Systematic reviews: finding and managing the evidence

When carrying out a systematic review, it's important to conduct a very thorough search which includes sources other than traditional databases like Medline or CINAHL. There are a variety of methods used to finding other relevant unpublished papers and reports not included  in traditional bibliographic databases, such as:

• "Hand-searching" of key journals (this can be done electronically by browsing the electronic table to contents for key journals)
   
• Citation searching (Web of Knowledge citation databases- University  subscription available- or Google Scholar allow you to track other authors who have cited a paper of interest)
   
• Contacting authors, experts, manufacturers via networks and mailing lists
   
• Searching targeted internet resource, such as Google scholar, government, academic or industry websites
   
• Searching conference proceedings (Web of Knowledge Conference Proceedings)
   
• Searching dissertations and theses (http://ethos.bl.uk)
   
• Searching national and international trials registers (https://sites.google.com/a/york.ac.uk/yhectrialsregisters/home)
   
• Searching grey literature - reports and documents not published in traditional ways. Key sources are http://www.opengrey.eu/ or HMIC (Health Management Information Consortium database). This resource presents a useful guide to more sources of grey literature http://allcatsrgrey.org.uk/wp/. Lens.org presents global science and technology knowledge from - use the Scholarly Search and Analysis to find resources.

It's important to keep a record of these other sources used, as well as your search terms, in order to properly document the search process.

Further reading on some of these issues can be found in the Cochrane Handbook  or the Centre for Reviews and Dissemination's guidance on systematic reviews.