Mapping reviews are focused on a visual synthesis of the data and are question based rather than topic based like the scoping review.
Mapping Reviews may be best designed for:
Limitations:
Timeframe: 12+ months, about same amount of time as a systematic review or longer.
Question: Questions are of a wider scope than a systematic review. A priori review protocol is recommended.
Sources and searches: Rapid as time allows searching aimed to give a broad overview, still aims to be thorough and repeatable. In some cases a mapping review may be limited to a certain type of article--may be limited to just review articles, just peer reviewed journals or just grey literature/research in progress. Must include a PRISMA flow diagram.
Selection: Based on inclusion/exclusion criteria. May require more time spent screening articles due to the larger volume of studies from covering a wider scope. Also necessary to group studies for the mapping of included studies.
Appraisal: None, only if appropriate, includes a quality assessment of study bias/validity.
Synthesis: (Graphical or Tabular, less narrative) Visual synthesis and classification of the available studies. A high level map visualizing the status of the field related to the research question.
(Sources: Petticrew and Roberts (2006), Peterson et al. (2008), Booth et al. (2016).