Subject guides: Medicine for Students: Critical Appraisal

Critical Appraisal

Critical appraisal is a key step in the research process. By evaluating the studies you find in your database searches, you are ensuring that you have the best evidence to use in your research.

Appraisal tools allow a clinician or researcher to assess evidence for its validity, reliability, and applicability to clinical practice. When an appraisal tool is used to evaluate an article, the article is checked for:

Strengths and weaknesses of the articles study design and methodology
Relevance to your clinical question
Importance of the research question being answered
Legitimacy of conclusions
Any potential conflicts of interest

Critical appraisal tools:

A Measurement Tool to Assess Systematic Reviews (AMSTAR)
A tool to appraise systematic reviews of randomised controlled trials. Systematic reviews including non-randomised trials can be assessed using AMSTAR 2 .
Consensus-based standards for the selection of health measurement instruments (COSMIN)
A checklist containing standards for evaluating the methodological quality of studies on the properties of health measurement instruments.
Critical Appraisal Skills Program checklists (CASP)
Offers checklists for 8 different types of research, including systematic reviews, qualitative studies, randomised controlled trials, case control studies, and diagnostic studies. Each checklist contains both yes/no and open ended questions.
Joanna Briggs: critical appraisal tools
The Joanna Briggs Institute produces 13 tools used to appraise different studies and levels of evidence. Each checklist contains a series of critical appraisal questions and ends with an overall appraisal decision.
Johns Hopkins research evidence appraisal tool
Contains questions that facilitate the evaluation of an article's study design and level of evidence. This tool includes three questions that allow the reviewer to determine the study's methodology, and utilises either a 16 item checklist for primary research or a 12 item checklist for systematic reviews and meta-analyses.
Newcastle-Ottawa Scale (NOS)
A tool for appraising and assessing non-randomised studies included in a meta-analysis.
Oxford Centre for Evidence-Based Medicine (CEBM)
Critical appraisal tools for systematic reviews, randomised controlled trials, and diagnostic and prognostic studies.
QUADAS-2
A tool for assessing the quality of diagnostic accuracy studies.
Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)
Evaluation checklists for cohort, case control, and cross sectional studies.

Risk of Bias tools:

RoB 2.0
Cochrane's risk of bias tool for randomised controlled trials.
ROBINS-I
Risk of Bias in Non-randomised Studies of Interventions. Evaluates the risk of bias in the studies that compare the health effects of two or more interventions.