Evidence of mechanisms in evidence-based policy.

Evidence-based policy has achieved great relevance in policy-making and social research. Nonetheless, over the past few years, several problematic aspects of this approach have been identified. This paper discusses whether, and to what extent, evidence of mechanisms could contribute to addressing certain difficulties faced by evidence-based policy. I argue that it could play a crucial role in the assessment of the efficacy of interventions, the extrapolation of interventions to target populations, and the identification of side effects. For analysing the potential contribution of evidence of mechanisms, the previous debate on the pluralist approach to evidence-based medicine is taken as reference.

Evidence of Biological Mechanisms and Health Predictions: An Insight into Clinical Reasoning.

Traditionally, the understanding of biological mechanisms has played a central role in clinical reasoning. With the rise of the evidence-based paradigm, however, this role has come under scrutiny. On the one hand, clinical guidelines now place less emphasis on the evidence of pathophysiological mechanisms, a shift motivated by the unreliability of our understanding of complex biological mechanisms. On the other hand, some scholars defend evidence of mechanisms as crucial for clinical practice. This article assesses the relevance of evidence of biological mechanisms in two types of clinical predictions: predictions about the efficacy and about the safety of a certain intervention for a particular patient. For each type of prediction, the article analyzes the two roles that evidence of mechanisms might have-confirming and disconfirming-depending on whether the evidence supports that certain epidemiological results apply to the single patient. The analysis shows that the "unreliability because of incompleteness" argument against the emphasis on mechanistic clinical thinking only applies to some of the considered cases. The article concludes by offering a model for a more granular view of the role that evidence of mechanisms should play in clinical practice.

Epidemiological models and COVID-19: a comparative view.

Epidemiological models have played a central role in the COVID-19 pandemic, particularly when urgent decisions were required and available evidence was sparse. They have been used to predict the evolution of the disease and to inform policy-making. In this paper, we address two kinds of epidemiological models widely used in the pandemic, namely, compartmental models and agent-based models. After describing their essentials-some real examples are invoked-we discuss their main strengths and weaknesses. Then, on the basis of this analysis, we make a comparison between their respective merits concerning three different goals: prediction, explanation, and intervention. We argue that there are general considerations which could favour any of those sorts of models for obtaining the aforementioned goals. We conclude, however, that preference for particular models must be grounded case-by-case since additional contextual factors, as the peculiarities of the target population and the aims and expectations of policy-makers, cannot be overlooked.

Evolutionary causes as mechanisms: a critical analysis.

In this paper, we address the question whether a mechanistic approach can account for evolutionary causes. The last decade has seen a major attempt to account for natural selection as a mechanism. Nevertheless, we stress the relevance of broadening the debate by including the other evolutionary causes inside the mechanistic approach, in order to be a legitimate conceptual framework on the same footing as other approaches to evolutionary theory. We analyse the current debate on natural selection as a mechanism, and extend it to the rest of the evolutionary causes. We focus on three approaches that we call the stochastic view, the functional view, and the minimalist view. We argue that all of them are unable to account for evolutionary causes as mechanisms. It is concluded that the current mechanistic proposals cannot be accepted as a common framework for evolutionary causes. Finally, we outline some guidelines and requirements that any mechanistic proposal should meet in order to be applied to evolutionary theory.