Question 1

When considering the number of studies included in a systematic review, the text suggests all of the following rules, EXCEPT:

Accepted Answer

A)   At least 10 studies are desirable for an adequate systematic review.
B)   Systematic reviews and meta-analyses should ideally include 20 or more studies.
C)   There is a tradeoff between the quality of studies and the number of studies available.
D)   Even a few studies provide just as strong of an evidence base as the larger number of studies. D

Question 2

The main difference between a systematic review and meta-analysis is:

Accepted Answer

A)   A systematic review uses a deliberate search approach.
B)   A systematic review has specific criteria for study inclusion.
C)   A meta-analysis calculates an average numerical effect of an intervention.
D)   A meta-analysis has clear implications for policy or practice. C

Question 3

Regarding limitations of systematic reviews and meta-analyses, which one of the following statements is INCORRECT?

Accepted Answer

A)   Most likely limitations of systematic reviews and meta-analyses are related to the quality of the included studies.
B)   It is common for systematic reviews to end up with too few studies, which is a clear limitation.
C)   Most meta-analyses do not have any limitations that need to be addressed by the researchers.
D)   Many meta-analyses include only published studies, which is often a limitation. C

Question 4

What is the most likely effect of biases on the results of a meta-analysis?

Accepted Answer

A)   The results will be statistically nonsignificant.
B)   The results will be highly statistically significant.
C)   The results will underestimate the effectiveness of an intervention.
D)   The results will overestimate the effectiveness of an intervention.

Question 5

What is the best way to address the problem of heterogeneity in a meta-analysis?

Accepted Answer

A)   Analyze the included studies as one group.
B)   Analyze the included studies by dividing them into groups.
C)   Exclude the studies that are outliers in the analyses.
D)   Add more studies to increase the diversity of research.

Question 6

Some evaluation criteria applied to meta-analyses can also be applied to regular empirical studies. Which one of the following evaluation questions is uniquely applicable to meta-analysis but NOT to other studies?

Accepted Answer

A)   Are the limitations of the study and analyses clearly explained?
B)   Are the issues of heterogeneity and bias among the included studies addressed?
C)   Are the numerical results explained in a way understandable to an intelligent layperson?
D)   Are results interpreted to draw clear implications for policy or practice?

Question 7

All of the following elements are essential for data extraction and coding to summarize the studies included in meta-analyses, EXCEPT:

Accepted Answer

A)   The number of authors.
B)   The size of the sample.
C)   The type of intervention.
D)   The measurement of outcomes.

Question 8

One of the most common problems in a meta-analysis is ___, which means the studies included are ___.

Accepted Answer

A)   heterogeneity; too similar
B)   heterogeneity; too different
C)   homogeneity; too similar
D)   homogeneity; too different

Question 9

All of the following features are unique to a systematic review compared to a regular empirical study, EXCEPT:

Accepted Answer

A)   A deliberate and precise search strategy is used to find relevant studies.
B)   All relevant studies meeting specific pre-determined criteria are included.
C)   The included studies are systematically examined in terms of their methods.
D)   The relevant implications for policy or practice are outlined.

Question 10

There are several common biases that can affect the results of meta-analyses and systematic reviews. Which one is NOT among them?

Accepted Answer

A)   Attrition bias.
B)   Selective reporting bias.
C)   Self-selection bias.
D)   Publication bias.

Question 11

Sometimes, a systematic search procedure yields too few studies for inclusion into a systematic review or meta-analysis. All of the following are good reasons for this, EXCEPT:

Accepted Answer

A)   There are too few databases for searching for relevant studies.
B)   The criteria for the search and selection of studies are too narrow.
C)   Too few studies have been conducted on the topic of interest.
D)   Too few studies used a strong enough methodology like a randomized controlled trial.

Question 12

When researchers report how they searched for relevant studies to include into a systematic review or meta-analysis, all of the following aspects are important to mention, EXCEPT:

Accepted Answer

A)   Which databases were searched.
B)   What days of the week the search took place.
C)   Which keywords were used in the search.
D)   What years of study publication were included.

Question 13

All of the following are various explanations of publication bias in systematic reviews and meta-analyses, EXCEPT:

Accepted Answer

A)   Publication bias means that studies with statistically significant findings are more likely to be published.
B)   Publication bias means that studies that find interventions to be effective are more likely to be published.
C)   Publication bias means that studies that have not uncovered any significant effects are unlikely to be unpublished.
D)   Publication bias means that studies that have been published before are unlikely to be replicated.

Exam 14: Evaluating Systematic Reviews and Meta-Analyses: Towards Evidence-Based Practice