(^98) Johns Hopkins Nursing Evidence-Based Practice: Model and Guidelines, Third Edition
Publications That Report Scientific Evidence
Research evidence can be broadly grouped into reports of single research stud-
ies (experimental, quasi-experimental, nonexperimental, qualitative designs) and
summaries of multiple research studies (systematic reviews with or without meta-
analysis or meta-synthesis). The level of research evidence for single studies is de-
termined by the study design. For summaries of multiple studies, the level of evi-
dence is based on the types of designs of the studies included in the summaries.
Most often, an evidence-based practice (EBP) team retrieves reports of primary
research studies. Primary research comprises data that are collected to answer
one or more research questions. Reviewers may also find secondary analyses
that use data from primary studies to ask different questions. EBP teams need to
recognize and appraise each evidence type and the relative strength it provides.
A working knowledge of the strengths and limitations of the various types of re-
search studies enables the nurse to judge the relative quality of evidence.Summaries of Multiple Studies
Published reports of summaries of multiple research studies, also referred to as
systematic reviews, can include quantitative, qualitative, or both types of re-
search. This section describes systematic reviews (with or without meta-analysis
or meta-synthesis—defined later in this discussion) as a source of evidence.
Notable efforts include the Cochrane Collaboration (2016), an international
nonprofit organization that produces and disseminates systematic reviews of
healthcare interventions, and Worldviews on Evidence-Based Nursing (2016),
a peer-reviewed journal developed by the Sigma Theta Tau International Honor
Society of Nursing. A less prominent but growing effort focused on methods and
processes involved in the synthesis of qualitative evidence has been undertaken
by the Cochrane Qualitative and Implementation Methods Group. The Cochrane
Handbook for Systematic Reviews of Interventions (Higgins & Green, 2015) in-
cludes a chapter providing guidance for using evidence from qualitative research
to help explain, interpret, and apply the results of a Cochrane review.