“…Arcaya et al systematically reviewed the methodological, theoretical, and philosophical aspects of health inequalities, which provides scientific guidance for the study of health ( 11 ). To better assess the equity of healthcare service, a series of indicators, such as the Kakwani index ( 12 , 13 ), the concentration index (CI) ( 14 , 15 ), and the horizontal inequity (HI) ( 16 , 17 ), are introduced to measure inequity in healthcare resource utilization and determine the contribution of different influences to the overall unfairness. Moreover, machine learning techniques are increasingly used to optimize health and social systems to ensure equality in healthcare delivery outcomes, performance, and resource allocation ( 18 , 19 ).…”