Showing 9 results for Mansournia
K Holakouie Naieni, A Ostovar, A Danesh, S Sadjedinejad, L Ghalichee, Gh Moradi, Ma Mansournia, Ss Hashemi Nazari,
Volume 6, Issue 2 (22 2010)
Abstract
Background and objective: The nested case-control study has become popular as an efficient alternative to the full-cohort design. This study compares the results of a nested case-control analysis approach with the full cohort analysis.
Methods: A cohort of 276 subjects (new cases from a TB registry) was used for this study. Cox Regression model was used for the full cohort analysis. In order to do the nested case-control analysis, for each death, three random controls were selected from those who did not suffer from the outcome at the time of the outcome took place. Case control data was analyzed by the conditional logistic regression model.
Results: Results from both cohort and nested case-control analyses show that treatment group is the only variable that affects on the outcome. Gender, place of residence, and age has no effect on the outcome. For binary exposure variables with trivial effects (e.g. Gender and place of residence), the relative efficiency of nested case-control study design is approximately 75%.
Conclusion: Results of this study show that nested case-control study is not only an easy and cost-effective method for data analysis but also is as robust as cohort analysis in rate ratio and its variance estimation.
S Akbarpour, Y Jahangiri-Noudeh, M Lotfaliany , N Zafari, D Khalili, M Tohidi, Ma Mansournia, F Azizi, F Hadaegh,
Volume 11, Issue 2 (Vol 11, No 2 2015)
Abstract
Background & Objectives: Considering the importance of CVD risk factors in diabetic and non-diabetic populations and the high prevalence of diabetes and cardiovascular risk factors, we studied the trend of anthropometric indexes, blood pressure, smoking and lipids in diabetic and non-diabetic populations.
Methods: The data of Tehran Lipid and Glucose Study was used in this investigation. The study population comprised 1045 diabetic and 5136 non-diabetic subjects. To investigate the secular longitudinal trends, the Generalized Estimation Equation method was employed. All statistical models were adjusted for age to eliminate the potential confounding effect of age. The interaction between the diabetes status and each phase of the study was checked in a separate model in GEE.
Results: Over a decade, the serum levels of TC, TGs, LDL-C and non HDL-C decreased although about 60% of the diabetic population did not reach the therapeutic goals of non-HDL-C and LDL-C levels until 2011. Control of hypertension was more successful in females, but about 60% of both males and females with diabetes were still hypertensive at the end of follow-up period. Smoking increased during the follow-up.
Conclusion: This study showed that among CVD risk factors, healthcare professionals paid more attention to hypercholesterolemia neglecting other risk factors including hypertension and central obesity.
P Kimyaiee, M Bakhtiyari, M Mirzamoradi, S Ashrafivand, Ma Mansournia,
Volume 11, Issue 3 (Vol 11, No 3 2015)
Abstract
Background and Objectives: GTN is a general term for an extensive range of malignant trophoblastic diseases including invasive mole, choriocarcinoma, epithelioid trophoblastic tumors and placental site trophoblastic tumors. The aim of this study was to predict the risk of GTN in patients with molar pregnancy in Tehran.
Methods: All cases with partial and complete mole with a record of at least 4 titers of β-hCG were included in this study. Before and after fitting the appropriate model for calculating the area under the curve of each predictor variable, the type of the relationship (linear or non-linear) was first determined using locally weighted scatter plot smoothing (Lowess Smoother) and fractional polynomial regression (Fracpoly); then, a model tailored to data processing was used for drawing the ROC diagram.
Results: Nonparametric chi-square analysis indicated no significant difference between the components of high-risk molar pregnancy and GTN (P=0.39). Generally, among 201 cases of molar pregnancy, 61 (30%) had one of the components of high-risk molar pregnancy. The ROC curve with an AUC of 0.86 showed that the regression slope of β-hCG with 73% sensitivity and 88% specificity could be used as a predictor.
Conclusion: The serum β-hCG measurement after 21 days of molar pregnancy evacuation and the slope of the linear regression line of β-hCG were found be good tests to distinguish between patients who will benefit from spontaneous disease remission and patients developing GTN.
F Bagheri Amiri , Ar Bahonar, E Mostafavi, Ma Mansournia, N Rasouli , Mh Fallah Mehrabadi, D Abdollahi, Sholepash,
Volume 12, Issue 1 (Vol 12, No.1 2016)
Abstract
Background and Objectives: Foot-and-mouth disease (FMD) is one of major contagious animal. The purpose of this study was to evaluate the determinants associated with FMD occurrence in farms.
Methods: A case- control study was carried out in cattle farms. The cases were farms with new reports of FMD and controls were units without any report of FMD in last 6 month. For assessing the risk factors, a researcher- made questionnaire was used. Statistical analyses were done with SPSS version 16 using the logistic regression test.
Results: Purchase of new livestock [OR: 14.69 (CI95%: 4.29, 50.36)] and passing migratory livestock [OR: 13.32 (CI 95%: 1.74, 101.87) were identified as the risk factors of the disease. Visiting the farm by the vaccinator in last 2 weeks [OR: 0.17 (CI 95%: 0.05, 0.63)] and buying new livestock from the same village/ city where the farm is located [OR: 0.16 (CI 95%: 0.04, 0.58)] were considered as protective factors.
Conclusion: Considering the role of infected livestock in the country, the most important steps for effective preventation are: areadherence to biosecurity as well as quarantining new purchased animals, and informing and training farmers to not purchase new animals from farms that are located in the infected areas and around the times of outbreak.
K Holakouie Naieni , Ma Mansournia, Mh Panahi, A Elduma, Sh Nematollahi ,
Volume 12, Issue 3 (Vol 12, No 3 2016)
Abstract
Case-Cohort and nested case-control designs are the most well-known and cost-effective derivatives of prospective studies. Due to the popularity of these designs in recent years, the aim of this study is to provide a comprehensive and up-to-date description of them with respect to methodological issues such as sampling scheme, effect measure estimation, and analysis strategies. Overall, random sampling of controls in case-cohort and matching for time in nested design are considered their hallmarks. Eventually, decision on a better design depends on study objectives, sub-cohort selection, case and control determination, and method of data collection. It should be kept in mind that any particular study requires unique elaboration and delicate examination to choose from the designs.
M Shakiba, Ma Mansournia, H Soori,
Volume 13, Issue 1 (Vol 13, No 1, Spring 2017)
Abstract
Standard methods for estimating exposure effects in longitudinal studies will result in biased estimates of the exposure effect in the presence of time-dependent confounders affected by past exposure.
In the present review article, we first described the assumptions required for estimating the causal effect in longitudinal studies and their structure regarding various types of exposure and confounders; then, we explained the bias of standard methods in estimating the causal effect.
Two types of bias, i.e. over-adjustment bias and selection bias, occur in estimating the effect of time-varying exposure in the presence of time-dependent confounders affected by previous exposure using standard regression analysis. Standard regression methods cannot sufficiently modify time-dependent confounders and estimate the total causal effect of the exposure.
K Holakoui-Naeini, Ma Mansournia, Sh Naderian, R Beiranvand, M Bidkhori, Kh Maajani, Sh Nematollahi,
Volume 17, Issue 2 (Vol 17,No.2, Summer 2021 2021)
Abstract
Background and Objectives: Pre-natal mental health problems are major causes of disease burden, especially in lower socio-economic groups of population. The present study used data of a prospective cohort study to estimate the risk of mental health problems, including depression, anxiety, and stress, on birth weight.
Materials and Methods: This study used data of 398 pregnant women who were participants of the Bandar Abbas Pregnancy Cohort Study (BAPC) during 2017-2020. Data of depression, anxiety, and stress were collected using DASS-21items questionnaire in pregnancy. Low Birth Weight (LBW), as birthwieght below 2500 grams, was calculated according to infant`s vaccination log. Modified Poisson regression models with logarithm link function and significance level of 5% were applied to estimate the effect of depression, anxiety and stress on LBW.
Results: Compared to the subjects without mental health problems, the risk of LBW increased by 8.03 times in the severe depression (95% CIs: 5.55-11.62), by 8.06 times in the moderate stress (95% CIs: 5.64-11.51), by 3.13 times in the severe anxiety (95% CIs: 1.18-8.31), and by 8.43 in the highly severe anxiety (95% CIs: 5.80-12.25).
Conclusions: Severe and moderate levels of depression, anxiety, and stress all had statistically significant effects on LBW. Pre-natal screening services can help mitigate the burden of mental health by timely detection and referral. Moreover, designing and implementing consultation programs for pregnant women and their fsmilies, expecially their spouses, to provide emotional support and to improve marital relationship are amongst the suggestions.
Sa Hashemi, K Holakoui-Naeini, Ma Mansournia, R Akrami, M Nomali, T Valadbeigi, V Mennati, Ha Adineh, Mr Taghavi, M Ghafouri, S Poorbarat, A Hoseinzadeh, M Farahdel, Mr Armat, M Haresabadi,
Volume 17, Issue 3 (Vol 17,No.3, Atumn 2021 2021)
Abstract
Background and Objectives: COVID-19 is a new disease and little information is available on its risk factors. The aim of this study was to determine the mortality risk factors in patients with COVID-19 in the northeast of Iran.
Materials and Methods: A case-control study was conducted. Patients of both sexes with a confirmed diagnosis of Covid-19 infection who died during the study were studied as the case group and patients who were in good general health and ready for discharge were studied as the control group. Data analysis was performed with the STATA software version 14 using descriptive statistics and univariate and multiple logistic regression tests.
Results: Six hundred and eleven patients were studied (27% cases and 73% controls). Multiple logistic regression analysis showed that the odds of death were 2.8 times higher in patients over 80 years compared to patients aged 50-60 years. In addition, age under 40 years reduced the odds of mortality by 85% and living in rural areas increased odds of death by 2.2 times. Cough, general fatigue, pain, nausea and vomiting increased the odds of COVID19 survival.
Conclusion: The odds of mortality were higher in elder patients with COVID-19. In addition, living in rural areas increased the odds of mortality in patients. Cough and fatigue reduced mortality; however, it is needed to address other hidden factors for sound judgment.
Y Salimi, Ma Mansournia, I Abdollahpour, S Nedjat,
Volume 17, Issue 3 (Vol 17,No.3, Atumn 2021 2021)
Abstract
Background and Objectives: Using a random sample of women aged 15 to 50 years in Tehran, this study sought to estimate the lifetime prevalence of abortion (intentional and unintentional) and to identify its associated factors.
Materials and Methods: The control data of a population-based case-control study conducted in 2014 in Tehran was used in the present study. Data from 544 randomly selected women aged 15-50 living in municipality areas of Tehran were included in this study. A multiple logistic regression model was used to investigate factors associated with abortion and to estimate the adjusted odds ratios (ORs) and 95% confidence intervals.
Results: Overall, 102 women (18.8%, 95% CI (22.4% -15.8%)) reported a lifetime history of abortion. In the logistics regression model, being single (OR =3.46, 95% CI: 1.42-8.47) older age (OR = 1.07, 95% CI: 1.04-1.11) increased the odds of a positive lifetime history of abortion. However, having a child (OR = 0.27, 95% CI: 0.11-0.65)), more education years (OR = 0.89, 95% CI: 0.82-0.96)) and higher religious beliefs (OR = 0.65, 95% CI: (0.45-0.93)) decreased the odds of a positive lifetime history of abortion..
Conclusion: High reported lifetime prevalence of abortion in the present study and its subsequent risks to maternal health highlight the need for educational interventional programs taking into account the level of education and knowledge of mothers along with their religious.
