Multidimensional graphical representation of treatment target population
Authors: Malik Fardeheb, Michel Cucherat, Margaret Haugh, Florent Boutitie, Jean-Pierre Boissel (The French Cochrane Centre, France)
Background: When choosing the best treatment for a given patient, a physician must compare the patient's profile with each treatment's target population. A treatment target population needs to be defined using variables that interact with the size of the treatment effect. These variables include the patients' characteristics, treatment and dose, and also compliance among others. For each set of values for these variables the quantity of treatment effect will be different. The structure of the target population can be represented simply using multidimensional graphical techniques, and this approach may help to determine the optimal treatment-patient association.
Objectives: To develop a graphical tool to represent the evolution of the quantity of treatment effect in a space of variables that interact with all the possible treatments corresponding with the therapeutic objective identified. The limitations we set were that the graphical representation(s) chosen had to be, reproducible, simple to use and readily understandable by physicians without particular training.
Methods: We reviewed the available multidimensional graphical methods which have no limits for the number of variables (both qualitative and quantitative), and these methods were used to represent the target populations.
Results: Among these techniques, both linear and polar profiles offer the advantages of allowing the quantity of treatment effect to be visualised as a function of the variables that interact with the treatment effect. The target population can also be visualised, a given patient can be positioned in the space of the target population, and the expected treatment effect for a given patient can be expressed. Furthermore, those techniques satisfy the requirements of reproducibility and simplicity of use for untrained physicians.
Conclusions: This approach should be investigated further to evaluate its acceptability to a larger sample of physicians.
EPIDAS: a randomised controlled clinical trial to assess the efficacy of the transmission of therapeutic information
Authors: Jean-Pierre Boissel, Margaret Haugh, Michel Cucherat, Catherine Brun, Evelyne Gauthier (Serivce de Pharmacologie Clinique & The French Cochrane Centre, France)
Background: Several trials have shown that there is a discrepancy between prescribers behaviour and results from clinical trials. The reasons for this gap are probably manifold, but access to pertinent information is almost certainly one important reason.
Objectives: To assess the efficacy of the transmission of therapeutic information to general practitioners.
Methods: At least 2000 French general practitioners will be enrolled in a randomised controlled trial with a factorial design. Therapeutic information for a restricted number of pathologies (depression, stomach ulcers, cystitis, menopausal hormone replacement therapy) will be collected and synthesised by invited expert committees. This information will then be translated into a message, which will be a format more readily assimilated by the prescriptors. These messages will be transmitted using a paper form (regular bulletin) or by a free-phone (or fax) service for a three-month period.
The physicians (in geographical clusters of about 10) will be allocated to receive the bulletin, to have access to the free-phone service, to have both, or to have neither, giving 4 cells. In addition, half the physicians in each group will attend a half-day seminar on the concepts used in therapeutic information, giving a total of 8 cells. To assess the efficacy of the transmission, the physicians will pass a knowledge test, reply to a series of simulated cases, and collect their prescriptions for a week before and after the 3-month intervention.
The primary analysis will assess the change in the percentage of replies for the simulated cases judged to be conform with the information transmitted. The secondary analysis will assess this change for the prescriptions that concern the pathologies chosen for the trial.
Two pilot studies will be completed in May - June 1996. The first will assess the seminar on therapeutic information, and the second will assess the acceptability of the forms to be used for the data collection (i.e. multiple-choice test, simulated cases prescriptions, and prescriptions using a trial-specific prescription form).
Development of a Cardiac Outcomes Register in the West Moreton Region of Queensland
Authors: Ian Scott, Suzanne Hux1ey, Margo Eyeson-Annan, Alun Richards, Helen Le Goode.
Background: The West Moreton region of Queensland covers an area of 7,970 km' west of Brisbane, with a population of approximately 160,000. The standardised mortality ratios in West Moreton region are significantly increased for ischaemic heart disease (IHD), accounting for 30.4% of all deaths in 1986-92, compared to 27.5% for the state as a whole, representing an annual excess of 44 deaths per year. The excess morbidity is unable to be ascertained, but is probably even more sicgnificant. Over 85% of residents of West Moreton region requiring hospital treatment for IHD present to one of the two major hospitals in the region.
Objectives: The purpose of this project is to create a seamless multi-sectoral model of care, rehabilitation and secondary prevention for patients with IHD in West Moreton region.
Methods: A Cardiovascular Outcomes Council was established to draw together services who could impact on improving the outcomes for people who have experienced a cardiac event and to identify barriers preventing this process. The council consists of representatives from Population Health, Community and Rural Health Services, the participating hospitals and the Division of General Practice.
Results: One the major barriers identified was the lack of cardiac outcomes data. A cardiac outcomes register was established to collect preadmission, inpatient management and rehabilitation data including risk factors and quality of life indices.
Conclusions: Following the establishment of the cardiac outcomes register information is becoming available to enable measurement and evaluation of outcomes of clinical care, rehabilitation, changes in quality of life indices and risk factor profiles resulting from different interventions.
Increasing Evidence-Based Decision Making in Public Health
Authors: Donna Ciliska, Larry Chambers, Sarah Hayward, Marilyn James, Jane Underwood (Regional Municipality of Hamilton-Wentworth, Department of Public Health Services, and McMaster University, Canada)
Background: Research and evaluation is intended to support decision-making by policy-makers, managers and clinicians. Concern over failures to use these findings has led many disciplines to make dissemination and application of research a priority. In addition, multidisciplinary groups have formed with the same priorities. While these various groups are focused, as most health care dollars are, on acute care, there is also much work being done in public health. The Regional Municipality of Hamilton-Wentworth Department of Public Health Services, is a Teaching Health Unit associated with McMaster University and the University of Guelph in Ontario, Canada.
Objectives: To identify public health effectiveness literature (published and unpublished), to critically appraise it, and to synthesize that information for answering various questions.
Methods: In order to meet that objective, a number of activities have been initiated such as the identification of public health studies, production of reviews and dissemination activities.
Results: RCTs and CCTs published in the Canadian Journal of Public Health have been identified. Several overviews have been produced on topics such as maternal-infant community interventions, community-based heart health interventions, community development, prevention of adolescent suicide, and home visiting by public health nurses as a care delivery strategy.
Conclusion: There is adequate literature in public health to conduct overviews which can be disseminated for decision-making.
When there is no evidence - an RCT for treatment of otitis media with asymptomatic effusion (OME) in Aboriginal infants
Authors: Amanda Leach, Peter Morris, Philip Baker, John Mathews Menzies School of Health Research
Background: Otitis media in Aboriginal children with high rates of chronic disease is poorly managed.
Objective: To describe the process of obtaining evidence for a benefit or otherwise of treatment for OME in Aboriginal infants living in a remote, disadvantaged and cross-cultural setting.
Methods: Natural history and pilot antibiotic treatment studies were required to provide scientific evidence and a rationale for an RCT of OME treatment.
Results: The natural history and aetiology of OME in populations of low socio-economic status had previously been poorly understood. Metaanalyses show limited benefits of treatment in low-risk populations with higher natural cure rates. Our prospective studies showed that onset of OME occurred within weeks of birth and persisted throughout early childhood. Nasopharyngeal colonisation with respiratory bacteria was predictive of OM onset. Uncontrolled studies showed that early treatment led to less perforation but facilitated the spread of an antibiotic resistant strain of Streptococcus pneumoniae. Challenges in implementing an RCT include issues related to the cross-cultural and disadvantaged setting, ethical approval, obtaining clinical trial expertise and procurement of placebo.
Conclusion: A strong rationale for an RCT was established during 3 years of preliminary research. Successful conduct of this RCT will have implications for management of otitis media with effusion and will provide incentives for further RCTs that address the many health problems of Aboriginal Australians.
Can Systematic Reviewing be Adapted for Hypothesis Testing in Medicine and Biology?
Author: Robert Miller, Department of Anatomy and Structural Biology, University of Otago Medical SchoolDunedin, New Zealand. Background: Reviewing procedures inspired by Cochrane improve evaluation of treatment procedures by accessing all relevant RCTs, specifying search procedures and data used, with subjective judgements minimized by crosschecking between reviewers. The weaknesses of conventional approaches to reviewing, which led to the Cochrane movement also apply more widely when reviews attempt to evaluate hypotheses, for instance about aetiopathological bases of disease. This is closely related to treatment evaluation because many treatment procedures derive from inadequate hypotheses which cannot survive critical scrutiny in a systematic review.
Objectives: This paper discusses possibilities of systematic reviewing for hypothesis testing in medicine.
Discussion: Testing disease hypotheses is more complex than evaluating RCTs, because relevant information is more diverse. Nevertheless, if a definite hypothesis is identifiable, explicit predictions and ways of falsifying it can be deduced. Specific questions can than be posed, which recognize practical limitations on available information. Then methods of systematic reviewing of existing evidence, similar to those used for RCTs can begin, with explicit statements of the literature search strategies, and where appropriate, the pooling of data across studies. Complete systematization and objectivization of hypothesis testing is less easily achieved than for RCT evaluation. A crucial final stage is thus to specifiy questions not answered by existing evidence, to which further studies should be directed.
Illustration: The interrelation between hypothesis testing and RCT evaluation is illustrated from reviewing work in progress on efficacy of classical antipsychotic drugs.
Conclusion: There is much scope for increased systematization of procedures for reviews which attempt to test hypotheses about disease processes. Increased systematization of reviews is also needed more widely in the basic sciences which are the foundation of scientific medicine.
A systematic review of the cost-effectiveness of colorectal cancer screening
Authors: John Moss, David Weller, Nick Shipp.
Background: Colorectal cancer is a major public health problem in Australia, being second only to lung cancer as a cause of death. For most of this century there has been a consistently upward trend in age-standardized mortality rates for colorectal cancer in Australian men and women. Mass screening offers the prospect of early disease detection and mortality reduction. Several randomized trials of mass screening for colorectal cancer have been published, one providing evidence of a favourable effect on mortality. Since overall resources are limited, costeffectiveness analysis can assist in setting priorities by comparing the gain in health outcome with the opportunity cost to society of the resources used.
Objectives: To estimate the likely costeffectiveness of mass screening for colorectal cancer should it be introduced in Australia.
Methods: Two options were considered. One was to identify all cost-effectiveness analyses of colorectal cancer screening from the literature and adjust them to Australian conditions. However, neither the costs nor the outcomes may be those anticipated in Australia. Our preferred method was to use systematic review to determine the best current estimate of effectiveness in Australia, and then to combine this with an Australian-based valuation of the cost items identified in the literature as essential.
Therefore, a computerised literature search was undertaken using MEDLINE, EMBASE, CANCERLIT, and ECONLIT data bases. Key researchers were identified, and approached in writing to provide results of recent work in the area of cost effectiveness of colorectal cancer screening, including unpublished material and conference presentations. The review covered scientific studies, editorial reviews, conference proceedings and papers, consensus statements and guidelines developed by medical and other relevant groups, and reports of national health technology assessment and related agencies.
Results: An estimate of the cost-effectiveness of mass screening for colorectal cancer in Australia will be presented, and the factors influencing this estimate will be discussed.
Consumer participation in resource allocation decisions: a systematic review
Authors: David Newby, David Henry, Dianne O'Connell, Sue Hill, Peter O'Connell, Jill Cockburn, Nick Higginbotham
Background: It is argued that by virtue of their financial contributions, the public has a right to be involved in decisions regarding resource allocation in health. As the allocation of resources with fiscal constraints becomes more difficult, decision makers are increasingly faced with difficult tradeoffs between costs and perceived benefits. Consumer involvement is seen as an "ethically attractive" way of dealing with these decisions.
Objectives:
(1) To examine the published literature for methodologies used to obtain consumer participation in health resource allocation.
(2) To develop a framework to incorporate consumer participation in resource allocation in health in Australia.
Method: The Medline (1966+), Exerpta Medica (1974+), Health Planning and Administration (1975+) and Current Contents databases were searched for articles on health resource allocation and decision making with the terms "public", "lay", "citizen" and "consumer". The bibliographies of key articles, policy statements and health policy references were searched.
Results: Only six examples of consumer participation in resource allocation have been found so far. The bibliography search has suggested that many examples remain unpublished as policy documents for State Health departments and local government authorities. These have largely relied on low level participation by consumers using polling and survey techniques. Only a few have attempted to incorporate the views of consumers and these have used facilitated group discussions. Most have avoided the consideration of costs.
Conclusion: Consumer participation in resource allocation is poorly indexed in the current biomedical literature and many examples remain unpublished. This makes systematic reviews of this area difficult.
This page was last updated on 18 November 1996
Comments for improvement or correction are welcome.
georg.koch@cochrane.de