Methods for evidence synthesis in interventional pain management

Healthcare decisions are increasingly being made on research-based evidence, rather than on expert opinion or clinical experience alone. Consequently, the process by which the strength of scientific evidence is evaluated and developed by means of evidence-based medicine recommendations and guidelines has become crucial resulting in the past decade in unprecedented interest in evidence-based medicine and clinical practice guidelines. Systematic reviews, also known as evidence-based technology assessments, attempt to minimize bias by the comprehensiveness and reproducibility of the search for and selection of articles for review. Evidence-based medicine is defined as the conscientious, explicit and judicious use of the current best evidence in making decisions about the care of individual patients. Thus, the practice of evidence-based medicine requires the integration of individual clinical expertise with the best available external evidence from systematic research. To arrive at evidence-based medicine decisions all valid and relevant evidence should be considered alongside randomized controlled trials, patient preferences and resources. However, many systematic reviews in interventional pain management fail to follow evidence-based medicine principles. Clinical practice guidelines are systematically developed statements that assist clinicians, consumers and policy makers to make appropriate healthcare decisions. The complex processes of guideline development depend on integration of a number of activities, from collection and processing of scientific literature to evaluation of the evidence, development of evidence-based recommendations or guidelines and implementation and dissemination of the guidelines to relevant professionals and consumers. Guidelines are being designed to improve the quality of healthcare and decrease the use of unnecessary, ineffective or harmful interventions. This review describes various aspects of evidence-based medicine, systematic reviews in interventional pain management, evaluation of the strength of scientific evidence, differences between systematic and narrative reviews, rating the quality of individual articles, grading the strength of the body of evidence and appropriate methods for searching for the evidence.