Evidence Based Health Policy,

More than 55 % of the world's population lives in cities. The world's urban population has grown rapidly from 30 % in 1950 and is projected to reach 68 % by 2050. By increasing urbanization, the countries have been facing the problem of city slum (1).
Slum is a phenomenon that has been formed and expanded as a result of uncontrolled growth of urbanization, the concentration of all facilities in cities, especially large cities, and migration from rural to urban areas to seek greater prosperity. This phenomenon has been caused by the unbalanced development of cities. In the simplest definition, slum is a densely populated human habitat without standard housing, and with dirty and polluted neighborhoods. According to the United Nation Center of Human Settlement, one in eight people in the world live in slum condition (2).
The slum areas face numerous social, economic, cultural, and health challenges, and the scope of these challenges extends to urban areas. Most of the residents of these areas have poor economic conditions and due to lack of knowledge and expertise, it is not possible for them to find suitable jobs. On the other hand, cultural homogeneity is weak in these areas; therefore, social cohesion and control is low (3). Also, according to the Chicago School, the city is an alien world where criminals get lost in the crowd. Therefore, a suitable context is provided for the occurrence of crime, as slum dwellers can come to the centers of the city commit crime and return to their slum (4).  
Slum areas also have numerous health challenges, because they are a perfect place for the transmission of various infections, including tuberculosis, respiratory infections, AIDS and hepatitis. These areas also have some environmental health and nutritional challenges, including access to safe drinking water, proper nutrition, waste disposal, and air pollution (5–7).
On the other hand, this phenomenon also creates some challenges for the places that migrants come from. For instance, first of all work force leaves these places and this leads to further underdevelopment of these areas (8), and second, it will increase unemployment rate in the cities. Also, the age and gender composition of the population in places where the migrants come from is disturbed, which can make marriage difficult and consequently, reduce the marriage rate (9).
Urban population growth and the phenomenon of slum are not unique to developed countries, and developing countries are also not immune to this problem. Estimates indicate that, the urban population in these countries, with a 6 -fold growth between 1925 and 2025, will reach to 57 % (10). According to the United Nations Center for Human Settlement, informal settlements are a phenomenon that accounts for more than 50 % of the city population in low-income countries and 20 % in the middle-income countries. Obviously, the consequences of this challenge will be more tangible in these countries; since overcrowding in a few urban areas makes it more difficult to manage these areas (11). Iran is also one of the middle-income countries that face this problem (12).
The growth of urbanization and marginalization in Iran has been significant in the last fifty years. Thus, the urban population of Iran has escalated from 31 % to 71 % and the rural population has decreased substantially from 68 % to 28 % during 1956-2011. In the interim, however, the global urbanization rate has increased from 34 % to 54 %. These statistics indicate the rapid shift of Iran towards the urban settlement pattern. This pattern shift has led to the increasing growth of informal and marginal settlements not only around large cities, but also around small towns in Iran, and consequently many challenges have been posed in these areas (13).
In general, creation and expansion of city slums is one of the concerns of policy-makers and over the years, many policies have been developed in this regard worldwide (14) with Iran being no exception. In this regard, many documents have been created that are valuable asset for the analysis of policies and detection of overall approaches taken by government to deal with city slums. Therefore, since almost all studies on city slums have been focusing on different challenges of slums in Iran, and very few studies have been conducted to review and analyze the upstream national documents related to city slums, the present study was conducted to identify and analyze the upstream national documents related to city slums in Iran. In order to identify the actions and policies related to city slums in Iran.
Materials and Methods
This was a qualitative study with content analysis approach that was conducted to analyze the upstream national documents related to city slums in Iran. Upstream national documents refer to all government documents related to city slums published during Feb 1979 to Dec 2020 (published after the Iranian revolution to the time of the study) in Iran, which are made available to the public free of charge. All documents which were produced by private organizations and state documents which were not available to the public were excluded from the study.
The research team purposefully identified the key upstream national documents by searching through the websites of ministries of health and medical education, interior, and roads and
urban development, as well as anti-narcotics headquarters, welfare organization, judicial system, Islamic consultative assembly, and the office of supreme leader, and also by attending the state organizations, including housing and urban development, municipality, Bam University of Medical Sciences and the office of the governor. The documents of interest were selected based on Jupp’s four considerations, including originality, validity (accuracy), being representative (all the documents in that class), and meaning (what is said). According to these considerations, documents can be reviewed and analyzed only if their contents are drawn up by the competent authority, the accuracy of their contents is ensured, are comprehensive among other documents related to the field of interest, and fully convey the concept. The documents in the current study were evaluated separately and selected by two members of the research team based on the mentioned considerations. Disputes were discussed and resolved in a meeting attended by all members of the research team. The review process was initiated after selecting the documents (15).
Finally, 26 upstream national documents were reviewed in this study (Table 1).
The conventional content analysis method was used for data analysis. First, the documents were reviewed several times by two members of the research team and sections related to city slums were identified. Then, each selected section was reviewed again by the same two members of the research team and the content of each section was extracted and formulated into a code. After encoding the whole text, the identified codes were merged based on their similarities and differences and then, the similar codes were classed in the main category.
The identified codes and sub-category were then evaluated by each of the two members and the dissimilarities were identified. In a meeting attended by all the team members afterwards, the dissimilarities were inquired and resolved.
Accuracy and stability of the findings
Spending enough time on data analysis and in the research environment, external review, and researcher’s competence were required to boost the acceptability of the qualitative research. Overall, four characteristics, including validity (and reliability), credibility, transferability, and confirmability have been proposed for the acceptability of the qualitative research. In the current research, the validity and reliability of the data were determined using Lincoln and Guba’s criteria (16). To ensure the credibility of the results, the issues raised at different stages of the study were resolved by a collaborative reflection of all the team members. Confirmability was guaranteed by preserving the documents in all stages of the research. The researchers' interest in the study subject, their long-term engagement with the data, and the attempt to obtain other team members’ opinions were also considered to enhance the confirmability of the findings. Besides, the implementation of the present study as a team project, benefiting from the guidance and supervision of experts, further assured the validity and reliability of the findings.
This study was extracted from a Ph.D dissertation in health services management at the North Tehran Branch Islamic Azad University. This study was approved by the Ethics Committee of the North Tehran Branch Islamic Azad University (Ethics code: IR.IAU.TNB. REC.1399.003.). Thanks are owed to all the people who cooperated in conducting this study.
Results
A total of 26 documents were reviewed with the aim of analyzing the content of upstream national documents in the field of city slums in Iran. Table 2 shows the main categories and subcategories identified in this study. In total, two main categories of policies related to preventing the creation of slums, and policies related to providing service and rehabilitation of slum areas were identified.
Policies related to preventing the creation of slums
Policies related to preventing the creation of slum areas is one of the main categories identified in this study. It refers to the fact that policies have been adopted to prevent the emergence of slum areas. This prevention includes preventing migration to cities, especially large cities, providing facilities and paying special attention to rural areas, forced confrontation, creating physical barriers, and preventing migration from inner cities to slum areas. Therefore, this category consists of 6 sub-categories, including preventing migration from inner cities to slum areas, poverty alleviation, preserving the rural fabric through the village guide plan, balanced distribution of population with landscaping and land development approach, creating green belts around cities, and forced confrontation with illegal constructions in slum areas.
Preventing migration from inner cities to slum areas
This sub-category refers to one of the significant factors in creation of slum areas, where migration from inner cities to slum areas is due to the inability of low-income families to pay accommodation rent. Various documents point to the prevention of migration from inner cities to slum areas through the production of affordable housing and/or supply of land to low-income families living in cities with the help of public sectors. “The strategy of strengthening, ensuring, and regulating the role of public sector for public access to affordable housing, especially for low-income urban dwellers” (17). 
Poverty alleviation
Another sub-category identified in the field of prevention is poverty alleviation. This sub-category points out that one of the reasons for living in slum is the poor living conditions of people in villages and small towns, and also the favorable socio-economic and cultural conditions of the cities. The difference in income, the difference between city and village as well as between big cities and small towns, and the dream of a desirable life and high income in cities cause people to migrate from villages and small towns to big cities. However, after migration to big cities, due to poverty and inability to pay for appropriate housing in cities, people are forced to live in slum areas. Thus, poverty alleviation has been mentioned as one of the policies to prevent city slums in the upstream national documents. Poverty alleviation refers to the elimination of poverty in all economic, social and cultural dimensions. “Paying attention to poverty alleviation programs and creating a link between physical and socio-economic development of the city were among factors mentioned in the upstream national documents" (18). 
Preserving rural fabric through the village guide plan
Another sub-category identified in this study is the preservation of rural fabric through the village guide plan. This plan intends to examine the existing fabric of village and modify and organize it. In fact, this study aimed to create a suitable ground for the development of villages according to cultural, economic, and social conditions and also to create the necessary facilities to improve the housing of villagers and provide environmental and public services.
"Village guide plan is a plan that while organizing and modifying the existing fabric, determines the amount and location of future expansion and use of land for various residential, productive, commercial and agricultural purposes. It also determines the facilities, equipment, and general needs of villages through approval plans for organizing space and rural settlements or comprehensive regional plans.”(19).
Balanced distribution of population with landscaping and land development approach
This sub-category refers to the logical and geographical distribution of population and activities in Iran, which makes it possible to improve the physical structure of country's development by emphasizing on the organization and strengthening the links between populations in organized urban centers and rural and nomadic areas. According to this policy, population growth should be limited in saturated areas where the population is larger than the infrastructure capacity of the regions. Also, medium cities should be equipped and strengthened to accept the overflow of population from rural areas. Small towns should also be equipped and strengthened as a link between urban and rural societies by improving the service capacity of these cities, especially in the field of service delivery, to develop integrated urban and rural communities. Moreover, the migration from rural to urban areas should be limited and the capacity of rural facilities should be increased in order to reduce the gap in social services. The trade between urban and rural communities should also be promoted and strengthened. Furthermore, rural centers and central villages should be strengthened and city village should be created in order to facilitate services to rural areas by creating suitable grounds for establishing non-agricultural activities in rural areas. Finally, the maintenance of nomadic population should be based on the balanced relationship between livestock ratio and rangeland capacity, and provision of productive jobs for surplus nomads in population centers with priority in rural areas, by creating suitable places in accordance with the characteristics of nomadic production.
Creating a green belt around the cities
Another subcategory identified in this study is the creation of green belts around the cities. By creating a green belt around cities, in addition to helping to reduce pollution, the empty space around cities, which can be a good place for creating slum and informal settlements, will be eliminated. "Design and creation of green belts around population centers by municipalities with the participation of the government to reduce the empty space around cities"  (20).
 Forced confrontation with illegal constructions in slum areas
This sub-category refers to the fact that clear and unambiguous restraining laws should be enacted regarding unauthorized constructions in slum areas. Illegal constructions in slum areas should also be demolished with the cooperation of judicial system. "Establishing preventive regulations and enforcing the ban on all infrastructure services for illegal constructions outside the city and villages, and also demolition of illegal settlements with the cooperation of the judiciary"(20).
Policies related to providing services and rehabilitation of slum areas
Policies related to providing services and rehabilitation of slum areas were identified as the main category in this study. This category refers to the fact that policies have been adopted to provide service and rehabilitate the slum areas. This means that, the phenomenon of city slum has been accepted and measures have been taken to rehabilitate and reduce the harm in these areas. This category consists of several subcategories, including the impulse phenomenon of social harms, the allocation of state financial facilities to organize informal settlements, the renovation of informal settlements, the establishment of satellite towns, and the provision of primary health care services in the form of health care network system.
Impulse phenomenon of social harms
One of the identified subcategories in this study is the impulse phenomenon of social harms. This subcategory means that social harms have acted as an impulse phenomenon for the discussion about city slum. In fact, social harms and their consequences have been raised as an important issue in the policy agenda, considering that slum areas are one of the socially vulnerable areas, so the discussion of slum areas entered the agenda with the help of social harms. " In order to prevent and reduce social harms, the government is obliged to prepare a comprehensive plan to reduce social harms with an emphasis on the prevention of drug addiction, and also to identify vulnerable and socially critical areas in the urban and slam regions and focus on social support, health services, assistance, social and legal counseling, and employment programs by implementing a cross-sectoral cooperation strategy and social harm management system in these areas" (21).
Allocation of state financial facilities to organize informal settlements
This sub-category indicates that the government has accepted the phenomenon of slum and seeks to provide various financial facilities, including granting legal status to informal settlements, and granting subsidized loans to improve the environment of informal and slum settlements. "Matching the granting concessions of public and government sectors (such as granting legal status to informal settlements, providing services, such as loans and credits) with the qualitative and quantitative participation in promoting the environments of existing informal settlements" (17).
Renovation of informal settlements
Another subcategory identified in this field was the renovation of informal settlements. This sub-category points out that, in order to accept the phenomenon of city slum and take measures to reduce the harm, the government has provided services, such as transferring of government-owned land at low prices and offering low interest rate loan to renovate informal settlements. "The government is allowed to transfer the land under its ownership by applying a discount, installment or transfer of the right to use through a cheap leasing service in the form of a program to support the improvement and renovation of informal settlements" (22).
Establishment of satellite towns
This subcategory refers to the fact that one of the policies mentioned by the documents to serve the slum is to create satellite towns in the city suburbs to organize the slums. " Organizing the suburban areas designated by the Supreme Council of Urban Planning and Architecture of Iran through the development and implementation of legal, financial, and cultural mechanisms to establish satellite towns in order to accommodate the migrant population" (17).
Providing primary health care services in the form of health care network system
This sub-category refers to the fact that health services are provided in the form of referral system and health care network in Iran, and these services are provided especially in rural areas. One of the policies mentioned in the documents to provide health services in the slum areas was the provision of services in the form of health care network system. The services provided in these areas are similar to the services provided in health centers. The health service packages of this program include 4 groups of basic personal, general, medical, and special services. Public health services include service packages that are currently available to the community, and include environmental health services, school health services, and social health services. Primary personal health care includes health service packages that are integrated into health care networks, such as family and population health programs, infectious disease control programs, prevention and control of risk factors for chronic and non-communicable diseases, nutritional services, and mental health services that are provided according to the structure of population covered and different age groups. The package of medical services includes services that are provided according to the individual's needs for referrals by the family health professional/expert. Special health services include services, such as rehabilitation services, addiction control, violence, and smoking cessation, which are provided based on the health problems and needs assessment. "Comprehensive and public health service system will be redesigned based on primary health care, and its executive plan is approved with the coordination of the Deputy of High Council of Health and Food Security with the priority of benefiting less developed areas, especially villages, slums, and nomadic areas"(20).