Clinical Guidelines The methods used to assess the quality and strength of the evidence by the National Guidelines Clearinghouse include expert consensus (alone and through committee and/or Delphi methods), subjective review, and weighting according to a rating scheme (in which the scheme may be give or not given). The methods use to collect and/or select the evidence that will be evaluated include the following: Hand-searches of published literature (primary sources and secondary sources), searches of electronic databases, and searches of patient registry data. The methods used to create, formulate, or establish the recommendations include: Informal expert consensus, expert consensus (alone, and through Delphi methods, nominal group technique, and/or consensus development conference), and balance sheets.

The guidelines comparisons of the National Guidelines Clearinghouse indicate that the rating schemes for the strength of the recommendations are derived from the weighted scheme used the developer of the guideline. These rating schemes are used to ascertain the relative importance of the recommendations that are made. The factors that drive the recommendations include evidence quality and evidence strength, the associated clinical perspective, or a combination of both of these.

The EPC selected four major domains (risk...

The EPC reviewers proceed by aggregating judgments regarding the strength of evidence in each of the domains into an overall evidence grade that is associated to each major outcome. The sets of domains are then considered from two categorical perspectives: required and additional. The EPC recognizes that the strength of evidence is best evaluated separately for each substantive comparison for each of the key questions. This consideration is based on the fact that the strength of evidence may vary among the comparisons within each key question and may vary between the key questions when a systematic review is conducted.
The evidence grading used by Agency for Healthcare Research and Quality seem to be the most robust of the organizations. Overall, each of the grading systems includes several methods and techniques to arrive at a consensus about the strength and quality of the evidence. The processes employed and the methods used are not exact matches across the organizations, however, the constellation of methods used by any one organization is designed to use data triangulation and multiple methods to support the…