Showing 2 results for Yaseri
N , , , , H Poustchi, M Yaseri,
Volume 13, Issue 4 (VOl 13, No.4, Winter 2018)
Abstract
One of the traditional methods used for the analysis of survival data is the Cox regression technique. This method calculates the conditional risk ratio. However, when the aim of the study is to estimate the effect of exposure in the total population level, using these conditional methods is not apposite. Furthermore, the hazard ratio has disadvantages of its own such as being non-collapsible, having the risk of structural selection bias and variability in time. Given the limitations, it is recommended to use the marginal hazard ratio, which estimates the average causal effect of exposure in the total population level.
This study introduces the inverse probability treatment weighting (IPTW) as a method of estimating the marginal causal effect. Finally, to illustrate IPTW method, we used Golestan Cohort Study and estimated the marginal causal effect of smoking on time to death due to the upper gastrointestinal cancer (esophageal-gastric).
A Mehri, M Yaseri, D Rahimi, S Nejat,
Volume 16, Issue 2 (Vol 16, No.2 2020)
Abstract
Background and Objectives: Self-confidence is an individual characteristic in students that enables them to have a positive or realistic view of themselves. The purpose of present study was to evaluate the validity and psychometric properties of the Self-confidence Questionnaire (PEI)
Methods: This cross-sectional study was conducted on 100 students of four medical universities. Validation of this questionnaire included the steps of translation, content validity, face validity, repeatability and internal consistency.
Results: The mean age of the participants in this study was 32.1 (SD = 5.5) years. The majority of the students were postgraduate students (47%) and the least (11%) were undergraduate students. The results of this study showed that the overall relevancy and clarity of the questions were 92% and 83%, respectively. The percentage of agreement on overall comprehensiveness was 100%. Cronbach's alpha coefficient and interclass correlation coefficient were higher than 0.7 in all domains. The ICC of each question was also between 0.72 and 0.98.
Conclusion: Based on the results of this study, the Persian version of the PEI questionnaire has an appropriate reliability for use in the student population of Iranian universities.
