Journal of General Internal Medicine

, Volume 17, Issue 6, pp 469–476

Determination of the clinical importance of study results

A review
  • Malcolm Man-Son-Hing
  • Andreas Laupacis
  • Keith O’Rourke
  • Frank J. Molnar
  • Jeffery Mahon
  • Karen B. Y. Chan
  • George Wells


Formal statistical methods for analyzing clinical trial data are widely accepted by the medical community. Unfortunately, the interpretation and reporting of trial results from the perspective of clinical importance has not received similar emphasis. This imbalance promotes the historical tendency to consider clinical trial results that are statistically significant as also clinically important, and conversely, those with statistically insignificant results as being clinically unimportant. In this paper, we review the present state of knowledge in the determination of the clinical importance of study results. This work also provides a simple, systematic method for determining the clinical importance of study results. It uses the relationship between the point estimate of the treatment effect (with its associated confidence interval) and the estimate of the smallest treatment effect that would lead to a change in a patient’s management. The possible benefits of this approach include enabling clinicians to more easily interpret the results of clinical trials from a clinical perspective, and promoting a more rational approach to the design of prospective clinical trials.

Key Words

clinical importance clinical significance study results minimal clinically important difference review 


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Copyright information

© Society of General Internal Medicine 2002

Authors and Affiliations

  • Malcolm Man-Son-Hing
    • 1
    • 2
    • 3
  • Andreas Laupacis
    • 5
  • Keith O’Rourke
    • 1
  • Frank J. Molnar
    • 1
    • 2
    • 3
  • Jeffery Mahon
    • 6
  • Karen B. Y. Chan
    • 1
  • George Wells
    • 1
    • 4
  1. 1.Received from the Clinical Epidemiology Unit, Ottawa Health Research InstituteOttawa HospitalCanada
  2. 2.the Institute on Health of the Elderly, Sisters of CharityOttawa Health ServiceCanada
  3. 3.the Division of Geriatric MedicineUniversity of OttawaOttawa
  4. 4.the Department of Community Medicine and Epidemiology (GW)University of OttawaOttawa
  5. 5.the Institute for Clinical Evaluative Sciences and Faculty of MedicineUniversity of TorontoToronto
  6. 6.the University of Western OntarioLondonCanada
  7. 7.Ottawa Hospital-Civic CampusGeriatric Assessment UnitOttawaCanada

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