مجله اپیدمیولوژی ایران
سال دوازدهم شماره 3 (پیاپی 43، پاییز 1395)

Social determinants of health affect a wide range of health consequences. The aim of this study was to analyze the effects of social determinants of health factors on survival in patients with malignant brain tumors.
This cross-sectional retrospective study was done in Imam Khomeini and Shariati Hospitals in 2014. Based on inclusion criteria, the data of 148 patients were collected. The collected data included demographic information (including age, sex, education level, employment status, marital status, health insurance status, number of household members), information about the tumor and disease (stage / grade), The first and the last time of follow-up, type of selected treatment, and the duration of survival after treatment. We used SPSS 15 to analyze data.
Our results showed a significant relationship between survival and variables such as the size of the household, education, employment status, and age. Patients with grade 3 tumors had a lower relative risk of dying while employed patients, patients in the age range 18-30 years, and male patients had a higher relative risk of dying (lower survival).
Lack of reliable databases and appropriate integration and communication between different organizations recording to patient data, and also probable sensitivity in obtaining personal information has led to the lack of systematic information about the impact of social determinants of health. it is recommended that a system of recording integrated information for different disease should be established in the country for designing informed policies based on the evidence.

The main question that arises in ‘Quality of Life’ (QOL) studies is how people assess this phenomenon and what factors affect it. Using these answers, we can better analyze the findings of QOL studies in our country.
In this content analysis, we carried out semi-structured interviews, and applied maximum variation opportunistic sampling in terms of gender, age, education, ethnicity, and economic status. First, we asked the participants to answer the question on QOL by thinking aloud. Then, they were asked to discuss the factors that affected their choice a posteriori. Finally, the inductive qualitative analysis was done and the mental model of the participants was extracted.
We extracted five main categories and 33 themes. These categories included physical factors, psychological factors, socioeconomic factors, family issues, and environmental factors. Physical health, expectations, satisfaction, community engagement, financial problems, environmental pollution, leisure and recreation, family environment, family relationships and the role of the wife were the most important factors affecting the QOL in the participants’ opinions.
In addition to the health status, family issues such as the family environment and financial problems affected the QOL. Moreover, the participants believed environmental health was an integral part of QOL.

Colorectal cancer is the third most common cancer in men and the second most common cancer in women in the world. The colorectal cancer screening program was conducted in Iran as a pilot in the late 2010 with the aim of reducing the burden of colorectal cancer. The aim of this study was to evaluate the colorectal cancer screening program in Iran.
This cross-sectional study was conducted on data from the pilot colorectal cancer screening programs. First, the indicators of the colorectal cancer screening program were determined through a comprehensive review of scientific databases, interviews with experts and implementation of pilot evaluation. Then, the indicators were calculated through descriptive analysis using SPSS version 18.
The indicators and their values were as follows: coverage rate 33.04%, participation rate 53.3%, percentage of consulted people 99.6%, percentage of blood samples 37%, percentage of colonoscopy 54.8%, cancer detection rate 2.7%, and polyp detection rate 18.1%. Among people who gave blood samples 1.6% had familial adenomatous polyposis (FAP) syndrome, 43.06% had hereditary no polyposis colorectal cancer (HNPCC) syndrome, and 29% were sporadic cases.
The screening program in Iran has differences with other countries which have affected the indicators.

Lifestyle is one of the most important indicators of improving the quality of the people's lives. Given the key role of employees as valuable human resources, the aim of this study was to evaluate the lifestyle of the employees working in Ardabil University of Medical Sciences in 2015.
In this cross-sectional study, 320 employees working in Ardabil University of Medical Sciences were randomly included. The data collecting tools were a demographic form and the Walker questionnaire, which contained two questions related to the six dimensions of lifestyle. Data were analyzed with correlation tests, Chi-square, T-test, and Linear regression using SPSS.
The lifestyle score was poor in 6.9%, moderate in 75.3%, and good in 17.8% of the employees. The mean and standard deviation of lifestyle dimensions was 22.19±4.9 for health responsibility, 27.93±5.2 for spiritual growth, 24.29±4.6 for interpersonal relations, 20.51±4.4 for stress management, 17.53±4.8 for physical activity, and 23.95±4.2 for nutrition. Women had higher scores than men in most items. There were significant relationships between gender and age with stress management (P=.002), gender and health responsibility (P=.002), educational level and health responsibility (P=.001), educational level and nutrition (P=.004), income and nutrition (P=.001), and educational level and interpersonal relations (P=.003).
The majority of employees their lifestyle was in the middle. The lowest score was related to physical activity and stress management. Interventions for promoting physical activity and stress management among employees is proposed.

In studies in which each person may experience an event at different times, they are recurrent events.One of the most popular approaches in analyzing recurrent event is obtaining an estimate of the means/rate of events at different times. In this context,one of the things that could help to better understand the effect of this factor on the response is determining the variability due to quantitative variables in the rate of events over time. In this study,we applied kernel and B-spline methods to estimate coefficients in the time dependent-coefficients rate model and showed its application in data of psoriasis.
In this study,data of patients with psoriasis who had a relapse leading to hospitalization in the Dermatology Department of Imam Khomeini Hospital,between 2005 and June 2013 were used. To investigate the relapse rate during these years,time-dependent coefficients rate model was used and the variability of these effects was assessed using the Wald test. Both b-Spline and kernel methods were used for estimating time varying coefficients in the time-dependent rate model.Finally,the results of the methods were compared based on estimates obtained.
The results of this study showed that according to Wald test,the effect of the variables such as the season on the occurrence of psoriasis was significantly different (P-value When the effect of a variable on the occurrence of the events is different at different time, then time-dependent coefficients rate model may provide a better estimate of the effect of variable on response.

Salmonella spp. are one of the most important zoonotic agents with a worldwide distribution. Asymptomatic cats which may excrete Salmonella. spp for weeks can play important role in environmental contamination. The aim of this study was to access the role of rural cats in dissemination of Salmonella. spp.
Salmonella excretion was evaluated in 170 samples (rectal swabs) of apparently healthy rural cats from Golestan and Mazandaran provinces using PCR and conventional microbial culture tests. After serotyping, the presence of spv R and spv B genes and the antibiotic resistance pattern of isolated Salmoella spp. were surveyed.
Out of 170 samples, 25 (14.7%) cases with Salmonella spp., including: 13 (52%) cases of S enteritidis, 7(28%) cases of S Dublin, and 5 (20%) cases of S typhymurium were recovered.
The presence of spv R and spv B genes was detected in 5 out of 25 isolated Salmonella spp. The highest resistance of isolated Salmonella spp. was to Streptomycin, Lincospectin, and Tetracycline. The rate of Salmonella isolation was similar in male and female rural cats and also Golestan and Mazandaran provinces.
Detection of zoonotic serotypes of Salmonella spp with spv R and spv B genes and multidrug antibiotic resistance in apparently healthy rural cats make them a potential significant threat to public health. Similar studies on different populations of cats must be taken in consideration when prevention, control or eradication programs of salmonellosis are going to be carried out.

A small sample size can influence the results of statistical analysis. A reduction in the sample size may happen due to different reasons, such as loss of information, i.e. existing missing value in some variables. This study aimed to apply bootstrap and jackknife resampling methods in survival analysis of thalassemia major patients.
In this historical cohort study, the data of 296 patients with thalassemia major who were visited at Zafar Clinic, Tehran, from 1994 to 2013 were used. Parametric survival models were used to analyze the data. The log – normal survival model was selected as the best model and then the bootstrap and jackknife resampling algorithms were used for this model. Data analysis was carried out with the STATA 12.0 software.
The results of the resampling methods showed that standard errors decreased and confidence intervals were shortened. In addition, the result of the bootstrap and jackknife resampling methods showed that age group and the relationship of the parents (P0.900).
Comparison of the confidence intervals suggests that the jackknife resampling method can be used when the sample size is small.

Case-Cohort and nested case-control designs are the most well-known and cost-effective derivatives of prospective studies. Due to the popularity of these designs in recent years, the aim of this study is to provide a comprehensive and up-to-date description of them with respect to methodological issues such as sampling scheme, effect measure estimation, and analysis strategies. Overall, random sampling of controls in case-cohort and matching for time in nested design are considered their hallmarks. Eventually, decision on a better design depends on study objectives, sub-cohort selection, case and control determination, and method of data collection. It should be kept in mind that any particular study requires unique elaboration and delicate examination to choose from the designs.