MUSM Libraries: Evaluating a SYSTEMATIC REVIEW article

Validity issues |  Size of treatment effect | Finding articles

Validity issues

Are the results valid?

  1. Did the review explicitly address a sensible question?
  2. Was the search for relevant studies detailed and exhaustive?
  3. Were the primary studies of high methodologic quality?
  4. Were the assessments of included studies reproducible?

What are the results?

  1. What are the overall results of the review?
  2. Were the results similar from study to study?

How can I apply the results to patient care?

  1. How can I best interpret the results to apply them to the care of patients in my practice?
  2. Were all patient important outcomes considered?
  3. Are the benefits worth the potential costs and risks?

Size of treatment effect

A systematic review is a concise summary of the best available evidence that addresses a sharply defined clinical question.

A meta-analysis is a systematic review that uses quantitative methods to summarize the results.

The test of homogeneity gauges whether it is reasonable to combine the results of individual studies. It asks if the differences in treatment effect from study to study are greater than one would expect as a result of chance alone.

For meta-analyses of therapy, the results are interpreted as in for articles of therapy:

Treated (Y) a b
Control (X) c d

Risk of Outcome: Y = a/(a+b)
Risk of Outcome: X = c/(c+d)

Experimental group size:
Control group size:
Events in experimental group:
Events in control group:


Finding articles of systematic reviews

PubMed for Handhelds (Memorial On-Campus/Remote One and Mercer On-Campus access)
PubMed for Handhelds (Mercer Off-Campus access)


From: Guyatt, G. Users' Guides to the Medical Literature: Essentials of Evidence-based Clinical Practice. AMA Press, 2002 and Straus. Evidence-Based Medicine. How to Practice and Teach EBM. Churchill-Livingstone, 3rd edition, 2005 (pocket cards).

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