Mostafa Rahmiani Iranshahi, Masoud Shafiee Motlagh, Elahe Dortaj, Maryam Farhadian,
Volume 9, Issue 4 (Iranian Journal of Ergonomics 2022)
Abstract
Background and Objectives: Visual comfort is an important and influential factor on safety, mental health, sleep quality, and musculoskeletal disorders of employees in the workplace. This study aimed to design and develop a questionnaire to assess the visual comfort of employees in the workplace.
Methods: The study was performed on 101 participants (88 men and13 women) in the food industry. First, the available lighting questionnaires in the field of lighting were reviewed, and a question bank was set up. Twenty questions were considered in two sections of natural and artificial lighting (10 questions in each section) based on the opinion of 10 experts in this field. The validity of the questionnaire was assessed using the content validity index (CVI) based on the comments of experts. To validate the questionnaire in the workplace, The lighting of employees' workstations was evaluated according to the Illuminating Engineering Society of North America (IESNA) standards and compared with the results of the questionnaire.
Results: The Cronbach's alpha of natural and artificial lighting visual comfort questionnaire was 0.858 and 0.922, respectively. The total CVI of the questionnaire was 1. There was a significant positive relationship between the score of the visual comfort questionnaire and the workstations' illumination (P = 0.001). More than 97% of employees who had workstations with the desired lighting reported excellent levels of visual comfort.
Conclusion: The visual comfort questionnaire had good and acceptable reliability and validity. This tool is recommended for the use of visual comfort asessments of employees in work environments given the fewer number of and simplicity of sentences.
Mis Afrouz Rostampour, Mr Heidar Mohammadi, Mr Razzagh Rahimpour, Mis Fatemeh Sarvi, Mis Elahe Dortaj, Mr Mansour Ziaei, Mis Simin Safarpour, Mr Abdolrasoul Rahmani,
Volume 9, Issue 4 (Iranian Journal of Ergonomics 2022)
Abstract
Background and Objectives: Mental and physical fatigue of airport staff reduces their job standards and productive concentration. The objective of this study was to examine the sleep quality and its effect on cognitive failure and job performance among airport staffs.
Methods: In this descriptive-analytical study, 200 staff of an airport were chosen by simple random sampling method. The data collecting tools were four questionnaires that comprised demographic characteristics, sleep quality, cognitive failures, and job performance. Data was analysed using descriptive statistics and regression tests.
Results: Based on the findings, the mean total scores of the sleep quality, cognitive failures, and job performance were 6.78 ± 3.23, 65.22 ± 20.36 and 39.59 ± 5.59, respectively. The results showed that the mean score of sleep quality in the two areas of sleep latency (1.5 ± 0.82) and sleep duration (1.43 ± 1.05) was higher than other subscales. According to the findings, there was a significant inverse relationship between sleep quality score and cognitive failures score with job performance score (r = -0.195, P < 0.05), While the sleep quality score and cognitive failure score showed a positive and significant correlation (r = 0.389, P < 0.05).
Conclusion: The findings demonstrated a significant relationship between sleep quality and cognitive failure, so that with decreasing this factor, cognitive failure of airport staff also increased and the probability of the human error increased. Therefore, enhancing the sleep quality and comfort by providing ergonomic solutions the cognitive failure in staff and consequently job performance would be greatly prevented.
