Adam La Caze

Evidence-based policy is gaining support in many areas of government and in public affairs more generally. In this paper we outline what evidence—based policy is then discuss its strengths and weaknesses. In particular, we argue that it faces a serious challenge to provide a plausible account of evidence. This account needs to be at least in the spirit of the hierarchy of evidence subscribed to by evidence-based medicine (from which evidence—based policy derives its name and inspiration). Yet evidence-based policy’s hierarchy needs to be tailored to the kinds of evidence relevant and available to the policy arena. The evidence required for policy decisions does not easily lend itself to randomised controlled trials (the "gold standard" in evidence-based medicine), nor, for that matter, being listed in a single all—purpose hierarchy

Most agree that, if all else is equal, patients should be provided with enough information about proposed medical therapies to allow them to make an informed decision about what, if anything, they wish to receive. This is the principle of informed choice; it is closely related to the notion of informed consent. Contemporary clinical trials are analysed according to classical statistics. This paper puts forward the argument that classical statistics does not provide the right sort of information for informing choice. The notion of probability used by classical statistics is complex and difficult to communicate. Therapeutic decisions are best informed by statistical approaches that assign probabilities to hypotheses about the benefits and harms of therapies. Bayesian approaches to statistical inference provide such probabilities.

Proponents of Evidence-based medicine (EBM) do not provide a clear role for basic science in therapeutic decision making. Of what they do say about basic science, most of it is negative. Basic science resides on the lower tiers of EBM's hierarchy of evidence. Therapeutic decisions, according to proponents of EBM, should be informed by evidence from randomised studies (and systematic reviews of randomised studies) rather than basic science. A framework of models explicates the links between the mechanisms of basic science, experimental inquiry, and observed data. Relying on the framework of models I show that basic science often plays a role not only in specifying experiments, but also analysing and interpreting the data that is provided. Further, and contradicting what is implied in EBM's hierarchy of evidence, appeals to basic science are often required to apply clinical research to therapeutic questions. © 2010 Springer Science+Business Media B.V

Evidence-based medicine (EBM) puts forward a hierarchy of evidence for informing therapeutic decisions. An unambiguous interpretation of how to apply EBM's hierarchy has not been provided in the clinical literature. However, as much as an interpretation is provided proponents suggest a categorical interpretation. The categorical interpretation holds that all the results of randomised trials always trump evidence from lower down the hierarchy when it comes to informing therapeutic decisions. Most of the critical replies to EBM react to this interpretation. While proponents of EBM can avoid some of the problems raised by critics by suitably limited the claims made on behalf of the hierarchy, further problems arise. If EBM is to inform therapeutic decisions then a considerably more restricted, and context dependent interpretation of EBM's hierarchy is needed

Proponents of evidence-based medicine (EBM) provide the “hierarchy of evidence” as a criterion for judging the reliability of therapeutic decisions. EBM's hierarchy places randomized interventional studies (and systematic reviews of such studies) higher in the hierarchy than observational studies, unsystematic clinical experience, and basic science. Recent philosophical work has questioned whether EBM's special emphasis on evidence from randomized interventional studies can be justified. Following the critical literature, and in particular the work of John Worrall, I agree that many of the arguments put forward by advocates of EBM do not justify the ambitious claims that are often made on behalf of randomization. However, in contrast to the recent philosophical work, I argue that a justification for EBM's hierarchy of evidence can be provided. The hierarchy should be viewed as a hierarchy of comparative internal validity. Although this justification is defensible, the claims that EBM's hierarchy substantiates when viewed in this way are considerably more circumscribed than some claims found in the EBM literature.

Evidence-based policy has support in many areas of government and in public affairs more generally. In this paper we outline what evidence-based policy is, then we discuss its strengths and weaknesses. In particular, we argue that it faces a serious challenge to provide a plausible, over-arching account of evidence. We contrast evidence-based policy with evidence-based medicine, especially the role of evidence in assessing the effectiveness of medicines. The evidence required for policy decisions does not easily lend itself to randomized controlled trials, nor, for that matter, being listed in a single all-purpose hierarchy.

A number of arguments have shown that randomization is not essential in experimental design. Scientific conclusions can be drawn on data from experimental designs that do not involve randomization. John Worrall has recently taken proponents of randomized studies to task for suggesting otherwise. In doing so, however, Worrall makes an additional claim: randomized interventional studies are epistemologically equivalent to observational studies, providing the experimental groups are comparable according to background knowledge. I argue against this claim. In the context of testing the efficacy of drug therapies, well-designed interventional studies are epistemologically superior to well-designed observational studies because they have the capacity to avoid a type of selection bias. Although arguments for interventional studies are present in the medical literature, these arguments are too often presented as an argument for randomization. Randomization in interventional studies is defended on Bayesian grounds

Deborah Mayo's view of science is that learning occurs by severely testing specific hypotheses. Mayo expounded this thesis in her (1996) Error and the Growth of Experimental Knowledge (EGEK). This volume consists of a series of exchanges between Mayo and distinguished philosophers representing competing views of the philosophy of science. The tone of the exchanges is lively, edifying and enjoyable. Mayo's error-statistical philosophy of science is critiqued in the light of positions which place more emphasis on large-scale theories. The result clarifies Mayo's account and highlights her contribution to the philosophy of science -- in particular, her contribution to the philosophy of those sciences that rely heavily on statistical analysis. The second half of the volume considers the application (or extension) of an error-statistical philosophy of science to theory testing in economics, causal modelling and legal epistemology. The volume also includes a contribution to the frequentist philosophy of statistics written by Mayo in collaboration with Sir David Cox.

Background There is a need for clearer guidance for pharmacists regarding their responsibilities when selling complementary medicines. A recently published ethical framework provides guidance regarding the specific responsibilities that pharmacists need to meet in order to fulfil their professional obligations and make a positive contribution to health outcomes when selling complementary medicines. Objective Evaluate the acceptability and feasibility of a new ethical framework for the sale of complementary medicines in community pharmacy. Methods Australian community pharmacists were invited to participate in online focus groups and interviews. Participants were recruited via multiple methods, including social media and the professional networks of pharmacy groups. Participants were provided the ethical framework prior to the discussion. Discussions were transcribed verbatim and analysed using thematic analysis. Results Seventeen community pharmacists participated in the study. There was good representation among participants in terms of gender, years of practice, pharmacy location and script volume. Participants differed in how proactive they were in relation to selling and providing advice on complementary medicines, how they interpreted evidence in relation to complementary medicines, and how they navigated their practice within the retail environment of community pharmacy. The majority of participants found the framework was acceptable for practice and was feasible for implementation with targeted support. Participants identified two important areas for targeted support in implementing the framework: improved access to evidence-based information resources on complementary medicines and independent evidence-based education and training on complementary medicine for pharmacists and pharmacy support staff. Conclusion The ethical framework addresses an important gap in providing specific professional guidance to pharmacists when selling complementary medicines. The results of the study suggest that the framework may be acceptable to community pharmacists and be feasible to implement with targeted support.