Does the Weight of Evidence Signal the End of Homeopathy?

The National Health and Medical Research Council (NHMRC) recently completed a review of the evidence for homeopathy’s effectiveness and, after analysing systematic reviews of clinical trials, concluded there was “no reliable evidence for homeopathy and that it cannot demonstrate efficacy.” To judge the efficacy, and hence the value, of homeopathy on the basis of randomised controlled trials misses the point. Such trials are the gold standard for conventional drugs because they test a medication’s effect across a population, eliminating placebo effects and other forms of perception bias. But – and here’s the crux – homeopathic medicines are not drugs and homeopathy involves much more than the use of a particular therapy. People don’t visit a homeopath wanting a drug, in fact they often quite deliberately don’t want one; they want individualised treatment

Does the Weight of Evidence Signal the End of Homeopathy?

The National Health and Medical Research Council (NHMRC) recently completed a review of the evidence for homeopathy’s effectiveness and, after analysing systematic reviews of clinical trials, concluded there was “no reliable evidence for homeopathy and that it cannot demonstrate efficacy.” To judge the efficacy, and hence the value, of homeopathy on the basis of randomised controlled trials misses the point. Such trials are the gold standard for conventional drugs because they test a medication’s effect across a population, eliminating placebo effects and other forms of perception bias. But – and here’s the crux – homeopathic medicines are not drugs and homeopathy involves much more than the use of a particular therapy. People don’t visit a homeopath wanting a drug, in fact they often quite deliberately don’t want one; they want individualised treatment

Weight of evidence: a framework for the appraisal of the quality and relevance of evidence

Knowledge use and production is complex and so also are attempts to judge its quality. Research synthesis is a set of formal processes to determine what is known from research in relation to different research questions and this process requires judgements of the quality and relevance of the research evidence considered. Such judgement can be according to generic standards or be specific to the review question. The judgements interact with other judgements in the review process such as inclusion criteria and search strategies and can be absolute or weighted judgements combined in a weight of evidence framework. Judgments also vary depending upon the type of review that can range from statistical meta analysis to meta ethnography. Empirical study of the ways that quality and relevance judgements are made can illuminate the nature of such decisions and their impact on epistemic and other domains of knowledge. Greater clarity about such ideological and theoretical differences can enable greater participative debates about such differences

The 'weight of evidence' concerning tobacco harm: beliefs in mid-twentieth century America

We present a version of Chern et al.'s (1995) Bayesian model of `health risk belief' to track the evolution of the `weight' of epidemiological evidence concerning tobacco harm that was in the possession of the U.S. Tobacco Industry Research Committee (T.I.R.C.) and the U.S. Public Health Service and related groups during the 1950s and early 1960s. We compare our results with public statements assessing the evidence that were made by the organisations during the same period. The results from the models for the U.S. Public Health Service and related groups are not in disagreement with the public statements of these organisations; the results from the lung cancer model for the T.I.R.C. are in disagreement with the assessments of the evidence made by the T.I.R.C.'s Scientific Director in his annual reports. We discuss possible reasons for this, relating our findings to present-day academic and legal debates about the `controversy' surrounding tobacco harm during the mid-twentieth century.

Weight of evidence to assess sediment quality

Estuaries are perhaps the most threatened environments in the coastal fringe; the coincidence of high natural value and attractiveness for human use has led to conflicts between conservation and development. These conflicts occur in the Sado Estuary since its location is near the industrialised zone of Peninsula of Setúbal and at the same time, a great part of the Estuary is classified as a Natural Reserve due to its high biodiversity. These facts led us to the need of implementing a model of environmental management and quality assessment, based on methodologies that enable the assessment of the Sado Estuary quality and evaluation of the human pressures in the estuary. These methodologies are based on indicators that can better depict the state of the environment and not necessarily all that could be measured or analysed. Sediments have always been considered as an important temporary source of some compounds or a sink for other type of materials or an interface where a great diversity of biogeochemical transformations occur. For all this they are of great importance in the formulation of coastal management system. Many authors have been using sediments to monitor aquatic contamination, showing great advantages when compared to the sampling of the traditional water column. The main objective of this thesis was to develop an estuary environmental management framework applied to Sado Estuary using the DPSIR Model (EMMSado), including data collection, data processing and data analysis. The support infrastructure of EMMSado were a set of spatially contiguous and homogeneous regions of sediment structure (management units). The environmental quality of the estuary was assessed through the sediment quality assessment and integrated in a preliminary stage with the human pressure for development. Besides the earlier explained advantages, studying the quality of the estuary mainly based on the indicators and indexes of the sediment compartment also turns this methodology easier, faster and human and financial resource saving. These are essential factors to an efficient environmental management of coastal areas. Data management, visualization, processing and analysis was obtained through the combined use of indicators and indices, sampling optimization techniques, Geographical Information Systems, remote sensing, statistics for spatial data, Global Positioning Systems and best expert judgments. As a global conclusion, from the nineteen management units delineated and analyzed three showed no ecological risk (18.5 % of the study area). The areas of more concern (5.6 % of the study area) are located in the North Channel and are under strong human pressure mainly due to industrial activities. These areas have also low hydrodynamics and are, thus associated with high levels of deposition. In particular the areas near Lisnave and Eurominas industries can also accumulate the contamination coming from Águas de Moura Channel, since particles coming from that channel can settle down in that area due to residual flow. In these areas the contaminants of concern, from those analyzed, are the heavy metals and metalloids (Cd, Cu, Zn and As exceeded the PEL guidelines) and the pesticides BHC isomers, heptachlor, isodrin, DDT and metabolits, endosulfan and endrin. In the remain management units (76 % of the study area) there is a moderate impact potential of occurrence of adverse ecological effects and in some of these areas no stress agents could be identified. This emphasizes the need for further research, since unmeasured chemicals may be causing or contributing to these adverse effects. Special attention must be taken to the units with moderate impact potential of occurrence of adverse ecological effects, located inside the natural reserve. Non-point source pollution coming from agriculture and aquaculture activities also seem to contribute with important pollution load into the estuary entering from Águas de Moura Channel. This pressure is expressed in a moderate impact potential for ecological risk existent in the areas near the entrance of this Channel. Pressures may also came from Alcácer Channel although they were not quantified in this study. The management framework presented here, including all the methodological tools may be applied and tested in other estuarine ecosystems, which will also allow a comparison between estuarine ecosystems in other parts of the globe

A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

Weight of Evidence Method and Its Applications and Development

AbstractThe development and applications about the weight of evidence technology in recent years are reviewed. This paper introduced the improved weight of evidence in remote sensing image processing and in different fields of application. Summary its constraints and existent problems. Look forward to the weight of evidence for the practical application