Classification of Evidence for Specific Tests or Procedures

Class or Category I

• Evidence or agreement that a procedure or test is useful or effective

Class or Category II

• Conflicting evidence or opinion about procedure or test's effectiveness
• IIa: Evidence/opinion in favor
• IIb: Evidence/opinion less in favor of performing test or procedure

Class or Category III

• Evidence/opinion that a test or procedure is not indicated and in some cases might be harmful