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REA Toolkit

What is a Rapid Evidence Assessment?

Literature review

Not Systematic. Collates relevant studies and draw conclusions from them.
Time taken: 1 week to 2 months

Literature reviews collate studies that are relevant to a particular topic and summarise and appraise the research in order to draw conclusions from it. However, literature reviews do not explicitly set out how the studies will be found, included and analysed; their findings should therefore be treated with a great deal of caution.

When is it good to do a literature review?

Literature reviews can be useful for providing information on a specific topic in a very short period of time. It is feasible to carry out a literature review alone and is therefore a suitable method when time, money and access to external support are limited.

What are the disadvantages?

Literature reviews are prone to selection and publication bias; that is, they only tend to review evidence that is readily available, and they can be over reliant on sources that disproportionately report studies with positive outcomes. They are also not clear on methodology in that they do not state their inclusion or exclusion criteria (which specify the studies to be included and excluded in the REA); how they have appraised the research; or how conclusions have been reached.

The literature review was the dominant model until the late 1980s, when, in the health field, a number of studies were published which showed inadequacies and bias in the process. One study, for example, showed that successful treatment for heart attacks would have been identified earlier if systematic review methods had been used to summarise knowledge (Antman et al 1992). Illustrating that literature reviews are weak when the review question aims to synthesis findings on the outcomes from specific interventions.

Methods for reviewing evidence index