A “systematic literature review”, “systematic review”, or “SLR”, is is a type of secondary research that evaluates information from all relevant previous studies in a systematic way.
The goal of a systematic review is to answer a specific research question such as:
“In patients aged 70 years or older, how does the administration of an influenza vaccine compared with not administering a vaccine affect the risk of developing influenza during the winter?”
“Systematic” means that the review methods are planned in advance. The methods are transparent, objective, and structured so as to reduce bias and allow others to repeat the review in a consistent way.
Systematic reviews are methodical, reliable, and comprehensive. This is why SLRs are more valuable than a traditional “literature review” / “narrative review” / “review article”.
• are methodical
• are repeatable
• are comprehensive
• require at least two authors so that judgments and interpretations can be cross-checked and discussed
• are usually descriptive
• may not include all the available data
• do not analyze the data rigorously
• are commonly performed by one author