Question 1

All of the following features are unique to a systematic review compared to a regular empirical study, EXCEPT:&#10;A) A deliberate and precise search strategy is used to find relevant studies.&#10;B) All relevant studies meeting specific pre-determined criteria are included.&#10;C) The included studies are systematically examined in terms of their methods.&#10;D) The relevant implications for policy or practice are outlined.

Accepted Answer

While all of the other options are unique features of systematic reviews, outlining relevant implications for policy or practice is not necessarily unique to systematic reviews and can be included in regular empirical studies as well.

Question 2

The main difference between a systematic review and meta-analysis is:&#10;A) A systematic review uses a deliberate search approach.&#10;B) A systematic review has specific criteria for study inclusion.&#10;C) A meta-analysis calculates an average numerical effect of an intervention.&#10;D) A meta-analysis has clear implications for policy or practice.

Accepted Answer

The main difference between a systematic review and meta-analysis is that a meta-analysis calculates an average numerical effect of an intervention, while a systematic review involves a deliberate search approach and specific criteria for study inclusion. While both can have implications for policy or practice, this is not a distinguishing factor between the two.

Question 3

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:&#10;A) Which databases were searched.&#10;B) What days of the week the search took place.&#10;C) Which keywords were used in the search.&#10;D) What years of study publication were included.

Accepted Answer

The days of the week the search took place are not relevant to the search strategy and do not need to be mentioned in a report. However, the other aspects listed (databases searched, keywords used, and years of study publication included) are important to mention in order to transparently report the search methodology and ensure reproducibility of the study.

Question 4

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:&#10;A) There are too few databases for searching for relevant studies.&#10;B) The criteria for the search and selection of studies are too narrow.&#10;C) Too few studies have been conducted on the topic of interest.&#10;D) Too few studies used a strong enough methodology like a randomized controlled trial.

Accepted Answer

There are a large number of databases available for searching relevant studies, so it is unlikely that too few databases are responsible for yielding too few studies for inclusion. Instead, it is more likely that the criteria for search and selection of studies are too narrow or too few studies have been conducted on the topic of interest. Another possible reason could be inadequate search strategy.

Question 5

When considering the number of studies included in a systematic review, the text suggests all of the following rules, EXCEPT:&#10;A) At least 10 studies are desirable for an adequate systematic review.&#10;B) Systematic reviews and meta-analyses should ideally include 20 or more studies.&#10;C) There is a tradeoff between the quality of studies and the number of studies available.&#10;D) Even a few studies provide just as strong of an evidence base as the larger number of studies.

Accepted Answer

The text suggests that all studies, regardless of the number, should be considered in a systematic review. Therefore, option D is incorrect as it suggests that only a few studies are enough for strong evidence. The other options are consistent with the text.

Question 6

One of the most common problems in a meta-analysis is ___, which means the studies included are ___.&#10;A) heterogeneity; too similar&#10;B) heterogeneity; too different&#10;C) homogeneity; too similar&#10;D) homogeneity; too different

Accepted Answer

Heterogeneity is a common problem in a meta-analysis, which means the studies included are too different. This can lead to difficulties in combining the results and drawing meaningful conclusions. Homogeneity, on the other hand, refers to studies that are too similar, which can lead to a lack of diversity and potential bias in the findings. Therefore, the correct answer is B.

Question 7

What is the best way to address the problem of heterogeneity in a meta-analysis?&#10;A) Analyze the included studies as one group.&#10;B) Analyze the included studies by dividing them into groups.&#10;C) Exclude the studies that are outliers in the analyses.&#10;D) Add more studies to increase the diversity of research.

Accepted Answer

The best way to address heterogeneity in a meta-analysis is to analyze the included studies by dividing them into groups based on factors that may contribute to the heterogeneity. This allows for a more accurate analysis of each subgroup and can help identify underlying sources of variability. Simply analyzing all studies as one group or excluding outliers may not fully address the issue of heterogeneity. Adding more studies may help increase the overall strength of the meta-analysis but may not directly address the heterogeneity.

Question 8

There are several common biases that can affect the results of meta-analyses and systematic reviews. Which one is NOT among them?&#10;A) Attrition bias.&#10;B) Selective reporting bias.&#10;C) Self-selection bias.&#10;D) Publication bias.

Accepted Answer

Self-selection bias is not a common bias in meta-analyses and systematic reviews. The other biases listed (attrition bias, selective reporting bias, and publication bias) are all well-known sources of bias in these types of studies. Self-selection bias occurs when study participants are allowed to choose whether or not they want to participate in the study, which can lead to a non-representative sample. However, this type of bias is more commonly associated with individual studies rather than meta-analyses or systematic reviews.

Question 9

What is the most likely effect of biases on the results of a meta-analysis?&#10;A) The results will be statistically nonsignificant.&#10;B) The results will be highly statistically significant.&#10;C) The results will underestimate the effectiveness of an intervention.&#10;D) The results will overestimate the effectiveness of an intervention.

Accepted Answer

Biases can lead to overestimation of treatment effects in meta-analysis, as studies with larger treatment effects are more likely to be published and included in the analysis, while studies with smaller or no effects may not be reported or excluded from the analysis. This can lead to a distortion of the overall effect size estimate.

Question 10

All of the following are various explanations of publication bias in systematic reviews and meta-analyses, EXCEPT:&#10;A) Publication bias means that studies with statistically significant findings are more likely to be published.&#10;B) Publication bias means that studies that find interventions to be effective are more likely to be published.&#10;C) Publication bias means that studies that have not uncovered any significant effects are unlikely to be unpublished.&#10;D) Publication bias means that studies that have been published before are unlikely to be replicated.

Accepted Answer

All of the other options (A, B, and C) provide various explanations of publication bias, while option D is not an explanation of publication bias, but rather a statement about the likelihood of replication of published studies.

Question 11

All of the following elements are essential for data extraction and coding to summarize the studies included in meta-analyses, EXCEPT:&#10;A) The number of authors.&#10;B) The size of the sample.&#10;C) The type of intervention.&#10;D) The measurement of outcomes.

Accepted Answer

The answer of All of the following elements are essential...

Question 12

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?

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?

Accepted Answer

The answer of Some evaluation criteria applied to meta-analyses can...

Question 13

Regarding limitations of systematic reviews and meta-analyses, which one of the following statements is INCORRECT?&#10;A) Most likely limitations of systematic reviews and meta-analyses are related to the quality of the included studies.&#10;B) It is common for systematic reviews to end up with too few studies, which is a clear limitation.&#10;C) Most meta-analyses do not have any limitations that need to be addressed by the researchers.&#10;D) Many meta-analyses include only published studies, which is often a limitation.

Accepted Answer

The answer of Regarding limitations of systematic reviews and meta-analyses,...

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