Evidence-Based Practice

The History of Evidence-Based Practice

The conscientious, judicious, and explicit application of best evidence in a profession or to a professional's practice is a contested and frequently divisive concept that is viewed, after David Sackett's work in particular, as a professional imperative, an ideology, or a myopic dogma. Many professions now claim, or aspire to claim, that practice in their domain should be based on “evidence”—including medicine, nursing, teaching, policing, management, social policy, economics, and social work. What this evidence consists of and where qualitative research fits remain contested.

The concept of evidence-based practice dates back to the 19th century but has emerged into prominence in debate and policy since the early 1990s. Reasons for this include growth in the perceived need for greater effectiveness and efficiency during an era of increased public accountability and managerialism, increased capacity for systematic electronic data collection (and monitoring of performance), and developments in communications technology that facilitate rapid dissemination of research findings.

Knowledge derived from research has consistently been recognized as a central (and often the central) component of evidence. However, not all research methods have been equally esteemed. Hierarchies of evidence were developed to categorize studies into [Page 309]levels of strength. These hierarchies frequently positioned expert opinion as the least trustworthy source and randomized control trials and/or systematic reviews as the strongest, most reliable forms of evidence. The most trustworthy research, when synthesized into systematic reviews or practice guidelines, could then be disseminated to practitioners in a parsimonious and accessible form purportedly ripe for application to practice.

The case for evidence-based practice has been promoted through political, empirical, ethical, practical, educational, and ideological means. With such powerful forces at play, it was difficult to argue that practice should be anything other than evidence based. From the early 1990s, numerous influential organizations, commentators, and researchers have championed the ethical and social need for greater reliance on evidence to improve outcomes and make decision making more transparent and effective. Professionals have been urged by government, the scientific community, and regulatory bodies alike that it is not only desirable but also ethically essential for them to practice in accordance with “the evidence.” Practice guidelines proliferated. These guidelines were often developed by professional bodies and/or experts who had a priori screened and appraised studies and reviews in an existing area. These guidelines were replete with the findings of meta-analyses, randomized trials, and larger scale observation studies because they held higher status in the methodological hierarchies. Universities responded by creating new curricula around the need to practice in accordance with the evidence.

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