The psychometrics of instruments in safety performance evaluation is essential for the accreditation of an organization’s safety evaluation and has been emphasized in many studies. Psychometrics pertains to the validity and reliability of an evaluation instrument and describes its precision and consistency. The aim of the present study was to evaluate the psychometrics of safety level and safety culture questionnaires to provide a reliable and valid instrument for safety performance evaluation in industries. This descriptive cross sectional study was conducted with the intention of psychometric instruments used to evaluate the safety level and the safety climate at the Mapna Pars power plant generator manufacturing and engineering company. The face validity of the questionnaires was analyzed quantitatively and qualitatively. In the quantitative method, the importance of the influence score was applied and the content validity was calculated using the Lawshe method. Content Validity Ratio (CVR) and Content Validity Index (CVI) were also used. For this purpose, elicitation was obtained from experts within the professional health and safety community. The reliability of the instruments was determined via the Cronbach's alpha test and the Interclass Correlation Coefficient (ICC) test. Finally, the standardized questionnaires were used to evaluate the safety level and safety climate of the industry as a case study. The obtained data were analyzed using SPSS software solution v20.  Based on the quantitative face validity results obtained at the Mapna Pars Company, one question was removed from each of the final instruments. The content reliability analysis revealed that the safety level questionnaire had a CRI of 0.99, CVR of 0.91, and was accepted. The safety climate questionnaire had an acceptable CVI of 0.95 and an acceptable CVR of 0.82. Regarding the reliability analysis, a Cronbach's alpha of 0.72 and 0.89 was obtained for the safety level questionnaire and the safety climate questionnaire, respectively. It can be concluded that both questionnaires had an acceptable level of internal consistency. The re-application of the questionnaires after two weeks revealed a relatively consistent safety level (ICC=0.90) and safety climate (ICC=0.74).  Analyzing the data obtained in the present study showed that the safety level questionnaire with 66 questions and the safety climate questionnaire with 93 questions had acceptable validity and reliability. Thus, it may provide a useful approach for safety evaluations in similar industries.

Received: December 2016, Accepted: January 2017Background: Manual handling, lifting, or carrying of material is responsible for non-fatal injuries among employees in industries. It is the second most prevalent reported risk factor in workplaces that can lead to potential manual handling accidents and longer-term musculoskeletal disorders (MSDs). The aim of this study was the evaluation of manual material handling using the American National Institute for Occupational Safety and Health (NIOSH) equation in a tile and ceramic factory in Tehran, Iran, in 2016. Material and Methods:This cross-sectional study was carried out in a tile and ceramic factory in Tehran, Iran, in 2016. Three tile production lines (A, B, and C) were selected. On each line, cartons were lifted from a conveyor and placed onto a pallet. The task variable data were measured and recorded according to the NIOSH equation. Results: According to the results, composite-lifting index (CLI) value in all three lines exceeded 3 (3.34, 4.53, and 5.99, respectively, for lines C, B, and A). The values of frequency-independent recommended weight limit (FIRWL) and single-task recommended weight limit (STRWL) in all tasks were less than load weight. In addition, values of frequency-independent lifting index (FILI) and single-task lifting index (STLI) in all tasks exceeded 1.0. Conclusions:The results show that CLI value for these jobs exceeded 3, which means that a significant level of physical stress is associated with these jobs for nearly all workers. Both strength and endurance are a problem for many workers. Therefore, the first priorities of job redesign should be the decreasing of the physical demands through modifying the job layout, and decreasing the physiological demands through reducing the frequency rate or duration of continuous lifting.

Background: Road accidents, as the main causes of mortality and disability in the world, have been seriously endangering human health. Human factors are among the most significant causes of road accidents. This study aimed to investigate the association between high-risk behaviors among truck drivers with their fatigue and drowsiness in the occurrence of road accidents and near miss accidents. Materials and Methods: This descriptive study was conducted recruiting 200 truck drivers in Tehran using two-stage cluster sampling method, in 2019. A standard driver safety questionnaire was used to collect data, with its reliability measured by the testretest method. The Fisher's test, a chi-squared test, and the Pearson's correlation were used to analyze the data. Results: The mean age of the drivers and the mean hour of driving were 47.5 ± 9.05 years and 10.66 ± 2.52 hours, respectively. In addition, the number of accidents had a significant association with the drivers' age, drowsiness, talking on the cell phone, texting, eating snacks, and driving hours. However, it had no significant relationship with drinking tea and smoking. Furthermore, the rate of road accidents had a significant correlation with the drivers' driving time and rest hours. Conclusion: Behaviors and factors, such as talking on the cell phone, texting, eating snacks, long hours of driving per day, long hours of nonstop driving, low rest hours, and drowsiness were among the major causes of accidents among trucks drivers. In this regard, authorities are recommended to run educational courses to modify high-risk driving behaviors so as to reduce road accidents.

Article Info Background: The revised National Institute for Occupational Safety and Health (NIOSH) lifting equation (RNLE) is commonly used for risk assessment of manual handling, and can estimate low back pain (LBP) biomechanical stressors of lifting and/or lowering of loads. The aim of this study was to evaluate manual material handling by using the RNLE, LBP, and LBP disability index (LBPDI) among workers in a tile and ceramic industrial unit in Tehran, Iran. Materials and Methods: A sample of 30 workers (manual workers) in a tile and ceramic production line was recruited. Low back pain prevalence and disability index were measured using body map questionnaire combined with visual analog scale and self-report Oswestry disability index (ODI), respectively. Statistical data analysis was done using SPSS software, version 22. Results: According to results, composite lifting index was 14.77. Low back pain prevalence among workers was reported equal to 100%; also, Low back pain intensity was equal to 68.8 ± 17.8. The mean of Low back pain disability index among workers has been reported equal to 41.3 ± 17.1 (severe crippled). Conclusions: The results show that composite lifting index value for these jobs exceeded 3, which means that there is a significant level of physical stress associated with these jobs for nearly all workers. Both strength and endurance for this job are high; therefore, job redesigning could decrease the physical demands, Low back pain prevalence, and Disability index, through modifying the job layout and work stations.

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