Beoordelen van bewijs voor nieuwe behandelingen

• For new interventions, the results of sequential randomized or non-randomized trials and meta-analysis can differ significantly.
• Evaluation of the evidence for the effect of a new treatment is a complex interplay of several factors, including the methodological design, the risk of a coincidental finding and applicability in practice.
• For proper appraisal of the design of trials, the use of aggregate scores should be avoided and individual study limitations should be mentioned.
• With the use of additional analyses we can now test whether meta-analyses contain sufficient data to find potentially relevant differences.
• The new ‘Grading of recommendations assessment, development and evaluation’ (GRADE) system is a consensus guideline that combines multiple factors into an easily interpreted judgment of the strength of evidence.
• Concise presentation of important quality factors for each outcome significantly increases clarity.
• A more realistic assessment of the reliability of the evidence decreases the risk of major fluctuations in treatment policy.

Conflict of interest and financial support: ICMJE forms provided by the authors are available online along with the full text of this article.