The most powerful tool to develop guidelines for the recommendation of evidence based medicines is the Grading of Recommendation Assessment,
Development and Evaluation (GRADE) system. It is not used by all existing guidelines (which are often based on ‘expert opinions’), but it is the most stringent system assuring that the therapeutic recommendations
are really based on evidence. It is the only system that the World Health Organisation (WHO) uses
for its recommendations.
The GRADE system drives the experts who are designing new guidelines, through a pathway which starts from the review of the quality of the available evidence (which may be high, moderate, low and very low) and arrives
at a certain recommendation (which may be strong or weak/conditional).
Figures 3 and 4 below show the different aspects taken into consideration by the GRADE system to evaluate the quality of the evidence and influence the final recommendation(s).
Figure 3: Aspects taken into consideration by the GRADE
system.
Figure 4: Grade quality of the evidence and strength of
the recommendation.
