GRADE system classification scheme: Difference between revisions

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==Overview==
==Overview==
The Grading of Recommendations Assessment, Development and Evaluation (GRADE ) is a system developed by a widely representative group of international guideline developers for rating quality of evidence and strength of recommendations that is explicit, comprehensive, transparent, and pragmatic. It is increasingly being adopted by organisation's worldwide for systematic reviews and health technology assessments, as well as guidelines.
Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was developed to determine the '''strength of recommendations''' as strong (1) or weak (2) and to guide assessment of '''quality of evidence''' from high (A) to very low (D).<ref>{{Cite journal| doi = 10.1136/bmj.39489.470347.AD| issn = 1756-1833| volume = 336| issue = 7650| pages = 924–926| last1 = Guyatt| first1 = Gordon H.| last2 = Oxman| first2 = Andrew D.| last3 = Vist| first3 = Gunn E.| last4 = Kunz| first4 = Regina| last5 = Falck-Ytter| first5 = Yngve| last6 = Alonso-Coello| first6 = Pablo| last7 = Schünemann| first7 = Holger J.| last8 = GRADE Working Group| title = GRADE: an emerging consensus on rating quality of evidence and strength of recommendations| journal = BMJ (Clinical research ed.)| date = 2008-04-26| pmid = 18436948| pmc = PMC2335261}}</ref>


==Levels of Evidence<ref name="Guyatt-2008">{{Cite journal  | last1 = Guyatt | first1 = GH. | last2 = Oxman | first2 = AD. | last3 = Vist | first3 = GE. | last4 = Kunz | first4 = R. | last5 = Falck-Ytter | first5 = Y. | last6 = Alonso-Coello | first6 = P. | last7 = Schünemann | first7 = HJ. | last8 = Alderson | first8 = P. | last9 = Alonso-Coello | first9 = P. | title = GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. | journal = BMJ | volume = 336 | issue = 7650 | pages = 924-6 | month = Apr | year = 2008 | doi = 10.1136/bmj.39489.470347.AD | PMID = 18436948 }}</ref>==
==Strength of Recommendations==
The GRADE system classifies recommendations as '''strong (grade 1)''' or '''weak (grade 2)'''. Factors influencing this determination are as follows:


{|class="wikitable"
{| style="margin: 5px 10px; width: 80%;"
!Quality of evidence!! Definition
! style="font-size: 85%; background: #545454; color: #F8F8FF; padding: 5px 10px;" | What Should be Considered
! style="font-size: 85%; background: #545454; color: #F8F8FF; padding: 5px 10px;" | Recommended Process
|-
|-
| High quality (Grade A)|| Further research is very unlikely to change our confidence in the estimate of effect.
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" | High or moderate evidence (Is there high or moderate quality evidence?)
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" | The higher the quality of evidence, the more likely a strong recommendation.
|-
|-
| Moderate quality (Grade B) || Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
| style="font-size: 85%; background: #F5F5F5; padding: 5px 10px;" | Certainty about the balance of benefits vs. harms and burdens (Is there certainty?)
| style="font-size: 85%; background: #F5F5F5; padding: 5px 10px;" | The larger the difference between the desirable and undesirable consequences and the certainty around that difference, the more likely a strong recommendation. The smaller the net benefit and the lower the certainty for that benefit, the more likely a weak recommendation.
|-
|-
| Low quality (Grade C) || Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" | Certainty in or similar values (Is there certainty or similarity?)
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" | The more certainty or similarity in values and preferences, the more likely a strong recommendation.
|-
|-
| Very low quality (Grade D)|| Any estimate of effect is very uncertain.
| style="font-size: 85%; background: #F5F5F5; padding: 5px 10px;" | Resource implications (Are resources worth expected benefits?)
| style="font-size: 85%; background: #F5F5F5; padding: 5px 10px;" | The lower the cost of an intervention compared to the alternative and other costs related to the decision–ie, fewer resources consumed–the more likely a strong recommendation.
|}
 
==Quality of Evidence==
The GRADE system classifies quality of evidence as '''high (grade A)''', '''moderate (grade B)''', '''low (grade C)''', or '''very low (grade D)'''. Determinants of the quality of evidence are as follows:
 
{| style="margin: 5px 10px;"
! style="font-size: 85%; background: #545454; color: #F8F8FF; padding: 5px 10px;" | Underlying methodology
|-
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" |
* A (high) — RCTs
* B (moderate) — Downgraded RCTs or upgraded observational studies
* C (low) — Well-done observational studies with control randomized controlled trials
* D (very low) — Downgraded controlled studies or expert opinion based on other evidence
|-
! style="font-size: 85%; background: #545454; color: #F8F8FF; padding: 5px 10px;" | Factors that may decrease the strength of evidence
|-
| style="font-size: 85%; background: #F5F5F5; padding: 5px 10px;" |
* Poor quality of planning and implementation of available RCTs, suggesting high likelihood of bias
* Inconsistency of results, including problems with subgroup analyses
* Indirectness of evidence (differing population, intervention, control, outcomes, comparison)
* Imprecision of results
* High likelihood of reporting bias
|-
! style="font-size: 85%; background: #545454; color: #F8F8FF; padding: 5px 10px;" | Main factors that may increase the strength of evidence
|-
| style="font-size: 85%; background: #DCDCDC; padding: 5px 10px;" |
* Large magnitude of effect (direct evidence, relative risk > 2 with no plausible confounders)
* Very large magnitude of effect with relative risk > 5 and no threats to validity (by two levels)
* Dose-response gradient
|}
|}


==References==
==References==
{{Reflist|2}}
{{Reflist|2}}
==External Links==
* [http://www.gradeworkinggroup.org GRADE working group]

Latest revision as of 17:54, 3 March 2015

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was developed to determine the strength of recommendations as strong (1) or weak (2) and to guide assessment of quality of evidence from high (A) to very low (D).[1]

Strength of Recommendations

The GRADE system classifies recommendations as strong (grade 1) or weak (grade 2). Factors influencing this determination are as follows:

What Should be Considered Recommended Process
High or moderate evidence (Is there high or moderate quality evidence?) The higher the quality of evidence, the more likely a strong recommendation.
Certainty about the balance of benefits vs. harms and burdens (Is there certainty?) The larger the difference between the desirable and undesirable consequences and the certainty around that difference, the more likely a strong recommendation. The smaller the net benefit and the lower the certainty for that benefit, the more likely a weak recommendation.
Certainty in or similar values (Is there certainty or similarity?) The more certainty or similarity in values and preferences, the more likely a strong recommendation.
Resource implications (Are resources worth expected benefits?) The lower the cost of an intervention compared to the alternative and other costs related to the decision–ie, fewer resources consumed–the more likely a strong recommendation.

Quality of Evidence

The GRADE system classifies quality of evidence as high (grade A), moderate (grade B), low (grade C), or very low (grade D). Determinants of the quality of evidence are as follows:

Underlying methodology
  • A (high) — RCTs
  • B (moderate) — Downgraded RCTs or upgraded observational studies
  • C (low) — Well-done observational studies with control randomized controlled trials
  • D (very low) — Downgraded controlled studies or expert opinion based on other evidence
Factors that may decrease the strength of evidence
  • Poor quality of planning and implementation of available RCTs, suggesting high likelihood of bias
  • Inconsistency of results, including problems with subgroup analyses
  • Indirectness of evidence (differing population, intervention, control, outcomes, comparison)
  • Imprecision of results
  • High likelihood of reporting bias
Main factors that may increase the strength of evidence
  • Large magnitude of effect (direct evidence, relative risk > 2 with no plausible confounders)
  • Very large magnitude of effect with relative risk > 5 and no threats to validity (by two levels)
  • Dose-response gradient

References

  1. Guyatt, Gordon H.; Oxman, Andrew D.; Vist, Gunn E.; Kunz, Regina; Falck-Ytter, Yngve; Alonso-Coello, Pablo; Schünemann, Holger J.; GRADE Working Group (2008-04-26). "GRADE: an emerging consensus on rating quality of evidence and strength of recommendations". BMJ (Clinical research ed.). 336 (7650): 924–926. doi:10.1136/bmj.39489.470347.AD. ISSN 1756-1833. PMC 2335261. PMID 18436948.

External Links