In recent years there has been a pronounced shift in health care towards “evidence-based practice” (EBP), which brings together research evidence, clinical expertise and patient values to support decision-making in patient care. The goal of employing EBP is to improve patient outcomes by ensuring that treatment decisions are based on the best information available, and not solely on tradition and provider experience.
Research evidence is an important part of EBP, but health care providers and policy makers are inundated with scientific literature. Health information is everywhere. So how do we “evaluate the evidence” across this wide and varying landscape in order to make the best possible health care decisions? The answer is “evidence synthesis,” the collection and integration of information in order to summarize and interpret a body of scientific knowledge. This blog is the first in a series which will highlight topics important to understanding evidence synthesis in health care.
Evidence synthesis is based on explicit and transparent methods, and often takes the form of systematic reviews or meta-analyses, where research is identified, appraised and interpreted according to a systematic methodology. Evidence synthesis can also mean integrating the conclusions of several systematic reviews and meta-analyses on the same topic.
Unlike an evidence synthesis, individual studies may reach different conclusions, and their results may be affected by methodological flaws, small sample sizes or bias. Synthesizing results from multiple, similar studies (a body of evidence) provides more certainty about the effects than using results from a single research study. Appraising the quality of individual studies within a systematic review or meta-analysis enables us to determine how much confidence we can have in the observed effect.
In the Military Health System (MHS), evidence synthesis is often used to identify gaps in knowledge, inform policy decisions and shape clinical practice guidelines (CPGs). The Deployment Health Clinical Center (DHCC) utilizes evidence synthesis in many forms, including systematic reviews and meta-analyses, as well as emerging methodologies such as evidence maps, rapid reviews and evidence briefs. These reports provide information about psychological health care topics that are important to providers and policy makers across the MHS, to aid them in making the best health care decisions possible.
Stay tuned for upcoming blogs in the evidence synthesis series on topics including strengths and weaknesses of different types of evidence and how clinical practice guidelines are developed and used within the MHS.
The views expressed in Clinician's Corner blogs are solely those of the author and do not necessarily reflect the opinion of the Psychological Health Center of Excellence or Department of Defense.