The Department of Psychiatry's strategic plan for research includes this tactic:
Require a review of the empirical evidence base for any clinical topic presented in Grand Rounds.
So how do you identify the empirical evidence base?
Definition: empirical evidence is defined in the APA Dictionary of Psychology as "derived from or denoting experimentation or systematic observations as the basis for conclusion or determination"
Approaches in narrowing searches or results to empirical evidence:
Levels of evidence are assigned to studies based on the methodological quality of their design, validity, and applicability to patient care.
There are several well-known levels of evidence schemas:
There are different "evidence pyramids" or paradigms for hierarchy of levels of evidence.
Types of studies higher up the pyramid are generally considered to be stronger evidence than types of studies or resources lower down in the evidence pyramid. The pyramid below does not show where qualitative research fits into your evidence, but it is worthy for consideration as you review the literature.
Evidence-Based Medicine (EBM) Pyramid
EBM Pyramid and EBM Page Generator, copyright 2006 Trustees of Dartmouth College and Yale University. All Rights Reserved. Produced by Jan Glover, David Izzo, Karen Odato and Lei Wang.
Another representation of the evidence-based pyramid
New York Medical College. Retrieved from https://guides.library.nymc.edu/c.php?g=944467&p=6807843 .
Search for the best evidence first.
Cochrane Library and Campbell Collaboration are databases focused on systematic reviews, links to both can be found below.
Systematic reviews can also be found by searching on your topic in PsycINFO or PubMed (MEDLINE) and using the filters in Additional Limits (PsycINFO) or on the left-hand side of the search results page (PubMed) to limit to Systematic Reviews. See links below.
You can also reference the A-Z list of databases listed below provided by the OHSU Library.
If a systematic review already exists on your question, evaluate the quality of this review and search for other articles on this topic that have been published since the existing systematic review came out. For example, if the most recent systematic review you have found was published in 2013, you would want to search for all articles on this topic published from then to the present and incorporate this new overview/synthesis into what the scientific community knew about this up to 2013, as represented by the systematic review.
If you cannot find any systematic review after looking at Cochrane, Campbell, and in PubMed, it is probable that one does not exist. This gives you the opportunity to be the person to conduct such a systematic review, thus providing a foundational overview on this topic to the field.
If you do not find any systematic reviews where someone else has synthesized the evidence on your topic, you will need to do this evaluation or appraisal of the evidence directly from the individual research articles. Ways to critically appraise research studies are listed below:
When appraising research, keep the following three criteria in mind:
Trials that are randomized and double blind, to avoid selection and observer bias, and where we know what happened to most of the subjects in the trial.
Trials that mimic clinical practice, or could be used in clinical practice, and with outcomes that make sense. For instance, in chronic disorders we want long-term, not short-term trials. We are [also] ... interested in outcomes that are large, useful, and statistically very significant (p < 0.01, a 1 in 100 chance of being wrong).
Trials (or collections of trials) that have large numbers of patients, to avoid being wrong because of the random play of chance. For instance, to be sure that a number needed to treat (NNT) of 2.5 is really between 2 and 3, we need results from about 500 patients. If that NNT is above 5, we need data from thousands of patients.
These are the criteria on which we should judge evidence. For it to be strong evidence, it has to fulfill the requirements of all three criteria."