1. Introduction
The global shift from infectious diseases to chronic diseases is a global problem that will reduce the quality of life and increase the need for rehabilitation services and services related to disability [1, 2]. Population aging is a success of human society and outcomes of pervasive development. If properly managed and aware of the status quo, potential and actual capacities, and needs of the elderly, it will provide a wide opportunity for society. It allows the elderly to participate actively in society, but without proper planning and management and a lack of proper national programs and interventions, it can pose a severe threat to the health care economy and care delivery. [3, 4] An important discussion is related to aging, preventive care, and managing it globally. As a systematic review, this study has conducted a comparative study on the management of preventive health care for the elderly in the world.
2. Methods
The present study was a systematic review study based on Prisma guidelines to conduct a comparative study between different countries to identify the first-level services provided to the elderly from a managerial and systemic perspective in 2020. The reason for choosing each of these countries was the difference in their health system and an indicator of a specific type of health system and its location by continent. National and international databases including Magiran, Iranmedex, Irandoc, Medlib, Medline and Web of Science, Embase, PubMed, Cochrane, Scopus were searched for the articles. Inclusion condition includes all articles found in searchable databases based on keywords and exclusion criteria included: duplicate report of results in other articles, reporting on a specific part of the health system, not reporting on the elderly, and not being in the field of health management and economics. 
The titles of the articles obtained by the researchers were reviewed, and duplicates were removed. Then, the titles and abstracts of the remaining articles were carefully studied, unrelated articles were rejected, the full text of possible related articles was reviewed, and relevant articles were selected. Finally, 200 relevant articles were identified, categorized and their management system was compared. After collecting the articles, the data of the countries considered for comparative study, including Iran, Germany, England, USA, Italy, Turkey, Sweden, Norway, Canada, South Korea, Japan, Singapore, Australia, and Cuba, were extracted. Each of the mentioned countries was evaluated in terms of the number of the elderly population, the way of financing the elderly services, the existence of insurance for the elderly, the way of management and the level of concentration, the service provider and the way of control and accordingly arranged and proceeded to report.
3. Results
First, 545 articles were obtained from searching various databases based on the search strategy. 195 articles were deleted by reviewing the title and the abstract of the article. These studies met the inclusion criteria, but some were not considered and excluded due to lack of relevance to the subject and reporting on the elderly. Finally, 200 articles entered the final stage, of which 29 articles related to harassment of the elderly, 9 articles related to infectious diseases, 22 articles related to mental illness of the elderly, 31 articles related to Non-communicable diseases, 18 articles related to nutrition, 52 articles related to trauma included accidents and falls of the elderly and 39 articles related to planning and elderly management. Among the countries surveyed, the provision of geriatric services in Singapore was more significant than in other countries. The Ministry of Health mostly did management and organization at the national level and supervision. In 50% of the countries surveyed, they had insurance coverage for the elderly. In 64% of countries, the management and organization of health prevention services was national, 7.5% local, 21.4% state-federal, and 7.1% national-local. How to finance the provision of services for the elderly in 50% of the countries surveyed through taxes, 14.2% insurance premium, 7.1% national health system, 7.1 individual reserve funds, and the rest of the countries through the payment of the federal government, health insurance and... In 50% of the countries surveyed, the providers of first-level services were the public-private sector, 28.5% were the private sector, and the rest were municipalities, governments, and so on.
There is no insurance coverage for the elderly in Iran, but several private insurers have provided services and financial reserves for the elderly. Government financing of services is insurance and out-of-pocket payment and is not significantly different from other services. Management and organization of services are concentrated and governmental and are done by the Ministry of Health and Medical Education in Iran; the local health system is in charge of medical universities, which provide elderly services by the health departments of these universities. However, all of them provide services under the direction and supervision of the Ministry of Health, and the services are highly concentrated. Service providers include both public and private providers who contract with insurance companies.
4. Discussion
Studies have shown that the health system of countries has different characteristics in terms of attention to the elderly, and in most countries, the systems of elderly support and primary health care for the elderly are intertwined in the main health system and have a similar function to the primary health care system of that country. Establishing a collaborative organization to plan and direct activities related to the elderly as a strategic measure can be a way to improve support services for the elderly. Planning in the form of a health network system (health house) to establish facilities for providing primary health care services in order to solve the problems and issues of the elderly in the early stages of prevention should be done and in this regard, all organizations to provide programs for education in the field of improving healthy living and active aging at the provincial and national levels. It is necessary to formulate laws to protect the elderly by welfare organizations such as welfare and social security and other responsible organizations.
Ethical Considerations
Compliance with ethical guidelines
Ethical principles of research in this article was extracted from the PhD dissertation at Islamic Azad University, South Tehran Branch (Code: 164100).
Funding
This research did not receive any grant from funding agencies in the public, commercial, or non-profit sectors. 
Authors' contributions
All authors participated equally in all stages of the research.
Conflicts of interest
The authors declared no conflict of interest.