Systematic Approaches to a Successful Literature Review by 
An Introduction to Systematic Reviews by 
Handbook for Systematic Reviews of Interventions by 
Doing a Systematic Review by A systematic review:
| Systematic Review | Systematic Literature Review |
| Collates ALL relevant studies that answer a specific question | Critically appraises studies and literature on a topic |
| Comprehensive search of published and unpublished material | Thorough search of published material |
| Has a detailed protocol (see examples on Cochrane) | Includes a detailed search strategy that can be replicated |
| Involves a team of researchers to avoid bias | Usually produced by a single person therefore subject to bias |
| Takes months or even years to produce | Takes weeks or months to produce |
The Cochrane Library is a collection of databases that contain different types of high-quality, independent evidence to inform healthcare decision-making.
The Cochrane Database of Systematic Reviews (CDSR) is the leading resource for systematic reviews in health care. CDSR is built throughout the month, with new and updated reviews and protocols being continuously published when ready.
The Cochrane Central Register of Controlled Trials (CENTRAL) is a highly concentrated source of reports of randomized and quasi-randomized controlled trials. They do not contain the full text of the article. CENTRAL is published monthly.
Cochrane Clinical Answers (CCAs) provide a readable, digestible, clinically-focused entry point to rigorous research from Cochrane Reviews.
More information about the Databases can be found on About the Cochrane Library webpage
The Campbell Collaboration is an international research network that produces systematic reviews of the effects of social interventions in
The Campbell Collaboration's Information Retrieval Methods Group has published a guide to information retrieval for systematic reviews: "Searching for studies: A guide to information retrieval for Campbell Systematic Reviews". This is based on the searching chapter within the Cochrane Handbook but adapted to suit the different subject area.
PICO is a technique used to help make the process of finding an answer to a clinical question easier, by identifying appropriate keywords that can be used to conduct a literature search.
Examples of questions that it may be used for (not a conclusive list):
Treatment - establishing whether a particular treatment would benefit a patient
Diagnostic: confirm or exclude a diagnosis
Prognosis: estimate the likely course of a medical condition
Prevention: reduce the chances of disease by identifying risk factors
