Literature Searching and Reviews

The selected studies are critically assessed according to the study type.

The synthesis includes a qualitative analysis (which is a methodological description of the strengths and limitations of the included studies) and, if possible, a quantitative analysis.

Studies need to be assessed on their own terms and there are a variety of tools available to critically assess different studies:

• Assessment of guidelines: AGREE II 
• Assessment of randomized controlled studies (RCT): Cochrane Risk of Bias Tool - RoB 2
• Assessment of observational studies (interventions): ROBINS-I 
• Assessment of diagnostic primary studies: QUADAS-2 
• Assessment of systematic reviews: Amstar 2 (MeaSurement Tool to Assess systematic Reviews)
• Assesement of qualitative studies (strength and weakness of methods): Cochrane-Campbell Handbook for Qualitative Evidence Synthesis (create a Cochrane profile for access)

An overview of a variety of tools can also be found on Latitudes Network, and Critical Appraisal Skills Programme (CASP) offers a series of checklists to critically assess different study types.

GRADE (The Grades of Recommendation, Assessment, Development and Evaluation) is a systematic approach to assessing the confidence in the evidence in systematic reviews and guidelines. 
See e.g.Cochranes site on GRADE and BMJ Best Practice. (2023): What is GRADE?

The overall evidence is assessed on 5 parameters, resulting in an overall rating: 

• Risk of bias
• Imprecision
• Inconsistency
• Indirectness
• Publication bias

CEBMO offers workshops and consultations in relation to the creation of reviews, including critical assessment of studies.