Assessing racial disparities in healthcare expenditure using generalized propensity score weighting

We found that generalized propensity score weighting (GPSW) methods are valuable quantitative tools to standardize and compare characteristics as well as outcomes of non-manipulable groups. This helps assess disparities across multiple racial and ethnic groups, as demonstrated in this study. These methods offer flexible and semi-parametric analysis on the primary causal parameters of interest (such as the racial disparities), with straightforward and intuitive interpretations. In addition, when there is violation of the positivity assumption, OWATT serves as an excellent alternative due to its greater efficiency, evidenced by relatively smaller variance. More importantly, the OWATT uses the entire dataset by assigning weights to all participants, regardless of their propensity score values. This feature of OWATT circumvents the need to specify user-defined thresholds, as required in ATT trimming or truncation, and retains as much data information as possible, leading to more reliable estimation results.