Stuart Barton

Which clinical studies provide the best evidence? : The best RCT still trumps the best observational study

A common question in clinical consultations is: “For this person, what are the likely effects of one treatment compared with another?” The central tenet of evidence based medicine is that this task is achieved by using the best evidence combined with consideration of that persons individual needs.1 A further question then arises: “What is the best evidence?” Two recent studies in the New England Journal of Medicine have caused uproar in the research community by finding no difference in estimates of treatment effects between randomised controlled trials and non-randomised trials. The randomised controlled trial and, especially, systematic reviews of several of these trials are traditionally the gold standards for judging the benefits of treatments, mainly because it is conceptually easier to attribute any observed effect to the treatments being compared. The role of non-randomised (observational) studies in evaluating treatments is contentious: deliberate choice of the treatment for each person implies that observed outcomes may be caused by differences among people being given the two treatments, rather than the treatments alone. Unrecognised confounding factors can always interfere with attempts to correct for identified differences between groups. These considerations have supported a hierarchy of evidence, with randomised controlled trials and derivatives at the top, controlled …

Influences of practice characteristics on prescribing in fundholding and non-fundholding general practices: an observational study

Abstract Objective: To investigate the variation in prescribing among general practices by examining the contribution to this variation of fundholding, training status, partnership status, and the level of deprivation in the practice population and to investigate the extent to which fundholding has been responsible for any changes in prescribing. Design: Analysis of prescribing data (PACT) for the years 1990-1 (before fundholding) and 1993-4 (after fundholding). Use of multiple linear regressions to investigate the variation among practices in total prescribing costs (net ingredient cost per prescribing unit), prescribing volume (items per 1000 prescribing units), and mean cost per item in each of the two years and also the change in these variables between years. Setting: Former Mersey region. Subjects: 384 practices. Results: The models developed explained the variation in cost per item (43% of variation explained for 1990-1, 38% for 1993-4) and prescribing volume (34% for 1990-1, 38% for 1993-4) better than the variation in total prescribing costs (3% for 1990-1, 7% for 1993-4). The models developed to explain the change in these variables between years did not explain more than 10% of the variation. Most of the explained variation in the change in total prescribing costs was accounted for by fundholding. Of the £3.71 saved by first wave fundholders compared with non-fundholders £3.57 was attributable to fundholding alone. Conclusion: In neither year did fundholding make a major contribution to the variation in prescribing behaviour among practices, which was better explained by deprivation, training status, and partnership status, but it did seem largely responsible for differences in the rise of total prescribing costs between fundholders and non-fundholders. Key messages Much of the variation in prescribing practice remains unexplained. Fundholding is the major contributor to the differences in the rise in prescribing costs between fundholders and non-fundholders.

The association of some practice characteristics with antibiotic prescribing

Antibiotic prescribing in general practice is often considered inappropriate, and its volume excessive. Considerable variation in antibiotic prescribing volume and costs exists among practices.

Economic evaluations of drug therapy: attitudes of primary care prescribing advisers in Great Britain

All health authorities in Great Britain have both medically or pharmaceutical qualified staff to advise both the authority and the local primary care medical practitioners about drug use and prescribing. This study used a piloted postal questionnaire to assess the attitudes of these advisers to economic evaluations of drug therapy, and their perceptions of the barriers to achieving cost effective prescribing by use of these evaluations. There was a 65% response rate to the questionnaire. Economic issues were rated by advisers to be less important than clinical issues, but were considered at most meetings between advisers and primary care medical practitioners. Advisers wished to consider true cost effective prescribing but often felt obliged to consider drug acquisition costs and risks of budgetary overspends. The perceived inflexibility of existing structures within the British National Health Service and the lack of credibility of the evaluations (often perceived as pharmaceutical industry marketing) were the major barriers to the application of the evaluations. The paper concludes that advisers were keen to use economic evaluations to promote cost effective prescribing but were impeded by the perceived bias of existing studies and by rigid current NHS structures.

General practice fundholders' prescribing savings in one region of the United Kingdom, 1991-1994

Since 1991, fundholding general practitioners in the UK have had a financial incentive to contain prescribing costs. Research has confirmed that fundholding practices have contained their prescribing costs more effectively than non-fundholding practices, but how much fundholders have actually saved by changing their prescribing is difficult to quantify. Fundholders are allocated a prescribing budget, and the underspend on this budget has been taken to represent savings produced by changing prescribing behaviour. However, this assumes accuracy of budget setting, which has been questioned. The objective of this study was to estimate the true savings in prescribing made by fundholders during the first 3 years of fundholding, without making assumptions about the accuracy of budget setting. We compare this to underspends on prescribing budgets. The results suggest that budget setting did not give fundholders over-generous budgets and that budget underspends are justified by the true savings in prescribing.

The influence of practice characteristics on the prescribing of benzodiazepines and appetite suppressant drugs

Background—The prescribing volume of benzodiazepines and of appetite suppressant drugs have been suggested as possible indicators of prescribing quality.

DRUG RATIONING IN THE UK NATIONAL HEALTH SERVICE: CURRENT STATUS AND FUTURE PROSPECTS

SummaryThere are major problems in attempting to ration drug use in the UK. These include the large indigenous pharmaceutical industry, the nature of funding of drugs within the National Health Service (NHS) and the political sensitivities of rationing. Rationing of services within the NHS has therefore usually been implicit rather than explicit, and there is little public debate about rationing of health services.In relation to drug therapy, prescribing in primary care technically can only be rationed by encouraging the general practitioner (GP) to contain his or her own costs — effectively moving the difficult decision to the GP. Direct incentives to the GP, in the form of incentive payments or by fundholding seem to have some success in containing costs, largely by simple generic substitution.There are established systems in hospitals to control the costs of drugs, including formularies and drug management committees. Hospitals commonly try to transfer drug costs to the GP budget. While in part this is clinically appropriate, it can lead to tensions. Health authorities and GP fundholders now include prescribing, particularly at this interface, in their contracts with hospitals.Economic evaluations currently play little part in aiding decisions about choice of drug. These decisions tend to be dominated by the need for short term cost containment in the UK. Recent reforms of the NHS have moved responsibility for the rationing of services to the local authorities or purchasers; this might in time create an additional, local hurdle for pharmaceutical companies trying to market new drugs. A proposal to introduce a national limited formulary in which drugs will be selected partly on the basis of an economic evaluation seems impractical, although similar ideas might be further developed.

Development of an economic model for the management of upper gastrointestinal disease in primary care. Preliminary findings.

Health economic models for identifying therapeutic options that maximise health benefits from limited healthcare resources are being developed in a number of therapeutic areas. The development of such a model for upper gastrointestinal (UGI) symptoms to support decision-making by primary care clinicians is of particular importance, given the prevalence of this symptomatology. This economic model was based upon the clinical guidelines aimed at improving the management of UGI disorders at the primary care level that were developed by the International Gastro Primary Care Group. This paper discusses the derivation, methodology and results of the economic model developed to assess the resource implications arising from these clinical guidelines.In order to construct the economic model, it was necessary to identify the following: • every therapeutic pathway followed by patients • resource use along each pathway • the probabilities of following alternative pathways.One crucial factor underlying the interpretation of results obtained from any economic model is the time period covered by the model. The model presented here analysed the initial 12-month treatment period of ‘new’ patients presenting with UGI symptoms. In order to test the implications of a longer term perspective, the model is currently being developed to analyse resource use over a 24-month period.The model demonstrates that utilising the predominant symptom approach to the diagnosis and treatment of patients with UGI disorders appears to provide significant benefits in terms of patient management and effective resource use. This factor, together with the more intensive use of Helicobacter pylori eradication therapy, provides the potential to reduce the cost of drugs for the treatment of UGI disorders by approximately 15% in the UK.A major strength of the model is its adaptability to a wide range of clinical and cost scenarios. Such adaptability enables the model to effectively reflect the potential resource implications in countries exhibiting significantly different levels of cost and patient management. In this manner, the model provides one valuable method by which clinicians can be supported in optimising the management of UGI disorders within current resource constraints.

Doctors' knowledge about evidence based medicine terminology: General practitioners may not know the jargon, but could use the knowledge

Primary care p 950 In a report published in this issue (p 950) Australian general practitioners rated themselves and were then tested on their evidence based medicine skills.1 The results are not encouraging. Fifty general practitioners in Australia rated their understanding of seven common terms from evidence based medicine from “It would not be helpful for me to understand this term” to “I understand this and could explain it to others.” On average, only 22% said they understood each term and could explain it to others. Worse still, in the subsequent structured interview only one general practitioner could provide a fully satisfactory explanation of any of the terms, and many of the explanations revealed considerable misunderstanding. The authors of the study argue that general practitioners need to understand these terms to practise evidence based medicine and that there is little good research on how this can be done. …

Cost effectiveness of lowering cholesterol. Study did not take account of confounders.

EDITOR,—We welcome the approach taken by P D P Pharoah and W Hollingworth in using life tables to evaluate the cost effectiveness of reducing cholesterol concentration.1 This approach has been widely used elsewhere2 and is a valuable technique for evaluating health service interventions aimed at modifying the risk profiles of a population. Unfortunately, however, their analysis may be flawed as such analyses depend on obtaining an accurate assessment of the overall manner in which population death rates are influenced by the intervention …