Iranian Journal of

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Background and Objectives: Missing data exist in many studies, e.g. in regression models, and they decrease the model's efficacy. Many methods have been suggested for handling incomplete data: they have generally focused on missing outcome values. But covariate values can also be missing.
Materials and Methods: In this paper we study the missing imputation by the EM algorithm and auxiliary variable and compare the result with case-complete analysis in a logistic regression model dealing with factors that influence the choice of the delivery method.
Our data came from a cross-sectional study of factors associated with the choice of the delivery method in pregnant women. The sample size in this cross-sectional study was 365 and the data were collected through interviews, using questionnaires covering several demographic variables, delivery history, attitude, and some social factors. We used standard deviations to compare the efficiency of the two methods.
Results: The results show that maximum likelihood analysis by EM algorithm is more effective than case-complete analysis.
The problem of missing data is common in surveys and it causes bias and decreased model efficacy. Here we show that the EM algorithm for imputation in logistic regression with missing values for a discrete covariate is more effective than case-complete analysis.
Conclusion: On the other hand if missing values occur for a continuous covariate then we have to use other methods or change the variable into a discrete one.

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Background & Objectives: Although Cox regression is commonly used to detect relationships between patient survival and demographic/clinical variables, there are situations where parametric models can yield more accurate results. The objective of this study was to compare two survival regression methods, namely Cox regression and parametric models, in patients with gastric carcinoma registered at Taleghani Hospital, Tehran.
Methods: Using data from 746 patients who had received care at Taleghani Hospital from February 2003 through January 2007, we compared survival rates between different patient groups with both parametric methods and Cox regression models. The former group included Weibull, exponential and log-normal regression we used the Akaike Information Criterion (AIC) and standardized parameter estimates to compare the efficiency of various models. All the analyses were performed with the SAS software and the level of significance was set at P< 0.05.
Results: The results showed a significantly higher chance of survival in the following subgroups: those with age at diagnosis < 35 years, lower tumor size and those without metastases (P< 0.05). According to AIC, Cox and exponentials model are similar in multivariate analysis but in univariate analysis parametric models are more efficient than Cox, except in the case of tumor size. Log-normal appears to be the best model.
Conclusions: Cox and exponential models have similar performance in multivariate analysis. However, it seems that there is no single model that performs substantially better than others in univariate analysis. The data strongly supported the log-normal regression among parametric models it can give more precise results and can be used as an alternative for Cox in survival analysis of patients with gastric cancer.

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Background and Objectives: There are conflicting data on the effects of different types of fat on aortic atherosclerosis. This study used Wister rats to compare the atherogenic effects of a standard diet with a diet containing fish oil and another diet containing mixed oils (typical of the current consumption pattern in Iran).
Methods: Thirty female Wistar rats were randomly assigned to three diet groups: a standard diet (containing soy bean-oil as the only dietary fat), a diet containing fish oil and another diet which contained mixed oils and was designed on the basis of the current fat consumption pattern in Iran (butter, hydrogenated vegetable oil and sunflower oil). Mothers in each group were fed the same diet during pregnancy and lactation the litters were also weaned onto the same diet. Aortic samples were taken from the offspring at the time of weaning and puberty. Data were analyzed using SPSS software Kruskal-Wallis test was applied for comparison among groups.
Results: Rats that were fed soy bean oil showed less extensive fatty streaks and intimal thickening of aorta on weaning and at puberty. Rats fed fish oil and mixed oils showed more atherosclerosis lesions compared to those receiving soy bean oil.
Conclusions: It seems that diets with an omega-3 to omega-6 ratio of 0.6 can enhance aortic atherosclerosis. Diets with an Iranian fat consumption pattern also increase aortic atherosclerotic lesions because they contain substantial amounts of saturated fat.

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Background & Objective: Malnutrition is one of the main nutritional problems among children under 5 years especially in developing countries. The effects of malnutrition in this range of age group includes disorder of mental and physical growth and development, increase in the morbidity and mortality, decrease of the learning capacity. A detailed epidemiological picture of the prevalent malnutrition status among children under 5 years in different regions of Iran enables health policy makers to identify priorities, establish political commitment and design appropriate interventional programs to prevent and control malnutrition and improve nutritional status of children. To determine the prevalence rate of malnutrition among children under 5 years.
Methods: Demographic data, weight and height of 34200 Iranian children between 0-72 months old in 28 provinces of the country in 2005 year based on a cluster sampling were gathered. The subjects' weight and height were measured by trained staff. Prevalence of underweight, stunting, and wasting indicators was determined by measuring the weight and height of subjects in urban and rural areas. EPI6 statistical software, version b6/04, was used for all statistical analyses.
Results: 4.7% of the children aged less than five years suffered from stunting (95% CI: 4.5- 4.9%) The prevalence of this type of malnutrition among urban children is significantly less than rural children (95% CI: 3.1- 3.5% and 6.5-7.1% respectively). Meanwhile the prevalence of underweight was 5.2% in the country (95% CI: 5.1-5.4% while the prevalence of this type of malnutrition was significantly less among urban children than those in rural ones. Moreover, the prevalence of wasting was 3.7% (95%CI: 3.5-3.9%) and there was a significant difference in this regard between the urban and rural children. Thus this indicator was significantly higher among urban children than those in rural areas (95%CI: 3.8-4.3% and 3.0-3.5% respectively).
Conclusion: The results of the study show that the prevalence of protein-energy malnutrition was low among Iranian children under five years old. In comparison with previous studies, it is felt that there has been a prudent decrease in all malnutrition in all levels. However, there were significant differences in the prevalence of malnutrition in different provinces, which has resulted in the differences in their developmental stages as well. It appears that subjective strategies are required to improve the nutritional and health status among children under five in all provinces.

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Background & Objectives: Self-poisoning is one of the oldest and most common forms of self-harm and a frequent incident of referring to hospital poisoning wards. Especially for cases involving suicidal intention, incidence and secular trends are closely related to the types of drugs and substances available.
Methods: This research was conducted in 2004 to examine the epidemiology of attempted suicide by poisoning and the total case load of hospital poisoning wards. The study involved 723 poisoning cases in major referral hospitals located in cities of Tehran, Shiraz, Tabriz, Kermanshah, Mashad, and Esfahan.
 Results: Seventy-six percent of the cases were identified as suicide attempts the most common substances used for this purpose were medications (80.9%), chemical poisons (10.7%), psychotropic substances (5.1%), and other chemicals such as detergents and bleaching agents (3.2%). Notably, about a third of the cases were due to benzodiazepine ingestion. The most common cause of accidental poisoning was psychotropic substance overdose (44.2%), predominantly opioids.
 Conclusions: Considering the prevalent use of medications and psychotropic agents in suicide attempts and the relatively high proportion of suicide cases in hospital poisoning wards indicating strategies for primary, secondary and tertiary prevention of this common and urgent problem.

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Background and objectives: People with thalessemia and chronic renal failure on maintenance hemodialysis are prone to blood-born infections, especially hepatitis C due to the long-term transfusion. Recently, hepatitis C has been one of the main health concerns in these patients. The aim of this study was to determine the prevalence of hepatitis C and its risk factors in these groups of patients in Kerman province of Iran.
Methods: HCV RNA in blood sample of 384 patients (203 hemodialysis cases and 181 thalassemia cases) was evaluated.
Results: One hundred thirty (130) out of 384 were infected by HCV. Infected male was predominant (83%).
Conclusions: It seems that the frequency of hepatitis C infection in Kerman is higher than the other provinces of Iran. Therefore more attention should be paid to screen of blood before transfusing for these group of patients.

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Background & Objectives: The repression of retinoic acid receptor-β2 (RARβ2) expression is a concerning aspect of breast cancer, which is often induced by hypermethylation at promoter of the gene. We aimed to explore the correlation of plasma folate, vitamin B12 and total homocysteine (tHcy) levels with hypermethylation status of RARβ2 gene among Iranian breast cancer patients.
Methods: The hypermethylation status was investigated in 137 specimens tissues from primary breast cancer patients aged 28-85 years thorough methylation-specific PCR.
Results: Hypermethylation at RARβ2 gene was observed in 36.5 %. The hypermthylated RARβ2 associated with younger age at diagnosis and negative family history of breast cancer. The plasma level of folate was found lower in cases aged ≥48 years with hypermethylated RARβ2 gene (P<0.05). In contrast the level of tHcy was shown higher in cases aged <48 y (P<0.05). The risk of hypermethylation at RARβ2 gene increased with low plasma levels of folate (OR=0.21, 95%CI: 0.05-0.88) and vitamin B12 (OR=0.04, 95%CI: 0.01-0.92) and high plasma level of tHcy (OR=7.55, 95%CI: 1.07-25.7) in cases older than 48y.
Conclusions: Low plasma levels of folate, Vitamin B12 and high plasma level of total homocysteine could have important roles as prognostic factors in hypermethylation status of RARβ2 gene in breast cancer.

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Background and Objectives: Anaphylactic reaction is one of the most important transfusion anaphylactic reactions in medicine. During transfusion if Individuals with IgA deficiency take blood which containing IgA, they would suffer from severe allergic reaction. Since there is a little known about this in different ethnic groups in Iran we have decided to evaluate this issue in Sistan & Baluchestan province in Iran. Methods: During one year, blood samples were collected from 3837 volunteer blood donors. Then the serum samples were tested for IgA titer by nephlometry and SRID techniques.
Results: According to our results only, one donor (0.026%) was found to have IgA less than 5mg/dl and 34(0.9%) cases had IgA: 5-30 mg/dl while 3798(99%) had IgA more than 30mg/dl.
Conclusions: With regards to very low prevalence of IgA deficiency in blood donors in Southeast part of Iran, it seems that anaphylactic reactions most likely be due to other factors in the individuals that receive blood products.

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Background & Objective: Road traffic injuries (RTIs) are the leading cause of burden of disease in Iran. Determination of road safety situation as a complex issue can reduce injury and death rates on roads. This study aimed to determine the effective indicators of road safety and introduce approaches to combine different indicators for implementation index to assess the road safety situation of Iran.
Methods: In this analytical and comparative study eleven indicators which have been categorized in nine dimensions were employed. Indicators normalized with maximum and minimum measures and three approaches were used to calculate the index. In order to put index into practice, data collected from eleven Association of Southeast Asian Nations (ASEAN) countries. Comparison was performed by al-Haji index which has been development for ASEAN countries in 2007.
Results: The findings indicated that weighted index results based on previous experience are similar to al-Haji index and correlations between them are statistically significant (r=0.997). This study showed a remarkable difference between some selected countries. Singapore and Brunei have the best index records, Malaysia, Thailand, Philippines have the medium index records, Iran (with score 36.81), Indonesia, Myanmar, Cambodia, Vietnam and Laos have the least index records.
Conclusions: Findings of study indicate that Iran needs implementation composed index of risk factors to prevent RTIs and to assess better performance on road safety. The road safety in our country is still far from the desired condition therefore, more attention is necessary to be done to reduce injury and mortality rates in Iran.

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Methods: Thirty female Wistar rats were randomly allocated to three dietary groups: a standard diet (containing soy bean-oil), diet containing fish oil and diet containing mixed oil which was designed based on Iranian population fatty acid intake. Dams in each group were fed one of the diets during pregnancy and lactation and the pups were also weaned onto the same diet. Fasting serum glucose (Photometry) and insulin (ELISA) in pups were assessed and insulin sensitivity calculated on puberty.
Results: Fasting serum insulin in fish oil-fed group was significantly less than two other groups (P=0.018) and insulin sensitivity in fish oil-fed rats was significantly more than two other groups (P=0.002).
Conclusions: It seems a diet containing fish oil (rich in long chain omega-3 fatty acids) causes more insulin sensitivity comparing to diet containing soy bean oil (rich in omega-6 fatty acids) and diet with Iranian population fatty acid intake pattern (rich in saturated fatty acids).

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Background & Objectives: Cholera is always being considered as a public health threat in poor and developing countries. However outbreaks of cholera are not very common in central area of Iran in 2008 district health authority reported a cluster of diarrhea cases. We investigated this cluster to identify the etiological agent, source of transmission and propose control measures.
Methods: We analyzed the data of total of 1219 patients with colorectal cancer who registered between 1 January 2002 to 1 October 2007. Data were analyzed using univariate and multivariate Accelerated Failure Time (AFT) parametric survival model with frailty, utilizing STATA statistical software.
Results: In the univariate analysis for age at diagnosis, gender, marital status, race and education level, the survival of patients with colon cancer were approximately between half to one fourth and for BMI, alcohol history, Inflammatory Bowel Disease (IBD), familial history of cancer and the pathologic stage of tumor, the survival of patients with colon cancer were significantly (between 0.12 to 0.56 times) shorter than those patients with rectal cancer. In the multivariate analysis, for age at diagnosis (45-65 years), there was significant difference between colon and rectum cancer. But for BMI, alcohol history, IBD and pathologic stage there were not significant differences. The adjusted survival and 1, 2, 3, 4 and 5 year survival of patients with rectal cancer were better than those with colon cancer.
Conclusions: Site-specific evaluation of colon and rectum could give a better perspective of factors affecting these cancers. It may help to design of clinical trials, better diagnosis of diseases and optimal administration of specific treatments.

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Background & Objectives: The rate of suicide varies amongst different parts of Iran. Since there is little knowledge about the risk factors for suicide attempts we carried out this study to determine the status of psychiatric disorders and risk factors of repeated attempted suicide in suicide attempters whom admitted to poisoning emergency in Isfahan, Iran.

Methods: Patients with having attempt to suicide, admitted to emergency ward in Khorshid Hospital in Isfahan and were interviewed by a trained psychiatrist during 2009 year. Interview was based on DSM-IV.

Results: Participants consisted of 703 individuals (424 of them were female) with mean age of 25.9±9.7. One hundred twenty five (125) had positive family history of suicide attempt, 501 people were first time suicide attempters, 106 second, 58 third, and the others were forth time or more suicide attempters. Bipolar spectrum disorders, unipolar depression and adjustment disorders were the more frequents psychiatric disorders respectively. Age, family history of suicide, kind of diagnosed psychiatric disorder and method of attempted suicide were meaningfully related to mean of attempt suicide frequency.

Conclusion: Bipolar spectrum disorders, especially recurrent depressive episodes is the major risk of repeated suicide attempt and co-morbidity of another psychiatric disorders increase highly the risk of suicide reattempt.

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Background & Objectives: Sterpococcosis/lactococcosis is an economically important zoonotic disease in aquaculture industry particularly in farmed rainbow trout. The annual loss due to the disease is tens millions US dollars. This descriptive study was aimed to identify the regional distribution of these economically important bacterial diseases in 50 farmed trout in Charmahal-va-Bakhteyari (25 fish farms) and Kohgiloyeh-va-Boyerahmad (25 fish farms) provinces plus detection of the relative prevalence of the presence of 20 risk factors.
Methods: Each trout farm was clinically inspected to identify the risk factors, followed by sampling of the clinically affected fish for bacteriological and molecular studies.
 Results: The results showed that form 25 fish farms examined in Charmah-va-Bakhteyari, 56.% (13 fish farms) were affected with Lactococcus garvieae and 20%(5 fish farms) were affected with Streptococcus iniae, while these were 64% (16 fish farms) and 12% (3fish farms) in Kohgiloyeh-va-Boyerahmad, respectively. The relative prevalences of the presence of 10 and 16 risk factors were above 80% and 50% in the trout farms of both provinces.
Conclusion: These results clearly demonstrated that occurrence of streptococcosis and lactococcosis in farmed trout has a wide regional distribution in trout farms of these provinces and the presence of risk factors are remarkable in the examined fish farms.

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  Background & Objectives: Since the human diet is a combination of different foods and that this combination will affect the body differently from when these foods are received separately, the evaluation of dietary patterns is of great importance. The primary aim of this study was to examine the association between dietary patterns during pregnancy and postpartum depression.

  Methods : This population-based, cross-sectional study was conducted on 771 women who attended the Ardabil's health care network. This study was carried out in a period of 4 months. In this study, systematic random sampling was used. Dietary data was collected using the Willett-format Dish-based 106 items Semi-quantitative Food Frequency Questionnaire (DS-FFQ) which was designed and validated specifically for Iranian adults. Dietary patterns were identified through exploratory factor analysis based on 34 predefined food groups. In the present study, individuals who obtained a rating of 13 or higher were considered to be suffering from postpartum depression. Logistic regression was used to estimate OR and 95% CI for postpartum depression in each quartile of patterns.

  Results : In the present study, three dietary patterns were identified: mixed dietary pattern, semi-healthy dietary pattern, and fruits and vegetables dietary pattern. The last one was significantly associated with a reduced risk of postpartum depression.

  Conclusion : The findings show that a diet of fruits and vegetables during pregnancy is associated with a reduction in the risk of PPD. Additional studies are recommended to confirm these finding.

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  Background and Objectives : recent years, considerable attention has been paid to statistical models for classification of medical data according to various diseases and their outcomes. Artificial neural networks have been successfully used for pattern recognition and prediction since they are not based on prior assumptions in clinical studies. This study compared two statistical models, artificial neural network and logistic regression, to predict the survival of patients with breast cancer.

  Methods: Two models were applied on cancer registry data, Kerman, southeast of Iran, to predict survival. The data of 712 breast cancer patients in the age group 15 to 85 years was used in this study. The logistic regression and three-layer perceptron neural network models were compared in terms of predicting the survival. Sensitivity, specificity, prediction accuracy, and the area under ROC curve were used for comparing the two models.

  Results : In this study, the sensitivity and specificity of logistic regression and artificial neural network models were (0.594, 0.70) and (0.621, 0.723), respectively. Prediction accuracy and the area under ROC curve for two models were (0.688, 0.725) and (0.70, 0.725), respectively.

  Conclusion: Although there were insignificant differences in the performance of the two models for predicting the survival of the patients with breast cancer, the corresponding results of artificial neural network were more appropriate for predicting survival in such data.

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  Background and Objectives : Influenza is an acute, contagious, and zoonotic viral disease. It is caused by a virus of the Orthomyxoviridae family. This very infectious is caused by different subtypes of type A influenza virus in the poultry, turkey, and many other birds. In this study, the serum status of rural domestic poultry was investigated for influenza subtype H9N2.

 Methods: This cross sectional study was done from August to October in 2013 in Iranian villages through sampling domestic poultry. The sampling was accidental and was done based on the GIS 11-digit code. In each village, blood samples were taken from at least 28 birds from different species. Then, ELISA was used for screening followed by the HI test. A total of 397 villages and 11546 birds (10145 chickens, 1413 ducks, 397 turkeys, 10 pigeons, and 175 other species) were sampled.

  Results : Three hindered and forty nine (88%) out of 397 villages were positive on ELISA. In addition, 341 villages (86%) were positive and 56 (14%) were negative on the HI test for antibody titers. Also, among the considered variables, weather was a risk factor and the prevalence was significantly lower in villages near the rivers, lagoons and lakes (up to a radius of 3 Km).

  Conclusion: The high seroprevalence of influenza H9N2 in rural domestic poultry indicates that the disease is becoming endemic. As there is no eradication policy for influenza H9N2 in Iran, using effective vaccines can reduce the infection with influenza virus in domestic and rural poultry.

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  Background and Objectives : I In the classification proposed by Holmes and colleague, the stress of divorce has been identified as the greatest one among all types of stresses in the world. This global stress is on the rise in Iran so that Iran is the fourth country in this regard. The purpose of this study was to present a comprehensive and systematic model of the factors affecting divorce in the country.

 Methods: The method used in this study was qualitative and a type of meta-study known as meta-synthesis. The study population consisted of all relevant papers with research topics. In order to perform the research, after designing research questions, a systematic search was carried out based on relevant key words (divorce, spousal conflict, separation) from the databases Science Direct, IEEE, Emerald, ISC, IRANDOC, SID, Civilica, Scopus and also Google Scholar between 1365 to early 1392 .

  Results : By reviewing 61 articles out of 8477 primary ones, both foreign and domestic, researchers identified 15 dimensions and 64 components as the factors affecting divorce. Based on these factors, the final integrated model was presented and validated.

  Conclusion: The results of this study can be used as a basis for planning pre-marriage counseling programs by identifying factors affecting divorce on the basis of all available resources in the years 1365 to 1392.

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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: Out-of-pocket (OOP) expenditure is one of the main indicators in health financing, indicating risk pooling and risk spreading. This study aimed to calculate the total health expenditure (THE), the THE per capita and share of OOP in each province from 2008 to 2014.

Methods: The present cross-sectional study was done by collecting provincial health expenditure data from public and private organizations during 2008-2014. The data were approved by board of trustees or board of directors in each organization. The relevant data on household health expenditures were collected from the Statistical Centre of Iran, as well.

Results: Even though the absolute monetary value (IRR) of OOP in the study years showed an increase, it decreased from 51.9% in 2008 to 40.6% in 2014 in terms of share. The absolute monetary value (IRR) of THE and THE per capita increased about 3.5 times in all provinces. So, during the study years, Tehran and Sistan and Baluchistan Provinces had the highest and lowest absolute monetary values (IRR) in THE per capita and this difference increased from 2.12 million Rials in 2008 to 10.56 million Rials in 2014.

Conclusion: Although the share of OOP decreased in all provinces in the country during the study years, it is still far from the objective of the national development plans (30% OOP). In order to improve the study indices and reduce the provincial inequity, it is suggested to put more emphasis on prepaid-based mechanisms, insurance system improvement, and equitable distribution of financial resources should be compatible with the deprivation of the area and its infrastructures.

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Background and Objectives: One of the fair financial protection indexes in monitoring health systems is estimating impoverishment due to health care expenditure. The aim of this study was to measure the percentage of households impoverished due to out-of-pocket(OOP) payments in Iran provinces during2008-2014.

Methods: The present retrospective descriptive study was conducted based on data from Household Income and Expenditure Survey in both rural and urban households. The proportion of households that moved below the poverty line after deducting health care costs was calculated. The poverty line for urban and rural areas was calculated based on household food expenditure. To show the provincial dispersion of the index during this period, the coefficient of variation(CV) was used. Mann-WhitneyU test and descriptive statistics were used to analyze the data.

Results: Golestan, North Khorasan, and Kerman had the highest impoverishment rate due to OOP Moreover, Alborz, Tehran, and Bushehr had the lowest impoverishment rate due to OOP. In all the study years, the average impoverishment due to OOP was significantly higher in rural areas compared to urban areas. Provincial dispersion CV for this index did not have a constant trend.

Conclusion: The results of this study provide valuable evidence for policy-makers to estimate the impact of OOPs on household impoverishment. In order to reduce impoverishment due to OOP, supportive targeted interventions for vulnerable and low-income households, especially rural households, in addition to decreasing the share of OOP, are essential, such as developing health subsidies and improving insurance service packages.