In randomized controlled trials (RCTs) and Meta-analysis, effect modification (EM) is often used to explore the differences in intervention effects across populations. However, a large number of EM claims actually stem from random error, multiple testing or selective reporting, and lack reliable verification, which may mislead clinical decision-making and thus urgently necessitates dedicated credibility assessment tools for identification. The Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN) has developed differentiated assessment frameworks for individual RCTs and Meta-analysis respectively, covering multiple core dimensions, and ultimately comprehensively rates the credibility into four grades: very low, low, moderate and high. This paper aims to interpret the conceptual framework, scope of application and key operational points of ICEMAN, and to provide a reference for domestic researchers in applying this tool.

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