The literature existing for a specific topic can be summarized in either a systematic review or literature review. So, both these topics are easily confused, until one delves into the dynamics of both these systems. Even though they are used to fulfil a similar requirement, a literature review is significantly different from a systematic review.
A literature review involves the qualitative summarization of a topic, typically using informal or subjective methods to collate and interpret data. On the other hand, a systematic review involves high-level study of the primary research using a focused approach toward identification, selection, synthesis, and appraisal of all relevant questions involved in the research. From the definition itself, it is evident that the latter review format is more comprehensive as compared to the former.
Both these review systems are inherently different and require specific requirements for their appropriate use. Inappropriate use of either of them can defeat the purpose of the review system.
A systematic review system is appropriate in cases when a focused question requires a pertinent answer. This system is primarily used to remove any bias from the review. Such a review system can be used to answer a clearly defined clinical question. The components of a systematic review include a pre-specified eligibility criterion, systematic search strategy, assessment of the findings’ validity, interpretation and presentation of the results, and a reference list. The number of authors needs to be three or more. An average time required to complete a systematic review is 18 months, on average. The timeline usually goes into months and sometimes, into years. From the above, it is understandable that a thorough knowledge of the topic is required, and a comprehensive statistical analysis of the resources is needed to be done. Such a review system supports the techniques of evidence-based practice.
On the other hand, a literature review is fairly basic in comparison to a systematic review. It is basically a qualitative summary of evidences on a particular topic using informal/subjective methods of collation of data. It can be used to provide a summary or overview of a particular topic; the topic can be generic in nature or a specific query. The principal components of this review system are introduction, methods, discussion, conclusion, and bibliography. The number of authors can be one, or even more. Since it is not comprehensive in nature as compared to a systematic review, the timeline required to finish this review ranges in weeks to months. A comprehensive understanding of the topic under review is not required.