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Nursing Research Guide

Library resources for the School of Nursing

Where can I search for Systematic Reviews and/or Controlled Trials?

You can search for systematic reviews and/or randomized controlled trials (level 1 or level 2 research) as publication types using CINAHL or Cochrane Library.

See the next sections on this page for instructions for using publication types in both CINAHL and Cochrane Library.

NOTE: While some databases like CINAHL and Cochrane Library have limiters to help you narrow your searches to particular types of research studies, you can also always use the type of study as a search term in addition to your topic: randomized controlled trial, systematic review, longitudinal, qualitative, etc. While not perfect, this will work to some extent in any database (including CINAHL or Cochrane Library).

CINAHL - Searching by Publication Type

From the CINAHL Advanced Search screen:

  1. Scroll down until you see the Limit Your Results section.
  2. Check the box next to the Randomized Controlled Trials limiter.
  3. Use the Publication Type menu to select meta-analysis and/or systematic review.

Experiment with these tools to limit your search results to one or more of these types of publications, depending on the specifics of your assignment; you are not required by the CINAHL database to select all three types at once, but you can if you need or wish to do so.

CINAHL Publication Type limiters.

Cochrane Library - Searching by Publication Type

From the Cochrane Library Advanced Search screen:

  1. Scroll down until you see the Search Options section.
  2. Check the box next to the Randomized Controlled Trials limiter.
  3. Use the CMR Keyword menu to select meta-analysis and/or systematic review.

Experiment with these tools to limit your search results to one or more of these types of publications, depending on the specifics of your assignment; you are not required by the database Cochrane Library to select all three types at once, but you can if you need or wish to do so.

Cochrane Library Publication Type limiters.

What are Nursing Levels of Evidence?

NOTE: At the graduate level, EKU's Nursing department uses the hierarchy in Evidence Based Practice in Nursing and Healthcare by Melnyk and Fineout-Overholt. Undergraduate nursing students may be asked to refer to a different hierarchy.

 

Levels of evidence (sometimes called hierarchy of evidence) are assigned to students based on the methodological quality of their design, validity, and applicability to patient care. These decisions give the "grade (or strength) of recommendation."

Hierarchy of Evidence for Intervention Studies

Type of evidence Level of evidence Description
Systematic review or meta-analysis I A synthesis of evidence from all relevant randomized, controlled trials.
Randomized, controlled trial II An experiment in which subjects are randomized to a treatment group or control group.
Controlled trial without randomization III An experiment in which subjects are nonrandomly assigned to a treatment group or control group.
Case-control or cohort study IV

Case-control study: a comparison of subjects with a condition (case) with those who don’t have the condition (control) to determine characteristics that might predict the condition.

Cohort study: an observation of a group(s) (cohort[s]) to determine the development of an outcome(s) such as a disease.
Systematic review of qualitative or descriptive studies V A synthesis of evidence from qualitative or descriptive studies to answer a clinical question.
Qualitative or descriptive study VI

Qualitative study: gathers data on human behavior to understand why and how decisions are made.

Descriptive study: provides background information on the what, where, and when of a topic of interest.
Opinion or consensus VII Authoritative opinion of expert committee.