Steps in the Evidence Analysis Proces


The Evidence Analysis Manual has been created by the Academy of Nutrition and Dietetics to help expert work members and evidence analysts understand and carry out the process of evidence analysis -- a complex process. The outcome has been the Evidence Analysis Library© - a online resource which summarizes relevant nutritional research and includes Evidence-Based Nutrition Practice Guidelines.

Steps in the Evidence Analysis Process

  • Step 1: Formulate the Evidence Analysis Question - Specify a focused question in a defined area of practice Three key items are used to generate good quality questions: an analytical framework to identify links between factors and outcomes; the PICO format to write questions; and the Nutrition Care Process to serve as a framework.
  • Step 2: Gather and Classify the Evidence - This step involves developing a search plan to conduct a detailed literature search. The search plan clearly defines the inclusion and exclusion criteria and identifies the key search terms and outcomes necessary to conduct a comprehensive search. The search plan and all literature searches results are documented and assessed for inclusion eligibility.
  • Step 3: Critically Appraise Each Article (Risk of Bias) - This step involves critically assessing each included article for methodologic quality. Each study is evaluated based on appropriateness of study design and the quality of how the study was conducted by using the Academy's risk of bias tool called the Quality Criteria Checklist (QCC). 
  • Step 4: Summarize the Evidence - This step involves achieving two major tasks. First, key data from the included articles is extracted by using the Academy's web-based data extraction template. Second, summarizing the evidence extracted from each study into a brief, coherent, and easy-to-read summary. The end result of this phase is called the Evidence Summary.
  • Step 5: Write and Grade the Conclusion Statement - This step includes developing a concise conclusion statement for the research question and assigning a grade to the conclusion statement. The grade reflects the overall strength and weakness of evidence in forming the conclusion statement. The grading scale used by the Academy is: Grade I (good/strong), II (fair), III (limited/weak), IV (expert opinion only), or V (not assignable).

To learn more about the Academy's rigorous process, download Academy of Nutrition and Dietetics Methodology for Conducting Systmatic Reviews for the Evidence Analysis Library JAND Feb2016 Vol 116(2):311-318