A systematic review identifies and analyses all available evidence-based literature on a specified research question. Methodology follows a structured research process, is transparent and reproducible and attempts to minimize possible bias. Key results and conclusions provide comprehensive evidence-based findings to inform those making practice and policy decisions.
A meta-analysis uses statistical methods to combine numerical data from separate research studies in a systematic review to reach a new statistical conclusion. This provides stronger statistical evidence than that found in an individual study.
"A rapid evidence assessment (REA) is a research methodology which uses the same methods and principles as a systematic review but makes concessions to the breadth or depth of the process, in order to suit a shorter timeframe. The advantages of REAs are that rigorous methods for locating, appraising and synthesising evidence from previous studies can be upheld and results can be produced in a shorter time than that required for a full systematic review." (From Varker, T., Forbes, D., Dell, L., Weston, A., Merlin, T., Hodson, S. & O’Donnell, M., (2014). A Developer’s Guide to Undertaking Rapid Evidence Assessments (REAs). Guide repared for the Department of Veterans Affairs. Australian Centre for Posttraumatic Mental Health)