Analysis
This study conducted a descriptive analysis of the demographic and payment data. Additionally, the study evaluated payment concentrations using the Gini index, as previously described [21,23]. Payment values were converted from Japanese yen to U.S. dollars using the 2020 average monthly exchange rates of 106.8 yen per $1. Quality of evidence of recommendations in the CPG was initially presented on a four-point scale. As all data used in this study were publicly available and met the definition of non-human subjects research, no institutional review board approval was required.