Considering inclusion and exclusion criteria, of 126 articles, 78 abstracts screened and consequently 25 articles that met eligible criteria remained for data extraction (Fig. 1). All retrieved articles published in English or Persian language and related to 2001 to 2019. Three interventional study, a historical cohort study, a case control study, a descriptive analysis of information in health centers, two data analysis of referral system and screening, and remained article by 18 cross sectional study bring out this systematic review results. All studies were at sub-national level. Except two study that use information of referral systems, the others targeted households or individual people live in suburban and slums area. In general, present result attributed to 1769 household, 35918 individuals (4164 children), and 374 peoples attempt to suicide. Eight studies focused on female sex and the remained considered both sex. In included articles, health related subjects were studied. Therefore, we categorized them according to their main theme in seven categories; Quality of life, Reproductive health, Communicable diseases, Non-communicable diseases and their risk factors, Mental health, Social health, Health system. The result of one article present in three categories. The details of results presented in Table 1.
3.1. Quality of life
Four articles address Quality of life in slums of Kermanshah, and Hamadan. Their participants' recruitment was done through random sampling methods. They were young-adult. Two studies focused on female sex, and the others considered both sex (21–24).
The studies revealed that women worried about their security and health. The woman reported the health related quality of life factors in slums were not acceptable they need to improve physical ,and environmental health. The other study on women demonstrated one fifth of participants were not satisfied from their leisure time. Unavailability of facilities and their economic situation led to unpleasant leisure time for them (22, 23).
The studies on both sex shown the slum residence have not been satisfied with physical environment. Also, the slums had concern about their social and environmental situation. They need to socio-environmental promotion, socioeconomic status improvement, and their awareness increment related to quality of life. Comparison the mean scores of health-related quality of life subscales revealed the mean score in mental health was lower than general health (58.67 vs 60.41) (22, 24).
3.2. Reproductive health
From three studies categorized in reproductive health subject, two case related to child health and the other one was about women health. A case control study in slum area of Ardabil revealed that the important cause of death among neonates was prematurity and congenital abnormality. There was association between neonatal mortality and parents’ education, income, and smoking of father (25).
A two years’ interventional study on under five children living in slum area of Kerman bring about decrease stunting and proper nutrition in children. This study showed positive correlation between appropriate nutrition status and mothers’ literacy and their socioeconomic level (45).
A study in Shiraz demonstrated about 5% of the eligible women use contraceptive method, and about 50% of slums women screened by pap smear test. About One third of pregnant women hadn’t received prenatal and postpartum care. The most important reason of this situation was low awareness of women, and low access of them to health services in slum area. (15)
3.3. Communicable Diseases
Three studies in slums area of Gorgan and Mashad, and Shiraz performed through a screening data analysis, a descriptive study on health centers information, and a cross sectional study, respectively. These studies showed tuberculosis (TB) incidence rate in slums of Gorgan was 17.5 per 100000. In addition, they revealed living area situation such as living near major traffic arteries correlate with risk of TB in Mashad (28, 29).
The other study in Shiraz showed the prevalence of leishmaniosis in slum area was 8.5% witch one third of them referred to public health sector. Also, HIV infection was important issue in this area, but 18.6% of slum residential had poor knowledge about prevention of HIV/AIDS.(15)
3.4. Non-Communicable Diseases and their Risk Factors
Three cross sectional study by participation women of slum area address the risk factors of NCDs. These studies showed unhealthy life style and unsuitable health status of slum dwellers women. Among them, inadequate intake of fruits and vegetables, low physical activity, and smoking were considerable health problems in slums of Bandar-abbas, Zahedan, and Tehran (31, 32, 34).
A community based intervention in suburb residence of Yasouj showed the effect of nutrition education and physical activity promotion on decreasing FBS, HbA1C, TG and cholesterol significantly (33).
3.5. Mental Health
A cross sectional study in suburb area of Tehran showed the inhabitants preferred receiving help from friends. In addition, most of them had concern about cost of mental health services. The other study in Tehran demonstrates 67.1% of Self-burning suicide cases were residents in suburban areas. Self-burning suicide was frequent in females, youth, and who had low level education. Socioeconomic factors could be determinants of mental health status (35, 36).
3.6. Social Health
A cross sectional study in households living in suburb of Ardabil demonstrates the most prevalent social harms in this area was addiction, and stealing (38). Another study in Qom showed health indicators measure was lower in illiterate slums than educated people. There is correlation between social support and social health (37).
3.7. Health system
A comprehensive study in Fars province on 372 household slums showed one fifth of them has not access to health centers. Health care coverage among them was about 10%. The essential source of health information in slums was radio. Although, health workers had inconspicuous role in informing slums peoples. Inadequate awareness of slums’ inhabitants about health care facilities was the main barrier of their utilization. But, vaccination coverage among children of this area was 98% (15).
The other studies about vaccination in slums settled in Kermanshah, Tehran, Esfahan, Arak, Mashhad, and Zahedan. These studies showed the most important reason for delay in vaccination was unawareness of parents about the time and necessity of vaccination. Delay in vaccination mostly occurred for MMR vaccination at 18 months. There is positive correlation between on-time vaccination and parents’ educational level (40–42, 46).
The other study in Kerman demonstrate, 21% of people who required outpatient services and 31% of people who needed hospitalization were able to use these services. In slums of Karaj, a cross sectional study by participation of married woman showed they need to nutritional and psychological consultation (43).