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Evidence Based Nursing

EBN Pyramid

Evidence pyramid

WHICH DATABASES TO FIND EVIDENCE IN

Clinical Practice Guidelines:

The National Guideline Clearinghouse is an excellent place to look.

Systematic Reviews:

Take a look in the Cochrane Library

You can also look in PubMed Clinical Queries  The draw back with that database is that it is a citation database.  Once you find a systematic review, you may have to request it through our document delivery service if you are unable to locate it in the Library.

You can also look in Medline Complete When searching in Medline Complete, add the keyword "systematic review" to your search terms. For example:  hospice "systematic review"

There is also an option in the advanced search of this database under Publication Type for Meta-Analysis

Cinahl Plus with Full Text has an option in the advanced search for Clinical Queries.  It includes reviews.  Scroll through the box until you see Review.  You can choose all three options by holding down the CTRL key and clicking on each option.

Clinical Queries

There is also an option for Meta Analysis under Publication Type

Publication types

Randomized Controlled Trials (RCT)

Medline Complete and Cinahl are good places to go for RCTs.  You can search both of them by adding "randomized controlled trials" to your search term.  For example:  hospice "randomized controlled trials"

For both of them, there is an option under Publication Type to limit to Randomized Controlled Trials.

For Cinahl:

Publication types RTC

For Medline Complete:

Publication types

THE RESOURCES

Experimental Studies

Evidence-Based Guidelines:  Once a systematic review has been done, then a clinical guideline is written based on the findings of the reviews. The best practice is put forward out of the different techniques and interventions that had been studied. (Level I Evidence)

Systematic Reviews & Meta Analysis:  This is when an extensive literature review is done on a topic, examined and the results are compared to see which research or interventions had the most favorable results.  Hundreds of studies can be reviewed by a committee of experts in the field before findings are published.  The process can take a year or so for each topic. (Level I Evidence)

Randomized Controlled Trials: For these studies, the participants are randomly assigned to either the control group or the experimental group.  The only difference between the groups is the variable being studied. (Level II Evidence)

Observational Studies

Cohort Studies:  A group of people that do not have a disease but have been exposed to a risk factor are followed over time to see who in the group develops a disease associated with the risk factor.  The study can be done retrospectively (looking at medical records or histories) or prospectively (following them over a certain number of years). (Level IV Evidence)

Case Control Studies:  Here patients who have a disease are compared to patients who do not have the disease.  Both groups' histories are examined to see how frequently each of them had run into risk factors to try and determine the relationship between the disease and the risk factor. (Level IV Evidence)

Case Reports (Case Study):  An article describing an individual case written in a narrative format.  While this is low in the pyramid, it is included because if multiple case reports are written describing different cases with the same issues, this would help highlight an area that needs further research. (Level IV Evidence)

Quick Guide

The pyramid to the left shows the different publication types for evidence based practice.  The higher up in the pyramid you go the better the quality of the research.  The box on the right defines the different types of resources.