Covid-19 and Reimbursement Mechanisms in Medical Economics; Retrospective(ffs) or Prospective(drg) Payment Healthcare Systems, Which One?

index. COVID-19 disease has economic and financial effects at both macro and micro levels. At the macro level, the economic effects of this pandemic disease have emerged as a shock or economic crisis, meaning that it has affected the financing and economic structure of countries, in other words, the economic pattern and turnover worldwide. At the micro-level, funding sources and health care reimbursement mechanisms in hospitals have been severely affected. In this study, health care repayment and financing systems in the health sector, especially hospitals, were studied. In addition, are retrospective health financing and repayment systems better or prospective repayment systems in times of crisis or economic shock caused by COVID-19 disease? The types of financing mechanisms and current repayment methods, depending on the type of health system as well as other conditions and requirements of each country, have strengths and weaknesses [1-3]. The results of a study (Ahangar et al ., 2021) at Iran University of Medical Sciences show that before and after COVID-19 disease, hospitals with prospective repayment systems (such as DRG, Global, Per Capita mechanisms) compared to hospitals with retrospective repayment systems were more efficient in controlling costs and resources, as well as better managing the quality of hospital care.


Introduction
Today, the health sector is one of the most important service sectors and health status is one of the indicators of development and social welfare, so economic recognition and a kind of financial re-engineering of this sector is important in the COVID-19 Period.
Health systems are one of the largest sectors of the world economy.
Global spending on health care accounts for approximately 8% of GDP. In most developing countries, about 5 to 10 percent of government spending goes to the health sector [1][2][3].
Health is one of the most important issues for governments in the field of public services and welfare, and its establishment health costs is complete and flawless, and each will somehow direct financial risk to the recipients or service providers. Therefore, health care providers are expected to choose a combination of the best options in order to cover as many services and efficiency as possible, the most important tools in the health system, according to the socio-economic conditions. It is obvious that efficient and effective payment and payment systems in society should consider the rights of all parties in a reasonable and fair manner. What the current system of the country shows is the high percentage of the people's share in providing health expenses, which should be addressed by adopting appropriate policies [2][3]. One of the most immediate and important challenges for many developing and underdeveloped (low-income) countries is the provision of health care mechanisms for the more than 1.5 billion poor living on the surface. Worldwide, more than 80 percent of the total health expenditures of low-income countries are related to out-of-pocket (OOP) payments. High OOP index, high costs of medical care, and diagnostic treatment are the main reasons for catastrophic health costs (CHE) as well as poor health costs;(Limited financial resources have posed various challenges to most of the world's health systems in terms of service quality, efficiency and effectiveness, and justice [1][2][3].
Health, as a necessary commodity is very sensitive, because insufficient attention to this category can, in addition to the damage to the health of society, cause the huge resources that are spent in this sector to be wasted. One of the important goals that all countries pursue in their reforms in the health sector is cost control, which, of course, along with other goals such as increasing efficiency and effectiveness in the health system and ultimately improving the quality of services. In the literature of health financing, there are three main and definite issues: first, that the cost of health services is increasing day by day, and second, that science and technology are constantly evolving without stopping. Third, the demographic picture of the world is on the rise [4][5][6]. Today, having a more successful financial balance is one of the main and key criteria for the success of any organization or manufacturing or service institution such as hospitals and insurance companies. Hospitals as a subset of the health care system, regardless of the fact that the services they provide related to human life, but the need for proper management of resources, including physical, financial, and human resources to minimize costs and optimal and effective use of resources in Existence is inevitable [1,3,7].
One of the most important control nobs in the health system is financing systems and repayment mechanisms. All organizations that mobilize and circulate funds for the health sector must decide who is to be paid, why, and how much. One of the most important ways to control treatment costs in different health systems is to use proper payment systems in the health sector [8]. Reimbursement mechanisms for healthcare have used a variety of payment mechanisms with varying degrees of effectiveness. Whether these mechanisms are used singly or in combination, it is imperative that the resulting systems remunerate on the basis of the quantity, complexity, and quality of care provided. Expanding the role of the reimbursement and health financing structure to monitor provider practice, patient responsiveness, and functioning of the healthcare organization has the potential to not only enhance the accuracy and efficiency of reimbursement mechanisms but also to improve the quality of medical care [9][10][11].
Care payment mechanisms should be designed and implemented in a way that allows service providers to attract enough revenue so that they are sufficiently motivated to give high quality services and prevent them from moving to more lucrative jobs [11].
Studies show that the prevalence of COVID-19 pandemic disease has significant effects on the financing structure and health economy in several ways: [9][10][11] These effects are divided into three categories: short-term, medium-term, and long-term. Short-term effects: COVID-19, on the one hand, due to the nature of its acute respiratory infection, causes an increasing trend in the cost of health (such as elective surgery), which in turn creates an extra financial burden on future health care budgets. Third, long-term effects; The costs of rehabilitating the physical and mental health caused by the disease (and the resulting recession) will continue even after the COVID-19 incidence rate is eliminated or remain constant in the coming years, putting continued pressure on national health budgets for It will have years to come [10][11].
COVID-19 has affected the performance and economy of hospitals in several ways. The first is from the perspective of the recipient of services and care, the second is from the perspective of the provider of care and diagnostic services (medical and nursing team, hospital). From the first perspective, recipients of health care are two groups of outpatients and inpatients who are referred to the hospital for COVID-19 and other non-COVID-19 diseases.
Since the outbreak of COVID-19, physician visits have declined significantly, due in part to the cancellation or postponement of scheduled visits for surgery by patients (public fear of -COVID 19) or hospital (Allocation of inpatient beds, specialized medical and nursing teams for outpatient visits and providing inpatient care and other diagnostic and therapeutic services for patients with or suspected of having COVID -19. It has also reduced activity time and in some cases even disabled hospital operating rooms, especially elective (non-emergency) surgeries [10][11][12].
One of the most important components of a hospital economy is healthcare reimbursement systems [2]. health care reimbursement mechanisms in health systems include methods such as Global Fee for Services (FFS), Per capita, Salary, Performance Pay (P4P), and Diagnostic Payments (DRGs, Diagnostic Related Groups). Health reimbursement mechanisms vary from country to country, which means that some countries may include a combination of all of these mechanisms, or some countries may have one or two of these reimbursement mechanisms. But the important point is that each of these repayment mechanisms has been created for various reasons such as globalization, having strengths or weaknesses, enforceability and operationalization according to specific social, economic, and political situations. Studies show that these mechanisms in health systems reflect different dimensions of the quantity, complexity, and quality of health care in varying degrees if health reimbursement mechanisms are combined and updated with other technologies such as HIS, HIT. In this case, the efficiency and performance of each of these mechanisms or a combination of these mechanisms will be better [13][14].
Repayment methods in the health system are various and in the country, based on the needs and facilities, one or a set of several methods are used to compensate for services. The effects and incentives of the payment system, both in terms of demand and supply, are to some extent dependent on an effect called ethical risk. In terms of supply, the payment system gives rise to a complex response from physicians and hospitals. The impact of payment on the volume of care occurs because physicians can induce demand for their services [15]. The types of financing mechanisms and current repayment methods, depending on the type of health system as well as other conditions and requirements of each country, have strengths and weaknesses. According to studies, health care reimbursement systems are divided into two general categories, retrospective, and prospective reimbursement systems.
In retrospective reimbursement systems, the service provider is unaware of the exact amount of money it will receive and usually receives a fee shortly after the service is provided. The following methods are retrospective, such as FFS(Fee-For-Services) and pay for a day. In prospective reimbursement systems, the provider is not only aware of the amount received, but in some cases even receives the cost before the service is provided, and in fact, the service provided by him is pre-purchased. Prospective reimbursement systems are such as GLOBAL Budget, DRG (Diagnosis Related Groups), Pay per Capita [16][17][18][19].
In the world, health systems have different health financing Answering these questions, the need to discuss key concepts such as "health financing", "risk accumulation", "risk sharing", "health care repayment systems", retrospective repayment mechanism, prospective repayment mechanism "in the economic literature Explains the health and economy of the hospital more than ever [18][19][20].

Method
The present study is a cross-sectional and applied research. In (falls) and subsequently improves slowly, but never returns to preeconomic shock. U-shaped As the recession escalates, this does more damage to labor productivity and productivity. The third type is the L-shaped economic shock (such as Greece, Iran) (in this type, economic growth is slow but economic growth is never Does not improve). In general, the worst type of economic shock is L-shaped and then U-shaped economic shock [19][20].
According to economists, the main determinant of the economic shock caused by COVID-19 is the ability of the shock to damage the supply and demand pattern of the economy (mainly the supply side of the economy) and, more specifically, on investment and GDP. Is. This means that with the onset of COVID-19 economic shock, first, credit intermediation factors (between stakeholders such as input suppliers, producers, distributors, and ultimately consumers) are disrupted., Consequently, capital stocks do not grow, economic growth slows (and even stagnates), and this leads to unemployment (dismissal) of workers from the workforce, skills are lost, productivity is reduced, and ultimately leads to Shock occurs systematically or structurally [20,21].
According to various studies, health and its components (health financing structures) by economic growth and social development of communities and vice versa, economic growth is also affected by the health status of communities. In recent years, countries with higher economic growth are more likely to have more coherent health financing structures. This means that with the improvement and economic growth of countries, the percentage of GDP allocated to the health sector increases and, so, the probability that the state of health indicators will improve, as well as improving the health of society, ie having healthy and productive human capital, Increase GDP, and subsequently reach and socio-economic development of societies [22]. On the other hand, with the pandemic outbreak of COVID-19 over the past two years, it has slowed economic growth and even recession in countries reduced gross domestic product (GDP), and subsequently affected health care financing and repayment systems. While increasing total health expenditures, it affects health status (health outputs) such as mortality rates, fertility, and productivity, life expectancy, etc [3,9,23].
According to WHO data (2020) over the past decades, economic development was positively associated with total health spending and a shift away from a reliance on out-of-pocket (OOP) towards government spending. The largest health spending growth rates were in lower-middle-income groups (5·0%), in low-income countries (grew nearly as fast, at 4·6 %,). In 2018, in the world outof-pocket (OOP) was 18.18% of total health spending (from 19.39% in 2000 to 18.12% in 2018) and in low-income and lower-middleincome countries, 29·1% of all health spending was financed by the government, and 58·0% of spending was OOP spending and 12.9% of spending was development assistance [3,9,22]. Also, it is estimated that by 2040, the growth of health expenditure in government spending as a share of the total for Africa (39·0%), in Out-of-pocket spending (31·1%) and in development assistance for health for Africa (14·4%) [22].
A crucial concept in health financing is that of risk-pooling, and the larger the degree of pooling, the fewer people will have to bear the financial consequences of their own health risks. Health financing systems encompass various degrees of risk-sharing. pre-negotiated fees" [24].
Several studies (such as Ahangar et al. 2021, Ikegami 2009, Ikegami 2015) [13][14][15]  The important point is that the repayment mechanism has an effect on good quality in good competitive conditions, but the same repayment mechanism, if not in competitive conditions, and may lead to the induced demand phenomenon (SID), is poor in terms of quality criteria [25][26][27].

Discussion
During COVID-19, one of the biggest problems for hospitals is the problem of hospital economics and the challenge of resource Awareness of the financial burden-sharing of effective factors in providing hospital services and procedures, especially global service packages, ultimately lead to optimal resource management, cost control, and rationalization, as well as providing better quality care to patients. In particular, the LOS (Length of Stay) index, the difference between better days and the standard set in the future global repayment system compared to the retrospective Fee-For-Services has decreased in most cases and the difference between the average hospital days has been significant. Therefore, according to the above cases, it is necessary to review the payment system, set up a prospective repayment system based on DRG and Case-Mix disease coding systems and implement a futuristic payment system in the country. The results of a study (Ahangar et al., 2021) at Iran University of Medical Sciences show that before and after COVID-19 disease, hospitals with prospective repayment systems (such as DRG, Global, Per Capita mechanisms) compared to hospitals with retrospective repayment systems were more efficient in controlling costs and resources, as well as better managing the quality of hospital care.

Financial Support and Sponsorship
This study was conducted with the financial support and assistance of Iran University of Medical Sciences, Research Center for Preventive Medicine and Population Health.