Evidence Based Practice: Appraising the Evidence

When appraising evidence at any level--but particularly those on the lower half of the Pyramid--you must ask questions to determine the usefulness of the evidence, particularly in terms of validity and importance.

Is the Study Valid?

• Is there a clear, defined research question?
• Was the study "blinded"?
• Was the test evaluated?
• Are the methods clear?
• Is the study reproducible?
• What were the outcome measures?
• Are studies consistent in systematic review?

Are the Results Important?

• Is the evidence relevant to your question?
• Is the methods section clear?
• In a systematic review, are individual studies considered for validity?
• Are studies consistent?
• How precise are the results?
• Are results statistically significant?

After locating evidence and determining how useful the information will be for the patient's unique situation, you will need to determine how best to apply the evidence to practice.

Consider:

Study similarities to your setting

The available alternatives

How similar your patient is to those studied

Whether studied outcomes are realistic in your clinical setting

Whether potential benefit outweighs potential risk

How the intervention relates to the patient's values and experiences

What the outcome will be if no intervention is applied

Critical appraisal checklists/worksheets help you appraise the reliability, importance and applicability of clinical evidence.  There are different types of worksheet and checklists available.

Checklists:

These checklists were adapted from a number of sources including the JAMA series on "How to read the Medical Literature", the UK Workshops on Teaching Evidence-based Health Care and the Critical Appraisal Skills Programme (CASP), Oxford.  And can be found here: https://www.gla.ac.uk/schools/healthwellbeing/research/generalpractice/ebp/checklists/