Iranian Journal of Epidemiology

A Study of the Epidemiology of COVID-19 in the City of Tehran, Iran

Hamid Soori

Background and Objectives: COVID-19 pandemic caused a lot of severe problems in the world. This study investigated the epidemiology of the disease in Tehran in the first quarter of the epidemic's beginning.
Methods: The available information recorded for patients from 20 February 2020 to 20 May 2020 in Tehran was used. To prepare disease-related distribution maps, the addresses of patients' residences in Google Earth were called to ARC-GIS version 10-4. The methods used in GIS include IDW, Hotspot and also software development.
Results: Overall, 3699 individuals whose PCR results were positive in Tehran were included in the study. Out of the total number of them, 550 people died and the fatality rate of the disease in hospitalized patients was 14.9%. One thousand five hundred thirty patients (41.4%) have recovered, and the remaining 1619 patients were under treatment until data collection. Of the total, 1479 confirmed cases were women (40%). The average age was 57.4 years (SD=16.5). The density of cases in areas 4, 8 and 13, and the existence of some cluster diseases in neighborhoods such as Tehran Pars, Ayat and Pirouzi streets are noteworthy points.
Conclusion: The trend of the COVID-19 epidemic is dire and requires long-term measures. Nevertheless, to control this disease, the health system, the policy of isolating patients and suspicious people, wear masks especially in densely populated areas, are the most important controlling factors.

Evaluation of Tuberculosis Status in Family Members of Patients with Pulmonary Tuberculosis in Bam City in 2019

Naser Nasiri

Background and Objectives: Screening for home contact with TB patients is essential to identify new infections. This study aimed to evaluate the tuberculosis status in family members of patients with pulmonary tuberculosis in Bam.
Methods: This cross-sectional study was conducted as a census of patients' family members whose records are registered during 2013-2019 in Bam Health Center. Patients' information was collected based on a checklist, and then sputum smear-positive patients were identified using tuberculin and sputum smear tests.
Results: Ninety-seven of the patients had a positive sputum smear test result. Based on the records of these patients, 237 members of their families were examined as contact persons. Most of the patients were female and in the age group of 40-50 years; 76.8% of them had unprotected close contact, and 78.9% had a history of permanent contact with patients. Five (2.1%; 95% confidence intervals: 0.7-4.9) sputum-positive smear pulmonary tuberculosis cases were found in contacts of patients, most of them were over 50 years old and primarily women. 40% of these people had unprotected close contact, and 80% had a house with less than 70 square meters.
Conclusion: in this study, 2.0% of the family members of patients were sputum smear-positive. Identifying patients and following them up is essential to prevent the spread of tuberculosis in those people around them. Therefore, screening the patient's family members can significantly help ease the disease burden in Iran.

Probabilistic Carcinogen Risk Assessment from Exposure to Chromium in Drinking Water Resources in Rural Areas of Qazvin Province

Hamid Karyab

Background and Objectives: Chromium is a heavy metal that toxic to humans in small concentrations. This study aimed to evaluate the cancer risk of exposure to chromium in drinking water in rural areas of Qazvin province.
Methods: Water sampling was performed according to the standard methods for water and wastewater examination and chromium analysis was performed with ICP-OES. Exposure factors were determined using a validated questionnaire. Finally, the risk assessment of oral and dermal exposure to chromium was performed using the risk assessment technique. Monte Carlo simulation was also used to determine the uncertainty caused by point risk estimation.
Results: The mean concentration of chromium in drinking water was 2.8±5.04 μg/l. The excess lifetime cancer estimated by the Monte Carlo simulation was 30.8 cases per 100,000 in the studied population, indicating 100 cases of cancer in the population living in rural areas of the Qazvin province.
Conclusion: Based on the obtained results, it can be concluded that although the concentration of chromium was lower than the maximum allowed in the national standard (0.05 mg/l), the risk of carcinogenesis was higher than the acceptable risk level of WHO (1 case per 100,000). Also, using the results obtained from the Monte Carlo simulation instead of point estimation provides higher confidence in risk management decisions.

Association Between Fear of COVID-19 and Death Anxiety with Moderator Role of Self-Regulation Among Older Adults Residing in Qazvin

Seyedeh Ameneh Motalebi

Background and Objectives: Fear of COVID-19 is common among older adults and negatively impacts on their physical and mental health. Self-regulation is an essential factor for controlling or managing excitement and anxiety. So, this study aimed to determine the relationship between fear of COVID-19 and death anxiety with the moderator role of self-regulation among the elderly residing in Qazvin.
Methods: This descriptive and cross-sectional study was performed on 430 elderly aged 60 and over living in Qazvin in 2021. Samples were selected by cluster sampling method. The demographic checklist, Templer death anxiety scale, fear of COVID-19 questionnaire, and Self-Regulation Inventory were used for collecting the data. The data were analyzed using the Path Analyze test.
Results: The mean age of the elder participants in the study was 66.88 ± 6.40 years old. The results showed a significant and positive relationship between fear of COVID-19 and death anxiety (β=0.60, P<0.001) and an inverse association between fear of COVID-19 (β=-0.24, P=0.021) and death anxiety (β=-0.10, P=0.021) with self-regulation. Furthermore, the results of the Path analysis confirmed the moderator role of self-regulation in the association between fear of Covid-19 and death anxiety among the elderly residing in Qazvin, Iran.
Conclusion: Given the mediator role of self-regulation in the relationship between fear of COVID-19 and death anxiety, it is suggested to use teaching strategies to the older adults to improve self-regulation to control and mitigate the negative impacts of the fear of COVID-19 in this vulnerable population.

Association of Tea, Coffee, Caffeine and Chronic Kidney Disease: Tehran Lipid and Glucose Study

Zahra Bahadoran

Background and Objectives: Dietary intakes are one of the factors influencing the incidence of chronic kidney disease. The present study was performed to investigate the possible long-term effects of caffeine, tea and coffee consumption on the incidence of chronic kidney disease.
Methods: 1780 adults participating in the third phase of the Tehran Lipid and Glucose Study (TLGS) (2006-2008) were selected for inclusion criteria. Dietary intakes were assessed using a food frequency questionnaire (FFQ). Demographic variables, anthropometrics, and biochemical data were measured at baseline and after six years of follow-up. To estimate the risk of chronic kidney disease, logistic regression analysis, adjusted for possible confounding variables, was used.
Results: Participants’ mean (±SD) age at baseline was 33.96±15.40 years. During six years of follow-up, the incidence of chronic kidney disease (CKD) in the population studied was 17.9%. After adjusting confounding variables, the incidence of CKD did not show any significant relationship with tea, coffee, or caffeine intakes (adjusted odds ratio and confidence intervals for CKD in the third tertile of tea and caffeine intake compared to the first tertile and in coffee drinkers compared to non-drinkers were 0.92 (0.68-1.25), 0.87 (0.63-1.21) and 1.17 (0.90-1.51), respectively).
Conclusion: Inverse and non-significant relationship between tea and caffeine consumption with the incidence of CKD and a direct and non-significant relationship between coffee consumption and the incidence of CKD were observed in this study, necessitating further prospective studies to investigate the effects of dietary intakes on CKD.

Structural Validity of the Persian Version of Impact of Weight on Quality of Life Questionnaire (IWQOL-lite) Using Multilevel Confirmatory Factor Analysis Model

Hoosein Fallahzadeh

Background and Objectives: Today, overweight and obesity are among the significant challenges in the world. They can have adverse effects on quality of life. Quality of life is determined by social and physical environment. The present study investigated the construct validity of the Persian version of the Impact of Weight on Quality of Life (IWQOL-lite) questionnaire using multilevel confirmatory factor analysis.
Methods: The present study was conducted on 310 people over 18 years old living in Yazd city. The data were analyzed using m-plus6.2 software.
Results: The mean age of the participants in this study was 33.97± 4.70 years. Sixty percent (N=183) of subjects were male. The indices of the one-level model were more appropriate than those of the two-level model, and the one-level confirmatory factor analysis model had a good fitting to the data (CLI: 0.98, TLI: 0.98, RMSEA: 0.038).
Conclusion: The results of this study indicated the need for more effectiveness of urban areas on quality of life. The one-level confirmatory factor analysis model confirmed the construct validity of the IWQOL-lite questionnaire. This questionnaire can be used in the Iranian population.

Epidemiological Study of Factors Related to the Mortality of Under-Five Years in Isfahan Province in the Years 2018 to 2021

Omid Iravani

Background and Objectives: childhood is the most dangerous period of the life of humans. So, investigating the causes of children's death and preventing them has an essential role in the health and productivity of the family and society. This study aims to investigate the epidemiological factors related to the mortality of under-five years in Isfahan province.
Methods: In this cross-sectional-analytical and retrospective study, the files of 194 children under five years (109 boys and 85 girls) who were referred to Isfahan Legal Medicine Center between 2017 and 2021; were investigated and the causes of death and their demographic and clinical characteristics were extracted. The obtained data were analyzed using the Chi square statistical test and Fisher’s exact test.
Results: In terms of the distribution, unnatural causes of death was, 30.4% died due to domestic incidents, 22.7% died due to chronic diseases, 21.1% died due to vehicle accidents, 17.5% died due to acute diseases, 2.1% Death due to asphyxia, 1.3% death due to sudden death syndrome and 1.3% death due to various causes. There is a statistically significant difference between the cause of death and age group, place of death, disease history and year of death (P<0.05), but there is no statistically significant difference between the cause of death and gender and nationality (P>0.05).
Conclusion: Considering the ability to take preventive measures against child deaths and its trend in the country, it is necessary to make future policies to promote legal investigations to ensure children's health and safety.

Identification Symptoms and Underlying Diseases Related to COVID-19 And Prediction of Death Status Using Artificial Neural Network and Logistic Regression: A Data Mining Approach

Mohammad Taghi Shakeri

Background and Objectives: Due to the high prevalence of COVID-19 disease and its high mortality rate, it is necessary to identify the symptoms, demographic information and underlying diseases that effectively predict COVID-19 death. Therefore, in this study, we aimed to predict the mortality behavior due to COVID-19 in Khorasan Razavi province.
Methods: This study collected data from 51, 460 patients admitted to the hospitals of Khorasan Razavi province from 25 March 2017 to 12 September 2014. Logistic regression and Neural network methods, including machine learning methods, were used to identify survivors and non-survivors caused by COVID-19.
Results: Decreased consciousness, cough, PO2 level less than 93%, age, cancer, chronic kidney diseases, fever, headache, smoking status, and chronic blood diseases are the most important predictors of death. The accuracy of the artificial neural network model was 89.90% in the test phase. Also, the sensitivity, specificity and area under the rock curve in this model are equal to 76.14%, 91.99% and 77.65%, respectively.
Conclusion: Our findings highlight the importance of some demographic information, underlying diseases, and clinical signs in predicting survivors and non-survivors of COVID-19. Also, the neural network model provided high accuracy in prediction. However, medical research in this field will lead to complementary results by using other methods of machine learning and their high power.