[G methods for handling time-varying confounding in the longitudinal study].

The conventional analytical methods cannot effectively adjust for time-varying confounding that occur in a longitudinal study and thus cannot correctly estimate the causal effects. This study explains the necessity of precisely controlling time-varying confounding and outlines G methods, including parametric g-formula, inverse probability of weighting, and G-estimation. We also compare the methods above to provide a reference for correctly estimating causal effects in the longitudinal study.