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.