Risk factors for stomach cancer: a systematic review and meta-analysis / 한국역학회지

OBJECTIVES@#This report provides information on 14 behavioral and nutritional factors that can be addressed in stomach cancer prevention programs. @*METHODS@#PubMed, Web of Science, and Scopus were searched through December 2018. Reference lists were also screened. Observational studies addressing the associations between stomach cancer and behavioral factors were analyzed. Between-study heterogeneity was investigated using the χ2, τ2, and I2 statistics. The likelihood of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. @*RESULTS@#Of 52,916 identified studies, 232 (including 33,831,063 participants) were eligible. The OR (95% CI) of factors associated with stomach cancer were as follows: Helicobacter pylori infection, 2.56 (95% CI, 2.18 to 3.00); current smoking, 1.61 (95% CI, 1.49 to 1.75); former smoking 1.43 (95% CI, 1.29 to 1.59); current drinking, 1.19 (95% CI, 1.10 to 1.29); former drinking, 1.73 (95% CI, 1.17 to 2.56); overweight/obesity, 0.89 (95% CI, 0.74 to 1.08); sufficient physical activity, 0.83 (95% CI, 0.68 to 1.02); consumption of fruits ≥3 times/wk, 0.48 (95% CI, 0.37 to 0.63); consumption of vegetables ≥3 times/wk, 0.62 (95% CI, 0.49 to 0.79); eating pickled vegetables, 1.28 (95% CI, 1.09 to 1.51); drinking black tea, 1.00 (95% CI, 0.84 to 1.20); drinking green tea, 0.88 (95% CI, 0.80 to 0.97); drinking coffee, 0.99 (95% CI, 0.88 to 1.11); eating fish ≥1 time/wk 0.79 (95% CI, 0.61 to 1.03); eating red meat ≥4 times/wk 1.31 (95% CI, 0.87 to 1.96), and high salt intake 3.78 (95% CI, 1.74 to 5.44) and 1.34 (95% CI, 0.88 to 2.03), based on two different studies. @*CONCLUSIONS@#This meta-analysis provided a clear picture of the behavioral and nutritional factors associated with the development of stomach cancer. These results may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Equivalence model: A new graphical model for causal inference / 한국역학회지

Although several causal models relevant to epidemiology have been proposed, a key question that has remained unanswered is why some people at high-risk for a particular disease do not develop the disease while some people at low-risk do develop it. The equivalence model, proposed herein, addresses this dilemma. The equivalence model provides a graphical description of the overall effect of risk and protective factors at the individual level. Risk factors facilitate the occurrence of the outcome (the development of disease), whereas protective factors inhibit that occurrence. The equivalence model explains how the overall effect relates to the occurrence of the outcome. When a balance exists between risk and protective factors, neither can overcome the other; therefore, the outcome will not occur. Similarly, the outcome will not occur when the units of the risk factor(s) are less than or equal to the units of the protective factor(s). In contrast, the outcome will occur when the units of the risk factor(s) are greater than the units of the protective factor(s). This model can be used to describe, in simple terms, causal inferences in complex situations with multiple known and unknown risk and protective factors. It can also justify how people with a low level of exposure to one or more risk factor(s) may be affected by a certain disease while others with a higher level of exposure to the same risk factor(s) may remain unaffected.

Risk factors for stomach cancer: a systematic review and meta-analysis / 한국역학회지

OBJECTIVES@#This report provides information on 14 behavioral and nutritional factors that can be addressed in stomach cancer prevention programs. @*METHODS@#PubMed, Web of Science, and Scopus were searched through December 2018. Reference lists were also screened. Observational studies addressing the associations between stomach cancer and behavioral factors were analyzed. Between-study heterogeneity was investigated using the χ2, τ2, and I2 statistics. The likelihood of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. @*RESULTS@#Of 52,916 identified studies, 232 (including 33,831,063 participants) were eligible. The OR (95% CI) of factors associated with stomach cancer were as follows: Helicobacter pylori infection, 2.56 (95% CI, 2.18 to 3.00); current smoking, 1.61 (95% CI, 1.49 to 1.75); former smoking 1.43 (95% CI, 1.29 to 1.59); current drinking, 1.19 (95% CI, 1.10 to 1.29); former drinking, 1.73 (95% CI, 1.17 to 2.56); overweight/obesity, 0.89 (95% CI, 0.74 to 1.08); sufficient physical activity, 0.83 (95% CI, 0.68 to 1.02); consumption of fruits ≥3 times/wk, 0.48 (95% CI, 0.37 to 0.63); consumption of vegetables ≥3 times/wk, 0.62 (95% CI, 0.49 to 0.79); eating pickled vegetables, 1.28 (95% CI, 1.09 to 1.51); drinking black tea, 1.00 (95% CI, 0.84 to 1.20); drinking green tea, 0.88 (95% CI, 0.80 to 0.97); drinking coffee, 0.99 (95% CI, 0.88 to 1.11); eating fish ≥1 time/wk 0.79 (95% CI, 0.61 to 1.03); eating red meat ≥4 times/wk 1.31 (95% CI, 0.87 to 1.96), and high salt intake 3.78 (95% CI, 1.74 to 5.44) and 1.34 (95% CI, 0.88 to 2.03), based on two different studies. @*CONCLUSIONS@#This meta-analysis provided a clear picture of the behavioral and nutritional factors associated with the development of stomach cancer. These results may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Equivalence model: A new graphical model for causal inference / 한국역학회지

Although several causal models relevant to epidemiology have been proposed, a key question that has remained unanswered is why some people at high-risk for a particular disease do not develop the disease while some people at low-risk do develop it. The equivalence model, proposed herein, addresses this dilemma. The equivalence model provides a graphical description of the overall effect of risk and protective factors at the individual level. Risk factors facilitate the occurrence of the outcome (the development of disease), whereas protective factors inhibit that occurrence. The equivalence model explains how the overall effect relates to the occurrence of the outcome. When a balance exists between risk and protective factors, neither can overcome the other; therefore, the outcome will not occur. Similarly, the outcome will not occur when the units of the risk factor(s) are less than or equal to the units of the protective factor(s). In contrast, the outcome will occur when the units of the risk factor(s) are greater than the units of the protective factor(s). This model can be used to describe, in simple terms, causal inferences in complex situations with multiple known and unknown risk and protective factors. It can also justify how people with a low level of exposure to one or more risk factor(s) may be affected by a certain disease while others with a higher level of exposure to the same risk factor(s) may remain unaffected.

Survival rate and the determinants of progression from HIV to AIDS and from AIDS to the death in Iran: 1987 to 2016

Objective: To examine the prognostic factors of progression from HIV to AIDS and AIDS to the death in people living with HIV/AIDS in Iran. Methods: In this registry-based retrospective cohort study, we recruited 28 873 HIV-infected people from 158 Behavioral Diseases Counseling Centers of Iran. Two outcomes of interest included survival rates from HIV diagnosis to AIDS and from AIDS to the death. We used Kaplan-Meier and Cox regression model to investigate survival rate and factors affecting on survival controlling effect of confounding factors. Results: The one, three, five, and ten-year survival rate from HIV to AIDS were 85%, 73%, 61% and 32%, and for AIDS to death were 90%, 81%, 74% and 55%, respectively. Multivariate Cox regression analysis indicated that the risk of progression from AIDS phase toward death in individuals with CD4 less than 200/mm

Spatial inequalities and predictors of HIV/AIDS mortality risk in Hamadan, Iran: a retrospective cohort study / 한국역학회지

OBJECTIVES: Understanding the geographic variation of HIV/AIDS mortality risk and human immunodeficiency virus (HIV) infection could help identify high-burden areas. The aim of our study was to evaluate the effects of predictors of the time interval between HIV diagnosis to death, while accounting for spatial correlations across counties, and to assess patterns of spatial inequalities in the risk of HIV/AIDS mortality in Hamadan Province, Iran.METHODS: This retrospective study was conducted on 585 patients. The outcome in this study was the time period between the date of HIV/AIDS diagnosis and the date of death. A Weibull regression model with spatial random effects was used.RESULTS: According to multivariate analysis, there were significant associations between age, tuberculosis co-infection, and marital status and the risk of death. In terms of spatial inequalities, a cluster of counties was identified with a somewhat higher death hazard in the north, northwest, northeast, and central regions. Additionally, a cluster with a somewhat lower hazard was identified in the south, southwest, southeast, and west regions.CONCLUSIONS: The spatial pattern of HIV/AIDS death risk could reflect inequalities in access to antiretroviral therapy and public health services. Our results underscore the importance of attention to vulnerable groups in urban areas.

Spatial inequalities and predictors of HIV/AIDS mortality risk in Hamadan, Iran: a retrospective cohort study / 한국역학회지

OBJECTIVES: Understanding the geographic variation of HIV/AIDS mortality risk and human immunodeficiency virus (HIV) infection could help identify high-burden areas. The aim of our study was to evaluate the effects of predictors of the time interval between HIV diagnosis to death, while accounting for spatial correlations across counties, and to assess patterns of spatial inequalities in the risk of HIV/AIDS mortality in Hamadan Province, Iran. METHODS: This retrospective study was conducted on 585 patients. The outcome in this study was the time period between the date of HIV/AIDS diagnosis and the date of death. A Weibull regression model with spatial random effects was used. RESULTS: According to multivariate analysis, there were significant associations between age, tuberculosis co-infection, and marital status and the risk of death. In terms of spatial inequalities, a cluster of counties was identified with a somewhat higher death hazard in the north, northwest, northeast, and central regions. Additionally, a cluster with a somewhat lower hazard was identified in the south, southwest, southeast, and west regions. CONCLUSIONS: The spatial pattern of HIV/AIDS death risk could reflect inequalities in access to antiretroviral therapy and public health services. Our results underscore the importance of attention to vulnerable groups in urban areas.

Spatial inequalities and predictors of HIV/AIDS mortality risk in Hamadan, Iran: a retrospective cohort study / 한국역학회지

OBJECTIVES@#Understanding the geographic variation of HIV/AIDS mortality risk and human immunodeficiency virus (HIV) infection could help identify high-burden areas. The aim of our study was to evaluate the effects of predictors of the time interval between HIV diagnosis to death, while accounting for spatial correlations across counties, and to assess patterns of spatial inequalities in the risk of HIV/AIDS mortality in Hamadan Province, Iran.@*METHODS@#This retrospective study was conducted on 585 patients. The outcome in this study was the time period between the date of HIV/AIDS diagnosis and the date of death. A Weibull regression model with spatial random effects was used.@*RESULTS@#According to multivariate analysis, there were significant associations between age, tuberculosis co-infection, and marital status and the risk of death. In terms of spatial inequalities, a cluster of counties was identified with a somewhat higher death hazard in the north, northwest, northeast, and central regions. Additionally, a cluster with a somewhat lower hazard was identified in the south, southwest, southeast, and west regions.@*CONCLUSIONS@#The spatial pattern of HIV/AIDS death risk could reflect inequalities in access to antiretroviral therapy and public health services. Our results underscore the importance of attention to vulnerable groups in urban areas.

Diagnostic accuracy of cone-beam computed tomography scans with high- and low-resolution modes for the detection of root perforations

PURPOSE: This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars. MATERIALS AND METHODS: The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact (control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables. RESULTS: In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D. CONCLUSION: The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

Using the capture-recapture method to estimate the human immunodeficiency virus-positive population / 한국역학회지

OBJECTIVES: The capture-recapture method was applied to estimate the number of human immunodeficiency virus (HIV)-positive individuals not registered with any data sources.METHODS: This cross-sectional study was conducted in Lorestan Province, in the west of Iran, in 2016. Three incomplete sources of HIV-positive individuals, with partially overlapping data, were used, including: (a) transfusion center, (b) volunteer counseling and testing centers (VCTCs), and (c) prison. The 3-source capture-recapture method, using a log-linear model, was applied for data analysis. The Akaike information criterion and the Bayesian information criterion were used for model selection.RESULTS: Of the 2,456 HIV-positive patients registered in these 3 data sources, 1,175 (47.8%) were identified in transfusion center, 867 (35.3%) in VCTCs, and 414 (16.8%) in prison. After the exclusion of duplicate entries, 2,281 HIV-positive patients remained. Based on the capture-recapture method, 14,868 (95% confidence interval, 9,923 to 23,427) HIV-positive individuals were not identified in any of the registries. Therefore, the real number of HIV-positive individuals was estimated to be 17,149, and the overall completeness of the 3 registries was estimated to be around 13.3%.CONCLUSIONS: Based on capture-recapture estimates, a huge number of HIV-positive individuals are not registered with any of the provincial data sources. This is an urgent message for policymakers who plan and provide health care services for HIV-positive patients. Although the capture-recapture method is a useful statistical approach for estimating unknown populations, due to the assumptions and limitations of the method, the population size may be overestimated as it seems possible in our results.

Using the capture-recapture method to estimate the human immunodeficiency virus-positive population / 한국역학회지

OBJECTIVES: The capture-recapture method was applied to estimate the number of human immunodeficiency virus (HIV)-positive individuals not registered with any data sources. METHODS: This cross-sectional study was conducted in Lorestan Province, in the west of Iran, in 2016. Three incomplete sources of HIV-positive individuals, with partially overlapping data, were used, including: (a) transfusion center, (b) volunteer counseling and testing centers (VCTCs), and (c) prison. The 3-source capture-recapture method, using a log-linear model, was applied for data analysis. The Akaike information criterion and the Bayesian information criterion were used for model selection. RESULTS: Of the 2,456 HIV-positive patients registered in these 3 data sources, 1,175 (47.8%) were identified in transfusion center, 867 (35.3%) in VCTCs, and 414 (16.8%) in prison. After the exclusion of duplicate entries, 2,281 HIV-positive patients remained. Based on the capture-recapture method, 14,868 (95% confidence interval, 9,923 to 23,427) HIV-positive individuals were not identified in any of the registries. Therefore, the real number of HIV-positive individuals was estimated to be 17,149, and the overall completeness of the 3 registries was estimated to be around 13.3%. CONCLUSIONS: Based on capture-recapture estimates, a huge number of HIV-positive individuals are not registered with any of the provincial data sources. This is an urgent message for policymakers who plan and provide health care services for HIV-positive patients. Although the capture-recapture method is a useful statistical approach for estimating unknown populations, due to the assumptions and limitations of the method, the population size may be overestimated as it seems possible in our results.

Seroprevalence of Brucellosis in Human Immunodeficiency Virus Infected Patients in Hamadan, Iran

OBJECTIVES: Brucellosis is a systemic disease with a wide spectrum of clinical manifestations. This study aimed to determine the seroprevalence of brucellosis in human immunodeficiency virus (HIV) infected patients in Hamadan Province in the west of Iran. METHODS: A total of 157 HIV-infected patients were screened through standard serological tests, including Wright’s test, Coombs’ Wright test, and 2-mercaptoethanol Brucella agglutination test (2ME test), blood cultures in Castaneda media, and CD4 counting. Data were analyzed using Stata version 11. RESULTS: Wright and Coombs’ Wright tests were carried out, and only 5 (3.2%) patients had positive serological results. However, all patients had negative 2ME results, and blood cultures were negative for Brucella spp. Moreover, patients with positive serology and a mean CD4 count of 355.8 ± 203.11 cells/μL had no clinical manifestations of brucellosis, and, and the other patients had a mean CD4 count of 335.55 ± 261.71 cells/μL. CONCLUSION: Results of this study showed that HIV infection is not a predisposing factor of acquiring brucellosis.

association between maternal serum magnesium level and pregnancy outcomes

Objective: To find out the association between maternal serum magnesium levels and preterm labor, neonatal weight, and the duration of labor

Methodology: This observational study was conducted at the Social Security Hospital in Hamadan City, the west of Iran, from October 2014 to January 2015. The case group included 32 preterm labour women [28 to <37 weeks pregnant women] and the control group included 32 term pregnant women. The maternal serum magnesium level, the duration of the first and second stage of labor were measured in both the groups

Results: The duration of gestational age was significantly lower in cases compared to controls [P<0.001]. The average birth weight was significantly lower in the case group than in the control group [P<0.001]. The mean [SD] level of maternal serum magnesium was 2.12 [0.27] and 1.95 [0.16] in the control and case groups, respectively [P=0.004]. The duration of the first stage of labor was lower in the case group than in the control group [P=0.001]. There was a positive correlation between maternal serum magnesium level and gestational age [0.3305] and neonatal weight [0.2975] and a negative correlation between maternal serum magnesium level and the duration of the first and second stage of labor [-0.0184 and -0.0445, respectively]

Conclusion: Low level of maternal serum magnesium is associated with poor pregnancy outcomes, including preterm labor and low birth weight

Successful pregnancy and live birth after intrauterine administration of autologous platelet-rich plasma in a woman with recurrent implantation failure: a case report

Background: platelets contain a significant amount of growth factors that have positive effects on local tissue repair and endometrial receptivity

Case: here we present a 45-yr-old woman with primary infertility and two failed in vitro fertilization [IVF] cycles who was candidate to receive donor eggs. Five consecutive frozen-thawed embryo transfer cycles with good quality embryos were performed within 2 yr. With the diagnosis of recurrent implantation failure [RIF], the patient was treated for improving endometrial receptivity with intrauterine administration of autologous platelet-rich plasma [PRP], 24 hr before embryo transfer. The patient gave birth to a healthy baby boy weighing 2350 gr in the cesarean section

Conclusion: extensive literature search suggests that this is the ?rst successful pregnancy after administration of PRP in a woman with RIF. Local administration of PRP before embryo transfer may play a vital role in successful implantation

Prediction of Kidney Graft Rejection Using Artificial Neural Network / 대한의료정보학회지

OBJECTIVES: Kidney transplantation is the best renal replacement therapy for patients with end-stage renal disease. Several studies have attempted to identify predisposing factors of graft rejection; however, the results have been inconsistent. We aimed to identify prognostic factors associated with kidney transplant rejection using the artificial neural network (ANN) approach and to compare the results with those obtained by logistic regression (LR). METHODS: The study used information regarding 378 patients who had undergone kidney transplantation from a retrospective study conducted in Hamadan, Western Iran, from 1994 to 2011. ANN was used to identify potential important risk factors for chronic nonreversible graft rejection. RESULTS: Recipients' age, creatinine level, cold ischemic time, and hemoglobin level at discharge were identified as the most important prognostic factors by ANN. The ANN model showed higher total accuracy (0.75 vs. 0.55 for LR), and the area under the ROC curve (0.88 vs. 0.75 for LR) was better than that obtained with LR. CONCLUSIONS: The results of this study indicate that the ANN model outperformed LR in the prediction of kidney transplantation failure. Therefore, this approach is a promising classifier for predicting graft failure to improve patients' survival and quality of life, and it should be further investigated for the prediction of other clinical outcomes.

Comparison of salivary PH, buffering capacity and alkaline phosphatase in smokers and healthy non-smokers

Objectives: Saliva contains alkaline phosphatase [ALP]-a key intracellular enzyme related to destructive processes and cellular damage-and has buffering capacity [BC] against acids due to the presence of bicarbonate and phosphate ions. Smoking may have deleterious effects on the oral environment due to pH changes which can affect ALP activity. This study aimed to evaluate the salivary pH, BC and ALP activity of male smokers and healthy non-smokers

Methods: this retrospective cohort study took place between August 2012 and December 2013. A total of 251 healthy male non-smokers and 259 male smokers from Hamadan, Iran, were selected. Unstimulated whole saliva was collected from each participant and pH and BC were determined using a pH meter. Salivary enzymes were measured by spectrophotometric assay

Results: mean salivary pH [7.42 +/- 0.48 and 7.52 +/- 0.43, respectively; P = 0.018] and BC [3.41 +/- 0.54 and 4.17 +/- 0.71; P = 0.001] was significantly lower in smokers compared to non-smokers. Mean ALP levels were 49.58 +/- 23.33 IU/L among smokers and 55.11 +/- 27.85 IU/L among non-smokers [P = 0.015]

Conclusion: significantly lower pH, BC and ALP levels were observed among smokers in comparison to a healthy control group. These salivary alterations could potentially be utilised as biochemical markers for the evaluation of oral tissue function and side-effects among smokers. Further longitudinal studies are recommended to evaluate the effects of smoking on salivary components

The Association between Body Mass Index and Hot Flash in Midlife Women: A Meta-analysis

OBJECTIVES: The association between body mass index (BMI) and hot flash risk has not been specifically clarifies yet. This meta-analysis was, therefore, conducted to estimate the association between overweight and obesity and hot flash risk. METHODS: We searched PubMed, Web of Science, and Scopus for observational studies addressing the association between BMI and hot flash until August 2015. Data were independently extracted and analyzed using 95% odds ratio (OR), and confidence intervals (CI) based on the random-effects models. RESULTS: We identified 2,244 references and conducted seven studies with 4,219 participants. The association between hot flash and overweight was estimated 1.13 (95% CI: 0.97-1.32) and that of obesity was estimated 1.79 (95% CI: 1.52-2.11). No evidence of heterogeneity and publication bias was observed. CONCLUSION: This meta-analysis demonstrated that, though not to a great extent, obesity does increase the risk of hot flash. The findings from this meta-analysis indicated that obesity is associated with an increased risk of hot flash. Further large prospective cohort studies are required to provide convincing evidence as to whether or not BMI is associated with an increased risk of hot flashes.

Prevalence of nasopharyngeal carriage of Streptococcus pneumonia in Iran: a meta-analysis

Background: Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide. Several studies have explored the nasopharyngeal carriage of S. pneumonia in Iran. This meta-analysis is aimed at exploring the overall prevalence of nasopharyngeal carriage of S. pneumoniae among healthy children and its resistance to antibiotics

Method: We have systematically reviewed published studies from international databases [PubMed, Web of Science, and Scopus] and national databases [Iranmedex, Magiran, Medlib, SID and Irandoc] and reference lists of articles published up to May 2015. Only cross-sectional studies supported with sensitivity test on samples collected from nasopharyngeal area were included and heterogeneity was assessed using Q-test and I[2] test statistic. Publication bias was explored using the Egger's and Begg's tests and the funnel plot. The overall prevalence of analyzed data were reported with 95% confidence intervals [CI] using the random-effects model

Results: A total of 16 studies were included in the final analysis. The pooled prevalence of S. pneumoniae nasopharyngeal carriage was 18% [95% CI: 14% - 23%]. Antibiotic resistance rates were 26% [95% CI: 15% - 37%] to penicillin, 30% [95% CI: 10% - 49%] to erythromycin and 34% [95% CI: 10% - 57%] to tetracycline respectively

Conclusion: This study could be able effectively estimate the overall prevalence of nasopharyngeal carriage of S. pneumoniae and its antibiotics resistance rate among healthy children in Iran. In addition, the findings evidenced the role of pneumococcal vaccination in reducing the prevalence of S. pneumoniae carriage among healthy children in Iran

Estimating the potential impact fraction of hypertension as the main risk factor of stroke: application of the distribution shift method

Few published studies have assessed the impact of quantitative risk factors such as high blood pressure on stroke. The aim of this study was to quantify the potential impact fraction [PIF] of hypertension on stroke in Hamadan Province, western Iran. Avoidable burden of stroke associated with high blood pressure was calculated using distribution shift at different scenarios. Data on the prevalence of high blood pressure among residents of Hamadan province older than 19 years were extracted from non-communicable diseases risk factors surveillance system in 2009. Five mmHg hypothetical reduction in systolic blood pressure above 140 mmHg, leads to 3.5% [PIF = 0.035] reduction in the total burden to stroke. This value may reach 7%, if systolic blood pressure decreases 10 mmHg. In addition, 5 mmHg hypothetical reduction in diastolic blood pressure above 82 mmHg, leads to 4.87% reduction in the total burden to stroke. PIF more than 10 mmHg modification on distribution of diastolic blood pressure was estimated as 9.38%. According to these findings, policy makers are advised to implement interventions on hypertension based on the distribution shift method rather than the proportion shift one