Paeds · professional-practice-and-evidence
Evidence-based medicine and critical appraisal
Also known as Evidence-based medicine in paediatrics · Critical appraisal of the medical literature · Hierarchy of evidence and levels of evidence · Risk of bias and validity appraisal · GRADE certainty of evidence
Fellowship guide to evidence-based medicine and critical appraisal in paediatrics: the five steps of evidence-based practice, PICO question formulation, hierarchy of evidence, validity and risk-of-bias appraisal (RoB 2, ROBINS-I, QUADAS-2), results appraisal (effect size, confidence intervals, number needed to treat), GRADE certainty of evidence, publication bias, and applicability to the child — with ANZ, UK, US and Canada guidance.
On this page
Study tools
Your progress
Saved on this device.
Practise this topic
Target exams
Red flags
- Reading the results before judging validity, and accepting a biased estimate as truth
- Quoting a relative risk reduction without the absolute baseline or number needed to treat
- Treating a confidence interval that crosses the null as a positive result
- Equating a small p-value with a clinically important effect
- Extrapolating trial results to a child who differs in age, severity or comorbidity without checking applicability
- Trusting a narrative review or an industry summary over an independent systematic review
Life stages
Care settings
Clinical exam formats
Board mappings
- Evidence-based medicine and critical appraisal
Two things that get mixed up
Internal validity
Applicability (external validity)
Is it valid — check design and risk of bias first · Results — magnitude and precision of the effect · Applicability — does it fit my patient · Versus the rest — how does it sit with the totality of evidence. Remember it as I-R-A-V: valid, results, applicable, versus. Never read the magnitude of an effect before you have judged whether the estimate can be trusted. [13] [14]
Overview & Definition
A parent hands you a printout claiming a new therapy halves the risk of their child's chronic illness, and asks whether to start it. Before you answer the clinical question, you face an evidence question: is the claim trustworthy, how large is the effect in absolute terms, and does the study describe a child anything like yours. Evidence-based medicine is the discipline that answers these. [1] [13]
Evidence-based medicine is the conscientious, explicit, and judicious integration of the best current research evidence with clinical expertise and patient or family values. It is not cookbook medicine, nor the worship of randomised trials for their own sake; the best evidence only ever informs a decision that still rests on your judgement and the family's circumstances. [1]
The work moves through five steps, often called the five A's: ask a focused question, acquire the best evidence, appraise it critically, apply it to the patient, and assess the outcome. This page owns the appraisal engine that drives them. The statistical machinery — sensitivity, specificity, likelihood ratios, confidence intervals, and effect measures — belongs to the dedicated leaves on diagnostic accuracy, clinical epidemiology, and biostatistics, and you should cross-link them rather than rebuild their content here. [1] [14]
References16ShowHide
- [1]Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS Evidence based medicine: what it is and what it isn't BMJ, 1996.PMID 8555924
- [2]Richardson WS, Wilson MC, Nishikawa J, Hayward RS The well-built clinical question: a key to evidence-based decisions ACP J Club, 1995.PMID 7582737
- [3]Jaeschke R, Guyatt G, Sackett DL Users' guides to the medical literature. III. How to use an article about a diagnostic test. A. Are the results of the study valid? Evidence-Based Medicine Working Group JAMA, 1994.PMID 8283589
- [4]Jaeschke R, Guyatt GH, Sackett DL Users' guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based Medicine Working Group JAMA, 1994.PMID 8309035
- [5]Schulz KF, Altman DG, Moher D CONSORT 2010 statement: Updated guidelines for reporting parallel group randomised trials J Pharmacol Pharmacother, 2010.PMID 21350618
- [6]Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement J Clin Epidemiol, 2009.PMID 19631508
- [7]Sterne JAC, Savović J, Page MJ, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials BMJ, 2019.PMID 31462531
- [8]Sterne JA, Hernán MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions BMJ, 2016.PMID 27733354
- [9]Balshem H, Helfand M, Schünemann HJ, et al. GRADE guidelines: 3. Rating the quality of evidence J Clin Epidemiol, 2011.PMID 21208779
- [10]Andrews J, Guyatt G, Oxman AD, et al. GRADE guidelines: 14. Going from evidence to recommendations: the significance and presentation of recommendations J Clin Epidemiol, 2013.PMID 23312392
- [11]Andrews JC, Schünemann HJ, Oxman AD, et al. GRADE guidelines: 15. Going from evidence to recommendation-determinants of a recommendation's direction and strength J Clin Epidemiol, 2013.PMID 23570745
- [12]Egger M, Davey Smith G, Schneider M, Minder C Bias in meta-analysis detected by a simple, graphical test BMJ, 1997.PMID 9310563
- [13]Greenhalgh T How to read a paper. Statistics for the non-statistician. II: Significant relations and their pitfalls BMJ, 1997.PMID 9277611
- [14]Murad MH, Montori VM, Ioannidis JP, et al. How to read a systematic review and meta-analysis and apply the results to patient care: users' guides to the medical literature JAMA, 2014.PMID 25005654
- [15]Whiting PF, Rutjes AW, Westwood ME, et al. QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies Ann Intern Med, 2011.PMID 22007046
- [16]Ioannidis JP Why most published research findings are false PLoS Med, 2005.PMID 16060722