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

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 α=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.

Modeling the recurrent failure to thrive in less than two-year children: recurrent events survival analysis

This study aimed to evaluate the failure to thrive [FTT] recurrent event over time. This longitudinal study was conducted during February 2007 to July 2009. The pri-mary outcome was growth failure. The analysis was done using 1283 children who had experi-enced FTT several times, based on recurrent events analysis. Fifty-nine percent of the children had experienced the FTT at least one time and 5.3% of them had experienced it up to four times. The Prentice-Williams-Peterson [PWP] model revealed significant relationship between diarrhea [HR=1.26], respiratory infections [HR=1.25], urinary tract infections [HR=1.51], discontinuation of breast-feeding [HR=1.96], teething [HR=1.18], initiation age of complementary feeding [HR=1.11] and hazard rate of the first FTT event. Recurrence nature of the FTT is a main problem, which taking it into account increases the accuracy in analysis of FTT event process and can lead to identify different risk factors for each FTT recurrences.

Milk and Protein Intake by Pregnant Women Affects Growth of Foetus.

The study assessed the effects of the daily intake of milk and protein by pregnant women on foetal growth and determined the growth pattern and velocity of growth. A total of 504 ultrasound observations from 156 respondents were collected following a cross-sectional design in the last trimester of pregnancy; majority of them were in the last month of pregnancy. De facto and purposive sampling was done, and direct interviews of affluent pregnant women were conducted. Kruskal-Wallis test shows that majority of the respondents had tendency to consume 155.65 to 465.17 mL of milk per day, resulting in better and higher foetal growth. Most respondents consumed about 50-70 g of protein per day, and the foetal growth measurements, such as abdomen-circumference, femur length, biparietal diameter, and head-circumference, on an average, were higher in the same group. Quadratic regression model exhibited that all the traits of growth pattern in Model 1 (low milk and protein intake) appeared to have more mode of decline, in contrast to Model 2 (more milk and protein intake), which shows better growth. In addition, velocity of growth pattern was obtained through the first derivative of quadratic regression of growth pattern. Moreover, 95% confidence interval calculated for regression line slope of Model 1 and Model 2 showed that the estimation point (2 B2) of Model 1 does not lay into 95% CI of Model 2; so, statistical significance assorted and also the same trend conversely hold for Model 2. The rate of growth was highly influenced by maternal milk and protein intake. These findings suggest that contribution of common nutrients or other nutritional factors present in milk and protein promote the growth of foetus.

[Road traffic injuries among patients attending central hospital of Masjed-Soleyman from March 2008 to 2010]

Objective [s]: To identify the predictive model of road traffic injuries by a time series model

Methods: This was an analytical study involving patients attending central hospital of Masjed -Soleyman [a city in Ahvaz Province], Iran during 24 months, from March 2008 to March 2010. Time series carried out to determine monthly occurrence of road traffic injuries in order to build a statistical model on data. The ARMA Box Jenkins linear model was used and an Autoregressive model was selected

Results: Out of all 1210 injured patients referring to the hospital, 78.5% [n=950] were men. The mean age of patients was 30.57+/-17.08 years. The majority of injured [35.1%] were 20-29 years old. Autoregressive model was appropriate to describe our data over time. The result indicated the road traffic injuries had an increased pattern by 7 times as compare with previous month on average

Conclusion: The frequency of road traffic injuries is high in men and young age adolescents. The pattern is increasing and there is need for serious public health considerations