Evidence-Based Practice for Nurses

is still relatively small and quantitative results are reported, then descriptive

statistics can be applied to the group of studies.

The final step of the systematic review is interpretation of the data and dis-

semination of the results (Cooper, 1998). The stated results should flow logically

from the data presented in the systematic review. The problem and research

questions should be answered from the data. Systematic reviews are written

using a format similar to that used in primary research reports, including the

introduction, methods, results, and discussion. Most often a table of the data

collected from each study is included in the systematic review article.

There are two additional types of syntheses that are less rigorous than system-

atic reviews. These include the traditional literature review and the integrative

review. A traditional literature review differs from a systematic review because

when a literature review is conducted, the author typically does not go to the

extreme lengths of obtaining all possible literature on a topic. When conduct-

ing a traditional literature review, the author may include only literature that

supports a particular point, excluding reports that have conflicting findings.

Nurses are very familiar with the traditional literature review because this is

the type of paper they wrote for many of their nursing courses.

Integrative reviews are more rigorous than traditional literature reviews, but

they are less rigorous compared to systematic reviews. Authors of integrative

reviews seek only published reports, whereas systematic reviewers use a more

rigorous method of obtaining both published and unpublished reports. Authors

follow very methodical approaches for both types of reviews. Because the scope

of integrative reviews is narrower, the findings are less likely to have external

validity than are the findings from a systematic review.

When the body of reports is large and homogenous, a meta-analysis can be

conducted. Meta-analysis is a statistical procedure that involves quantitatively

pooling data from a group of independent studies that have studied the same or

similar clinical problems using the same or similar research methods (Cooper,

Hedges, & Valentine, 2009). A pooled estimate of effect, called effect size (ES),

and a confidence interval (CI) are calculated. Effect size estimates the strength

of the relationship between two variables, and a confidence interval shows the

KEY TERMS

traditional

literature review:

Article based

on common

or uncommon

elements of works

with little concern

for research

methods, designs,

or settings; narrative

literature review

integrative review:

A scholarly paper

that synthesizes

published studies

to answer questions

about phenomena

of interest

meta-analysis: A

scholarly paper

that combines

results of studies,

both published and

unpublished, into a

measurable format

and statistically

estimates the

effects of proposed

interventions

Locate a systematic review of the literature that addresses a topic pertinent to your patients.

Evaluate the rigor of the study using the information presented in Box 12-1. How will you use the

results of the systematic review to enhance the evidence that you use to provide the best care

possible?

CRITICAL THINKING EXERCISE 12-3

316 CHAPTER 12 Other Sources of Evidence