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Showing 11 results for Reliability

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Volume 2, Issue 2 (9-2012)
Abstract

Introduction: Occupational injuries and accidents as one of the problems have always been considered important in occupational environments. Domino model that Heinrich was formed to pursue the idea of the cause of the accident is the man. Thus one of the effective way to reduce accidents will be control by the unsafe behaviors among workers by promoting safety culture.

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Material and Method: In this descriptive - analytical study, the reliability and exploratory factor analysis was used to evaluate the reliability of the questionnaire. In total 303 questionnaires were analyzed using SPSS 17 software.

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Result: The alpha crumbed, coefficient was 0/86. Structural factor of the questionnaire was evaluated using factor analysis. KMO and Bartlett’s sphericity test coefficient were 0/909 and 9785/057, respectively. The varimax rotation showed that all test questions are based on factors.

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Conclusion: The results indicated favorable validity of this questionnaire for use in detergents and cleaners industries within the country. Considering the load factor safety culture in detergents and cleaners industries, contained 5 factors including “management commitment”, “education and information exchange,” “supportive environment”, “barriers” and “priority to safety”. The obtained the correlations, the highest positive correlation was belong to the “management commitment” (r=0/952), as the strongest correlation with the safety culture.


S Kazronian, S. A. Zakerian, J. N. Saraji, M. Hosseini,
Volume 3, Issue 3 (12-2013)
Abstract

Introduction: currently, stress is known as one the most important issue among societies which may have positive or negative results. Stress is caused when there is not a harmony between job demands, capabilities and desires of a person. Most of the behavioral, physical and mental disorders are results of job stress. The objective of this study was Validity and Reliability analysis of NIOSH Generic Job Stress Questionnaire (GJSQ), in order to have an appropriate tool for evaluation and analysis of job stress in Iran.

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Material and Method: In this study, 228 members of Tehran fire-fighting office were chosen according to categorical and clustering sampling, methodology and they completed NIOSH Generic Job Stress Questionnaire (GJSQ). For Validity and Reliability of questionnaire, 20 persons of the group were chosen for content validity analysis of the questionnaire. For Reliability analysis of the result, Cronbach alpha test and in-cluster correlation test were used. SPSS software version 18 was used for analysis of the data.

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Result: The mean age of the participants was 30.8 years (SD=4.9) and the average of job tenure in fire-fighting office was 7.4 years (SD=4.8). In order to reliability analyze the questionnaire, Cronbach alpha coefficient of all influential factors was obtained more than 0.7. In-cluster correlation coefficient of the questionnaire is calculated using retesting on all influential factors. With the exception of Physical Environment and Mental Demands which were about average, all other coefficients were over 0.7, which is a very appropriate result.

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Conclusion: Considering that Validity and Reliability factors of the questionnaire were be appropriate, it can be recommended that NIOSH Generic Job Stress Questionnaire (GJSQ) can be used as a Valid and Reliable questionnaire for job stress evaluation in Iran.


Narmin Hassanzadeh-Rangi, Yahya Khosravi, Ali Asghar Farshad, Rezvan Abedinloo, Hamed Jalilian,
Volume 6, Issue 3 (9-2016)
Abstract

Introduction: In recent years, a growing attention has been paid to assess the physical characteristics of rich and poor urban districts to understand social health differences. Urban districts environment play a major role in health of the residents. Previous few studies have considered some aspects of limited neighborhood environment. The current study was designed to investigate the reliability of the Neighborhood Health, Safety and Environment (NHSE) tool in one of Tehran city neighborhoods.

Material and Method: Dimensions and related items of the NHSE were extracted based on the previous studies and interviews with city experts. Five observers completed the NHSE in a selected neighborhood in order to test inter and intra-rater reliability of the tool. Data analysis was done using the Cronbach’s alpha, Interclass Correlation Coefficient (ICC) and kappa coefficient.

Result: The ICC and Cronbach’s alpha were estimated 0.86 for all dimensions of the NHSE. The calculated kappa values were in the range of 57%-66% for inter-rater reliability and 0.47-0.62 for intra-rater reliability.

Conclusion: The NHSE tool was shown to have a desirable inter and intra-rater reliability and a good level of internal consistency for assessing the health, safety, and environment (HSE) of the neighborhoods.


Payam Heydari, Sakineh Varmazyar, Chia Hakimi, Sana Shokri,
Volume 7, Issue 2 (6-2017)
Abstract

Introduction: Given the increase of road transportation of dangerous materials, if an accident occurs, the first groups that present at the scene are rescue groups (emergency، red crescent and firefighters). The aim of this study was to investigate the validity and reliability of the questionnaire assessing level of knowledge in the rescue personnel regarding warning signs mounted on the road heavy machinery.

Material and Method: Firstly, a multiple-choice questionnaire was designed using the literature and material safety data sheets (MSDS). Validity of the questionnaire was examined using the viewpoints of 10 experts. The reliability of the questionnaire was assessed using test-retest in 20 subjects of the rescue groups in two-week intervals. The cut point of the questionnaire was determined by the Receiver Operating Characteristic (ROC).

Result: The mean of age and work experience of the participants was 32.42 ± 2.57 and 7.75 ± 2.70. The results of correlation between the questions of the test showed that Cronbach’s alpha is 0.708. Also, the stability and reliability of test scores over time showed that the correlation between the questions in the first and second series was significance at acceptable level (r=0.698 with P-value=0.012(. The best value of cut point in the questionnaire of knowledge in the rescue personnel as obtained 18.5, with the sensitivity of 60% and specificity of 50%.

Conclusion: The validity and reliability of the knowledge assessment questionnaire in the rescue personnel were confirmed regarding the warning signs mounted on the road heavy machines; therefore, it can be used in the future studies.


Davoud Mahmoudi, Seyyed Shamsaddin Alizadeh, Yahya Rasoulzadeh, Mohammad Asghari Jafarabadi,
Volume 8, Issue 4 (12-2018)
Abstract

Introduction: Disasters, incidents and crises are complex and controversial issues for the industries and organizations. Organizational resilience is an effective goal that continuously helps the organization’s performance throughout business, disasters and critical situations. Therefore, the present study aimed to investigate the validity and reliability of organizational resilience questionnaire in dealing with major accidents.
Material and Method: The present study was a descriptive-analytic study. At first, the concept of organizational resilience and its dimensions were determined for the review. Then, for evaluating the content validity, the designed questionnaire was distributed among members of the expert’s panel and the Content Validity Index (CVI) and Content Validity Ratio (CVR) were calculated based on the comments. The reliability of the questionnaire was determined after completing it by 272 employees of the studied industries.
Result: The CVR was higher than the standard value (0.50) considering all items. Also, all dimensions of the questionnaire, except for the responsibility dimension the CVI’s were above 90%. Cronbach’s alpha coefficient for all questionnaire dimensions except for the responsibility dimension was higher than the acceptable value (0.70). This coefficient for the whole questionnaire was 0.967 indicating that this index was in excellent level.
Conclusion: The findings showed that the organizational resilience questionnaire in dealing with major accidents had an acceptable validity and reliability and in order to examine the organizational resilience in organizations, it could be used as a comprehensive, strong and reliable tool.
Gholam Abbas Shirali, Davood Afshari, Sanaz Karimpour,
Volume 11, Issue 2 (6-2021)
Abstract

Introduction: Considering the accreditation of international standards of hospitals and the necessity to improve the safety and quality of patients’ care, this study aimed at evaluating reliability among nurses using predictive analysis of cognitive errors and human event analysis techniques.
Material and Methods: The analysis of nurses̓ tasks was done by HTA method. Then, the types of errors and their causes were identified by TRACER method. In the next step, the error probability of each task was calculated by ATHEANA method. In order to calculate the probability of total event, the probability of human error was imported to probabilistic risk assessment.
Results: Factors affecting performance of the nurses were included: the complexity of the work, high workload, nurse’s experience, work environment design, fatigue, anxiety, shortage of the workforce, insufficient time period for doing job, sleep disturbance, and poor lighting and noise pollution. According to the instruction of ATHEANA method, the error probability for each base event was considered 0.001. Given that there are 15 base events, the probability of human error in the heart attack event was calculated 0.015.
Conclusion: The finding of this study was indicated the need for providing required nursing workforce, reducing overtime, scientific planning for nurses’ work shifts and giving practical training and stress management methods in the emergency conditions.
Ehsan Ramezanifar, Kamran Gholamizadeh, Iraj Mohammadfam, Mostafa Mirzaei Aliabadi,
Volume 13, Issue 1 (3-2023)
Abstract

Introduction: Risk assessment is a scale for predicting reliability and can manage interactions between components and process variables. Moreover, the reliability of one component or barrier affects the overall risk of the system. Being one of the most critical safety barriers of the storage tank, the failures of Fixed Foam Systems (FFS) on demand can result in severe consequences. FFS, is of grave importance in decreasing the risks associated with fires and damages.
Material and Methods: This study aims to determine the probability of root causes related to FFS failure through Fuzzy Fault Tree Analysis (FFTA) to estimate system reliability. In conventional fault tree analysis, accurate data is usually used to assess the failure probability of basic events. Therefore, the introduced approaches were employed to quantify failure probabilities and uncertainty handling. Finally, system reliability was estimated according to the failure probability of the top event.
Results: The findings showed that 13 baseline events involved FFS performance. According to the results, failures of cable path and detection system (or resistance temperature detectors), set the activation switch (multi-position) incorrectly, and foam makers not continuously running are the three most critical basic events influencing the reliability of fixed foam systems. In addition, this paper estimated the system reliability at 0.8470.
Conclusion: The results showed that the FFTA could be used in matters such as reliability evaluation failure and risk assessment using experts’ judgment. This paper can also show the adaptation of the fuzzy approach to assess the failure probability of the basic event in the fault tree analysis (FTA).
Asghar Hadi, Hananeh Haghighatnia, Arina Hesami, Yahya Rasoulzadeh,
Volume 13, Issue 1 (3-2023)
Abstract

Introduction: Computer vision syndrome (CVS) is one of the most common health concerns associated with the extensive use of computers, particularly in the working environment. Since recent studies have shown the high prevalence of CVS, it is necessary to have an appropriate tool for assessing this prevalence. The present research aims to translate the CVS questionnaire and analyze its validity and reliability and assess the incidence of this condition among the staff members at Tabriz University of Medical Sciences.
Material and Methods: The translation of the main questionnaire into the Persian version was carried out in three steps. Two coefficients including the content validity ratio (CVR) and the content validity index (CVI) were used to evaluate the content validity of the questionnaire. The reliability of the questionnaire was examined using two methods including internal consistency (Cronbach’s alpha) and test-retest. In total, 240 participants were asked to fulfill the questionnaire in order to investigate the prevalence rate of CVS among the staff members of Tabriz University of Medical Sciences. After removing the ineligible ones, 219 questionnaires were examined.
Results: The internal consistency coefficient and Cronbach’s alpha coefficient were 0.91 and 0.89, respectively. Out of a total of 102 women and 117 men, only 19 women and 21 men did not have CVS. Among the studied symptoms, eye redness (78.1%), burning (76.7%), and headache (74%) were the most prevalent in the statistical population. No significant relationship was observed between the final score of CVS and gender.
Conclusion: In terms of validity and reliability, the questionnaire was found to be satisfactory. The prevalence of CVS among the staff members of Tabriz University of Medical Sciences was high (81%). To determine the etiologies, further research is needed.
Rajabali Hokmabadi, Esmaeil Zarei, Ali Karimi,
Volume 13, Issue 2 (6-2023)
Abstract

Introduction: Reliability is always of particular importance in system design and planning; thus, improving reliability is among the approaches for achieving a safe system. Simulation methods are widely used in system reliability assessment. Therefore, this study aims to assess the reliability of the City Gate Gas Station (CGS) using Monte Carlo Simulation (MCS).
Material and Methods: This descriptive and analytical study was conducted in one of the CGSs of North Khorasan Province in 2021. The CGS process was carefully examined and its block diagram was plotted. Then, failure time data of CGS equipment were collected over 11 years and time between failures of subsystems was calculated. The failure probability distribution function of subsystems was determined using Easy Fit software and Kolmogorov-Smirnov test. Moreover, subsystems’ reliability was estimated by MCS. Finally, station reliability was calculated considering the series-parallel structure of the CGS.
Results: The results revealed that the failure probability density distribution function of CGS subsystems was based on gamma and normal functions. The reliabilities of filtration, heater, pressure reduction system, and odorize were calculated as 0.97, 0.987, 0.98, and 0.992 respectively, and their failure rates were 0.000003477, 0.0000014937, 0.0000023062, and 0.0000009169 failures per hour respectively. The station reliability was calculated as 0.93.
Conclusion: The failure probability distribution function and reliability assessment of subsystems were determined by data modeling and MCS respectively. Filtration and pressure reduction systems had the highest failure rate and required a proper maintenance program.
Zeinab Rostami, Mohammad Reza Abedi, Parisa Nilforooshan,
Volume 13, Issue 4 (12-2023)
Abstract

Introduction: Due to the lack of an instrument for measuring the career issues of those with bipolar disorder, the present study was conducted to develop and examine the psychometric characteristics of the Career Issues Inventory for Persons with Bipolar Disorder (CII-BD).
Material and Methods: To check the diagnostic validity, via purposive sampling and interviews by a psychiatrist, 108 people were selected from two sample groups (53 normal people and 55 participants with bipolar disorder). The items were extracted from three sources including scientific articles related to the career issues of bipolar people, interviews with individuals with bipolar disorder, and interviews with experts using the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) systematic qualitative method. Finally, the items of the CII-BD were reduced to 81 questions. Content, construct, and convergent validity plus factor analysis of CII-BD were also examined. The reliability of CII-BD was evaluated by internal consistency and test-retest method with seven weeks intervals after the initial implementation of the CII-BD.
Results: The convergent validity of the sum score of CII-BD with the sum score of the symptom inventory of people with bipolar disorder among the sample of normal people and the sample of persons with bipolar disorder was (r=0.79, P<0.01, N=53) and (r=0.78, P<0.0001, N=53) respectively. In construct validity examination, nine subscales were extracted using the factor analysis method with varimax rotation, which included communication problems, poor work performance, insecurity, grandiosity, unreliability, change-seeking, vulnerability, lack of boundaries, and lack of self-control towards the opposite sex. In the reliability analysis, Cronbach’s alpha coefficient was 0.96 (N=55, participants with bipolar disorder) and 0.86 (N=53, normal people), respectively, P<0.05, showing the high internal consistency of CII-BD. The test-retest correlation coefficient of the sum scores of the CII-BD was r = 0.91, P < 0.01, which indicated the credible stability of the CII-BD.
Conclusion: The CII-BD is a valid and reliable instrument to measure the specific career issues of bipolar persons and their early vocational rehabilitation. It is suggested that future research should focus on choosing a job and job placement for bipolar disorder persons.
Yalda Torabi, Neda Gilani, Yousef Mohammadian, Ali Esmaeili,
Volume 14, Issue 1 (3-2024)
Abstract

Introduction: Acceptance of Health, Safety, and Environment (HSE) rules plays a crucial role in determining the performance of employees in HSE-related areas at the workplace. This study aimed to design a questionnaire to investigate influential factors on acceptance of HSE rules among employees.
Material and Methods: The face validity of the survey was assessed by ten individuals from the target population, while content validity was evaluated by ten HSE experts using both quantitative and qualitative methods. The impact scores were calculated for the quantitative assessment of face validity, and the Content Validity Ratio (CVR) and Content Validity Index (CVI) values were used to assess content validity. Construct validity was determined through Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) involving 506 participants. The reliability of the survey was evaluated using Cronbach’s alpha and the Intraclass Correlation Coefficient (ICC).
Results: All items in the survey showed satisfactory levels of impact score (>1.5), CVR (>0.69), and CVI (>0.79). The mean values for the Impact score, CVI, CVR, and S-CVI-UA were 4.26, 0.963, 0.944, and 0.62, respectively. The survey and its dimensions demonstrated strong reliability, as indicated by Cronbach’s alpha and ICC values exceeding 0.70. Additionally, EFA successfully identified the structure of the questionnaire, and CFA confirmed its goodness of fit.
Conclusion: The Persian version of the questionnaire demonstrated satisfactory validity and reliability. This instrument can be effectively used to assess the factors that influence the acceptance of HSE rules among employees in various workplace settings.

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