Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN)

ICEMAN is an instrument designed to evaluate the credibility of a claim of effect modification (also called subgroup effect, statistical interaction, moderation, or heterogeneity of treatment effects).

ICEMAN is a questionnaire that provides key questions, response options, and an overall credibility rating. Two different versions are available for randomized controlled trials and meta-analyses of randomized controlled trials; a manual provides detailed explanations and examples from the literature. Click here to access the material.

Users of ICEMAN include

  • Investigators of trials or meta-analyses who are planning or considering the results of a subgroup analysis

  • Systematic review authors and guideline developers who are critically appraising subgroup claims made in trials or meta-analyses

  • Journal editors, referees, methods consultants, and others concerned with the quality of trials or meta-analyses

Cite ICEMAN as follows:

Schandelmaier S, Briel M, Varadhan R, Sauerbrei W, Devasenapathy N, Hayward RA, Gagnier J, Borenstein M, VanderHeijden GJMG, Dahabreh I, Schmid CH, Ioannidis JPA, Walsh M, Thabane L, Guyatt GH. Development of a new Instrument to assess the Credibility of Effect Modification ANalyses (ICEMAN) in randomized controlled trials and meta-analyses. CMAJ. 2020 192(32):E901-E906

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