Iranian Journal of

Background and Objectives: Ahvaz has become one of the most polluted cities in the world. Only on 11 November 2013, over one thousand residents in Khuzestan Province attended the nearest health center with severe symptoms, particularly shortness of breath, cough, wheezing, and high blood pressure. During a week, more than 7 thousand patients were registered with this syndrome. This study was conducted to investigate the evidence for the confirmation of an epidemic in acute respiratory syndrome among the residents of Ahwaz in November 2013.

Methods: In this cross-sectional study, we evaluated the data of the use of drugs related to acute respiratory attacks from November 2008 to 2013 in Ahvaz. Then, we conducted a descriptive study on the general population. The sample size was 120 and the study participants included different segments of the general population. The data collection tool was a researcher-made questionnaire and the data were analyzed using SPSS.18.

Results: The use of the respiratory drugs increased from 2008 to 2013. The drug consumption was markedly higher in November 2013. In the study of the general population, 93% of the participants declared that they had never seen a similar event, and 92.5% mentioned that they had never heard of a similar occurrence.

Conclusion: Due to the significant increase in respiratory medicine in November 2013 and the unexpected nature of the event, an epidemic seems to be obvious.

Background and Objectives: Spatial epidemiology is the description and analysis of geographic variations of diseases with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors. Disease mapping includes a set of statistical techniques that lead to providing clean maps based on estimation of the incidence, prevalence and mortality rates for the users to enable them to reliably estimate the distribution of the diseases. In this study, the spatial epidemiology of diarrhea was evaluated in Mazandaran.

Methods: In the present study, statistical methods like the Moran’s I spatial autocorrelation, Anselin local Moran’s I, K function and Ripley index were used to evaluate 4924 cases between 1385-1390, based on certain factors detected in diarrheal diseases.

Results: The results of the global Moran index showed that this disease provided adherence to a cluster pattern in the province. The results of the K function also showed that apart from the western regions of the province, the diarrheal disease followed the above-mentioned cluster pattern. The results of Anselin local Moran and sensitive indicators revealed that the central region of the province, including the cities of Sari, Qaymshmhr, and Babol had the highest prevalence of the disease.

Conclusion: The results showed that the prevalence of syndrome diarrhea follows the pattern cluster and the use of spatial analysis methods in a specific geographic area is appropriate for programs to reduce health risks. And in epidemiological studies, analysis and risk assessment diarrhea syndrome are very important.

Background and Objectives: Foot-and-mouth disease (FMD) is one of major contagious animal. The purpose of this study was to evaluate the determinants associated with FMD occurrence in farms.

Methods: A case- control study was carried out in cattle farms.  The cases were farms with new reports of FMD and controls were units without any report of FMD in last 6 month. For assessing the risk factors, a researcher- made questionnaire was used. Statistical analyses were done with SPSS version 16 using the logistic regression test.

Results: Purchase of new livestock [OR: 14.69 (CI95%: 4.29, 50.36)] and passing migratory livestock [OR: 13.32 (CI 95%: 1.74, 101.87) were identified as the risk factors of the disease. Visiting the farm by the vaccinator in last 2 weeks [OR: 0.17 (CI 95%: 0.05, 0.63)] and buying new livestock from the same village/ city where the farm is located [OR: 0.16 (CI 95%: 0.04, 0.58)] were considered as protective factors.

Conclusion: Considering the role of infected livestock in the country, the most important steps for effective preventation are: areadherence to biosecurity as well as quarantining new purchased animals, and informing and training farmers to not purchase new animals from farms that are located in the infected areas and around the times of outbreak.

Background and Objectives: Taking into account the roles and positions of WHO Collaborating Centers (WHOCCs) in the furtherance of national goals and the great impact of their interaction as well as cooperative relations between these centres, this study was conducted to assess the current status of WHOCCs, identify opportunities and threats, and provide practical solutions to solve WHOCCs problems.

Methods: This cross-sectional study was conducted using an open-ended questionnaire in 2014. The questionnaire revolved around the WHOCCs' status in terms of goal achievement, manpower problems, financial resources, communications, as well as suggestions to solve problems in these domains. These findings were approved in the second convention of the heads of WHOCCs in Kerman in 2014 and the questionnaires of the second phase were distributed and completed by participants. Data were analyzed using the content analysis method.

Results: The majority of the centres assessed their performance regarding the national goals (11.59) in comparison with international goals (14.20), and self-regulated goal setting (14.7o) in an unfavorable condition. Financial problems and lack of recruitment were the most important problems for WHOCCs. The support of the Ministry of Health, WHO, supporting universities, and establishing research networks at national and international levels to foster communication, contracts to share experiences and resources, considering the authors' rights as well as introducing the competencies of centres at national and international levels, were some of the suggestions proposed.

Conclusion: It seems that more support of the WHO, Ministry of Health, and supporting universities is needed to increase financial resources and recruit staff.

Background and Objectives: Cutaneous leishmaniasis (CL) is a public health problem in Iran and Kerman Province which is expanding to new foci. This study was conducted to estimate the incidence of CL by a simple and cost – effective method in a major focus of CL in the city of Kerman, southeastern Iran.

Methods: A combination of two longitudinal and cross – sectional studies was performed. First, the frequency of referred patients to the CL treatment clinic in 2009-2014 was assessed. Then, four highly infected zones consisting of 800 households in the city were selected. In addition, the relative proportions of referred and non – referred subjects were assessed. Eventually, the incidence of CL was calculated by dividing the number of CL cases over the total at risk population for the corresponding period (2009-2014).

Results: The mean annual incidence was 175 per 100000 (943 patients) in the city of Kerman, while it was 500 per 100000 people (0.5%) in the new foci. The highest CL infection was observed among the <25-year-old individuals but there was no significant difference between the sexes.

Conclusion:The incidence rate probably increased significantly following the 2003 Bam earthquake because of the migration of CL patients to southern, eastern, and northeastern areas of the city of Kerman. Since only 50% of the cases were passively referred to the CL treatment clinic, health authorities should actively detect CL cases by house – to – house visit for effective treatment strategies.

Background and Objectives: One of the main concerns of heart specialists is the occurrence of restenosis after coronary angioplasty which can lead to coronary artery bypass graft, myocardial infarction, and death. The present study was conducted to investigate the factors affecting the frequency of restenosis during four years in patients of Zanjan. 

Methods: In the present retrospective cohort study, all the patients who underwent angioplasty in Ayatollah Musavi Hospital of Zanjan from April of 2009 to June of 2011 were examined in terms of the frequency of restenosis. According to the patients’ medical records, all the demographic and clinical data of the patients were collected. Since the dependent variable was count in nature and the data were over-dispersed, negative binomial regression was used for modeling.

Results: The incidence of at least one restenosis during four years after angioplasty was calculated to be 43%. According to the negative binomial regression model, the ratio of restenosis in patients suffering from diabetes, unstable angina, chronic kidney disease, and myocardial infarction was 32%, 44%, 66%, and 30% more than other patients, respectively (P<0.05).

Conclusion: In the present study, the effective factors of restenosis were recognized as diabetes, unstable angina, chronic kidney disease, and history of myocardial infarction; hence, assessment and periodic follow-up of these patients are strongly recommended.

Background and Objectives: Infertility is one of the most important crises in the lives of couples, which create psychological consequences beside the economic, social and individual problems,. Decreased sexual satisfaction is one of the consequences of infertility. Given the importance of this concept in the life of infertile couples, a tool to measure the sexual satisfaction of this group of people is necessary. Thus, the study aimed to assess the psychometric properties of the Persian version of the LSSQ in Iranian infertile couples in 2013.

Methods: In this methodological study, 150 Iranian infertile couples completed the 25-item Larson's sexual satisfaction questionnaire in Qazvin. Its reliability was determined by the calculation of Cronbach's alpha coefficient. Exploratory and confirmatory factor analyses were done by SPSS-AMOS22.

Results: The internal consistency of the sexual satisfaction questions estimated with Cronbach's alpha was more than 0.7. Exploratory factor analysis was used to evaluate the construct validity of the questionnaire which showed 4 factors (desire to have sexual relations, sexual attitude, quality of sex life, and sexual compatibility) with Eigen values greater than one. Four latent factors explained 53.21% of the total variance. Confirmatory factor analysis confirmed the final model of the construct of the questionnaire.

Conclusion: The results of study showed that the Persian version of LSSQ has a suitable validity and reliability in the Iranian infertile couples. Factor analysis confirmed that the LSSQ had a multi-dimensional structure.

Background and Objectives: Syndromic surveillance systems are used to early detection of outbreaks. The purpose of this study was to determine the feasibility of clinical and non-clinical data sources used in influenza syndromic surveillance in Zanjan.

Methods: In this time series study, clinical and non-clinical data related to influenza like illness (ILI) as a potential data source of syndromic surveillance systems, including the number of missed school days collected from 12 schools and the data of over the counter (OTC) drug sale obtained from 15 pharmacies selected randomly in Zanjan during 2014 were used. We used the line plot and moving average chart to explore trends and detect potential explainable patterns of data sources. The autocorrelation function and cross correlation function besides corresponding graphs were used to assess the feasibility of school absenteeism and OTC sale in timely detection of influenza outbreaks. 

Results: Line plots indicated the presence of explainable patterns and the effect of the day of the week. The cross correlation value was 0.5 and cross correlogram revealed the similarity of both data sources in this study.

Conclusion: Our findings indicated the feasibility of influenza data sources, including school absenteeism and OTC, as potential data sources of syndromic surveillance systems.

Background and Objectives: Salmonella contamination of broiler breeder farms is of great importance regarding transmission of the bacteria through the production chain of poultry meat. The aim of this study was to determine the prevalence and management related factors of Salmonella contamination in broiler breeder flocks in Iran.

Methods: This cross sectional study was carried out between 2013 and 2014 in 23 provinces of Iran. Fecal samples were obtained from 139 broiler breeder farms and were subjected to standard bacteriological tests for Salmonella isolation. The serogroups of isolated Salmonella were determined using standard serological tests. Relevant information of sampled holdings was acquired from the GIS system and used for risk factor detection.

Results: The prevalence of Salmonella contamination in broiler breeder holdings was 7.9% and the more positive samples were from Tehran and Fars provinces. The flock age (P = 0.019) and the number of poultry houses in the farm (P = 0.037) were major risk factors of Salmonella contamination in broiler breeder farms.

Conclusion: This investigation showed that the prevalence of Salmonella contamination in broiler breeder farms was relatively high. It is necessary to establish an appropriate program for controlling Salmonella contamination in broiler breeder farms. Regular sampling for early detection of contaminated farms would be very important in this case. Sampling from old flocks should be the first priority.

Background and Objectives: Breast cancer is one of the most common malignancies in women which accounts for the highest number of deaths after lung cancer. The aim of the current study was to compare the logistic regression and classification tree models in determining the risk factors and prediction of breast cancer.

Methods: We used from the data of a case-control study conducted on 303 patients with breast cancer and 303 controls. In the first step, we included 16 potential risk factors of breast cancer in both the logistic regression and classification tree models. Then, the area under the ROC curve (AUC), sensitivity, and specificity indexes were used for comparing these models.

Results: From 16 variables included in the models, 5 variables were statistically significant in both models. Sensitivity, specificity, and AUC was 71%, 69%, and 74.7% for the logistic regression and 63.3%, 68.8%, and 71.1% for the classification tree, respectively.

Conclusion: The obtained results suggest that the classification tree has more power for separating patients from healthy people. Menopausal status, number of breast cancer cases in the family, and maternal age at the first live birth were significant indicators in both models.

Background and Objectives: Hirschsprung's disease is one of the congenital movement disorders of the bowel whose accurate and timely diagnosis in childhood is important. The disease occurs due to lack of ganglion cells in the distal part of the digestive system and leads to functional obstruction of the colon. Recently, by the frozen section method, the diagnosis and treatment of the disease is possible through one-stage surgery with fewer complications and lower costs without the need for early colostomy. The aim of this study was to evaluate the validity of frozen section in Hirschsprung's disease.

Methods: this retrospective study was done on 406 frozen section results obtained from patients admitted to Mofid Hospital during 1389-90. We evaluated the frequency of “positive” and “negative” samples and compared them with the results of the permanent section. Moreover, the validity, sensitivity, specificity, and positive and negative predictive value of frozen section were calculated.

Results: After examining 406 frozen section samples and comparison with the results of permanent section, the results were consistent for both methods in 369 cases (90.89%) while the results were inconsistent in 37 cases (9.11%). Frozen section showed 7 (1.7%) false negative and 30 false positive (7.3%) cases. The sensitivity, specificity, positive predictive value, and negative predictive value of frozen section was 94.44%, 89.29%, 79.87%, and 97.28%, respectively.

Conclusion: Frozen section is a good tool for screening and diagnosis. Its power to rule out the disease is rather more than its power to confirm its presence. so it is capable of ruling out the disease in 97% and confirming its presence in 80% of the cases.

Sampling hidden populations is challenging due to the lack of convenience statistical frames. Since most populations exposed to special diseases are hidden and hard to reach, sampling methods that produce representative and efficient samples from the populations have become a study subject for researches all over the world. Because of the unknown probability of selecting samples in conventional sampling methods and also invalidity of generalizing the results of non-probability sampling methods to the statistical population, the necessity of introducing probability chain-referral sampling methods, such as the respondent driven sampling method becomes imperative. In this article, besides introducing the respondent driven sampling method, some of the advantages of this method as relative decrease of the bias of estimates, declining the non-response rate by paying incentives and allocating weights proportional to reciprocal of the social network size of respondents to produce unbiased estimates are described. Moreover, some disadvantages of this method such as lack of producing differential samples by selecting similar seeds, lack of reaching more efficient method than snowball sampling by implementing this method improperly and lack of achieving to equilibrium by existing weak social networks among members of interested population are stated. Another aim of this article is to compare sampling methods of hidden population with the respondent driven sampling method which are the results of implementing this method in different surveys and existing simulations.

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.

Background and Objectives: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Background and Objectives: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Background and Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Background and Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: The screening program in Iran has differences with other countries which have affected the indicators.

Background and Objectives: 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.

Methods: 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.

Results: 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<0.01).Also, according to the estimated coefficients from both methods,there was a little difference between them.

Conclusion: 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.

Background and Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Background and Objectives: 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.

Methods: 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.

Results: 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 (P<0.001) were significant compared with the log-normal model (P>0.900).

Conclusion: Comparison of the confidence intervals suggests that the jackknife resampling method can be used when the sample size is small.