Definitions of systematic reviews vary but generally it is agreed that a systematic review is a structured literature review that involves identifying all relevant primary research using a rigorous search strategy to answer a focused research question. The next step is to assess the quality of the research and provide a summary and synthesis of all relevant available research on the topic.
Systematic reviews often refer to research undertaken by review groups with specialised skills such as the Cochrane collaboration.
This video from Cochrane explains why systematic reviews are important and how they are done.
Undertaking a systematic review as an individual researcher/ postgraduate student cannot be as thorough and in depth as a Cochrane review, however it does need to follow a structured process with identifiable stages. Cooper et al. (2018) examined the approaches to systematic reviews recommended in nine different documents including the Cochrane Handbook, Systematic reviews: the CRD’s guidance for undertaking reviews in health care, the Joanna Briggs Institute Reviewers’ Manual and the Campbell Handbook. These sources consistently described eight key stages, indicating there was a consensus on the key stages of literature searching that are required for a systematic review (Cooper et al., 2018, p.3).