Hierarchy of Evidence for Clinical Prediction Rules
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Level 1: Rules that can be used in a wide variety of settings with confidence that they can change clinician behavior and improve patient outcomes
  • At least one prospective validation in a different population and one impact analysis, demonstrating change in clinician behavior with beneficial consequences
Level 2: Rules that can be used in various settings with confidence in their accuracy.
  • Demonstrated accuracy in either one large prospective study including a broad spectrum of patients and clinicians, or validated in several smaller settings who differ from one another.
Level 3: Rules that clinicians may consider using with caution and only if patients in the study are similar to those in your clinical setting
  • These rules have been validated in only one narrow prospective sample
Level 4: Rules that need further evaluation before they can be applied clinically.
  • These CPRs have been derived but not validated or have only been validated in split samples, large retrospective databases, or by statistical techniques.