Review Article | Published:

How to critically appraise an article

Nature Clinical Practice Gastroenterology & Hepatology volume 6, pages 8291 (2009) | Download Citation

Subjects

Abstract

Critical appraisal is a systematic process used to identify the strengths and weaknesses of a research article in order to assess the usefulness and validity of research findings. The most important components of a critical appraisal are an evaluation of the appropriateness of the study design for the research question and a careful assessment of the key methodological features of this design. Other factors that also should be considered include the suitability of the statistical methods used and their subsequent interpretation, potential conflicts of interest and the relevance of the research to one's own practice. This Review presents a 10-step guide to critical appraisal that aims to assist clinicians to identify the most relevant high-quality studies available to guide their clinical practice.

Key points

  • Critical appraisal is a systematic process used to identify the strengths and weaknesses of a research article

  • Critical appraisal provides a basis for decisions on whether to use the results of a study in clinical practice

  • Different study designs are prone to various sources of systematic bias

  • Design-specific, critical-appraisal checklists are useful tools to help assess study quality

  • Assessments of other factors, including the importance of the research question, the appropriateness of statistical analysis, the legitimacy of conclusions and potential conflicts of interest are an important part of the critical appraisal process

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    and (2005) Growth and decentralisation of the medical literature: implications for evidence-based medicine. J Med Libr Assoc 93: 499–501

  2. 2.

    (2008) Information overload: what's behind it, what's beyond it? Med J Aust 189: 84–85

  3. 3.

    (Ed.; 2001) A Dictionary of Epidemiology (4th Edn). New York: Oxford University Press

  4. 4.

    et al. (2000). Evidence-based Medicine. How to Practice and Teach EBM. London: Churchill Livingstone

  5. 5.

    and (Eds; 2002). Users' Guides to the Medical Literature: a Manual for Evidence-based Clinical Practice. Chicago: American Medical Association

  6. 6.

    (2000) How to Read a Paper: the Basics of Evidence-based Medicine. London: Blackwell Medicine Books

  7. 7.

    (1994) READER: an acronym to aid critical reading by general practitioners. Br J Gen Pract 44: 83–85

  8. 8.

    and (2001) What is critical appraisal. Evidence-based Medicine 3: 1–8 [] (accessed 25 November 2008)

  9. 9.

    Public Health Resource Unit (2008) Critical Appraisal Skills Programme (CASP). [] (accessed 8 August 2008)

  10. 10.

    National Health and Medical Research Council (2000) How to Review the Evidence: Systematic Identification and Review of the Scientific Literature. Canberra: NHMRC

  11. 11.

    (1998) Critical Appraisal of Epidemiological Studies and Clinical Trials (2nd Edn). Oxford: Oxford University Press

  12. 12.

    Agency for Healthcare Research and Quality (2002) Systems to rate the strength of scientific evidence? Evidence Report/Technology Assessment No 47, Publication No 02-E019 Rockville: Agency for Healthcare Research and Quality

  13. 13.

    (1996) The Pocket Guide to Critical Appraisal: a Handbook for Health Care Professionals. London: Blackwell Medicine Publishing Group

  14. 14.

    et al. (2008) Critical appraisal for public health: a new checklist. Public Health 122: 92–98

  15. 15.

    et al. (1998) Randomised controlled trial of the READER method of critical appraisal in general practice. BMJ 316: 1134–37

  16. 16.

    et al. Teaching critical appraisal skills in health care settings (Review). Cochrane Database of Systematic Reviews 2005, Issue 3. Art. No.: cd001270. 10.1002/14651858.cd001270

  17. 17.

    and (2000) Assessing quality in qualitative research. BMJ 320: 50–52

  18. 18.

    (2003) On the Shoulders of Giants: the Great Works of Physics and Astronomy. Philadelphia, PN: Penguin

  19. 19.

    National Health and Medical Research Council (1999) A Guide to the Development, Implementation and Evaluation of Clinical Practice Guidelines. Canberra: National Health and Medical Research Council

  20. 20.

    US Preventive Services Taskforce (1996) Guide to clinical preventive services (2nd Edn). Baltimore, MD: Williams & Wilkins

  21. 21.

    and (1995) Should we be performing more randomized controlled trials evaluating surgical operations? Surgery 118: 456–467

  22. 22.

    (2002) Epidemiology: an Introduction. Oxford: Oxford University Press

  23. 23.

    and (2003) Improving the evidence-base in surgery: sources of bias in surgical studies. ANZ J Surg 73: 504–506

  24. 24.

    et al. (1995) Lessons learned from a prospective meta-analysis. J Am Geriatr Soc 43: 435–439

  25. 25.

    et al. (2001) Assessing the quality of reports of systematic reviews: the QUORUM statement compared to other tools. In Systematic Reviews in Health Care: Meta-analysis in Context 2nd Edition, 122–139 (Eds Egger M. et al.) London: BMJ Books

  26. 26.

    et al. (1991) Publication bias in clinical research. Lancet 337: 867–872

  27. 27.

    and (1989) Publication bias and dissemination of clinical research. J Natl Cancer Inst 81: 107–115

  28. 28.

    et al. (2000) Improving the quality of reports of meta-analyses of randomised controlled trials: the QUORUM statement. Br J Surg 87: 1448–1454

  29. 29.

    et al. (2007) Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 7: 10 [10.1186/1471-2288-7-10]

  30. 30.

    et al. (2000) Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA 283: 2008–2012

  31. 31.

    and (2003) Improving the evidence-base in surgery: evaluating surgical effectiveness. ANZ J Surg 73: 507–510

  32. 32.

    (1995) Subverting randomization in controlled trials. JAMA 274: 1456–1458

  33. 33.

    et al. (1995) Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 273: 408–412

  34. 34.

    et al. (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel group randomized trials. BMC Medical Research Methodology 1: 2 [] (accessed 25 November 2008)

  35. 35.

    et al. (2005) Reader's guide to critical appraisal of cohort studies: 1. Role and design. BMJ 330: 895–897

  36. 36.

    et al. (2005) Reader's guide to critical appraisal of cohort studies: 2. Assessing potential for confounding. BMJ 330: 960–962

  37. 37.

    et al. (2005) Reader's guide to critical appraisal of cohort studies: 3. Analytical strategies to reduce confounding. BMJ 330: 1021–1023

  38. 38.

    et al. (2007) Strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. BMJ 335: 806–808

  39. 39.

    (1991) Assessing bias in case-control studies: proper selection of cases and controls. Stroke 22: 938–942

  40. 40.

    (2003) Assessment of the accuracy of diagnostic tests: the cross-sectional study. J Clin Epidemiol 56: 1118–1128

  41. 41.

    and (2006) Sources of bias in diagnostic accuracy studies and the diagnostic process. CMAJ 174: 481–482

  42. 42.

    et al. (2003)The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration. Ann Intern Med 138: W1–W12

  43. 43.

    STARD statement (Standards for the Reporting of Diagnostic Accuracy Studies). [] (accessed 10 September 2008)

  44. 44.

    (1998) Economic evaluation: an introduction. BMJ 316: 1013–1014

  45. 45.

    et al. (1999) Economics notes: types of economic evaluation. BMJ 318: 1349

  46. 46.

    et al. (1999) Barriers to participation in randomized controlled trials: a systematic review. J Clin Epidemiol 52: 1143–1156

  47. 47.

    et al. (2004) Are claims of equivalency in digestive diseases trials supported by the evidence? Gastroentrology 126: 1700–1710

  48. 48.

    and (2006) Good enough: a primer on the analysis and interpretation of noninferiority trials. Ann Intern Med 145: 62–69

  49. 49.

    et al. (2006) Reporting of noninferiority and equivalence randomized trials: an extension of the CONSORT statement. JAMA 295: 1152–1160

  50. 50.

    et al. (2007) Inclusion of patients in clinical trial analysis: the intention to treat principle. In Interpreting and Reporting Clinical Trials: a Guide to the CONSORT Statement and the Principles of Randomized Controlled Trials, 92–98 (Eds Keech A. et al.) Strawberry Hills, NSW: Australian Medical Publishing Company

  51. 51.

    National Health and Medical Research Council (2007) National Statement on Ethical Conduct in Human Research 89–90 Canberra: NHMRC

  52. 52.

    et al. (2000) Conflict-of-interest policies for investigators in clinical trials. N Engl J Med 343: 1616–1620

  53. 53.

    et al. (2004) Potential research participants' views regarding researcher and institutional financial conflicts of interests. J Med Ethics 30: 73–79

  54. 54.

    and (2002) Ethical issues concerning the relationships between medical practitioners and the pharmaceutical industry. Med J Aust 176: 118–121

  55. 55.

    (1999) Research, ethics and conflicts of interest. J Med Ethics 25: 259–262

  56. 56.

    and (1998) Bioethics for clinicians: 17. Conflict of interest in research, education and patient care. CMAJ 159: 960–965

Download references

Author information

Affiliations

  1. JM Young is an Associate Professor of Public Health and the Executive Director of the Surgical Outcomes Research Centre at the University of Sydney and Sydney South-West Area Health Service, Sydney

    • Jane M Young
  2. MJ Solomon is Head of the Surgical Outcomes Research Centre and Director of Colorectal Research at the University of Sydney and Sydney South-West Area Health Service, Sydney, Australia.

    • Michael J Solomon

Authors

  1. Search for Jane M Young in:

  2. Search for Michael J Solomon in:

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Jane M Young.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/ncpgasthep1331

Further reading