Decomposition of Longitudinal Disparities: an Application to the Fetal Growth-Singletons Study

Music City Center 

Addressing health disparities across demographic groups remains a critical challenge in public health, with significant gaps in understanding how these disparities evolve over time. This paper extends the traditional Peters-Belson decomposition to a longitudinal setting, highlighting the impact of specific explanatory variables we call modifiers that account for complex interactions among the explanatory variables. The proposed method partitions disparities into three components: The explained disparity associated with differences in the conditional distribution of explanatory variables, assuming identical modifier distributions for majority and minority groups; The explained disparity arising from unequal distributions of the modifiers and their interaction with the rest of the covariates; The unexplained disparity. Instead of aggregating the first two components into a single overall explained disparity, the proposed method allows for a detailed analysis of the temporal dynamics, both associated and unassociated with the modifiers. We demonstrate the utility of the method through a fetal growth study, examining disparities in fetal development among racial/ethnic groups.

Disparity Decomposition Analysis

The Fetal Growth - Singletons Study

Longitudinal Analysis

Peters-Belson Approach 

Biometrics Section