Screen and include or exclude
Having located details of studies potentially relevant to your question, it is now time to screen them to make sure they fit your criteria precisely.
It is usual to conduct this screening in two stages:
- scan the title and abstracts of potentially relevant articles
- then, for those articles not excluded, obtain and re-screen the full-text of the article.
Stage one: Title and abstract
Articles and studies should be included or excluded based on the criteria set out in the protocol.
Ask the following sorts of questions:
- Does the article cover the right population?
- Does it cover the type of intervention set out in the review question or protocol?
- Is the outcome the one being examined in the review?
Screening should be carried out by more than one person - two with the possibility of referral to a third in case of dispute. If you are a student carrying out your own review you will need to rely solely on your own judgment.
Exercise caution at stage one - if there is any doubt about whether a particular study should be excluded keep it in.
Stage two: Full text
The full-text of any articles not excluded at stage one should be obtained and the screening process repeated so a final decision on which articles will form part of the systematic review can be reached.
Keep notes of which studies have been excluded and the reasons for exclusion - this is vital for any PRISMA flow diagram (see our Searching systematically page).
Articles may be available in full-text on one of the databases covering the subject area or in paper in the library.
For articles not available in our collection in paper or electronically try the following:
- If you are an RGU student or staff member in the Schools of Health Sciences, Nursing and Midwifery or Pharmacy and Life Sciences you can apply for an account on the NHS Knowledge Network. This provides access to some additional online journals and you may find some articles not available in our collection on that resource.
- Try searching for the article on Google Scholar in case a copy is available free on the web.
- Items not located elsewhere may be requested via our interlibrary loan service