A Systematic Scoping Review of Essential Methodological Elements for Developing a Tool to Improve the Reporting of Consensus Studies in Classification, Diagnostic Criteria, and Guidelines Development.

Introduction: A consensus is a general agreement among group members that is pivotal in gathering expert input for classification, diagnostic criteria, and guideline development. However, the absence of established methodological standards presents challenges in conducting and analyzing these studies. Objective: This scoping review explored the evidence on essential elements in consensus studies to create a list of candidate items for a standardized reporting tool. This tool is intended to improve the critical appraisal and methodological rigor of consensus studies. Methods: A systematic scoping review was conducted using predetermined criteria for study selecting studies and extracting data. A comprehensive literature search was performed without imposing date restrictions, covering multiple databases, including Medline, Embase, LILACS, SciELO, and up to March 2022. We included only English-language publications and excluded incomplete articles and conference reports. The risk of bias was assessed using the CASP checklist, and the study selection and data extraction were performed independently by two researchers in duplicate. Results: We identified 8360 references; 20 publications were included for data extraction. The majority (70%) used the Delphi method, and the remainder (30%) employed the modified Delphi method. Inconsistencies in reporting conflicts of interest and consensus timing were observed. Other methodologies, such as RAND/UCLA and Nominal Group Technique were excluded due to methodological limitations. Most studies exhibited a low risk of bias. Discussion: Our findings underscored the need for more standardization in definitions, methodology, and reporting within consensus studies. To address these gaps, we developed a checklist of key reporting items aimed at improving the planning, execution, and reporting consensus studies. Although the developed checklist requires validation, it offers a practical framework to enhance methodological transparency and reliability. Conclusion: Deficiencies and variability in consensus methodologies reporting underscore the need for a standardized approach. We propose the adoption of a checklist to strengthen the robustness of consensus studies, supporting advances in classification, diagnostic criteria, and guideline development.