Background Since the People’s Republic of China (PRC), or China, established the basic medical insurance system (MIS) in 1998, the medical insurance information systems (MIISs) in China have effectively supported the operation of the MIS through several phases of development; the phases included a stand-alone version, the internet, and big data. In 2018, China’s national medical security systems were integrated, while MIISs were facing reconstruction. We summarized China’s experience in medical insurance informatization over the past 20 years, aiming to provide a reference for the building of a new basic MIS for China and for developing countries. Objective This paper aims to sort out medical insurance informatization policies throughout the years, use questionnaires to determine the status quo of provincial MIIS-building in China and the relevant policies, provide references and suggestions for the top-level design and implementation of the information systems in the transitional period of China’s MIS reform, and provide a reference for the building of MIISs in developing countries. Methods We conducted policy analysis by collecting the laws, regulations, and policy documents—issued from 1998 to 2020—on China's medical insurance and its informatization; we also analyzed the US Health Insurance Portability and Accountability Act and other relevant policies. We conducted a questionnaire survey by sending out questionnaires to 31 Chinese, provincial, medical security bureaus to collect information about network links, system functions, data exchange, standards and specifications, and building modes, among other items. We conducted a literature review by searching for documents about relevant laws and policies, building methods, application results, and other documents related to MIISs; we conducted searches using PubMed, Elsevier, China National Knowledge Infrastructure, and other major literature databases. We conducted telephone interviews to verify the results of questionnaires and to understand the focus issues concerning the building of China’s national MIISs during the period of integration and transition of China's MIS. Results In 74% (23/31) of the regions in China, MIISs were networked through dedicated fiber optic lines. In 65% (20/31) of the regions in China, MIISs supported identity recognition based on both ID cards and social security cards. In 55% (17/31) of the regions in China, MIISs at provincial and municipal levels were networked and have gathered basic medical insurance data, whereas MIISs were connected to health insurance companies in 35% (11/31) of the regions in China. China’s MIISs are comprised of 11 basic functional modules, among which the modules of business operation, transregional referral, reimbursement, and monitoring systems are widely applied. MIISs in 83% (20/24) of Chinese provinces have stored data on coverage, payment, and settlement compensation of medical insurance. However, in terms of data security and privacy protection, pertinent policies are absent and data utilization is not in-depth enough. Respondents to telephone interviews universally reflected on the following issues and suggestions: in the period of integration and transition of MISs, close attention should be paid to the top-level design, and repeated investment should be avoided for the building of MIISs; MIISs should be adapted to the health care reform, and efforts should be made to strengthen the informatization support for the reform of payment methods; and MIISs should be adapted for the widespread application of mobile phones and should provide insured persons with more self-service functions. Conclusions In the future, the building of China’s basic MIISs should be deployed at the national, provincial, prefectural, and municipal levels on a unified basis. Efforts should be made to strengthen the development of standard codes, data exchange, and data utilization. Work should be done to formulate the rules and regulations for security and privacy protection and to balance the right to be informed with the mining and utilization of big data. Efforts should be made to intensify the interconnectivity between MISs and other health systems and to strengthen the application of medical insurance information in public health monitoring and early warning systems; this would ultimately improve the degree of trust from stakeholders, including individuals, medical service providers, and public health institutions, in the basic MIISs.

BACKGROUND Since the People’s Republic of China (“China” or the “PRC”) established the basic medical insurance system (MIS) in 1998, the medical insurance information systems (MIISs) in China have effectively supported the operation of the MIS through several phases of development, including the phases of stand-alone version, Internet and big data. In 2018, China’s national medical security systems (MSSs) were integrated, while MIISs were facing reconstruction. We summarized China’s experience in medical insurance informatization in the past 20 years, aiming to provide a reference for the building of China's new basic MIS and for developing countries. OBJECTIVE This Paper aims to sort out medical insurance informatization policies throughout the years, survey the status quo of provincial Medical Insurance Information Systems (MIISs)building in China by means of questionnaires about building of MIISs and their relevant policies, provide reference and suggestions for the top-level design and implementation of the information systems in the transitional period of China’s medical insurance system reform, and also provide a reference for the building of MIISs in developing countries. METHODS Policy Analysis - We collected the laws, regulations and policy documents on China's medical insurance (MI) and MI informatization issued from 1998 to 2020, as well as US HIPAA and other relevant policies; Questionnaire Survey - We sent out questionnaires to 31 Chinese provincial medical security bureaus to learn about information of network links, system functions, data exchange, standards and specifications, and building modes, etc.; Literature Review - We searched relevant laws and policies, building methods, application results and other literatures related to MIISs at PubMed, Elsevier, CNKI and other major literature databases; Telephone Interviews - We carried out telephone interviews to verify the results of questionnaires and to understand the focus issues concerning the building of China’s national MIISs during the period of integration and transition of China's MIS. RESULTS In 70.9% of the regions in China, MIISs were networked through dedicated optical fiber lines; In 65% of the regions in China, MIISs support identity recognition based on both ID cards and social security cards; In 51.6% of the regions in China, MIISs at provincial and municipal levels have been networked, and have gathered basic data of medical insurance, whereas MIISs are connected to health insurance companies in 35% of the regions in China. China’s MIISs comprise 11 basic functional modules, among which, the modules of business operation, trans-regional referral and reimbursement and monitoring system are widely applied. MIISs in 83% of Chinese provinces have stored data on coverage, payment and settlement compensation of medical insurance. However, in terms of data security and privacy protection, pertinent policies are absent, and data utilization is not in-depth enough. Respondents to telephone interviews universally reflected the following issues/suggestions: In the period of integration and transition of MISs, close attention should be paid to the top-level design and repeated investment should be avoided for the building of MIISs; MIISs should be adapted to the healthcare reform, and efforts should be made to strengthen the informationized support for the reform of payment methods; MIISs should be adapted to the widespread application of mobile phones, and provide the insured persons with more self-service ways. CONCLUSIONS In the future, the building of China’s basic MIISs should be deployed at the national, provincial and prefectural/municipal levels on a unified basis; Efforts should be made to strengthen the development of standard codes, data exchange and data utilization; Work should be done to formulate the rules and regulations for security and privacy protection, and balance the right to be informed with the mining and utilization of big data; Efforts should be made to intensify the interconnectivity between medical insurance systems and other health systems, and strengthen the application of medical insurance information in public health monitoring and early warning, in order to ultimately improve the degree of trust from stakeholders (including individuals, medical service providers and public health institutions, etc.) in the basic MIISs. CLINICALTRIAL