Survival analysis in gastric cancer: a multi-center study among Iranian patients.

BACKGROUND: Gastric cancer (GC) has been considered as the 5th most common type of cancer and the third leading cause of cancer-associated death worldwide. The aim of this historical cohort study was to evaluate the survival predictors for all patients with GC using the Cox proportional hazards, extended Cox, and gamma-frailty models. METHODS: This historical cohort study was performed according to documents of 1695 individuals having GC referred to three medical centers in Iran from 2001 to 2018. First, most significant prognostic risk factors on survival were selected, Cox proportional hazards, extended Cox, gamma-frailty models were applied to evaluate the effects of the risk factors, and then these models were compared with the Akaike information criterion. RESULTS: The age of patients, body mass index (BMI), tumor size, type of treatment and grade of the tumor increased the hazard rate (HR) of GC patients in both the Cox and frailty models (P < 0.05). Also, the size of the tumor and BMI were considered as time-varying variables in the extended Cox model. Moreover, the frailty model showed that there is at least an unknown factor, genetic or environmental factors, in the model that is not measured (P < 0.05). CONCLUSIONS: Some prognostic factors, including age, tumor size, the grade of the tumor, type of treatment and BMI, were regarded as indispensable predictors in patients of GC. Frailty model revealed that there are unknown or latent factors, genetic and environmental factors, resulting in the biased estimates of the regression coefficients.

Direct and indirect medical costs of functional constipation: a population-based study.

BACKGROUND: Constipation causes a large number of medical visits each year and imposes significant financial toll on healthcare systems worldwide. So the present community-based study was conducted in order to estimate attributable direct and indirect costs to functional constipation (FC) and to provide an overview of related physician visits in general population of Iran. METHODS: From May 2006 to December 2007, a total of 19,200 adult persons (aged 16 and above) were drawn randomly in Tehran province, Iran (response rate 94%). Participants who reported any gastrointestinal symptoms (2,790 persons) were referred to assigned physicians to be questioned about symptoms of functional bowel disorders according to the Rome III criteria. Direct and indirect costs to FC were calculated. Attributable costs were reported as purchasing power parity dollars (PPP$). RESULTS: Of the total 18,180 consenting participants in this study, 435 (2.4%) had FC according to Rome III criteria. Mean total cost of constipation per person was 146.84 PPP$, of which 128.68 PPP$ was related to direct costs and 18.16 PPP$ to indirect costs. Higher educated persons (189.75 PPP$), those above 64 years of age (373.42 PPP$), subjects with BMI of less than 18.5 kg/m(2) (510.84 PPP$), and widowed persons (258.50 PPP$) had the highest costs. CONCLUSIONS: This study determined that although the economic burden of FC does not seem to be substantial in comparison to other major health problems, it still exacts a substantial toll on the health system for two reasons: chronicity and ambiguity of symptoms.

Prognostic factors in gastric cancer using log-normal censored regression model.

BACKGROUND & OBJECTIVE: Gastric cancer is one of the most common cancers in the world. It is rarely detected early, and the prognosis remains poor. Cox proportional hazard model is used to examine the relationship between survival and covariates. Parametric survival models such as log normal regression model can also be used for this analysis. We used log normal regression model in this study to evaluate prognostic factors in gastric cancer and compared with Cox model. METHODS: We retrospectively studied the 746 patients diagnosed with gastric cancer admitted in a referral hospital in Tehran, Iran, from February 2003 through January 2007. Age at diagnosis, sex, extent of wall penetration, histology type, tumour grade, tumour size, pathologic stage, lymph node metastasis and presence of metastasis were entered into a log normal model. Hazard rate (HR) was employed to interpret the risk of death and the results were compared with Cox regression. The AIC (Akaike Information Criterion) was employed to compare the efficiency of models. RESULTS: Univariate analysis indicated that with increasing age the risk of death increased significantly in both log normal and Cox models. Patients with greater tumour size were also in higher risk of death followed by those with poorly differentiated and moderately differentiated in tumour grade and advanced pathologic stage. The presence of metastasis was significant prognostic factor only in log normal analysis. In final multivariate model, age was still a significant prognostic factor in Cox regression but it was not significant in log normal model. Presence of metastasis followed by histology type were other prognostic features found significant in log normal results. Based on AIC, log normal model performed better than Cox. INTERPRETATION & CONCLUSION: Our results suggest that early detection of patients in younger age and in primary stages and grade of tumour could be important to decrease the risk of death in patients with gastric cancer. Comparison between Cox and log normal models indicated that log normal regression model can be a useful statistical model to find prognostic factors instead of Cox.

Uninvestigated dyspepsia and its related factors in an Iranian community.

OBJECTIVE: To determine the prevalence and determinants of uninvestigated dyspepsia in the Iranian population. METHODS: A cross-sectional study conducted in Tehran province from May 2006 to December 2007, included 18,180 adult persons selected randomly. The study took place at Shahid Beheshti University, MC, Tehran, Iran. A questionnaire was completed in 2 steps. In the first part, personal characteristics and 11 gastrointestinal symptoms were inserted. Those who reported at least one of these 11 symptoms were referred for the second interview, which consisted of questions on different gastrointestinal disorders based on Rome III criteria, including uninvestigated dyspepsia. RESULTS: The prevalence rate of uninvestigated dyspepsia was 8.5% (10.9% in women and 6.4% in men). Among the subjects diagnosed with dyspepsia, bothersome postprandial fullness was the most common symptom (41.5%). Uninvestigated dyspepsia was more common in low educated and widowed participants. Approximately 41.4% of patients had a history of depression, and 66.1% had self report of stress. The prevalence of functional irritable bowel syndrome in patients with uninvestigated dyspepsia was 8.3% and gastroesophageal reflux disease was 64.9%. CONCLUSION: Uninvestigated dyspepsia has a less common prevalence in the general Iranian population than developed countries. Women, older, obese, widowed, and low education subjects are more likely to suffer from dyspepsia.

Comparing Cox regression and parametric models for survival of patients with gastric carcinoma.

BACKGROUND: Researchers in medical sciences often tend to prefer Cox semi-parametric instead of parametric models for survival analysis because of fewer assumptions but under certain circumstances, parametric models give more precise estimates. The objective of this study was to compare two survival regression methods - Cox regression and parametric models - in patients with gastric adenocarcinomas who registered at Taleghani hospital, Tehran. METHODS: We retrospectively studied 746 cases from February 2003 through January 2007. Gender, age at diagnosis, family history of cancer, tumor size and pathologic distant of metastasis were selected as potential prognostic factors and entered into the parametric and semi parametric models. Weibull, exponential and lognormal regression were performed as parametric models with the Akaike Information Criterion (AIC) and standardized of parameter estimates to compare the efficiency of models. RESULTS: The survival results from both Cox and Parametric models showed that patients who were older than 45 years at diagnosis had an increased risk for death, followed by greater tumor size and presence of pathologic distant metastasis. CONCLUSION: In multivariate analysis Cox and Exponential are similar. Although it seems that there may not be a single model that is substantially better than others, in univariate analysis the data strongly supported the log normal regression among parametric models and it can be lead to more precise results as an alternative to Cox.

Determinants of Physical Health of Older People in Iran.

Background. Many of the older people are encountered with physical and mental health problems, chronic diseases, and also living conditions. We aimed to evaluate the disability scores and its associated factors among a sample of older people in Iran. Material and Methods. 330 people aged 60-70 years were interviewed about daily living activities and physical functioning using two standard questionnaires. Results. According to univariate analysis, aging 66-70 years, being employed, and receiving financial aids were associated with better ADL mean score (P < 0.05). Also, being between 66 and 70 years of age, males, being illiterate, being employed, and receiving financial aids were statistically related to higher SF-36 mean scores (P < 0.05). Multivariate analyses have shown that higher age and receiving financial aids were related to less need for help and being unemployed with salary was related to higher need for help. However, being illiterate, being employed, and receiving financial aids were significant related factors for better physical functioning. Conclusions. Physical health in old people is decreased not only by aging of people but also by other factors such as financial problems and also employment status could decrease physical health of old people regardless of aging.

Evaluation of the benefit of addition of clidinium C to a Helicobacter pylori eradication regimen.

AIM: This study aimed to evaluate the success of H.pylori eradication therapy in patients with dyspepsia by therapeutics regimes with and without clidinium C. BACKGROUND: Helicobacter pylori infections are reported in all parts of the world. Appropriate antibiotic therapy can treat infection. The ideal treatment regimen has not been specified. PATIENTS AND METHODS: In a randomized, double blind clinical trials study, 250 patients with dyspepsia were enrolled. All patients were treated by Omeprazole, Metronidazole, Amoxicillin and Bismuth (OMAB) for two weeks. One tablet clidinium C before each meal was added to this regimen in the intervention group (A). Urea Breath Test (UBT) was carried out after 8-12 weeks after treatment for evaluation of H.pylori eradication. RESULTS: 132 patients in the intervention group (A) and 118 patients in the control group (B) were enrolled to the study. The rate of eradication in group A was significantly higher than group B (62.1% vs. 50%, p=0.04). CONCLUSION: The results supported the effect of clidinium C for increasing of helicobacter pylori eradication, but further studies need to be performed.

Specific count model for investing the related factors of cost of GERD and functional dyspepsia.

AIM: The purpose of this study is to analyze the cost of GERD and functional dyspepsia for investing its related factors. BACKGROUND: Gastro-oesophageal reflux disease GERD and dyspepsia are the most common symptoms of gastrointestinal disorders. Recent studies showed high prevalence and variety of clinical presentation of these two symptoms imposed enormous economic burden to the society. Cost data that related to economics burden have specific characteristics. So this kind of data needs to specific models. Poisson regression (PR) and negative binomial regression (NB) are the models that were used for analyzing cost data in this paper. PATIENTS AND METHODS: This study designed as a cross-sectional household survey from May 2006 to December 2007 on a random sample of individual in the Tehran province, Iran to find the prevalence of gastrointestinal symptoms and disorders and its related factors. The Cost in each item was counted. PR and NB were carried out to the data respectively. Likelihood ratio test was performed for comparison between models. Also Log likelihood, Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) were used to compare performance of the models. RESULTS: According to Likelihood ratio test and all three criterions that we used to compare performance of the models, NB was the best model for analyzing this cost data. Sex, age and insurance statues were being significant. CONCLUSION: PR and NB models were carried out for this data and according the results improved fit of the NB model over PR, it clearly indicates that over-dispersion is involved due to unobserved heterogeneity and/or clustering. NB model in cost data more appropriate fit than PR.

Anxiety and depression in a sample of Iranian patients with irritable bowel syndrome.

OBJECTIVE: Previous studies have shown that up to 50% to 70% of patients with irritable bowel syndrome (IBS) who seek treatment have psychiatric comorbidity. The aim of this study was to report the history of anxiety and depression in IBS patients. METHODS: The study, designed as a cross-sectional, was performed in a consecutive sample of individuals diagnosed with IBS in the Gastroenterology Clinic of Taleghani Hospital, Tehran province, Iran from October 2010 to October 2011. IBS was diagnosed according to the Rome III criteria. All participants were asked about perceived psychiatric symptoms such as depression and anxiety in the past six months. RESULTS: 153 treatment-seeking IBS patients were entered to the study. The mean age of IBS patients with history of psychiatric symptoms (33.9 years) was relatively lower than those without this history (39.3 years); p< 0.05. There was a significant difference regarding mean age of diarrhea-predominant IBS (IBS-D) patients with history of psychiatric symptoms (26.8 years) and without such history (37.9 years); p< 0.05. However, such a difference was not seen among other types of IBS. The most frequent psychiatric symptoms were reported by the constipation-predominant IBS (IBS-C) patients followed by mixed-IBS (IBS-M) and the least rate was seen in IBS-D. CONCLUSION: Approximately half of IBS patients reported anxiety and/or depression. IBS-C patients experienced higher proportions of anxiety and depression. DECLARATION OF INTEREST: None.

The efficacy and safety of adding the probiotic Saccharomyces boulardiito standard triple therapy for eradication of H.pylori: a randomized controlled trial.

AIM: Evaluating the efficacy and safety of adding the probiotic Saccharomyces boulardiito standard triple therapy for eradication of Helicobacter pylori. BACKGROUND: Several probiotics such as Saccharomyces boulardii have been investigated for their clinical efficacy. This probiotic, inhibit H. pylori urease by lowering the gastric pH, adhesion of H. pylori to gastric epithelial cells, stabilize the gastric barrier function and reduce the side effects of antibiotics. PATIENTS AND METHODS: In this randomized controlled trial we evaluated 160 adult patients with biopsy confirmed H. Pylori infection referred to gastroenterology ward of Taleghani hospital. The patients were randomized into two treatment regimens: patients in group A (n = 80) were given amoxicillin (1000 mg, b.i.d), clarithromycin (500 mg, b.i.d), omeprazole (20 mg, b.i.d) and probiotic of saccaromyces boularidi (Yomogi) (250 mg, b.i.d) for 14 days, moreover patients in group B (n = 80) were given amoxicillin (1000 mg, b.i.d), clarithromycin (500 mg b.i.d) and omeprazole (20 mg,b.i.d) for 14 days. RESULTS: 160 patients (66 male 41.25%, 94female 58.75%) with the mean age of 47.1±11.4 years were evaluated. The success rate for H. pylori eradication in group A was higher 75(87.5%) than group B 65 (81.2%), but the difference between two groups was not significant (p = 0.350). Moreover, in case group side effects as nausea, diarrhea, abdominal discomfort and bloating were significantly lower than control group in first and second weeks. CONCLUSION: This study showed that saccaromyces boularidi decreased the adverse effects associated with H.pylori therapy but did not significantly decrease the eradication rate of H.pylori.

Direct medical care costs associated with patients diagnosed with chronic HCV.

BACKGROUND: HCV virus (HCV) is a significant global problem with wide-ranging socio-economic impacts. Because of the high morbidity and mortality associated with end-stage liver disease, cirrhosis, and hepatocellular carcinoma (HCC), the economic burden of HCV infection is substantial. OBJECTIVES: This study aimed to estimate the direct medical care costs of chronic HCV infection. PATIENTS AND METHODS: For this cross-sectional study, 365 courses of HCV treatment were extracted from medical records of 284 patients being referred to Tehran HCV clinic, a clinical clinic of Baqiyatallah Research Center for Gastroenterology and Liver diseases, from 2005 to 2010. All the patients had been diagnosed with HCV. Direct medical care costs for each course of HCV treatment have been calculated based on Purchasing Power Parity Dollar (PPP$). RESULTS: Average direct medical costs for the courses treated with conventional interferon plus ribavirin (INF-RBV) were 4,403 PPP$, and 20,010 PPP$ for peg-interferon plus ribavirin (PEG-RBV) courses. There was an increase of the direct costs in both courses of treatment to achieve Sustain Viral Response (SVR). The costs amounted to 10,072 PPP$ in (INF-RBV) treatment and 34,035 PPP$ in (PEG-RBV). The significant difference between the costs of these two courses of treatment is attributable to high cost of Peg-interferon. This indicates that the medication costs are the dominant costs. CONCLUSIONS: According to the results, total direct medical costs for HCV patients in Iran exceeded 12 billion PPP$ in (INF-RBV) treatment and 55 billion PPP$ in (PEG-RBV).

An overview of colorectal cancer survival rates and prognosis in Asia.

Colorectal cancer is a rapidly rising trend in Asia. The incidence in many Asian countries is on par with the West. Several studies have provided data regarding the survival of patients with colorectal cancer. In Asia, the overall cure rate of colorectal cancer has not improved dramatically in the last decade, 5-year survival remaining at approximately 60%. Colorectal cancer survival time has increased in recent years, but mortality rate remains high. Although studies have determined a number of factors that can predict survival of patients after diagnosis, life expectancy has not been increased dramatically. It seems that among the prognostic factors explored so far, the most important are those that relate to early diagnosis of cancer. Primary detection is feasible since efficient screening modalities are available. Colonoscopic surveillance is needed, especially in subjects at higher risk.

Evaluation of psychological aspects among subtypes of irritable bowel syndrome.

CONTEXT: While some studies have found disparities between subtypes of irritable bowel syndrome (IBS), others did not found such differences. AIM: This study aimed to investigate whether there are differences in psychological features between the subtypes of IBS. SETTINGS AND DESIGN: A cross-sectional study was performed on all consecutive outpatients IBS diagnosed (from Oct. 2010 to Oct. 2011) in Taleghani Hospital gastroenterology clinic, Tehran, Iran. MATERIALS AND METHODS: A total of 153 consecutively diagnosed IBS patients (using Rome III criteria); including 80 constipation-predominant (IBS-C), 22 diarrhea-predominant (IBS-D), and 51 mixed IBS (IBS-M) were asked to complete the Symptom Checklist 90 Revised (SCL-90-R). STATISTICAL ANALYSIS: Pearson's chi-square test was used to compare nominal variables. One-way ANOVA was used to compare continuous variables. RESULTS: Although IBS-C patients were more suffered from psychiatric disorders, there were no statistical differences between mean score of IBS-C, IBS-D, and IBS-M patients regarding to all of SCL-90-R subscales and three global indices including Global Severity Index (GSI), Positive Symptom Distress Index (PSDI) and Positive Symptom Total (PST) (P<0.05). CONCLUSION: Our finding showed that there are no different symptomatic profiles between IBS subtypes.

History of upper gastrointestinal cancers in relatives: a community-based estimate.

AIM: The present study aimed to evaluate the prevalence of positive family history of these cancers in a large population-based sample of Tehran province, capital of Iran. BACKGROUND: Upper gastrointestinal (UGI) cancers (gastric and esophagus cancer) constitute a major health problem worldwide. A family history of cancer can increase the risk for developing cancer and recognized as one of the most important risk factors in predicting personal cancer risk. PATIENTS AND METHODS: This study designed as a cross-sectional survey in general population (2006-2007) of Tehran province. Totally 7,300 persons (age > = 20 years) sampled by random sampling on the basis of the list of postal, of whom 6,700 persons agreed to participate (response rate 92%). Respondents were asked if any first-degree (FDR) or second-degree (SDR) relatives had gastric or esophageal cancer. RESULTS: Totally, 6,453 respondents (48% male) entered to the study. The mean age of responders with positive FH was significantly higher than those with negative FH (P < 0.05). In total, 341 respondents (5.3%) reporting a history of UGI cancers in their relatives, 134(2.1%) in FDRs, and 207(3.2%) in SDRs. CONCLUSION: Our findings showed that the reported prevalence of FH of UGI cancers was relatively low and varied by specific respondent characteristics such as age and sex. However, the estimates of prevalence presented here are likely to be conservative compared with actual prevalence because of self-reported data gathering.

Increased oesophageal cancer mortality rate in Iran.

BACKGROUND AND STUDY AIMS: The aim of this study is to present the mortality trends of oesophageal cancer (EC) in the Iranian population, to provide updated information regarding time trends for this cancer. PATIENTS AND METHODS: We analysed the national death statistics reported by the Iranian Ministry of Health and Medical Education from 1995 to 2004. EC [International Classification of Diseases (ICD-9); C15] were expressed as the annual mortality rates/100000, overall, by sex and by age group (<15, 15-49 and ≥ 50 years of age) and age standardised rate (ASR). RESULTS: The age standardised mortality rate of EC increased dramatically during the study period. EC mortality was higher for males and the mortality rate also increased with age. CONCLUSION: This study provides a comprehensive projection for the burden of death due to EC, indicating that the trend of EC mortality dramatically increased in the recent decade.

Epidemiological features of gastro-esophageal reflux disease in Iran based on general population.

AIM: The aim of this study was to evaluate the epidemiology of GERD base on population study in Tehran providence. BACKGROUND: Gastro-esophageal reflux disease (GERD) is a common and chronic problem. Recent reports from developing countries indicate increment in the incidence and prevalence of the disease over the past. PATIENTS AND METHODS: This study was a cross-sectional household survey conducted from May 2006 to December 2007 in Tehran province, Iran. Participants completed a valid gastro-esophageal reflux Questionnaire. The questionnaire included personal and family characteristics such as age, gender, and educational status. In addition, interviewers asked them regarding 10 GI symptoms. RESULTS: Altogether 18180 individuals participated in this cross-sectional study. The mean ± SD age of participant was 38.7±17.1 and 9072 (49.9%) were women. The prevalence of GERD was 8.85 (8.43-9.26). There was significant relationship between age, sex, marital and educational status with GERD. GERD symptoms were more common in women, older people, individuals with low education and married people. There was overlap between GERD, irritable bowel syndrome (IBS) and uninvestigated dyspepsia (UD). CONCLUSION: According to our finding although the prevalence of GERD in our population is less than other studies, this prevalence is increasing in recent years.

Estimation of average diagnosis and treatment costs of hepatitis C.

AIM: The objective of this study was to estimate the average cost of diagnosis and treatment of hepatitis C among patients based on their treatment regime, during the one course of treatment and six-month after stopping that. BACKGROUND: Hepatitis C virus (HCV) infection is a major cause of liver-related morbidity and mortality worldwide and a major public health problem. PATIENTS AND METHODS: All data for this cross-sectional study were collected from medical records of 200 patients with hepatitis C, who referred to a private gastroenterology clinic between years 2005 through 2009. Information related to the 200 patients was extracted from their medical records and finally, 77 patients of them, who their treatment was not interfering with any other disease entered in this study. Therefore diagnosis and treatment costs of these patients were calculated. Attributable costs were reported as purchasing power parity dollars (PPP$). RESULTS: Mean costs of diagnosis and treatment in one course of treatment and six month after that with standard interferon plus ribavirin (INF-RBV) exceeds 3,850 PPP$ and for patients who treated with peg-interferon plus ribavirin (PEG-RIBV) was 16,494 PPP$. Also in both types of treatment, medication cost was found to be a dominant cost component. CONCLUSION: Hepatitis C represents a very important and potentially costly disease to managed care organizations. Patients with this disease require expensive drug therapies and consume significant health care resources.

Using statistical models to assess medical cost of hepatitis C virus.

AIM: This study compared PR and NB in predicting HCV patient costs. The objective of this study was to predict the direct cost of the HCV patient in Iran. BACKGROUND: Hepatitis C virus (HCV) is a common and expensive infectious disease in Iran. Cost associated with HCV and its complications has not been well characterized. Analysis of cost data is important in providing consistent information to aid budgeting decisions and certain statistical regression models need for prediction mean costs. Poisson regression (PR) and negative binomial regression (NB) are more common in cost prediction study. PATIENTS AND METHODS: This study designed as a cross-sectional clinic base from 2001 to 2010. First treatment period of each patient bring in study. We evaluated the doctor visiting, drugs, and hospitalization and laboratory tests of patients. Cost per person per one treatment period estimated in purchasing power parity dollars (PPP$). The PR is one of the models from general linear models (GLM) for describing count outcomes. The NB is another model from (GLM) as an alternative to the PR model. RESULTS: According to Likelihood ratio test NB was found to be more appropriate than PR (P < 0.001). Genotype, marriage, medication, and SVR were being significant. Genotype 3 versus 1 decreasing cost while marriage, consuming pegasys and SVR increasing. CONCLUSION: Choosing best model in cost data is important because of specific feature of this data. After fitting the best model, analyzing and predicting future cost for patient in different situation is possible.

Four years incidence rate of colorectal cancer in Iran: a survey of national cancer registry data - implications for screening.

INTRODUCTION: Design and implementation of screening programs in each country must be based on epidemiological data. Despite the relatively high incidence of CRC, there is no nationwide comprehensive program for screening in Iran. This study was designed to investigate national CRC data and help to determine guidelines for screening. METHODS: Incidence data used in this study were obtained from Iranian annual of National Cancer Registration report. Age standardized rates (ASR)were calculated using world standard population and were categorized by age, sex, anatomic subsite and morphology of tumor. Data were analyzed using SPSS.V.13 and Open Source Epidemiologic Statistics for Public Health software (OpenEpi v.2.3.1). RESULTS: A quarter of cases were less than 50 years of age. The majority of tumors were detected in the colon. The overall ASR in the four years period was 38.0 per 100000 and was higher for men compared women (P<0.05). Incidence rate of colorectal cancer increased with age. CONCLUSION: Results of present study indicated that incidence of colorectal cancer is relatively high in Iran. Incidence of CRC in people under 50 years and in rectum were reported higher than other countries that related etiologic factors should be investigate in further studies. According to the increasing of ASR after age 50 years, it seems that onset of screening at age 50 would be appropriate.

Irritable bowel syndrome, gastro-oesophageal reflux disease and dyspepsia: overlap analysis using loglinear models.

BACKGROUND AND STUDY AIMS: Irritable bowel syndrome (IBS), gastro-oesophageal reflux disease (GERD) and dyspepsia are three most important gastrointestinal disorders which occur frequently together in patients. This study aims to assess the association between IBS, GERD and dyspepsia by using loglinear model analysis. PATIENTS AND METHODS: This cross-sectional household survey, the purpose of which was to find the prevalence of gastrointestinal symptoms, disorders and the related factors, has been done from May 2006 to December 2007 in Tehran province, Iran. Subjects were interviewed by trained personnel. GERD was diagnosed as the experience of heartburn and/or acid regurgitation at least once a week for the last 3 months. IBS and dyspepsia were diagnosed according to the Rome III criteria. Loglinear models were applied to investigate the simultaneous association between IBS, GERD and dyspepsia. RESULTS: 77.9% of IBS patients had dyspepsia symptoms and 74.7% had GERD symptoms as well at the same time. As for the other two symptoms, 66% of GERD patients were also suffering from dyspepsia. CONCLUSIONS: These three symptoms frequently overlap; the overlap is systematic and not by chance or random.