Journal List > J Korean Med Assoc > v.54(7) > 1042466

Seo, Lee, Shin, Lim, Jang, Jung, and Park: Trend analysis of grading systems for level of evidence and strength of recommendation

Abstract

When clinicians or healthcare professionals are to make decisions, they can judge the quality of evidence and reliability of recommendations by 'Level of evidence' and 'Grade of recommendation'. Because of this, the step of grading evidence and recommendations is very important in developing clinical practice guidelines. The objective of this study was to identify the various grading systems and criteria of the clinical practice guidelines. We reviewed 101 guidelines from the National Guideline Clearinghouse Database and chose 66 guidelines to analyze in terms of the grading systems for level of evidence and strength of recommendation. The grading systems for 'Level of evidence' were classified into 4 types by criteria such as study design, study quality, consistency, limitations, strength of evidence, and validity. Type II was the most common evidence grading system applied by 12 organizations (37.5%) and 30 guidelines (45.5%). The grading systems for 'Grade of recommendation' were classified into 4 types by criteria such as level/quality of evidence, strength of recommendations, study quality, consistency, applicability, balance between benefit and harm, and effectiveness/usefulness. Type I was the most common recommendation grading system applied by 9 organizations (33.4%) and 23 guidelines (40.4%). A formal grading system based on consistent and clear approaches is needed because the process of grading work can be subjective when clinical practice guideline users are making decisions. It is necessary for clinical practice guideline developers to have a common criterion so that they can judge the grade of evidence and recommendations objectively in the development of clinical practice guidelines.

Figures and Tables

Table 1
Classification by criteria of evidence grading system
jkma-54-758-i001

See the Appendix for abbreviations of organizations.

Table 2
Comparison of the level of evidence grading system by organization: Type Ia)
jkma-54-758-i002

RCT, randomized controlled trial. See the Appendix for abbreviations of organizations.

a)The main grading criteria was study design and study quality (consistency).

Table 3
Comparison of the level of evidence grading system by organization: Type IIa)
jkma-54-758-i003

RCT, randomized controlled trial. See the Appendix for abbreviations of organizations.

a)The main grading criteria was study design.

Table 4
Comparison of the level of evidence grading system by organization: Type IIIa)
jkma-54-758-i004

RCT, randomized controlled trial. See the Appendix for abbreviations of organizations.

a)The main grading criteria was study design and limitation.

Table 5
Comparison of the level of evidence grading system by organization: Type IVa)
jkma-54-758-i005

See the Appendix for abbreviations of organizations.

a)The main grading criteria was strength of study design.

Table 6
Classification by criteria of recommendation grading system
jkma-54-758-i006

See the Appendix for abbreviations of organizations.

Table 7
Comparison grading system of recommendation by organization: Type Ia)
jkma-54-758-i007

See the Appendix for abbreviations of organizations.

a)The main grading criteria was study quality and level of evidence (consistency/applicability).

Table 8
Comparison grading system of recommendation by organization: Type IIa)
jkma-54-758-i008

See the Appendix for abbreviations of organizations.

a)The main grading criteria was level of evidence and strength of recommendations.

Table 9
Comparison grading system of recommendation by organization: Type IIIa)
jkma-54-758-i009

See the Appendix for abbreviations of organizations.

a)The main grading criteria was level of evidence.

Table 10
Comparison grading system of recommendation by organization: Type IVa)
jkma-54-758-i010

See the Appendix for abbreviations of organizations.

a)The main grading criteria was level of evidence and balance between benefit and harm.

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