Showing 4 results for Power
A Ardalan , K Holakouie Naieni , M Mahmoudi , R Majdzadeh , P Derakhshandeh Peykar ,
Volume 4, Issue 2 (5-2006)
Abstract
Background and Aim: Limitations of the traditional methods for assessing G*E interaction- including case-control studies- led to development of several non-traditional approaches. This study aims to assess the interaction between the genetic background (history of breast cancer in first degree relatives) and environmental influences (reproductive/menstrual factors) in patients with breast cancer we also compare the statistical efficiency and power of case-control and case-only designs in this setting.
Materials and Methods: In a matched case-control study in Mazandaran province (Iran), 250 incident biopsy-proven cases of breast cancer and 250 age-matched neighbor controls were interviewed. History of breast cancer in mother and/or sister(s) was taken as a surrogate measure of genetic predisposition, while age at first birth, parity, breast feeding, age at menarche and irregular menstruation were considered as relevant environmental factors. For the matched case-control design, we used a conditional logistic regression model to examine main effects and the G*E interaction. In the case-only design, logistic regression analysis was applied to obtain an estimate of G*E interaction, after checking for the independence assumption. We also calculated the power for detecting the interaction by matched case-control and case-only analyses.
Results: Age at first delivery did not meet the assumption of independence (p=0.02), and so was not included in the case-only analysis. No statistically significant interaction effect was seen in the case-control analysis, while case-only analysis showed significant negative interaction between disease in first-degree relatives on the one hand and parity and breast feeding on the other. We also detected a significant positive interaction between genetic predisposition and age at menarche. All the estimated 95% confidence intervals for OR in G*E interactions were narrower in the case-only analysis. For all factors, the power for detecting G*E interaction was greater in the case-only analysis compared to the case-control analysis, with ratios ranging from 1.08 to 2.23.
Conclusion: The case-only design is more efficient and powerful than the case-control design for detecting gene-environment interaction under the assumption of independence. Baseline disease risk, interactions and independent effects should be considered in using the control data for checking the assumption of independence. Considering the existence of another explanatory variable, eg. a mutant gene which may have passed unnoticed, would be the safest approach in a case-only study.
Zahra Kiani, Masoumeh Simbar, Mahrokh Dolatian, Farid Zaeri,
Volume 13, Issue 2 (9-2015)
Abstract
Background and Aim : Empowering women means enabling them to decide independently on the basic issues of life. The great challenge of fertility and reproductive health of women is indicative of their inability to make decisions . The third objective of the Millennium Development Goals is empowerment of women and the effect of social determinants of health in this regard has been recognized. This study was conducted to assess the relationship between structural social determinants of health and women's empowerment in reproductive health.
Materials and Methods: This was a descriptive-correlation study including 400 women consulting the Shahid-Beheshti University of Medical Sciences health centers in Tehran, Iran. In the first stage, the health centers were selected by the simple random method, followed by quota sampling the f inal sampling was done by the convenience sampling method. The tools for data collection were demographic and socio-economic questionnaires, as well as a questionnaire to obtain data on women's empowerment in reproductive health . Data were analyzed using SPSS-17.
Results: That data showed that the women’s empowerment in reproductive health was at an intermediate level. Structural social determinants of health were correlated with women’s empowerment in reproductive health the highest correlation was found to be with women’s education level (r= 0.44, P< 0.001).
Conclusions: Women's general empowerment, as well as their empowerment and in family planning needs special attention. Structural social determinants of health are correlated with women's empowerment in reproductive health . Thus, policies should be adopted and plans executed aiming at strengthening the role of women in the family and the society .
Jalal Abdi, Hasan Eftekhar, Mahmood Mahmoodi, Davoud Shojayzadeh, Roya Sadeghi,
Volume 14, Issue 1 (6-2016)
Abstract
Background and Aim: This study was conducted to evaluate the effect of an intervention based on modern communication technologies and the social cognitive theory on the lifestyle of the government employees in the City of Hamadan, Iran in 2014.
Materials and Methods: A randomized control trial [IRCT2014083118989N1] was conducted including a total 435 employees with overweight or obesity. They were divided into a control group receiving no education and two intervention (experimental) groups (IG1 and IG2) receiving a 6-month education under the title of “lifestyle program”. The educational intervention was “telephone-assisted” in IG1 and “web-assisted” in IG2. Six and nine months after the intervention the lifestyle and changes in in the constructs of the social-cognitive theory were determined and compared between the experimental and control groups. Data were collected and analyzed using SPSS-20.
Results: In both intervention groups, the lifestyle program resulted in promoting lifestyle status from “Good” to “Very good” (p=0.001). The intervention in the telephone-assisted group led to increases in the mean scores of the constructs of self-efficacy, environment, outcome expectations, and outcome expectancies, while in the web-assisted intervention group increases were observed only in the mean scores of the constructs of self-efficacy and outcome expectancies (p<0.05).
Conclusion: The results of the present study confirm the effectiveness of a lifestyle intervention based on modern communication technologies and the social-cognitive theory.
Azar Tol, Bahram Mohebbi, Elham Shakibazadeh, Mehdi Yaseri, Maryam Sabouri,
Volume 16, Issue 2 (9-2018)
Abstract
Background and Aim: In health promotion, empowerment is a process through which people gain greater control over decisions and actions affecting their health. This study aimed to assess the predictive factors of health care empowerment among women in reproductive age in 2016.
Materials and Methods: This cross-sectional study was conducted on 549women in reproductive age referring to health centers in South Tehran. The participants were recruited through cluster and multi-stratified sampling. Data were collected using the Health Care Empowerment Questionnaire (HCEQ), which has three subscales, namely, degree of control, involvement in interactions and involvement in decision-making. The data were analyzed using the descriptive and analytical tests and multi-regression analysis.
Results: Husbands' education level, women's employment, family size, ethnicity, history of chronic diseases and economic status were predictors of degree of control. Husbands' education level (under high school diploma and high school diploma), family size (2-3, 3-4) and moderate economic status (sufficient income) predicted involvement in interactions. In addition, husbands' education (incomplete high school diploma and high school diploma), family size (2-3, 3-4), women's employment and history of chronic diseases predicted involvement in decision-making.
Conclusion: The findings indicate that various individual, family and socio-economic conditions of reproductive-age women influence their potential empowerment for receiving health care services. A family-based approach to facilitate receiving reproductive health care seems to be essential.
