Chapter 22

Question 1

What is a systematic review?

Answer 1

Careful compilation and summary of all publications relevant to a particular research topic.

Question 2

What is a meta-analysis?

Answer 2

It creates a summary statistic for the results of systematically identified articles

Question 3

A review article in the health sciences requires:

Answer 3

1) An extensive search of the literature
2) The extraction of key information from relevant articles
3) The clear and concise presentation of this information

Question 4

What is one way to become an expert in the literature on a well-defined topic?

Answer 4

Writing a review article (a narrative review, systematic review, or meta-analysis).

Question 5

What often becomes foundational for a new research in the field?

Answer 5

Well written and comprehensive review articles, because they summarize what is known about an area of inquiry.

Question 6

What is more frequently cited in an individual field study:

Published review articles or the typical article? Why?

Answer 6

Published review articles, because they provide a concise summary of the literature.

Question 7

What are the limitations of review articles?

Answer 7

1) Not all journals publish review articles, so their likelihood of publication might be lower than that of other study approaches.
2) Reviews are sometimes regarded as exhibiting less originality than other types of scholarship. Reviews are perceived to be a less rigorous form of research than projects collecting new data and/or involving statistical analysis.

Question 8

When starting a tertiary analysis, the most important decision is:

Answer 8

The selection of a topic that is narrow enough that all the relevant publications can be acquired.

Question 9

The topic may need to be modified after a preliminary search depending on:

Answer 9

The number of articles available; if a search yields only eight articles, the topic needs to be expanded. If the search yields 400 articles, the topic needs to be narrowed.

Question 10

No review article can be written without:

Answer 10

Excellent library access, because EVERY relevant article must be identified and obtained during a systematic review.

Question 11

Before starting a review project, a researcher should check with a University librarian regarding:

Answer 11

1) The libraries journal access policies
2) The fees that patrons may have to pay to acquire articles that are not part of the libraries collections or subscription services.

Question 12

The researcher must prepare to maintain a meticulous system for:

Answer 12

Tracking articles that I’ve already been acquired, those that have been requested but not yet received, and those that need to be requested.

Question 13

What are narrative reviews?

Answer 13

They tell a story about a topic using evidence from the literature to support the “plot“.

Question 14

Narrative reviews are intended to:

Answer 14

Convey a perspective and NOT just compile facts.

Question 15

Narrative reviews must be carefully organized by:

Answer 15

Theme, methodology, chronology, or some other guiding principle.

Question 16

When a researcher has developed a unique conceptual framework or theory that can be illustrated with examples from the literature, which kind of review may be appropriate?

Answer 16

Narrative review

Question 17

This type of review works best when the researcher has a unique perspective on a topic and/or a particular expertise in the field that can be drawn on without using a systematic search strategy.

Answer 17

Narrative review.

Question 18

What are systematic reviews?

Answer 18

They use a predetermined and comprehensive searching and screening method to identify relevant articles.

Question 19

Which type of review is designed to minimize the bias that might occur when researchers handpick the articles they want to highlight?

Answer 19

Systematic reviews.

Question 20

After the identification of a focus study question, the most important decisions in a systematic review are:

Answer 20

The selection of keywords and inclusion criteria.

Question 21

What is the goal of a systematic review search?

Answer 21

To craft a search strategy that identifies all the articles ever published on the narrow, well defined area covered by the review.

Question 22

What are the steps of a systematic review process?

Answer 22

1) Define study question
2) Define search strategy
3) Search for abstracts by keyword
4) Screen abstracts
5) Check full-text articles for eligibility
6) Extract information
7) Summarize findings
8) Write and report

Question 23

After selecting a well defined study question, the next step in a systematic review or meta-analysis is to:

Answer 23

Compose appropriate search strings.

Question 24

A helpful first task for choosing appropriate search strings is an exploration of:

Answer 24

The MeSH dictionary (available through PubMed) in order to identify the definitions of key terms as well as synonyms and related terms. (Boolean included)

Question 25

What allows for the design of a database-appropriate search string?

Answer 25

Understanding the language used by MEDLINE and other databases. (like “child” is a person 6-12 yrs old).

Question 26

What can you do to check the appropriateness of search terms?

Answer 26

Identify a handful of articles not to be relevant, then confirm that the search string captures all of these articles. If the search misses one or more, than the search strategy needs to be modified. This process must not be used to exclude disliked articles (inclusion biased).

Question 27

True or false:
A researcher is lacking fluency in other languages is an acceptable justification for including only English language articles.

Answer 27

False; that is not an acceptable justification.

Question 28

Which is better:
Using built-in limiters (Artificially limiting the number of abstracts using filters) or using study specific exclusion checklists. Why?

Answer 28

Study specific exclusion checklists, because built-in limiters often exclude many studies that would otherwise be eligible.

Question 29

What an abstract is not available or the abstract does not allow determination about an eligibility to be made, what should be done?

Answer 29

The full text of the article must be read.

Question 30

What should researchers be able to justify?

Answer 30

1) Search limiters

2) Inclusion and exclusion criteria

Question 31

What three other strategies may complement database searches?

Answer 31

1) Snowballing: Looking up every article cited by eligible articles in order to identify other articles that might be relevant but not indexed in the selected databases.
2) Gray literature: Research reports that are available to the researchers but have not been externally reviewed and formally published.
3) Hand searching: All articles in the tables of contents of selected volumes of relevant journals or scans for reports on the topic of interest.

Question 32

The methods used for expanded searches (snowballing, gray literature, hand searching) must be:

Answer 32

Disclosed in the research report, and any documents found through the supplemental search methods must meet all of the inclusion criteria.

Question 33

Once all of the eligibile articles are identified, the contents of these articles is summarized in:

Answer 33

Data extraction tables.

Question 34

Data extraction tables lists descriptive characteristics such as:

Answer 34

1) Study location
2) The years of data collection
3) The study design
4) The study population and sample size
5) The definitions used for key exposures and outcomes
6) The key findings of interest, including both quantitative results and qualitative conclusions
7) An evaluation of the quality of the study

Question 35

A data extraction table allows for:

Answer 35

Easy compilation and comparison of observations relevant to the study question.

Question 36

What kind of statistical findings should be reported?

Answer 36

Significant and insignificant findings.

Question 37

One of the primary contributions of systematic reviews to the health science literature is the ability to:

Answer 37

Identify both areas of consensus and areas of disagreement and uncertainty that need to be further examined.

Question 38

What is publication bias?

Answer 38

Occurs when articles with statistically significant results are more likely to be published than those with null results.

Question 39

What is the goal of a meta-analysis?

Answer 39

To combine into one summary statistic the results of several high-quality quantitative studies that use similar methods to collect and analyze their data.

Question 40

Which review is very restrictive in its eligibility criteria?

Answer 40

Meta-analysis

Question 41

What are the steps of a meta-analysis?

Answer 41

1) Use a systematic search strategy to identify relevant articles
2) Carefully read each study
3) Assess the quality and comparability of each study
4) Extract statistical results from each of the studies that meet all of the inclusion criteria for the meta-analysis
5) Combine comparable statistical results into one summary statistic

Question 42

The summary statistic (meta-analysis) should usually adjust for:

Answer 42

The confidence intervals of the contributing statistical measures.

Question 43

Before pooling the statistical data, the researcher must show that the results of the studies are ___.

Answer 43

Comparable

Question 44

What kind of studies can be combined into a summary statistic?

Answer 44

Homogenous studies.

Question 45

The amount of variability in the measure across studies can be examined using:

Answer 45

1) Cochran’s Q statistic for homogeneity
2) I^2 (I squared) statistic that adjusts the Q statistics based on the number of studies being pooled. (Reported as percentage from 0-100%)

Question 46

What is the effect size?

Answer 46

The estimated value of a measure, like an odds ratio or efficacy etc…

Question 47

What are the two models that can be used for creating a pooled estimate of the effect size?

Answer 47

1) Fixed effects model: When studies are homogenous

2) Random effects model: When studies are heterogenous

Question 48

The contributing studies and the summary measure for a meta-analysis are often displayed using a ____.

Answer 48

Forest plot

Question 49

A forest plot usually has:

Answer 49

1) A horizontal axis showing effect size
2) A vertical line showing the effect size that indicates no effect (such as an odds ratio of one)
3) A row for information from each included study that uses a square (or other marker) to indicate the point estimate for the effect size and uses a horizontal line to show the 95% confidence interval {Markers are often presented in different sizes to show how each study was weighted in the meta-analysis. Small markers = small sample sizes, large markers = large sample sizes}
4) A representation of the summary measure and its confidence interval, often shown using a diamond shape.

Question 50

What are the two main threats to the validity of a meta-analysis?

Answer 50

1) Poor quality of included studies

2) Publication bias

Question 51

What can eliminate studies of questionable validity?

Answer 51

The selection criteria used during the systematic review process

Question 52

How can we examine the possibility of publication bias?

Answer 52

By using a funnel plot; Part of the cone will be missing. (In this case, the pooled estimate is likely to have overestimated the true effect size).