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:
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

Quizplus · 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.

Sometimes, a Systematic Search Procedure Yields Too Few Studies for Inclusion