Applying data mining techniques to extract hidden patterns about breast cancer survival in an Iranian cohort study

Background: breast cancer survival has been analyzed by many standard data mining algorithms. A group of these algorithms belonged to the decision tree category. Ability of the decision tree algorithms in terms of visualizing and formulating of hidden patterns among study variables were main reasons to apply an algorithm from the decision tree category in the current study that has not studied already

Methods: the classification and regression trees [CART] was applied to a breast cancer database contained information on569 patients in 2007-2010. The measurement of Gini impurity used for categorical target variables was utilized. The classification error that is a function of tree size was measured by 10-fold cross-validation experiments. The performance of created model was evaluated by the criteria as accuracy, sensitivity and specificity

Results: the CART model produced a decision tree with 17 nodes, 9 of which were associated with a set of rules. The rules were meaningful clinically. They showed in the if-then format that Stage was the most important variable for predicting breast cancer survival. The scores of accuracy, sensitivity and specificity were: 80.3%, 93.5% and 53%, respectively

Conclusions: the current study model as the first one created by the CART was able to extract useful hidden rules from a relatively small size dataset

Effects of Antibiotic Consumption on Children 2-8 Years of Age Developing Asthma / 한국역학회지

OBJECTIVES: Antibiotic exposure in children is a possible contributor to the increasing asthma prevalence in several countries. The present study aimed to investigate the association between antibiotic exposure and the risk of developing childhood asthma at 2-8 years of age. METHODS: A case-control study was undertaken among children aged 2-8 years old between March and September 2010 in the Urmia district in the northwest of Iran. The cases were doctor-diagnosed asthmatic children based on Global Initiative for Asthma criteria (n=207), and the controls were children without respiratory symptoms (n=400) selected by frequency matching by age and gender. Clinical data including antibiotic exposure was collected by a validated and reliable questionnaire, which was completed by interviewing parents/guardians. RESULTS: Antibiotic consumption during the first year of life increased the odds ratio [OR] of asthma symptoms at 2-8 years of age (crude OR, 2.26; 95% confidence interval [CI], 1.53-3.35; p<0.01), and the strength of association was similar after adjusting for a family history of asthma or atopic disorder, preterm delivery, birth order, and delivery method (adjusted OR, 1.91; 95% CI, 1.27-2.88; p=0.03). CONCLUSIONS: Our study suggests that antibiotic consumption in children was associated with an increased risk of childhood asthma, and an additional confirmative study is needed.

Assessing study skills among a sample of university students: an Iranian survey / 보건의료교육평가

PURPOSE: Numerous studies have revealed that study skills have a constructive role on the academic performance of students, in addition to educational quality, students' intelligence, and their affective characteristics. This study aims to examine study skills and the factors influencing them among the health sciences students of Urmia University of Medical Sciences in Iran. METHODS: This was a cross-sectional study carried out from May to November 2013. A total of 340 Urmia health sciences students were selected using a simple sampling method. Data were collected using the Study Skills Assessment Questionnaire of Counseling Center of Houston University and analyzed with descriptive and analytical statistics. RESULTS: The mean and standard deviation of the students' study skills were 172.5+/-23.2, out of a total score of 240. Around 1.2% of the study skills were weak; 86.8%, moderate; and 12%, good. Among the study skills, the scores of time management, and memory and concentration were better than the others. Also, there was a significant positive correlation between study skills scores and the students' family housing status and academic level (P<0.05). CONCLUSION: Although the majority of the participants had moderate study skills, these were not sufficient and far from good. Improving and promoting the study skills of university students require the designing and implementing of education programs for study strategies. Therefore, decision makers and planners in the educational areas of universities should consider the topic described above.

Parental risk factors of childhood acute leukemia: a case-control study

Leukemia is the most common cancer in children, accounting for near to half of all childhood cancers. Different risk factors might be effective in the occurrence of this cancer such as parental characteristics. This study was done in West Azarbaijan Province in order to determine the relation between parental characteristics and acute leukemia in children. This matched case-control study was conducted on children less than 15 years affected by acute leukemia from March 20, 2003 to March 20, 2009. Two control groups were selected, one from hospital and the other from the study population. Cases and controls were matched on age and sex. Logistic regression model was used for data analysis. This study was done on 130 patients, 108 [83.1%] were affected by Acute Lymphoblastic Leukemia and 22 [16.9%] by Acute Myeloblastic Leukemia. Seventy two of the patients were male [55.4%] and 58 were female [44.6%]. There was a statistically significant correlation between acute leukemia and variables such as mother's education [OR=4.2, 95% CI: 2.42, 7.34], mother's history of using Oral Contraceptive Pills [OR=1.77, 95% CI: 1.05, 2.82] and parental relationship [OR=2.05, 95% CI: 1.30, 3.23]. It seems that some parental characteristics have an important role in etiology of childhood leukemia

Long-term progression pattern of chronic allograft dysfunction among kidney transplant recipients

There is little data about the pattern of disease progression in kidney transplant recipients with chronic allograft dysfunction [CAD]. Extrapolating the current classification of chronic kidney disease for CAD, we studied the pattern of progression of CAD in 5 stages among our kidney transplant recipients. We performed a retrospective cohort study on 214 kidney transplant recipients with CAD. The selection criteria were a functioning kidney allograft for at least 1 year after transplantation and a progressive decline in allograft function. An event history analysis in survival data was carried out based on the stages of CAD at baseline and the end of the study. At the beginning of the study, 54.7% of the patients had CAD stage 1; 37.9%, stage 2, and 7.5%, stage 3. At the end of study, 10.3% were in stage 2; 39.7%, stage 3; 23.4%, stage 4; and 26.6%, stage 5. Patients with CAD stage 5 were 17.1% of those in stage 1, 32.1% of those in stage 2, and 67.7% of those in stage 3 at baseline. There was a significant correlation between stage of CAD at the beginning of the study and the stage of CAD at the end [r = 0.465, P < .001]. Because the decline in kidney allograft function was relatively faster in advanced stages of CAD, strategies to increase allograft survival by improving the baseline level of allograft function can be more effective than strategies to slow down progression of advanced stages of CAD