Determining the Conclusiveness of Systematic Review Evidence

BACKGROUND: Systematic reviews can inform research, funding, and guideline decisions. However, it can be challenging to know whether a systematic review has answered a research question conclusively, and it is unclear which methods exist for such assessments. PURPOSE: To map methods related to determining the conclusiveness of systematic reviews. DATA SOURCES: Medline (Ovid), Embase (Ovid), and Web of Science until 26 September 2025. STUDY SELECTION: Any documents describing methods for determining the conclusiveness of systematic reviews. DATA EXTRACTION: Two reviewers independently extracted data from the primary references of the included methods. Forward citation searches of the primary references were then conducted to identify examples of application of the methods. DATA SYNTHESIS: , and the fragility index. Mathematical approaches for cumulative meta-analyses comprised 15 methods categorized into 7 groups, including trial sequential analyses, sequential meta-analyses, and the law of the iterated logarithm methods. Nonmathematical approaches included 18 methods across 7 groups, such as GRADE (Grading of Recommendations Assessment, Development and Evaluation) frameworks, Ottawa methods, and the RAND method. LIMITATIONS: There was no assessment of which methods perform better. Not all methods strictly aimed to determine conclusiveness. CONCLUSION: This review identified various methods related to assessing the conclusiveness of systematic reviews to enhance their ability to guide research, funding, and clinical decisions. PRIMARY FUNDING SOURCE: Western Norway University of Applied Sciences. (Protocol registered in the Open Science Framework [https://osf.io/dthps]).