Evidence-Based Practice for Nurses

the systematic review, you can complete the search by searching for evidence

published during time spans not covered by the systematic review.

Making Sense of Types of Evidence

in the Literature

Evidence in the literature can be categorized in a variety of ways. Nurses find

that understanding the terms associated with these categories is helpful when

making decisions about evidence. Evidence can be categorized as: (1) primary

or secondary, (2) peer reviewed or not peer reviewed, and (3) scholarly, trade,

or popular.

Primary and Secondary Sources

Primary sources present original information by the person or people responsible

for creating it. Paintings, speeches, diary entries, autobiographies, and interviews

are some common examples. In the world of research, however, primary sources

are the journal articles, book chapters, dissertations, or conference proceed-

ings written by the people involved in the original research. Primary sources

always provide full references to other works cited within the paper. Secondary

sources are the resulting commentaries, summaries, reviews, or interpretations

of primary sources. Always written after primary sources are presented, and

often written by those not involved in the original work, secondary sources can

provide new insights or historical perspectives not previously available. Some

common secondary sources are textbooks, systematic reviews, biographies,

and general magazines. Secondary sources often do not cite the work of others.

For example, an original research paper on Internet use by patients with

diabetes was published in the scholarly journal Nursing Research. This publi-

cation of the paper is considered to be a primary source. Several weeks later,

Newsweek published a more general article about the effect of the Internet on

patient education. In this article, results from the original paper published in

Nursing Research were mentioned along with a short quote. This article consti-

tutes a secondary source about the original research conducted. Sometimes it

is important to eliminate secondary sources because of the bias inherent when

someone other than the original researcher provides the information. When

creating EBP, nurses should always read primary sources and draw their own

conclusions.

Peer-Reviewed and Refereed Sources

Research and empirical papers published as primary sources in scholarly lit-

erature undergo rigorous evaluation by experts and editors, which is known as

peer review or refereed judging. Subject significance, methods, and conclusions

KEY TERMS

primary sources:

Original information

presented by the

person or people

responsible for

creating it

secondary sources:

Commentaries,

summaries, reviews,

or interpretations

of primary sources;

often written by

those not involved

in the original work

peer review: When

experts and editors

rigorously evaluate

a manuscript

submitted for

publication

98 CHAPTER 4 Finding Sources of Evidence