Assessing Reliability and Validity of an Instrument for Measuring Resilience Safety Culture in Sociotechnical Systems

Shirali, Gholamabbas,Shekari, Mohammad,Angali, Kambiz Ahmadi Occupational Safety and Health Research Institute 2018 Safety and health at work Vol.9 No.3

Background: Safety culture, acting as the oil necessary in an efficient safety management system, has its own weaknesses in the current conceptualization and utilization in practice. As a new approach, resilience safety culture (RSC) has been proposed to reduce these weaknesses and improve safety culture; however, it requires a valid and reliable instrument to be measured. This study aimed at evaluating the reliability and validity of such an instrument in measuring the RSC in sociotechnical systems. Methods: The researchers designed an instrument based on resilience engineering principles and safety culture as the first instrument to measure the RSC. The RSC instrument was distributed among 354 staff members from 12 units of an anonymous petrochemical plant through hand delivery. Content validity, confirmatory, and exploratory factor analysis were used to examine the construct validity, and Cronbach alpha and test-retest were employed to examine the reliability of the instrument. Results: The results of the content validity index and content validity ratio were calculated as 0.97 and 0.83, respectively. The explanatory factor analysis showed 14 factors with 68.29% total variance and 0.88 Kaiser-Meyer-Olkin index. The results were also confirmed with confirmatory factor analysis (relative Chi-square = 2453.49, Root Mean Square Error of Approximation = 0.04). The reliability of the RSC instrument, as measured by internal consistency, was found to be satisfactory (Cronbach ${\alpha}=0.94$). The results of test-retest reliability was r = 0.85, p < 0.001. Conclusion: The results of the study suggest that the measure shows acceptable validity and reliability.

Assessing Reliability and Validity of an Instrument for Measuring Resilience Safety Culture in Sociotechnical Systems

Gholamabbas Shirali,Mohammad Shekari,Kambiz Ahmadi Angali 한국산업안전보건공단 산업안전보건연구원 2018 Safety and health at work Vol.9 No.3

Background: Safety culture, acting as the oil necessary in an efficient safety management system, has its own weaknesses in the current conceptualization and utilization in practice. As a new approach, resilience safety culture (RSC) has been proposed to reduce these weaknesses and improve safety culture; however, it requires a valid and reliable instrument to be measured. This study aimed at evaluating the reliability and validity of such an instrument in measuring the RSC in sociotechnical systems. Methods: The researchers designed an instrument based on resilience engineering principles and safety culture as the first instrument to measure the RSC. The RSC instrument was distributed among 354 staff members from 12 units of an anonymous petrochemical plant through hand delivery. Content validity, confirmatory, and exploratory factor analysis were used to examine the construct validity, and Cronbach alpha and test-retest were employed to examine the reliability of the instrument. Results: The results of the content validity index and content validity ratio were calculated as 0.97 and 0.83, respectively. The explanatory factor analysis showed 14 factors with 68.29% total variance and 0.88 Kaiser-Meyer-Olkin index. The results were also confirmed with confirmatory factor analysis (relative Chi-square = 2453.49, Root Mean Square Error of Approximation = 0.04). The reliability of the RSC instrument, as measured by internal consistency, was found to be satisfactory (Cronbach a = 0.94). The results of test-retest reliability was r ¼ 0.85, p < 0.001. Conclusion: The results of the study suggest that the measure shows acceptable validity and reliability.

Breast Cancer Risk Factors in Women Participating in a Breast Screening Program: a Study on 11,850 Iranian Females

Sepandi, Mojtaba,Akrami, Majid,Tabatabaee, Hamidreza,Rajaeefard, Abdolreza,Tahmasebi, Sedigheh,Angali, Kambiz Ahmadi,Rezaianzadeh, Abbas,Talei, Abdolrasoul Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

The incidence rate of breast cancer in developed countries is almost three-fold higher than in developing countries. Iran has had one of the lowest incidence rates for breast cancer in the world, but during the recent decades a marked increase has been seen. The purpose of this study was to investigate some established risk factors of breast cancer in Iranian women. A study of 11,850 women participating in abreast screening program was conducted. The 197 women diagnosed with breast cancer and 11,653 healthy women were compared. Logistic regression was performed to investigate associations of reproductive and anthropometric factors with breast cancer risk. Family history of breast cancer (OR=1.94, 95%CI=1.35-2.78), occupation (OR= 1.65,95%CI=1.20-2.25), education level (OR=0.50,95%CI=0.28-0.91), parity (OR=0.27, 95%CI=0.12-0.59), menopausal status (OR=3.15, 95%CI=2.35-4.21), age at menarche (OR=0.33, 95%CI=0.15-0.70), and age at the first pregnancy (OR=4.10, 95%CI=1.13-14.77) were related to the risk of breast cancer. Decrease in parity may to some extent explain the rising trend of incidence of breast cancer incidence in Iranian women.

Olive Leaf Extract Supplementation Combined with Calorie-Restricted Diet on Reducing Body Weight and Fat Mass in Obese Women: Result of a Randomized Control Trial

Haidari Fatemeh,Shayesteh Forough,Mohammad-shahi Majid,Jalali Mohammad-Taha,Ahmadi-Angali Kambiz 한국임상영양학회 2021 Clinical Nutrition Research Vol.10 No.4

The present trial aims to evaluate a supplementation of the olive leaf extract (OLE) in adjunct with a weight loss diet on anthropometric indices, glycemic indices, lipid profile, as well as the level of adipokines, and free fatty acid in obese women. We carried out an 8-week randomized, placebo-controlled, double-blind, parallel-group, clinical trial. The participants were randomly stratified according to age and they were assigned to one of the two study groups: Standard weight loss diet (estimated daily energy requirements minus 500 kcal) + OLE supplementation (n = 35) in intervention group or Standard weight loss diet (estimated daily energy requirements minus 500 kcal) + placebo (n = 35) in placebo group. The study groups were homogeneous regarding the baseline age, height, weight, body mass index (BMI), waist circumferences, married status, and physical activity levels (p > 0.05). The results of analysis of covariance presented significant decreases in BMI, fat mass, and body weight in the OLE group compared to those in the placebo group (p < 0.05). At the end of the study, the serum levels of fasting blood sugar, insulin, low-density lipoprotein cholesterol, total cholesterol, leptin, fatty free acid, and homeostasis model assessment–insulin resistance significantly decreased, and serum levels of high-density lipoprotein cholesterol and adiponectin elevated in the intervention group (p < 0.05). Based on results it seems that the addition of OLE to a hypocaloric diet for 8-week compared with a hypocaloric diet alone may be more effective in modifying obesity and metabolic risk factors.

Photocatalytic degradation of azo dye using nano-ZrO2/UV/Persulfate: Response surface modeling and optimization

Farshid Ghanbari,Mahsa Moradi,Mohammad Manshouri,Kambiz Ahmadi Angali 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

Dyes have always been considered in the context of recalcitrant organic pollutants in water. The present research has focused on the decolorization of Direct Blue 71 (DB71) using photocatalysis process of nano-ZrO2/UV/ Persulfate. Response surface method with central composite design was applied to determine the effects of four main factors (time, ZrO2 dosage, persulfate dosage and pH) on decolorization of DB71. The results indicated that the obtained quadratic model had a high R-squared coefficient based on the analysis of variance (ANOVA). Time had the highest effect (45.5%) on decolorization of DB71. The optimum condition predicted for complete decolorization was pH=7, 0.4 g ZrO2, 0.75 mM persulfate and 40 min reaction time. Verification experiments confirmed that there was good agreement between the experimental and predicted responses. The studied photocatalytic process could oxidize and destruct the structure of the DB71, and average oxidation state (AOS) significantly increased from −1.5 to +1.33, indicating the presence of more oxidized by-products and, consequently, improvement of biodegradability. The quenching tests showed that sulfate radical was the major agent in DB71 decolorization. It can be concluded that nano-ZrO2/ UV/Persulfate is a very effective process for decolorization of colored wastewater.