Grades of Recommendation


NASS uses the following grades of recommendation in its evidence analysis and research/clinical care projects.

  • Grades of Recommendation for Summaries or Reviews of Studies
  • A: Good evidence (Level I Studies with consistent finding) for or against recommending intervention.

  • B: Fair evidence (Level II or III Studies with consistent findings) for or against recommending intervention.

  • C: Poor quality evidence (Level IV or V Studies) for or against recommending intervention.

  • I: There is insufficient or conflicting evidence not allowing a recommendation for or against intervention.