LibGuides: Evidence-Based Practice: Prognosis

Critical Appraisal of Prognosis Articles

1. Are the results of the prognosis study valid?

Was there a well-defined and representative sample of patients at a similar point in the course of their disease?
Was patient follow-up adequately long and complete?
Were patients sufficiently homogneous in prognostic factors, if not, are adjustments for important prognostic factors made?
Was outcome criteria objective and unbiased?

2. What are the results?

Did the study have a sufficiently large sample size?
How large is the likelihood of the outcome event(s) over a specified period of time?

In clinical situations event rates usually vary over time. Is a survival graph provided showing the number of discrete events occurring over time or the chance of being free of these events over time?

How precise are the estimates of likelihood?

What are the confidence intervals for the event rate?

3. Are the results relevant to your patient?

Are the study results applicable to the patients in your practice?

Are the study patients similiar to your own?

Will the results lead directly to selecting or avoiding therapy.
Will the results impact how you counsel your patient?

Prognosis Critical Appraisal Worksheet

References

Critical Appraisal Questions come from:

Laupacis A., Wells G., et al. Users' guides to the medical literature. V. How to Use an Article About Prognosis. JAMA 1994. 272(3): 234-237.

Guyatt, G. Rennie, D. Meade, MO, Cook, DJ. Users’ Guide to Medical Literature: A Manual for Evidence-Based Clinical Practice, 2nd Edition 2008.

Sackett, DL, et al. Evidence Based Medicine: How to Practice and Teach EBM. 2nd ed. Edinburgh: Churchill Livingstone, 2000. BHSL Call Number: WB 102 E933 2000

Tips on Critical Appraisal of Evidence: Prognosis. Centre for Evidence Based Medicine (Toronto).