تحلیل فضازمانی بیماری های تنفسی در شهر تهران با استفاده از مدل تخمین تراکم کرنل

Introduction
Respiratory diseases are one of the most important diseases that have involved the world community (Kermani et al., 2015). According to the statistics of the World Health Organization, one-fifth of people in the world are suffering from these diseases, and in 2005, the ranking of chronic respiratory diseases was 13, and in 2016, the ranking of this disease reached 5. Also, chronic respiratory diseases ranked 11th in terms of the occurrence of physical disabilities in 2020 (World Health Center website, 2021). Respiratory disease, which is generally related to lung disease, includes a group of diseases that cause lung dysfunction by involving parts or parts of the respiratory system. Sometimes respiratory disease is caused by damage to the pleural membrane (pleura), pleural cavity, or respiratory muscles and nerves. Every year, lung diseases affect many people in society, which reduce the level of performance of a person in daily activities. Respiratory system diseases in England are the most common cause of referral to general practitioners (Etamidi et al., 2018). Respiratory diseases are classified into two types, infectious and non-infectious (Khoshdel et al., 2013), infectious respiratory diseases are widely distributed at the community level and are transmitted from person to person, often in the form of lung infection or the same essence. Pneumonia occurs (Gunathilakaabc, R., et al, 2018), and its non-infectious type is often caused by exposure to environmental and biological pollutants (Kimberly, A, 2017). Iran's respiratory diseases are always a major challenge. According to a four-year study, the rate of asthma in the adult population of the country is 9%, and in children and adolescents, it is 11%. In Iran, chronic respiratory diseases are the third cause of death after cardiovascular diseases and road accidents (Ethmarian et al., 2012).
On average, 200 people die in Kalansehr, Tehran, due to respiratory diseases per year (Kermani et al., 2015). Therefore, it is necessary to identify and plan for the reduction and prevention of these diseases in the city of Tehran. In order to make correct preventive plans, we must know how the diseases are distributed in the place, so that the influence of environmental factors on the increase or decrease of the affected people is necessary. to be able to measure specific diseases (Ghadami et al., 2012). In recent years, due to the spread of Corona, the number of respiratory diseases has increased significantly in the country, especially in Tehran. Most respiratory diseases lead to severe lung or pleural infections (pneumonia).
Geographical epidemiology is a part of descriptive epidemiology in the style of spatial analysis that examines the geographical distribution of morbidity and mortality rates (Rivero, A, et al, 2015). For the prevention, management, and control of diseases, various information technology methods such as geographic information systems (GIS) are used. Based on this, a geographic information system will be used in this study. The aim of this research is to analyze the spatiotemporal respiratory diseases in Tehran using the Kernel density estimation model using Geographical Information System (GIS).
Methodology
The current research was done based on the purpose, applied, and based on the descriptive-analytical method. In order to identify and understand the spatial patterns of respiratory diseases at the level of 22 districts of the Tehran metropolis, statistical and graphic models have been used in the geographic information system (GIS) environment. At first, to identify the foci of concentration of respiratory diseases, the analyzed data were considered as points, and mapping of the disease was done. Then, by using statistical tests, the general patterns of respiratory diseases were determined at the level of the regions of Tehran, and finally, disease maps were extracted using the kernel density method, and based on this, other analyzes were performed. The most important statistical tests used in this research are the mean center, standard deviation ellipse, clustering tests, and kernel density estimation methods. The statistical population of the research is the number of people suffering from respiratory disease (1995 people) within the legal limits of the city of Tehran, which is between the years 1397 and 1400.
Conclusion
Identifying and analyzing the ranges of diseases at the city level using the GIS geographic information system makes it possible for the health organization of any country to identify pathogenic factors and reduce its growth rate and apply preventive policies. Using the results of the analysis of this research in relation to respiratory diseases at the level of the regions of Tehran, it is possible to provide preventive measures. According to the analysis of the central mean and ellipse of standard deviation, District 12, as one of the central districts of the city, is the center of respiratory diseases in Tehran. The findings of the research showed that by using the closest neighborhood index in the clustering test, the distribution pattern of respiratory diseases data in Tehran city is uniform. Most of the respiratory diseases that spread in an infectious manner due to their contagious nature spread quickly in all areas of the city, and this is also true in the case of Tehran. According to the results of the ellipse of the standard deviation, the areas with the highest incidence of respiratory diseases in the city of Tehran are located in the northeast and southwest sides of the city. According to the findings of the research using the kernel density estimation model in the period of 1397-1400, in 1397 the areas that are in the neighborhood of District 12 are known as centers of respiratory disease in Tehran. In 2018, region 17 was introduced as the second main center of respiratory diseases in Tehran. In 2019, with preventive measures, region 17 moved away from the center of diseases, and after that, the neighboring areas of this region were not affected by the disease. Respiratory tracts stay away. In the year 1400, the northern areas of Tehran were introduced as new foci of the spread of respiratory diseases. The areas that are most affected by respiratory diseases are often the areas that are at a lower level in terms of social and environmental factors and generally have a low quality of living.