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  1. Describe the differences between a systematic review and a narrative review.

  2. State three differences between systematic reviews and randomized clinical trials.

  3. What elements of a systematic review impact applicability to a searchable clinical question?

  4. What is the PEDro scale, and how can it be used in a systematic review?

  5. How are systematic reviews used to inform clinical practice?


This chapter will help you understand the following:

  • The difference between systematic and narrative reviews

  • The difference between primary and secondary studies

  • The nature and value of systematic reviews

  • How to judge the applicability of a systematic review to your practice

  • How to judge the quality of a systematic review


Systematic reviews are a special type of research study characterized as secondary research. Secondary research studies are “studies of studies” that summarize information from multiple primary studies. Primary studies are “original studies,” such as the randomized clinical trials and cohort studies described in previous chapters. Systematic reviews are the principal scientific method for secondary research. They are developed using a documented, systematic approach that minimizes bias.1

In this chapter, you will also learn how to determine if a systematic review is of sufficient quality to inform clinical decisions. Just as with intervention, diagnostic, or any other type of research study, the quality of the study must be appraised before it can be appropriately applied in the clinic. Here we focus on systematic reviews of intervention studies; however, the same principles and appraisal processes can be applied to other types of systematic reviews. These sections are organized into parts A through D of Step 3, which include the following:

  • A: Determining the Applicability of Systematic Reviews

  • B: Determining the Quality of Systematic Reviews

  • C: Interpreting the Results of Systematic Reviews

  • D: Summarizing the Clinical Bottom Line of Systematic Reviews

What Is a Systematic Review?

Authors of a systematic review define a specific purpose for the study. Methods that minimize bias are determined prior to the start date. Unlike a randomized clinical trial, a systematic review does not include recruiting and enrolling participants. Specific inclusion and exclusion criteria are used to select appropriate studies to include in the review. The sample size for a systematic review is the number of studies identified that meet the specific criteria.

Systematic reviews of treatment interventions are most common; however, reviews can also appraise diagnostic tests, outcome measures, and prognostic factors. For example, Gismervik and colleagues2 conducted a systematic review of diagnostic studies to determine the diagnostic accuracy of physical examination tests for the assessment of shoulder dysfunction. In another example, Park conducted a systematic review of studies for assessing fall risk in elderly persons.3

A meta-analysis is a statistical technique that combines the quantitative outcomes across multiple primary studies, usually as a part of a ...

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