There were several findings in this study. First, constituent ratio of Chinese citizens’ sense of public medical fairness was familiar, the average of sense of public medical fairness was increased, and there was a significant move toward the direction of “very fair” of the radar map (P < 0.0001). In 2019, the number of people who believed that public medical fairness was fair was higher than in the evaluations in 2017 and 2015; conversely, the number of people who considered public medical fairness to be unfair was lower in 2019 than in 2017 and 2015. Second, in 2015, there was positive correlation between internet use and sense of public medical fariness, however internet usage became negative impact on the evaluation of sense of public medical fairness. Third, security such as pension insurance or pension, medical insurance or public medical care, maternity insurance, unemployment insurance, injury insurance and subsistence allowance are playing increasing roles in the evaluation of sense of public medical fairness and most of them had protective effect on sense of public medical fairness.
The sense of social justice will produce a wide range of social psychological effects, impacting people’s life satisfaction, social emotions, and sense of social trust [22]. Public medical fairness is a part of social fairness. The increasing improvement of the sense of public medical fairness observed in this study is positive feedback from the reform of the medical and health system and would play a positive role in promoting the relationship between doctors and patients and building a harmonious medical environment. The Outline of the 14th Five-Year Plan (2021–2025) for National Economic and Social Development and Vision 2035 of the People's Republic of China promulgated that "Make development results more and more equitable, benefit all people, and enhance the people's sense of gain, happiness, and security" [23]. The increase in the sense of fairness in public medical care has further strengthened Chinese people’s national self-confidence and pride and provided a powerful driving force for the establishment and improvement of a multi-level medical security system. According to data of the 2021 National Health Service Development Statistics Bulletin, at the end of 2021, there were 1,030,935 medical and health institutions in China, 8013 more than in the previous year; 13,983,000 health technicians, 508,000 more than in the previous year (an increase of 3.8%); and the total cost of health care accounted for 6.5% of gross domestic product (GDP) [24]. Medical resources are as scarce as other commodities and need to be allocated efficiently through market mechanisms to create the highest value with the lowest number of resources. The balance between health care equity and efficiency may become the focus of research in the new era. For example, exploring the possibility of adopting a development model that emphasizes both equity and efficiency with the premise of increasing the level of utilization of health care services for disadvantaged groups. Marketization has been achieved in certain health care fields without reducing the level of utilization of health care services for disadvantaged groups. Successful precedents in this area include the integration of commercial health insurance into the health care system, the price formation mechanism for medical services, and the centralized procurement system for drugs and medical supplies. As the reform of the medical system progresses, there are still some areas that need to be explored in depth, especially in the combination of government management service function and market regulation function. For example, participation of commercial medical institutions in the basic medical insurance system requires further investigation.
The 48th Statistical Report on Internet Development in China stated that "As of June 2021, China's Internet penetration rate has reached 71.6%, and the number of Internet users has reached 1.011 billion..." [25]. With the rapid economic development and popularization of the Internet, China has become the world's largest and vibrant digital society [26]. This study found that from 2015 to 2019, Internet use has evolved from not having an impact on the sense of public medical fairness to having an impact on two levels of the evaluation results—relatively fair and fair. This confirms, to a certain extent, that Internet use affects all aspects of citizens’ lives, especially the perception of fairness. However, with the popularization of Internet products and the development of the digital society, negative effects are inevitable. At present, the country is advancing the digitization of resources in public institutions such as hospitals and nursing homes, advancing the "Internet + public services", and innovating the channels and types of services provided. This has partially improved the accessibility of public services such as medical care. Simultaneously, decision makers should strengthen the supervision and management of internet products, improve the user experience of citizens, continuously update and improve functional mechanisms, and further develop the positive guiding role of the Internet in the medical and health fields. Such developments could include formulating telemedicine [27], paying more attention to health equity in implementation[28], and promoting the harmonious development of medical and health services. From the perspective of improving the system, the act of social insurance participation should focus on the starting point, the process, and the result of fairness. Social opinion usually focuses on the starting point and result, but not on the process or the combination of the three factors. Moreover, social opinion considers different systems for different people and different treatment for different people as unfair and often ignores whether the system at the starting point is in line with the national conditions, whether the process is sufficient to fulfill the obligations, and whether the rights and obligations in the combination of the process and the result match, etc.
In addition, with the improvement and development of the social security system, citizens became more concerned with the status of social security ownership, and the status of social security ownership had a significant impact on the fairness of public medical care. Compare with western society, medical insurance and other social insurance are key issues that need to be solved urgently. Therefore, further strengthening the construction of the social security system and exploring a more equitable, unified, and sustainable security model has played a positive role in the long-term and stable development of society.