Main description:

This book is open access under a CC BY license.

This book is the first to develop explicit methods for evaluating evidence of mechanisms in the field of medicine. It explains why it can be important to make this evidence explicit, and describes how to take such evidence into account in the evidence appraisal process. In addition, it develops procedures for seeking evidence of mechanisms, for evaluating evidence of mechanisms, and for combining this evaluation with evidence of association in order to yield an overall assessment of effectiveness.

Evidence-based medicine seeks to achieve improved health outcomes by making evidence explicit and by developing explicit methods for evaluating it. To date, evidence-based medicine has largely focused on evidence of association produced by clinical studies. As such, it has tended to overlook evidence of pathophysiological mechanisms and evidence of the mechanisms of action of interventions.

The book offers a useful guide for all those whose work involves evaluating evidence in the health sciences, including those who need to determine the effectiveness of health interventions and those who need to ascertain the effects of environmental exposures.

Contents:

1 Introduction1.1 What is a mechanism?1.2 Where does evidence of a mechanism come from?1.3 Why consider evidence of mechanisms?1.3.1 Evaluating efficacy1.3.2 Evaluating external validity1.3.3 Other questions1.3.4 Importance of considering evidence of mechanisms2 How to consider evidence of mechanisms: a summary2.1 Questions to address2.2 Quality level of evidence and status of claim2.3 Identifying evidence of mechanisms in the literature2.4 Evaluating evidence of mechanisms2.5 Using evidence of mechanisms to evaluate causal claims2.6 Overall approach3 Identifying evidence of mechanisms in the literature3.1 Hypothesize a mechanism3.2 Search the literature3.3 Identify the evidence most relevant to the mechanism hypothesis3.4 Presenting the evidence of mechanisms4 Evaluating evidence of mechanisms4.1 Considerations for evaluating evidence of mechanism4.2 Presenting quality of evidence of mechanisms5 Using evidence of mechanisms to evaluate efficacy and external validity5.1 Efficacy5.2 External validity6 Glossary7 References8 Acknowledgements9 Appendix A. A critical appraisal tool for evidence of mechanisms10 Appendix B. GRADE tables with mechanism assessment11 Appendix C: Databases for evidence of mechanisms12 Appendix D: Assessing exposures12.1 Example: carcinogenicity of benzo[a]pyrene12.2 Comparison to IARC12.3 Molecular epidemiology12.4 Comparison to SYRINA