Evidence based practice

Critical appraisal is an integral process in evidence based practice that seeks to identify the strengths and limitations of the studies found.

Criteria for appraisal of studies:

  1. Is the study relevant to my query?
  2. Does the study provide any new evidence?
  3. How current is the study?
  4. Was the trial of sufficient size to reach a meaningful conclusion?
  5. What role did the funder(s) play?
  6. Was there any bias in the methodology or selection of the subjects in the study?
    • were the subjects randomly selected?
    • blinding - were researchers and subjects unaware of who was in the intervention or control group?
    • were individuals treated equally through the trial?

The RAMMbo mnemonic may be helpful for critical appraisal of a study:

Recruitment - were all patients selected representative of the target population; have inclusion/exclusion criteria been taken into account

Allocation - was there randomisation

Maintenance - were all patients treated equally except for the intervention and was the allocation concealed

Measurements were:

  • blinded
  • objective

Critical appraisal tools

There are a number of tools available to assist you with appraising the quality of the article(s) you have found.

CASP helps people to find and interpret the best available evidence from health research.

The Centre for Evidence-Based Medicine in Oxford (UK) provides tools and downloads for the critical appraisal of medical evidence. Sample appraisal sheets are provided together with several helpful examples.

Provides access to critical appraisal tools for different types of studies including systematic reviews and RCTs.