Public-private relationship in surgical hospitalizations through the Unified Health System

Objective: to characterize surgical hospitalizations, length of stay, cost and mortality, according to the legal nature (public and private) of the hospital institution linked to the Unified Health System (Sistema Único de Saúde, SUS). Method: a descriptive study, of the survey type, with retrospective data collection (2008 to 2017) and a quantitative approach. The dependent variables surgical hospitalizations in Brazil, costs, length of stay and mortality and the independent variables regime/legal nature (public and private) were obtained from the Informatics Department of the Unified Health System. The Mann-Whitney test was used for analysis. Results: the average number of hospitalizations through the Unified Health System was 4,214,083 hospitalizations/year, 53.5% occurred in private hired hospitals and 46.5% in public hospitals (p=0.001). The financial transfer was greater for the private sector (60.6%) against 39.4% for the public (p=0.001). The average stay was 4.5 days in the public hospital and 3.1 days in its private counterpart (p<0.001). Mortality was higher in the public (1.8%) than in the private hospital (1.4%) (p<0.001). Conclusion: there was predominance of surgical hospitalizations through the Unified Health System in private hospitals with greater financial transfer to this sector, to the detriment of the public. The diverse evidence produced contributes to the debate and actions to avoid budgetary asphyxiation in the public sector in favor of the private sector.


Introduction
Affordable and safe surgical assistance is essential to reduce morbidity and mortality and disabilities resulting from surgical conditions. In addition to that, it improves the well-being of the population, economic productivity, and the capacity and freedom of the individuals, contributing to the long-term development of the countries (1) .
Despite this importance, access to surgery is not fully guaranteed to the population, especially in peripheral countries or without universal health systems, contributing to the occurrence of complication in cases that could be resolved with less complex surgeries (2) .
In the global context, it is estimated that approximately five billion people do not have access to essential, inexpensive and safe surgical and anesthetic care performed in a timely manner (1) , which makes it difficult to strengthen health systems and Universal Access to Health (3) .
According to the World Health Organization, Brazil is characterized as a middle-income country (4) and the context about guaranteeing access is no different from the aforementioned world scenario. Several studies show that, in the country, the surgical volume is lower than that recommended by the Lancet Commission on Global Surgery goal, which should be 5,000 per 100,000 inhabitants/year by 2030 (5)(6) . From 2008 to 2016, the mean surgical volume was 2,020 surgeries per 100,000 inhabitants/year performed by the Unified Health System (Sistema Único de Saúde, SUS) (6) .
In Brazil, it is worth noting that, in order to guarantee the population's access to the health services, including surgical procedures, in addition to the use of federal, state and municipal public services, SUS also hires private services, which include profit and non-profit institutions and philanthropic institutions in a complementary manner, as provided for in the 1988 Constitution (7) .
In this perspective, the scarcity of studies conducted on how surgical hospitalizations are distributed by SUS is highlighted, focusing on the legal nature of the hospital units, including all surgical specialties and of national geographic scope. In fact, an existing study with this focus was limited to addressing the public-private arrangement in only one surgical specialty (8) . Therefore, this study is a precursor in the production of this knowledge and can contribute to reducing the knowledge gaps and to the scientific advancement of this theme in Health and Nursing.
In view of the above, the following question was

Type of study
This is a descriptive, survey-type study with a quantitative approach.

Data collection place
The secondary source information was obtained through the database of the SUS Informatics Department (DATASUS) (9) . And, in the System, the geographic scope established was Brazil.

Variables
The dependent variables of the study were surgical hospitalizations, average length of stay, mean value of the hospitalization, value of the hospital service, and mortality rate.
The independent variables considered were the regime and legal nature of the hospital unit hired by SUS: public and private.

Data collection period
In the DATASUS, retrospective data collection took place in July 2018. To obtain the study variables, the period from 2008 to 2017 was considered. The initial period considered was 2008 because, in the DATASUS system, the consolidated data since 2008 provide more specific information, such as services and procedures performed, as well as groups and subgroups of these procedures (9) . And the complete annual data were available in the System until 2017; as a result, this time limit was established.

Data collection
In the DATASUS system, in the Health Information option (TABNET), the Health Care option was selected, For the analysis, the Mann-Whitney statistical test was used using the Statistica program, version 10. In the analyses, a 95% confidence interval and 5% significance level (p<0.05) were established. The data were presented in a table and boxplot graphs.

Ethical aspects
The study was approved by the Ethics Committee, CAAE number 14956719.6.0000.9247 and approval opinion number 3,387,441/2018.

Results
In the DATASUS, in ten years, 42,140,832 surgical hospitalizations through the SUS were registered (annual average of 4,214,083 hospitalizations). Of this number, 53.5% (22,543,816) occurred in private hospitals hired by the SUS, while in public hospitals they were 46.5% (19,594,158). And in 2,858 surgical hospitalizations, the regime/legal nature was not specified.
Regarding hospital stay, the average was 3.8 days.
In the public sector it was higher (4.5 days) than in the private sphere (3.1 days). In relation to mortality, the general rate established was 1.6%; this index was higher (1.8%) in public hospitals than in private hospitals (1.4%).
Regarding the differentiation between public and private, there was a statistically significant difference (p<0.05) in all the variables analyzed, as shown in Table 1. hospitals (approximately one third of hospitals), profitable private ones (also around one third) and philanthropic private institutions (idem) (12) . The total number of hospital beds in the country (including those hired and not hired by SUS) decreased from 460,656 in 2008 to 437,565 beds in 2018, with this reduction occurring fundamentally among private beds hired by SUS (13) .
This dynamics, of reducing the number of beds and increasing the number of hospitals, demonstrates a reduction in the mean size of the Brazilian hospitals in the last decades, with public hospitals having a mean number of beds lower than private ones (12) . Public beds increased in the period, but remain as a minority, representing only 35.8% of the total number of beds in the country in 2017 (10) . With that, currently, more than half of the hospitalizations by SUS remain in private hospitals, whether profitable and private or the so-called philanthropic institutions.
It is also worth mentioning the progressive decline in the number of beds per thousand inhabitants, from 4.1 in 1976, to 3.2 in 1995, and reaching 2.3 in 2019 (11)(12) .
Considering only the general beds available for the SUS, there were 0.91 beds per thousand inhabitants in 2019.
The rate of hospitalizations in the country has also declined since the implementation of SUS, related to changes in the care model and to policies to contain hospital expenses (12) .
In the Brazilian health system, hospital care is predominantly provided by private services, simultaneously serving users of the SUS and private insurance, implying funding provisions and complex assistance arrangements that hinder health integration and system regulation (14) .
In recent years, the transfer of the provision of public services to the private sector through various mechanisms such as outsourcing, public-private partnerships and Social Organizations (SOs), among others, has played an increasing role. Several authors point out that these mechanisms can lead to the distortion of the assumptions that define the health needs, favoring market interests (15)(16) .
In fact, the large number of public resources invested in private health contributes to the commercialization of health, making it interesting to investors, through tax exemptions, among other financial mechanisms (16)(17) . This the authors also evidenced that the hospitalizations in private institutions funded by the SUS exceeded those that occurred in public hospitals and were more expensive for the system (18) .
In addition to that, the private sector selects the most profitable services and procedures according to the remuneration in the SUS table (15) . Consequently, this dynamics of public-private division in procedures, services and remuneration values guided by market interests configure an important determination of the limits to the universality of access to health (16) .
The definition of the SUS Table as a reference and not as a limit also opens room for higher prices to be established by private providers, as it is common in contracts with municipal and state entities.
In a qualitative study conducted with municipal managers to analyze the relationship between public managers and private providers hired by SUS, the authors However, even if these aspects were not associated with differentials in the risk of death, within the same hospitals, the existence of different physical structures was noticed and, possibly, of resources, for SUS and non-SUS patients, indicating inequalities in the care process (14) .
In general, it is noticed that the selection of more profitable procedures leads to the tendency of concentration of private providers in the most profitable spheres, seeking better paid interventions and with shorter hospital stays, enabling greater productivity with the installed capacity. Often, the most chronic conditions, with longer stays, higher costs and higher mortality rates have predominantly depended on the public hospitals (12) . This trend is even present in other public systems with a strong private presence, such as the French social insurance (19) .
Although not analyzed in this study, possible differences in performance between public and private health services were object of analysis. In Brazil, even though there are few studies on the theme, and rarely conclusive, international studies in general point to the superiority of universal public systems with strong participation and state regulation and based on Primary Health Care as a gateway and care coordinator (3) .
In this sense, several authors point out that this excessive hiring of private services is in opposition to the SUS principles and guidelines, since it impairs care integration, longitudinality and user access (17,20) . Far from being a Brazilian dilemma, the obstacles to comprehensive care resulting from the public-private mix cover several countries, especially in Latin America (21) .
Although SUS constitutes an important universal system, the contradictory and complexly intertwined coexistence with the private sector has hindered the realization of the universal right to health (3) . Among social participation entities and health councils (16) .
To this worrying situation we must add the fact that, since its creation, SUS has presented itself with restricted public funding, relative to Gross Domestic Product (GDP), when compared to other countries with universal health systems (22) . As a result, several studies have highlighted some key elements to prevent the dismantling of the public system through privatization and underfunding (20,(22)(23)(24) .
On the one hand, the need to overcome the chronic underfunding of the SUS involves, in addition to the definition of new sources of financial resources, the prohibition of transferring the public fund to private insurance and companies, the end of the tax waiver for health plan operators, as well as greater State regulation on supplementary health (20) .
In addition to that, in order to guarantee comprehensive care, it is fundamental to expand the health reform to the hospital services, through their integration into the network as a territorial reference and support for Primary Care and for medium-complexity and urgency services. In this, the constitution of interdisciplinary teams for reference and matrix support plays an important role, strengthening the bond, continuity and coordination of care (24) .
It is clear that facing underfunding and privatization requires in-depth and up-to-date knowledge on these themes (16) , with a view to subsidizing popular participation and the efforts of movements in defense of the SUS (22)(23)(24) .
Therefore, this paper is part of this perspective.
With regard to the Health and Nursing area, the need to highlight the role and power of the private actors in the elaboration and conduction of the public policies stands out, despite the relative invisibility for broad social segments of their particularistic and market motivations, which implies rethinking strategies to guarantee the maintenance and expansion of social rights (25) .
The current context is probably the most difficult ever the analysis of the private presence complementary to SUS (16) , as the proposed here.
In addition, the diverse evidence generated can contribute to deepening reflection and debate, since the international and national actors and policies aimed at restricting social rights and privatizing public policies, including health, are still poorly investigated in Brazil (25) .

Conclusion
The fact, that during the analyzed period, the surgical hospitalizations in the SUS were carried out predominantly by private services, which presented a higher average value of hospitalization and absorbed most of the resources spent in this area, expresses how much, in this sphere, the public sector is presented as complementary, in opposition to the constitutional principles. At the same time, it was verified that the average stay and mortality rate were higher in the public sector, with a statistically significant difference between public and private for all the variables analyzed.
Therefore, it is hoped that this study may contribute to a critical reflection on the ongoing process of privatization and mercantilization of health in Brazil. The aim is to subsidize actions in order to avoid budgetary asphyxiation of the public sector in favor of the private sector, which feeds the capital accumulation cycle through the social policies and the transfer of the public fund, with significant implications for access and care.