RLO: Steps in conducting a systematic review


  1. Introduction
  2. Step One - Formulating a question
  3. Step Two - Conduct a search
  4. Step Three - Assess the quality
  5. Step Four - Summarise the evidence
  6. Step Five - Interpret the findings
  7. Activity
  8. Feedback
  9. Resources

Step Four

Step four involves summarising the evidence.

Data extraction forms

It is useful to use data extraction forms for the following reasons:

  1. The form is linked directly to the formulated review question and planned assessment of included studies.
  2. The form is the data repository from which the analysis will emerge.

Reviewers should use a double-abstraction process. This is where two independant reviewers extract the data for each study. The forms can be checked against each other and differences identified and corrected.

No two forms are the same, however, the forms should contain the following key components:

  1. Information about the study reference and reviewer
  2. Verification of study eligibility
  3. Study characteristics
  4. Research methods
  5. Participants
  6. Interventions
  7. Outcome measures
  8. Results

It is important that all forms should be pilot tested using a representative sample of the studies to be reviewed. This will save a lot of time later!