Development of the systematic review duplication (SRD) tool: a protocol for assessing duplication in intervention-based systematic reviews

The rapid expansion of systematic reviews (SRs) has led to increasing concerns about research duplication and redundancy. While several tools exist to assess the quality and risk of bias of SRs, no standardized instrument specifically evaluates the degree of duplication between SRs on similar topics. This protocol describes the development and validation of the systematic review duplication (SRD) tool, which is designed to systematically assess and quantify duplication between intervention-based SRs in healthcare.

The development process follows established guidelines for creating reporting and quality assessment tools and comprises three phases: (Ⅰ) preparatory work, including team formation and tool conceptualization; (Ⅱ) tool development, involving initial item generation through a systematic literature review and analysis of existing tools, item validation through pilot testing with 40 SRs across 17 disease categories, modified Delphi surveys, and consensus meetings; and (Ⅲ) dissemination through academic channels and professional networks. The SRD tool will evaluate duplication across four domains: research topic, research methods, research results, and research quality. Expert consensus will be achieved through a two-round modified Delphi process with an agreement threshold of at least 70%. Inter-rater reliability will be assessed using the intraclass correlation coefficient and Kendall’s W coefficient. Expected outcomes: The SRD tool is expected to provide a standardized, user-friendly instrument for distinguishing necessary replication from redundant duplication in SRs. It will be available as both web-based and Excel-based applications.

The SRD tool is intended to fill a critical gap in evidence synthesis methodology by enabling the systematic assessment of duplication and supporting informed decision-making by researchers, journal editors, guideline developers, and clinicians.