Methodology Overview

ADA is a leader in the process of Evidence Analysis

One reason for this is, in part, the combination of the rigor and transparency of our process. Our goal is not only to be as thorough as possible, but to make each step in our process completely clear.

The idea behind this is that, by using our process, other individuals and organizations could use our process and come to the same conclusions.

Recognition of ADA's Evidence Analysis Process

At the ADA, we are convinced that our rigorous process of evidence analysis is simply the best there is. But don't take our word for it. Consider the following:

ADA's Evidence Analysis process was recognized by JCAHO as exemplary of bringing the best research to practice
ADA's Evidence Analysis process was adapted by the FDA to assess the type of qualified health claim that can be put on food labels
ADA's Scientific Affairs & Research staff has trained staff and task force members for USDA, DHHS, and FDA.

Steps in the ADA Evidence Analysis Process

The table below offers a brief overview of the steps in our process. For a more detailed, step-by-step description of our Evidence Analysis process, see our Evidence Analysis Manual.

Step in the Evidence Analysis Process

Brief Description

Step 1

Formulate the Question

Specify a question in a defined area of practice; or state a tentative conclusion or recommendation that is being considered. Include the patient type and special needs of the target population involved, the alternatives under consideration, and the outcomes of interest.

Step 2

Gather and Classify Evidence Reports

Conduct a systematic search of the literature to find evidence related to the question, gather studies and reports, and classify them by type of evidence. Classes differentiate primary reports of new data according to study design, and distinguish them from reports that are a systematic review and synthesis of primary reports.

(Classes used by ADA are A, B, C, D, M, R, and X.)

Step 3

Critically Appraise Each Report

Review each report for relevance to the question and critique for scientific validity. Abstract key information from the research article and report it on the online worksheet. Answer the questions in the quality criteria checklist and assign a code to indicate the quality of the study.

(ADA uses the symbols: +, -, Ø, NA to designate positive, negative, neutral, or not assessed).

Step 4

Summarize Evidence in an narrative form and an overview table.

Combine findings from all reports into a narrative evidence summary and/or an overview table that summarizes the relevant information from each article worksheet and allows for comparisons across articles.

Step 5

Develop a conclusion statement and Grade the Strength of Evidence Supporting the Conclusion.

Arrive at a concise conclusion statement (the answer to the question). Take into account the synthesis of all relevant studies and reports, their class, and their quality ratings. Assign a grade to indicate the overall strength or weakness of evidence informing the conclusion statement.

ADA uses Grades I, II, and III, for strong, fair, and weak; Grade IV designates expert opinion only; and Grade V indicates not assignable (because there is no evidence that directly supports or refutes the question).

For more detail, please go to the "Evidence Analysis Process" tab on the EAL.