Iranian Journal of

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Background & Objectives: Breast cancer is a common malignancy in women in many parts of the world. The incidence of breast cancer in Iranian women is growing. Iranian patients are relatively younger than their western counterparts. We conducted a case-control study to determine roles of reproductive factors for breast cancer among women in Iran.
Methods: A hospital based case-control study was conducted in 2004 at a teaching hospital in Tehran, Iran. A total of 303 cases of breast cancer and 303 healthy controls were interviewed. Cases were identified through the oncology department of a university hospital and controls were recruited from other wards or out-patients clinics at the same hospital. Controls were matched to cases on age. Demographic and reproductive data were ascertained by personal interview using a structured questionnaire. Informed consent was obtained from cases and controls. Odds ratios and 95% confidence intervals for breast cancer were derived using logistic regression analysis.
Results: Mean ±SD age of cases and controls was 48.8 ±9.8 and 50.2 ± 11.1 years, respectively (range 24-84). The final model constructed after multivariate analysis indicated that factors such as never being married, menopause, older age at first live birth, parity, use of oral contraceptives, and history of chest X-ray between adolescence and the age of 30 yrs were significantly associated with breast cancer. Variables such as higher education, early age at menarche, abortion, breast feeding and its duration did not constitute significant risk factors.
Conclusions: Marital status, history of chest X-ray between adolescence and the age of 30, number of live births, and age at first live birth, menopause, and oral contraceptive use seem to increase the risk of developing breast cancer among women in Iran.

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Background and Objectives: Logistic regression is one of the most widely used generalized linear models for analysis of the relationships between one or more explanatory variables and a categorical response. Strong correlations among explanatory variables (multicollinearity) reduce the efficiency of model to a considerable degree. In this study we used latent variables to reduce the effects of multicollinearity in the analysis of a case-control study.
Methods: Our data came from a case-control study in which 300 women with breast cancer were compared to 300 controls. Five highly correlated quantitative variables were selected to assess the effect of multicollinearity. First, an ordinary logistic regression model was fitted to the data. Then, to remove the effect of multicollinearity, two latent variables were generated using factor analysis and principal components analysis methods. Parameters of logistic regression were estimated using these latent as explanatory variables. We used the estimated standard errors of the parameters to compare the efficiency of models.
Results: The logistic regression based on five primary variables produced unusual odds ratio estimates for age at first pregnancy (OR=67960, 95%CI: 10184-453503) and for total length of breast feeding (OR=0). On the other hand, the parameters estimated for logistic regression on latent variables generated by both factor analysis and principal components analysis were statistically significant (P<0.003). The standard errors were smaller than with ordinary logistic regression on original variables. The factors and components generated by the two methods explained at least 85% of the total variance.
Conclusions: This research showed that the standard errors of the estimated parameters in logistic regression based on latent variables were considerably smaller than that of model for original variables. Therefore models including latent variables could be more efficient when there is multicollinearity among the risk factors for breast cancer.

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Background and objectives: There is growing interest in assessing gene-environment interaction in the course of case-control studies. Difficulties related to the sampling of controls have led to the development of a range of non-traditional methods that do not require controls for estimating gene-environment interaction. One of these new modalities is the case-only approach, in which the assessment of gene-environment interaction is based on information from the cases only. The present article describes the application of this approach to data from breast cancer patients and compares its efficacy with that of a traditional case-control analysis.
Methods: We used age at first pregnancy, number of live birth, menopause and the total number of post-menopausal years as the "environment" factors and family history of breast cancer as the "gene" factor. We computed standard errors, 95% confidence intervals and (-2 log likelihood) to compare efficiency between case-control and case-only analyses.
Results: We observed significant interaction between menopause and family history of breast cancer by both methods (OR=4.32 CI: 1.10-16.90 for case-control analysis & OR=3.40 CI: 1.17-9.87 for case-only analysis). There was also a significant interaction effect between total years after menopause and family history of breast cancer (OR=1.07 CI: 0.98-1.16 in case-control analysis & OR=1.07 CI: 1.01-1.12 in case-only analysis). The case-only approach yielded narrower confidence intervals for the odds ratio, and the (-2 log likelihood) values computed by this method were correspondingly smaller.
Conclusions: Comparison of confidence intervals and (-2 log likelihood) values shows that the estimation of gene-environment interaction in breast cancer would be more efficient with the case-only approach than with the traditional case-control analysis.

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Background & Objectives: This research focused on estimating the mean of Neurological Soft Signs scores in children with Attention Deficit and Hyperactivity Disorder and comparing them with normal children.
Methods: We evaluated 25 children with Attention Deficit- Hyperactivity Disorder in the age group of 7-12 years (mean age: 10.16 ± 1.5y) using the DSM-VI Attention Deficit – Hyperactivity Disorder Questionnaire, Conner’s Parents’ Rating Scale, and the 28-item NES Questionnaire. There was no significant age difference between cases and controls. The mean total NES score was 11.4±4.14 in cases and 5.6± 2.79 in controls (P< 0.0001). Compared to the control group, the cases had significantly more problems with the glabellar reflex, rapid alternative movements and right-left discrimination.
Results: Soft Neurological signs are observed with greater frequency among children with ADHD compared to normal subjects and the difference is more significant in certain domains such as rapid alternative movements, right- left confusion, and glabellar reflex.
Conclusions: Considering the relatively high frequency of soft neurological signs in children with Attention deficit- Hyperactivity Disorder, earlier diagnosis and treatment of the disease might be possible through careful neurological examination.

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Background & Objectives: Adolescence is an important period of human development. Developmental traits in this period could be predisposing to behavioral problems, delinquency substance abuse and mental disorder. So this survey was designed to study the mental health status of adolescence in Kashan .
Methods: This cross sectional study involved 400 adolescent from Kashan high schools. They were chosen through randomized stratified sampling. SCL-90-R Questionnaire was used. Demographic information such as age, sex, birth order, history of addiction and any mental disorders ,educational level, age of parent were also asked . Descriptive and analytic statistics were done by SPSS software.
Results: Overall 10% of the high school adolescents had mental disorders. Common psychopathology demonstrations were as follows: Paranoid thought, interpersonal sensitivity, depression, anxiety, and aggression. There were significant relation between family history of addiction and mental disorder, history of physical abuse and age of adolescence with mental health (p<0/05). Total GSI in boys who were substance abuse was 1.9 while in boys who were not was 0.87 (p <0.05). There was not statically significant relation between total mean of GSI and gender however there were statistically significances between girls and boys in interpersonal sensitivity, depression, anxiety and depression.
 Conclusion: The responsible authorities should take steps in addressing these problems by initiating School Counseling Centers and also by including study material in the field of psychiatry and psychology in the adolescent students school curriculum.

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Normal 0 false false false EN-US X-NONE AR-SA Background & Objectives: Human papillomavirus (HPV) infection seems to be the most common sexually transmitted infection. High-risk (HR) human papillomavirus (HPV) prevalence has been shown to correlate well with cervical cancer incidence rates. Since there is little known about the epidemiology of this infection in Tehran, we designed to estimate the prevalence of HPV in some areas in Tehran. 
Methods: Cervical specimens were obtained from 825 married women aged 21-59 years from the general population of Tehran, Iran according to the standardised protocol of the IARC International HPV surveys. HPV was detected using a GP5+/6+ PCR-based assay.
Results: HPV prevalence in the general population was 7.8% (5.1% of high-risk types), with no statistically significant variations by age. Cervical intraepithelial neoplasia was diagnosed in 4.1% of women, of whom 35.3% were HPV-positive. HPV16 was confirmed as the most common type among women with both normal (1.8%) and abnormal (8.8%) cytology. HPV positivity was significantly higher among divorced women, women in polygamous marriages and those reporting husbands' extramarital affairs.
Conclusion: However the prevalence of HPV seems not high in comparison with other international data, more molecular and seroepidemiological survey in national level needs to have a better perspective.

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Normal 0 false false false EN-US X-NONE AR-SA Background & Objectives: Cardiovascular disease is the first cause of death and third place in disease burden in Iran. This study estimates population attributable fraction (PAF) of cardiovascular risk factors in Tehran population. PAF is one of the important parameters of measuring population affect of risk factors and evaluating potential impact of preventive strategies in community level.
Methods: In this study 5868 participants above 30 years old of Tehran lipid and glucose study (TLGS) were employed and 501 CVD events detected during 10 years follow-up. Direct estimate of adjusted PAFs using logistic regression which is one of less biased exist methods of PAF calculation were applied.
Results: Highest modifiable cardiovascular risk factor PAFs, in sequence, was smoking (14.16%), hypertension (11.73%), diabetes (7.32%), hypercholesterolemia (6.85%) and central obesity (5.91%) for men, and hypertension (19.25%), diabetes (18.82%), central obesity(9.88%) and hypercholesterolemia (7.95%), for women. Also PAF of hazardous age and premature family history of CVD, as most important nonmodifiable CVD risk factors, were 36.09%, 16.61% and 3.95%, 7.56% for men and women respectively.
Conclusion: According to the difference of risk factors PAFs ranking in men and women, it is suitable that CVD preventive interventions to be prioritized by sex separately. In this regard, besides special attention to control tobacco use in men, hypertension and diabetes in both sexes and high cholesterol in men and central obesity in women respectively, should be given in priority of preventive strategies.

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Background & Objectives: The aim of this study was to identify the quality of life (QOL) measures commonly used to assess disabled people compared to healthy individuals.
Methods: A cross-sectional study was conducted in 1000 disabled and healthy individuals aged between 15 to 75 years old during 2009 year. These groups were selected by random sampling method multistage cluster sampling from Crescent Comprehensive Rehabilitation Center located in Tehran. WHO's Quality of Life (WHOQOL-100) questionnaire was used to measure quality of life.
Results: The Mean age were 35.9±12.9 and 35.1±12.7 years amongst disabled and non disabled groups, respectively. There was a significant difference between two groups in terms of somatic health and independence of quality of life (P<0.001), in which the mean score in both domains were high in healthy individuals. No significant difference was observed between two groups in other scopes.
Conclusion: Findings of this study highlighted the lower quality of life in disabled people in Tehran, Therefore this group should be targeted for any relevant intervention in order to improve their care.

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Background & Objectives: Golestan province in Iran has been known as a high risk area for esophageal cancer (EC). This study was conducted to assess the population-based survival rate in EC patients in Golestan province of Iran.
Methods: In a longitudinal study, 223 EC patients registered in Golestan population-based cancer registry in 2007 and 2008 were recruited. Kaplan-Meier method was performed to calculate median survival and log rank test was also used to compare survival rates between subgroups of variables. Multivariate Cox regression model was employed to determine adjusted hazard ratios (AHR) for different variables.
Results: From 223 patient, 129 (57/8%) were male. The mean age of participants was 64/3 years. The median survival in our study was 11/08 months. Survival rates for 6, 12 and 36 months were 69%, 47% and 14%, respectively. The results of Cox regression analysis showed that the AHR for patients with metastasis stage (compared to those with localized stage) was 13.89 (95% CI: 7/93-24/32) and the AHR for workers (compared to clerks) was 2.4 (95% CI: 3/8-1/47).
Conclusion: Our results showed that survival rate of EC patients were higher than the rate reported in a previous study from this region. However the survival rate from this region seems still lower than those reported from developed countries. Implementation of appropriate screening programs in this region will result in early diagnosis of EC and consequently will increase survival rate in EC patients.

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Background & Objectives: We studied the risk of Chronic Kidney Disease (CKD), Metabolic Syndrome (MetS), and their interaction on the incidence of Coronary Heart Disease (CHD).
Methods: A population of 6568 participants (43.4% male) with a mean age of 48.4 years for males and 46.7 years for females and a median follow-up of 10.1 years was investigated. They were divided into 4 groups at baseline: CKD-/MetS-, CKD+/MetS-, CKD-/MetS+, CKD+/MetS+. Hazard Ratios (HRs) were calculated for each group and were compared to the first group using multivariate Cox regression analysis adjusted for age, education, smoking, total cholesterol, and the family history of cardiovascular diseases.
 Results: Men with CKD (without MetS) showed an HR of 1.74 (CI 95%: 1.16-2.60) for CHD events. The measured value was 2.34 (1.77-3.08) for men with MetS (without CKD). The respective results were in women 1.18 (0.64-2.19) and 2.59 (1.73-3.88). CKD and MetS had a significant negative interaction with CHD events (HR=0.40, 0.24-0.66). The interaction was not significant in women (P value=0.48).
Conclusion: The results of this study indicated that CKD without MetS was a risk factor for coronary heart disease in men but not in women.

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Background and Objectives: Colorectal cancer, as the third common cancer, is one of the main health problems in Iran. We assessed the burden of colorectal cancer, as one of the high-priority indices, in this cross-sectional study in Iran in 2008.

Methods: CANMOD software was used for calculation. The input data included the population of Iran, all-cause and colorectal cancer mortality rates, and incidence rate of colorectal cancer, which were all obtained from the Iran Statistic Center, Mortality Registry System, and Cancer Registry System.

 Results: The total burden of colorectal cancer according to DALY in Iran in 2008 was 52534 years in the total population. Years of lost life (YLL) amongst males and females were 26455 and 19887 years, respectively. Years lived with disability (YLD) were 3473 and 2719 years for males and females, respectively. The burden of colorectal cancer per 1000 population was 75.4 years for males and 65.7 years for females. The peak age of colorectal cancer burden rate was in the age group 45-79 years.

 Conclusion: The burden of the colorectal cancer in Iran has increased compared to the last study (2003) which is due to the increase in its incidence and the related mortality during this period. Due to the possibility of prevention and effective intervention, this cancer should be a priority in the health care system. However, the final judgment should be made after calculation of the burden of other cancers, diseases, and damages at the country level and their respective rankings.

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  Background and Objectives : Awareness of the cancer incidence is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimation. This study aimed to estimate the incidence of gastric cancer by the capture-recapture method based on Ardabil population-based cancer registry data.

 Methods: All new cases of gastric cancer reported by three sources, i.e. pathology reports, death certificates, and medical records, reported to Ardabil population-based cancer registry between 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of the first name, surname, and father's name were identified among sources. The estimated incidence was calculated by the log-linear method using the Stata 12 software.

  Results : A total 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rate was 35.3 and 32.5 per 100,000 population for the years 2006 and 2008, respectively. The estimated incidence rate calculated by the log-linear method for these years was 96.2 and 90.4 per 100,000 population, respectively.

  Conclusion: The results showed that none of the sources of pathology reports, death certificates, and medical records, individually or collectively, fully covered the incidence of gastric cancer. We can obtain more accurate estimates of the incidence rate using the capture-recapture method.

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  Background and Objectives : Breast cancer is the second most common cancer among Iranian women. The peak age of breast cancer in Iran is one decade lower than the global estimates. The aim of this cross-sectional study was to estimate the burden of breast cancer in Iranian women in the country level.

 Methods: In this study, the CANMOD software was used for the calculation of DALYs as the sum of YLL and YLD. The required data was the population of the Iranian women, mortality due to breast cancer, incidence cases of breast cancer, and mean time of the stages of breast cancer that was obtained from the Mortality Registry System, Cancer Registry System, and expert panel views .

  Results : In this study, the total burden of breast cancer in Iranian women was 75811 years in 2009. Moreover, the years of life lost (YLL) was 54938 years while years lived with disability (YLD) was estimated 20873 years. The rate of DALYs per 100000 female population was 220.9 years. The peak age of breast cancer burden was in the age group 45-59 years. The incidence to mortality ratio was 3/2.

  Conclusion: The incidence rate, mortality rate, and the burden of breast cancer in Iranian women increased in 2009 when compared to a previous study in 2003. The findings of this study may provide Iranian health managers with some information on the determinants of the burden of breast cancer in order to design preventive measures as well as screening programs for early detection of breast cancer.

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  Background and Objectives : Various studies have reported different survival rates of patients with gastric cancer in Iran, and there is no overall estimate of the survival rate. The aim of this study was to conduct a meta-analysis of one, three, and five-year survival rate of patients with gastric cancer in Iran.

  Methods: In this study, all of the national databases including Iran Medex, Magiran, SID, and Medlib and the English databases including Google Scholar and PubMed were searched by using the keywords “stomach cancer”, “survival rate” and other Persian and English synonymous keywords, in the period 1392-1339 . Then, all articles with inclusion criteria and acceptable quality were investigated. Der Simonian and Laird random effects models were used to combine the results of all studies. Other analyses including subgroup analysis, sensitivity analysis, and assessment of publication bias were performed by using the funnel plot, and Beg’s and Egger’s tests. Finally, the data was analyzed using STATA software.

  Results: Of the 235 articles found in the initial search, nine studies were eligible for this study. According to these studies, one, three and five-years survival rate of patients with gastric cancer was 0.57 (95% CI: 0.45-0.70), 0.29 (95% CI: 0.22-0.37), 0.17 (95% CI: 0.13-0.21), respectively.

  Conclusion : Researches conducted in different parts of Iran are limited and there are no exact statistics on the survival rate in other parts of Iran. Therefore, further studies in the whole country are required to obtain more precise estimates of the survival and factors affecting it.

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Background & Objectives: Some studies on chronic diseases have indicated that obesity may result in a paradoxically longer survival. The present study was aimed to investigate the effect of Chronic Kidney Diseases (CKD) and Metabolic Syndrome (MetS) on the incidence of Coronary Heart Disease (CHD).

Methods: In order to record time to CHD events, a sample of 6,507 individuals (mean age 47.4 years, 43.4% males) was followed for nearly 10 years. Participants were also categorized into four groups according to presence/absence of CKD and MetS. Then, using a Multivariate Cox Regression, the Hazard Ratio (HR) of each group was estimated relative to individuals free of both CKD and MetS separately for obese (BMI&ge27.1 Kg/m2) and non-obese persons (BMI<27.1 Kg/m2).

Results: HR for non-obese patients with CKD but not MetS was obtained 2.06 (95%CI: 1.28-3.31) in men and 2.56 (1.04-6.31) in women. However, these associations were not significant for obese patients. Furthermore, among non-obese men and women with MetS alone, HR was estimated 2.52 (1.71-3.73) and 4.68 (2.20-9.95), respectively. For obese patients, these values were 1.70 (1.05-2.78) and 1.90 (1.16-3.13), respectively.

Conclusion: The results reflect that among those who had MetS alone, the risk of CHD incidence was twice higher in non-obese individuals compared to obese patients.

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Background and Objectives: completeness of registration is used as one of the measures of the quality of a cancer registry, which is the degree to which reportable incident cases of cancer in the population of interest is actually recorded in the registry.

Methods: After removing the duplicates, a total of 471 new cases of esophagus cancer reported by three sources of pathology reports, medical records, and death certificates to Ardabil Province Cancer Registry Center in 2006 and 2008 were enrolled in the study. The incidence rate was estimated based on the capture-recapture method and the use of the log-linear models. BIC, G2 and Akaike statistics were used to select the best-fit model.

Results: In this study, a model with linkage between pathology reports and medical records and a model with death certificates alone, independent of the previous two sources, was the best fitted model. The estimated total completeness of esophagus cancer in 2006 and 2008 was 36% .The source that had the most completeness for esophagus cancers was pathology reports with 21.17%. The estimated incidence rate calculated by the log-linear method for the years 2006 and 2008 was 49.71 and 53.87 per 100,000 population, respectively.

Conclusion: Based on the obtained results, it can be concluded that the low degree of completeness in Ardabil Province requires some changes in data abstracting and case finding such as the use of personal national code and electronic health records to create a more accurate cancer registry.

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Background and Objectives: Colorectal cancer is the fourth leading cause of cancer death worldwide.  Annually 1430000 cases would be diagnosed and half of these people would die of the disease. In Iran, colorectal cancer is the fifth common cancer among men and is the thirdamong women. This study was designed to estimate survival rates for patients with colorectal cancer and related factors.  

Methods: During the 1384 to 1388 years 24,807 patients diagnosed with colorectal cancer were recorded in the Cancer Registry of the Ministry of Health and Medical Education. Age, gender, marital status, education, occupation, place of residence, tumor diagnosis, the clinical and demographic factors in colorectal cancer as effective on survival entered in Aalen’s additive hazard model and diagram Aalen's was used to study the effects of these factors over time. R 3.2.0 software was used for data analysis.

Results: Stage of tumor had a significant association with survival rates. In this study 1 to 5 year survival rate for patients with stage II tumors, was 100%, 98%, 96%, 93% and 93% respectively and for patients with stage III tumors 99%, 97%, 94%, 90% and 84%, respectively.

Conclusion: In spite of using Cox model in survival analysis by many researchers, Aalen’s model may yield new insights in prognostic studies of survival time of patients with colorectal cancer over time. Our results suggest that early detection of patients in primary stage is important to increase survival.

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In epidemiologic studies, the measurement of characteristics of interest is almost always subject to random measurement error. This error and its effects are usually overlooked by researchers. One of its effects is a widespread statistical phenomenon that is well known as regression to the mean. This phenomenon occurs whenever an extreme group of people is selected from a population based on their measurements of a variable. If a second measurement is taken in this group, the mean of the second measurement will be closer to the mean of the population.  In interventional studies, this increase (decrease) might be regarded as the effect of intervention, when in fact it has had no effect. Ignoring regression to the mean will lead to the erroneous conclusions and interpretation of the results of epidemiologic studies and affects the decisions in evidence-based medicine and planning for preventive and public health measures. This paper highlights the importance of this problem and its effects in epidemiologic studies and the ways to avoid it.

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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.

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Background and Objectives: Colorectal cancer is the fourth most common cancer and the fifth cause of cancer-related mortality in Iran. This study aimed to determine the incidence of colorectal cancer in men and women and to investigate its relationship with the human development index (HDI) and its components in Iranian provinces.
Methods: This ecological study was conducted to assess the correlation between age-specific incidence of colorectal cancer in men and women and the Human Development Index. We used the data of the Iranian Cancer Registry and Statistical Centre of Iran. We used a bivariate correlation method to assess the correlation of ASR and HDI. P values less than 0.05 were considered significant. All reported P-values are two-sided. Statistical analyses were performed using the SPSS software version 23.
Results: The highest incidence of colorectal cancer in men was seen in Tehran (78.16), Eastern Azerbaijan (41.14), and Semnan (62.13), and the highest incidence of colorectal cancer in women was seen in Tehran (47.18), Semnan (80.14), and Eastern Azerbaijan (82.12), respectively. The results showed that the incidence of colorectal cancer in men (r = 0.605) and women (r = 0.661) had a positive significant correlation with the Human Development Index (P<0.001).
Conclusion: The incidence of colorectal cancer was high in provinces with a higher human development index. Therefore, evaluation of the incidence of cancer by the Human Development Index and its components can be used to show a clearer picture of the distribution of cancer in each country and may be useful for cancer prevention plans.