Journal of the American College of Cardiology
ACCF/AHA Clinical Practice Guideline Methodology Summit ReportA Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines
Table5
4. Standards for Synthesizing the Body of Evidence | ||
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IOM Standards and Elements | ACCF/AHA Current Methodology | Workgroup 4 Proposal |
4.1 Use a prespecified method to evaluate the body of evidence | ||
| Currently, the ACCF/AHA does not systematically look at these characteristics. However, the ACCF/AHA does implicitly judge consistency, precision, and directness when using the COR/LOE to write recommendations. | The Workgroup proposes that these IOM-recommended basic characteristics of quality and elements be accepted for assessing and describing quality across studies. |
| A systematic assessment of these characteristics is performed on a case basis, depending on the study analyzed. |
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4.1.3 For each outcome specified in the protocol, use consistent language to characterize the level of confidence in the estimates of the effect of an intervention | By using the COR/LOE, the ACCF/AHA uses consistent language to characterize the level of confidence in the estimates of the effect of an intervention. | See above. The IOM standard should be followed. |
4.2 Conduct a qualitative synthesis | ||
4.2.1 Describe the clinical and methodological characteristics of the included studies, including their size, inclusion or exclusion of important subgroups, timeliness, and other relevant factors | This is currently presented in the form of evidence tables but may be presented in the text as well. |
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4.2.2 Describe the strengths and limitations of individual studies and patterns across studies | This is currently presented in the form of evidence tables but may be presented in the text as well. | The IOM standard should be considered. |
4.2.3 Describe, in plain terms, how flaws in the design or execution of the study (or groups of studies) could bias the results, explaining the reasoning behind these judgments | This is currently presented in the form of evidence tables but may be presented in the text as well. | The IOM standard should be considered. |
4.2.4 Describe the relationships between the characteristics of the individual studies and their reported findings and patterns across studies | This is currently presented in the form of evidence tables but may be presented in the text as well. | The IOM standard should be considered. |
4.2.5 Discuss the relevance of individual studies to the populations, comparisons, cointerventions, settings, and outcomes or measures of interest | This is currently presented in the form of evidence tables but may be presented in the text as well. | The IOM standard should be considered. |
4.3 Decide if, in addition to a qualitative analysis, the SR will include a quantitative analysis (meta-analysis) |
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4.3.1 Explain why a pooled estimate might be useful to decision makers | Reporting meta-analyses for the subject is encouraged. Limitations regarding meta-analyses are explained in the text. | This may be described in text. See above. |
4.4 If conducting a meta-analysis, then do the following: | ||
4.4.1 Use expert methodologists to develop, execute, and peer review the meta-analyses | Meta-analyses are not performed by GWC members, but published meta-analyses are reported. Meta-analyses used must be published in peer-reviewed journals, and any limitations of the meta-analysis are explained. |
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4.4.2 Address the heterogeneity among study effects | The ACCF/AHA does not explicitly do this but implicitly judges heterogeneity among study effects, which determines the need to downgrade recommendations. | The IOM standard should be considered. |
4.4.3 Accompany all estimates with measures of statistical uncertainty | This is not currently performed. | The IOM standard should be considered. |
4.4.4 Assess the sensitivity of conclusions to changes in the protocol, assumptions, and study selection (sensitivity analysis) | This is not currently performed. | The IOM standard should be considered. |
| The ACCF/AHA currently uses COR (I, IIa, IIb, III)/LOE (A, B, C), whereas other popular systems differ. |
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ACCF indicates American College of Cardiology Foundation; AHA, American Heart Association; COR, class of recommendation; CPG, clinical practice guideline; EPC, evidence-based practice center; GRADE, Grading of Recommendations Assessment, Development and Evaluation; GWC, guideline writing committee; IOM, Institute of Medicine; LOE, level of evidence; NHLBI, National Heart, Lung, and Blood Institute; PICO(TS), mnemonic: population, intervention, comparator, outcomes, timing and setting; QOE, quality of evidence; SR, systematic review; and Task Force, ACCF/AHA Task Force on Practice Guidelines.