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Biomedical subjects

John Hutton

Publications and source records attributed to John Hutton.

15 recordsLinked to original sources
PubMed2006

Reliability of ultrasound estimation of fetal weight in term singleton pregnancies.

AIM: To assess the reliability of ultrasound estimation of fetal weight undertaken antenatally at Wellington Hospital (Wellington City, New Zealand) in women with a singleton pregnancy = or >37 weeks gestation. METHOD: Data were collected retrospectively for pregnant women who had undergone ultrasound estimation of fetal weight <7 days prior to a term delivery (= or >37 weeks gestation) over the period of July 1998-June 2005. Stillbirths and multiple pregnancies were excluded. Ultrasound fetal weight estimations, calculated using a locally modified Woo formula, were compared with the infant's actual birth weight. RESULTS: A total of 1177 infants were studied. The mean absolute error and mean signed error (+/-SD) of ultrasound fetal weight estimations were 7.0+/-5.7% and -0.2+/-9.0%, respectively (n=1177). Three-quarters of estimations were within 10% of birth weight. Ultrasonic estimation of fetal weight tended to overestimate the weight of small infants (<2500 g; mean signed error = +3.5%+/-9.1%, n=98) and underestimate the weight of large infants (= or >4000 g; mean signed error = -3.3+/-8.7%, n=170). Both large and normal weight infants of women with diabetes tended to have their weight underestimated (mean signed error = -5.1+/-9.2%, n=48). Sensitivity, specificity, positive predictive value, and negative predictive value for ultrasonic detection of fetal weight = or >4000 g in non-diabetic women were 61%, 96%, 69%, and 94%, respectively. For detection of fetal weight = or >4500, the figures were 50%, 98%, 47%, and 98%, respectively. CONCLUSION: The accuracy of ultrasound estimations of fetal weight performed at Wellington Hospital within 7 days of delivery in term singleton pregnancies was at least similar and sometimes better than that reported in other studies. For one in four women, however, the fetal weight estimation was more than 10% different from the actual birth weight of their infant. Ultrasound measurements had a tendency to overestimate the weight of small infants while underestimating the weight of both large infants and the infants of diabetic mothers. As the reliability of ultrasound estimation of fetal weight to detect larger babies was poor, the use of such an objective measurement in the management of suspected macrosomia in term singleton pregnancies should be avoided.

Cohort Studies↗
PubMed2006

Framework for describing and classifying decision-making systems using technology assessment to determine the reimbursement of health technologies (fourth hurdle systems).

OBJECTIVES: Australia, Canada, and many European countries now use various forms of health technology assessment (HTA) in decision making regarding the reimbursement of drugs and other health technologies. To achieve a better understanding of the potential for use of HTA in this context, an analytical framework was developed to describe and classify existing fourth hurdle systems. METHODS: Based on a review of published literature, and official documentation, the key aspects of a fourth hurdle system were identified at two levels: policy implementation and individual technology decision. Characteristics of the systems were grouped under four main headings: constitution and governance, objectives, use of evidence and decision processes, and accountability. The comprehensiveness and relevance of this framework was assessed by an independent group of experts in HTA. A pilot study was undertaken, using only published sources, to test the feasibility of obtaining the information needed to complete the framework. RESULTS: The framework was found to be sufficiently broad to encompass all the issues of interest regarding the systems, but the proportion of information available from published sources was variable between sections of the framework and between countries, with average availability of 45 percent. CONCLUSIONS: The analytical framework will help researchers and policy makers in individual countries to understand their own systems and will allow some preliminary sharing of experience between countries. More experience of its application is needed to judge whether it will provide the basis for more formal comparison of systems and whether it will determine their appropriateness for particular decision contexts.

Australia↗
PubMed2005

Cost-effectiveness of oral ibandronate versus IV zoledronic acid or IV pamidronate for bone metastases in patients receiving oral hormonal therapy for breast cancer in the United Kingdom.

BACKGROUND: Oral ibandronate is a single-nitrogen bisphosphonate whose efficacy is similar to that of IV ibandronate for the treatment of bone metastases. OBJECTIVE: The aim of this study was to compare the cost-effectiveness of oral ibandronate with zoledronic acid and generic pamidronate (both administered by IV) for the treatment of bone metastases in patients with breast cancer receiving oral hormonal therapy in the United Kingdom. METHODS: A global economic model was adapted to the UK National Health Service. Patients were assumed to receive oral hormonal therapy for 50% of their projected 14.3-month survival. The primary outcome was incremental cost per quality-adjusted life-year (QALY). Bisphosphonate efficacy data for relative risk reduction of skeletal-related events (SREs) were obtained from clinical trials. Resource use data and costs associated with IV bisphosphonate infusions were derived from published studies and a unit cost database; monthly drug acquisition costs were obtained from the British National Formulary. Utility scores were applied to time with or without an SRE to adjust survival for quality of life. Therefore, differences in QALYs were driven by utility weights rather than survival time. Model design and inputs were validated through expert UK clinician review. The absence of comparative efficacy and safety data from clinical trials for the different bisphosphonates was a model limitation that we addressed by supporting our assumptions with UK expert clinician opinion and with expert clinician opinion outside of the United Kingdom, and by conducting sensitivity analyses. RESULTS: The projected total cost per patient was pound307 less with oral ibandronate compared with zoledronic acid, and pound158 less compared with the use of generic pamidronate (due to a reduction in staff time for infusions, avoidance of renal safety monitoring visits, and, in the case of IV generic pamidronate, a reduction in the number of SREs). Oral ibandronate was estimated to lead to a gain of 0.02 QALY, making it the economically dominant treatment option. CONCLUSIONS: In this study, we found that oral ibandronate was cost-effective for the management of bone metastases from breast cancer among patients receiving oral hormonal therapy in the United Kingdom. Oral ibandronate provided effective SRE and bone-pain management while avoiding resource use and costs associated with regular IV bisphosphonate infusions. Due to uncertainty surrounding the model assumptions, it would be valuable to repeat the analyses using data from comparative bisphosphonate trials, once they become available.

Administration, Oral↗
PubMed2003

Regulating the economic evaluation of pharmaceuticals and medical devices: a European perspective.

Throughout the developed world, economic evaluation of costly new pharmaceuticals and medical devices became increasingly widespread and systematic during the 1990s. However, serious concerns remain about the validity and relevance of this economic evidence, and about the transparency and accountability of its use in public sector reimbursement decisions. In this article, we summarise current concerns in Europe, based on interviews with European health economists from industry, universities, research institutes and consulting firms. We identify five challenges for European policy-makers, and conclude that there is considerable scope for improving decision-making without damaging incentives to innovate. The challenges are: (1). full publication of the economic evidence used in reimbursement decisions; (2). the redesign of licensing laws to improve the relevance of economic data available at product launch; (3). harmonisation of economic evaluation methodologies; (4). development of methodologies for evaluation of health inequality impacts; and (5). negotiation of price-performance deals to facilitate the use of economic evidence in post-launch pricing review decisions, as information is gathered from studies of product performance in routine use.

Clinical Trials as Topic↗
PubMed2003

Selecting methods for the prediction of future events in cost-effectiveness models: a decision-framework and example from the cardiovascular field.

Evidence on the cost-effectiveness of healthcare interventions is increasingly required by decision-makers. Economic models can provide timely information on the long-term impact of new technologies. However, models have been criticised because of the implicit assumptions they make, in particular the methods used to extrapolate data are rarely documented. This paper presents a systematic process for choosing a method of predicting events in economic models. This process is illustrated using a model examining the cost-effectiveness of a new HMG-CoA reductase inhibitor (statin) for primary prevention of cardiovascular disease (CVD). The prediction of future CVD events is a central component of the model, and the choice of method for predicting events was an important issue in the model's development. A literature review identified 11 studies with the information required to predict CVD events. A set of criteria were developed to assess the different methods of risk estimation, covering issues like scientific validity and acceptability to decision-makers. Risk equations derived from the Framingham Heart Study were found to be most suitable for predicting future events in the economic model. The paper illustrates how the development of economic models can be made more transparent, and suggests that the process outlined may be applied to other disease areas where there are several event prediction methods to choose from. In disease areas where published methods for predicting events are not available, the process outlined can make the uncertainty this leads to explicit, and highlight where further research is required. Such transparency can help decision-makers understand the scientific basis underpinning models, and therefore make these models more acceptable and useful for health policy-making.

Cardiovascular Diseases↗
PubMed2003

Military unique curriculum: identifying and prioritizing content.

We have identified and prioritized a series of objectives that warrant inclusion in the continuum of military medical education. Although participants in the 16th Conference on Military Medicine also discussed whether each objective should be taught at the medical student, resident, or staff physician level, to a large extent this distinction is not helpful, since many, if not most, of these topic areas would likely require incorporation at each of these three levels to achieve the desired level of competence in staff physicians. Incorporation of new curricular elements poses a significant challenge, since it is already difficult to fit the existing curriculum into the available time. It is not reasonable to consider increasing the number of lecture hours. Therefore, it is probable that some elements of the existing curriculum will need to be pared down or eliminated to incorporate new material. In the past, when new material has been added to the existing curriculum, such as when the pathogenesis of human immunodeficiency virus was added, it has generally been done at the individual teacher or at most departmental level. Although this approach has the advantage of having a subject matter expert decide how best to insert new material within the fabric of the existing curriculum, there are a couple of problems with widespread use of this approach. First, some of these new objectives may not fit clearly within an existing course curriculum or department's educational mission. Second, such an approach may not provide the degree of coordination that is necessary to ensure that a new curricular item is adequately covered in all respects, and it may result in unnecessary overlap in instruction when different professors incorporate similar elements. Therefore, the prioritization of newer curricular items, as has been done during this conference, may serve as a useful guide in this process. However, a corresponding effort is needed to identify and prioritize existing curricular components. Decisions need to be made regarding what, within the existing curriculum, should be cut out or reduced to make room for some or all of these new objectives. Finally, a decision needs to be made regarding which of these identified objectives should be inserted and when and within which courses they should be taught. These are important decisions that should not be left to the whims of chance. As the responsible recipients of Uniformed Services University and Health Professions Scholarship Program medical school graduates, the services' Surgeons General need to take an active role in helping to make these decisions. The outcome of these decisions will have a direct impact on the capabilities that these future junior medical officers will bring to the patients they will care for and to the line commanders that they will support.

Curriculum↗
PubMed2002

Developing the revised NICE appraisal technical guidance to manufacturers and sponsors: opportunity or threat?

One of the principal roles of the National Institute for Clinical Excellence (NICE) is to appraise selected existing and emerging healthcare technologies and, as a result, produce guidance for the National Health Service (NHS) in England and Wales. A central part of this appraisal is the potential for manufacturers and sponsors to make a data submission. This paper describes the process of development of the second edition of technical guidance to manufacturers and sponsors for submission to NICE. The revision process took place during the period May 2000 and January 2001 and involved a number of key steps -- establishment of a guidance steering committee, review of current international guidelines of clinical and cost effectiveness, drafting of the guidance, detailed consultation with stakeholders, revision of the guidance and, finally, publication. The lessons learnt from revision of the NICE guidance for manufacturers and sponsors and some main issues for its future development are discussed.

Biotechnology↗
PubMedDate not supplied

Cost-effectiveness analysis of interferon beta in multiple sclerosis: a Markov process analysis.

OBJECTIVE: The objective of this study was to examine the cost-effectiveness of preventive treatment with interferon beta (IFNB) versus no preventive treatment in patients with multiple sclerosis. METHODS: The setting for this study was the United Kingdom. A lifetime Markov process model was constructed to model the average quality-adjusted life years (QALYs) and the costs of both treatment strategies. Data for the construction of the model came from published literature, including large multicenter randomized clinical trials in relapsing-remitting and secondary progressive multiple sclerosis. Costs were obtained from published sources. RESULTS: The results of the baseline analysis from the National Health Service (NHS) perspective showed that the use of interferon beta as preventive treatment for MS increased the total average discounted cost from 51,214 Pounds to 221,436 Pounds per patient. The undiscounted effectiveness increased from 24.9 QALYs to 28.2 QALYs, resulting in an incremental cost-effectiveness ratio of 51,582 Pounds per QALY. Sensitivity analyses showed the robustness of this model for other interferons. CONCLUSION: The study showed that preventive treatment with interferon beta in patients with multiple sclerosis may not be fully justified from a health-economic perspective, although interferon beta is associated with an improved effectiveness compared with no preventive treatment.

Adjuvants, Immunologic↗
PubMedDate not supplied

Development of a decision-analytic model of stroke care in the United States and Europe.

OBJECTIVE: Stroke places a huge burden on society in terms of premature death, disability, and costs of care. Increasingly, the cost-effectiveness of new interventions needs to be demonstrated before their widespread implementation. Clinical trials are unable to measure the long-term impact of such new interventions in stroke care, and a modeling approach is necessary. The Stroke Outcome Model has been developed in four countries: France, Germany, the United Kingdom, and the United States as a flexible tool for this purpose. METHOD: The decision-analytic model represents the management of acute stroke and long-term care and prevention of recurrence for stroke survivors. The latter consists of semi-Markov state-transition processes, with health states defined by therapy, disability, and occurrence of further stroke. Sources of clinical data include trials, meta-analyses, and prospective cohort studies such as the Oxfordshire Community Stroke Project and the Northern Manhattan Stroke Study. Resource use data were obtained from published sources and expert clinician panels. Outcome measures used were strokes averted, life years, and quality-adjusted life-years gained. RESULTS: The model has been used to undertake economic analyses of antiplatelet therapy for the prevention of recurrent strokes, and of stroke unit care and thrombolytic therapy in acute stroke. From a health- and social-care perspective, new interventions were found to be cost saving or to provide health benefits at modest additional cost. Results were sensitive to the cost perspective, time horizon, baseline risk of stroke recurrence, and choice of effectiveness measure. CONCLUSION: The development of this model highlights the need for improved information on prognosis and resources used by stroke survivors and the importance of differentiating between economically distinct end points such as death, disabled survival and nondisabled survival, which may be combined as outcomes in clinical trials.

Acute Disease↗