk. MAIN OUTCOME MEASURES: Cost of the programme it self; overall short term cost to NHS; cost per 1% reduction in coronary risk at one year. RESULTS: Estimated cost of putting the programme into practice for one year was 63 pounds per person (95% confidence interval 60 pounds to 65 pounds). The overall short term cost to the health service was 77 pounds per man (29 pounds to 124 pounds) but only 13 pounds per woman (-48 pounds to 74 pounds), owing to differences in utilisation of other health service resources. The cost per 1% reduction in risk was 5.08 pounds per man (5.92 pounds including broader health service costs) and 5.78 pounds per woman (1.28 pounds taking into account wider health service savings). CONCLUSIONS: The direct cost of the programme to a four partner practice of 7500 patients would be approximately 58,000 pounds. Annually, 8300 pounds would currently be paid to a practice of this size working to the maximum target on the health promotion bands, plus any additional reimbursement of practice staff salaries for which the practice qualified. The broader short term costs to the NHS may augment these costs for men but offset them considerably for women.

Adult↗
PubMed1996

What can be concluded from the Oxcheck and British family heart studies: commentary on cost effectiveness analyses.

OBJECTIVES: To provide a commentary on the economic evaluations of the Oxcheck and British family heart studies: direct comparison of their relative effectiveness and cost effectiveness; comparisons with other interventions; and consideration of problems encountered. DESIGN: Modelling from cost and effectiveness data to estimate of cost per life year gained. SUBJECTS: Middle aged men and women. INTERVENTIONS: Screening for cardiovascular risk factors followed by appropriate lifestyle advice and drug intervention in general practice, and other primary coronary risk management strategies. MAIN OUTCOME MEASURES: Life years gained; cost per life year gained. RESULTS: Depending on the assumed duration of risk reduction, the programme cost per discounted life year gained ranged from 34,800 pounds for a 1 year duration to 1500 pounds for 20 years for the British family heart study and from 29,300 pounds to 900 pounds for Oxcheck. These figures exclude broader net clinical and cost effects and longer term clinical and cost effects other than coronary mortality. CONCLUSIONS: Despite differences in underlying methods, the estimates in the two economic analyses of the studies can be directly compared. Neither study was large enough to provide precise estimates of the overall net cost. Modelling to cost per life year gained provides more readily interpretable measures. These estimates emphasise the importance of the relatively weak evidence on duration effect. Only if the effect lasts at least five years is the Oxcheck programme likely to be cost effective. The effect must last for about 10 years to justify the extra cost associated with the British family heart study.

Adult↗
PubMed1996

The economic evaluation of the FIRST study: design of a prospective analysis alongside a multinational phase III clinical trial. Flolan International Randomized Survival Trial.

Prospective economic assessments of new pharmaceutical therapies are increasingly being incorporated into phase III clinical trials. We report on the design of an economic evaluation integrated into the Flolan International Randomized Survival Trial (FIRST). Economic evaluation was considered a critical component of the assessment of this therapy given the resources required to administer epoprostenol (Flolan), a therapy that would require lifelong continuous intravenous infusion. Economic secondary endpoints were incorporated in the clinical trial. The economic evaluation of the treatment was integrated into all aspects of study development, including study design, implementation, and monitoring. Since this was a multinational trial, special care was required to ensure that the protocol design was appropriate for all study countries. The economic assessment required the development of several methodologic components: a set of background economic concepts to guide protocol development, a set of resource items to be recorded when required for study participants; a set of data collection instruments for assessment of health-related quality of life for study patients; and a protocol for a resource costing exercise for the study. We report the data elements included in the study design, as well as a discussion of some of the issues faced in developing the economic evaluation for this trial.

Antihypertensive Agents↗
PubMed1996

Results of the economic evaluation of the first study. A multinational prospective economic evaluation. FIRST Investigators. Flolan International Randomized Survival Trial.

We present the prospective economic evaluation that served as a secondary endpoint for the FIRST study, a randomized international multicenter trial of patients with severe congestive heart failure. Although the clinical results of this study were disappointing, we demonstrated the feasibility of incorporating prospective economic evaluation in phase III clinical trials.

Aged↗
PubMed1996

The SECCAT survey: I. The costs and consequences of alcoholism.

The SECCAT survey assessed the Socio-Economic Costs and Consequences of Alcoholism Treatment. Basic demographic and health service resource use data (for a previous 6-month period) were obtained fro a cohort of 586 eligible patients who had had treatment at the Alcohol Problems Clinic (APC) in Edinburgh. The cohort was 75% male with a mean age of 46.0 years. Seventy-six per cent had an initial diagnosis of alcohol dependence and 21% alcohol abuse. Use of health services was highly variable. Thirty-six per cent agreed to be interviewed to provide data on their level of abstinence, on resource use, on quality of life (SF-36), on socio-economic characteristics and key adverse events. These 212 individuals had similar age and sex ratios to the full cohort, but alcohol abusers were under-represented. Nineteen patients reported no days of abstinence and 41 were abstinent over the whole 6-month period. Patients experienced a much poorer quality of life than a normal population in terms of all dimensions of the SF-36. The average total health care costs of the interviewed patients were 1134 pounds of which 38% were related to treatment at the APC. Analysis suggests that alcohol-dependent patients make substantially more costly use of resources than abusers and experience a much poorer quality of life. No clear relationship of cost to degree of abstinence has been found. There is a clear and consistent relationship of SF-36 scores and drinking behavior.

Adult↗