Relaxing parametric assumptions for non-linear Mendelian randomization using a doubly-ranked stratification method.

ABSTRACT: Non-linear Mendelian randomization is an extension to standard Mendelian randomization to explore the shape of the causal relationship between an exposure and outcome using an instrumental variable. A stratification approach to non-linear Mendelian randomization divides the population into strata and calculates separate instrumental variable estimates in each stratum. However, the standard implementation of stratification, referred to as the residual method, relies on strong parametric assumptions of linearity and homogeneity between the instrument and the exposure to form the strata. If these stratification assumptions are violated, the instrumental variable assumptions may be violated in the strata even if they are satisfied in the population, resulting in misleading estimates. We propos

SUBMITTER: Tian H 

PROVIDER: S-EPMC10343089 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature