MR Dictionary

Mode-based estimate

Synonyms: Weighted mode

Defined as the mode of either an unweighted or inverse variance weighted (IVW) empirical density function of the Wald ratio (or ratio estimates). 

This two-sample MR method requires that the largest subset of instrumental variables (IVs) which estimate the same causal effect to be valid IVs. The estimates can be either unweighted or, traditionally, weighted by the inverse variance of the association between the single nucleotide polymorphism (SNP) and the outcome but may be weighted using other methods. This relies on the additional assumption that the largest number of similar individual IV estimates comes from valid IVs, which is known as the "Zero Modal Pleiotropy Assumption (ZEMPA)". See NOME adjustment for more information on these types of weights.

References

Other terms in 'Pleiotropy-robust two-sample MR methods':