Effect of coronavirus epidemic on job stress and mental workload: A longitudinal study in a chemical industry

Background and aims: The outbreak of COVID-19 is currently a major concern, and timely understanding of peoplechr('39')s mental health status in the workplace has become an important issue. Physical-psychological parameters such as mental workload and job stress are among the most important components in determining the job performance of employees in work environments. This study aimed to evaluate the effect of COVID-19 epidemic on job stress and mental workload of employees in a chemical industry. Methods: This longitudinal study was conducted in two stages (before and during the COVID-19 outbreak in Iran) from December 2019 to May 2020 in a chemical industry in Bushehr province. It should be noted that the first phase of this study was conducted before the outbreak of coronavirus in the form of a cross-sectional study. However, after the outbreak of coronavirus and in order to investigate the changing trend in the parameters of mental workload and job stress among participants, this study was performed in two stages in the form of a longitudinal study.  The statistical population included all employees working in a chemical industry. The sample size was calculated using Cochranchr('39')s formula with an error level of 0.05 and included 182 workers who were selected by simple random sampling method. The inclusion criterion was having at least one year of work experience and exclusion criteria were the presence of chronic mental illness, the use of sedatives, and insufficient willingness to participate in the study. Participants were able to drop out of the study at any stage if they were unwilling. Before starting the study and completing the questionnaires, all the necessary information about how to complete the questionnaires was explained to the staff and they expressed their willingness to take part in the study. However, to prevent a decrease in the number of participants in the study, the number of employees who entered the study included 200 people (182 people + 10% of the total sample size (18 worker)). The NASA-TLX mental workload questionnaire and the HSE job stress questionnaire were used to evaluate mental workload and job stress, respectively. The data collected during the present study were analyzed using IBM SPSS statistical software version 25. The Kolmogorov-Smirnov test was used to test the normality of data distribution. The findings of this statistical test showed that the distribution of data was normal in all cases (p >0.05). Descriptive statistics (mean, standard deviation, frequency) were reported and statistical analysis was performed using paired sample t-test (to compare the mean of characteristics of the two psychological components of mental workload and job stress before and during the outbreak of coronavirus) as well as Chi-Square / Fisherchr('39')s exact test. All tests were performed at a significance level of 0.05. Results: The means of age and work experience of the subjects were 32.88±9.53 and 9.45±4.23 years, respectively. The results of mental workload assessment based on the NASA-TLX index showed that the mean score of mental workload before and during the prevalence of coronavirus disease was 56.32± 9.58 and 66.45±11.82, respectively, and  that there was a significant relationship between these values (p <0.05). Furthermore, a significant correlation was observed between the mean score of the dimensions of mental demand, overall performance, and frustration level before and during the outbreak of coronavirus. It was also found that the average score of all aspects of mental workload, except for temporal demand and overall performance, increased during the outbreak of coronavirus. The greatest increase was observed in the values of mental demand components and frustration level (Table 2). The results of the job stress assessment showed that the mean score of job stress before and during the outbreak of coronavirus disease was 80.78±18/29 and 68.88±12.74, respectively. Moreover, it was found that the prevalence of coronavirus disease significantly increased the job stress level of employees (p <0.05). Ultimately, these findings showed a significant relationship between the values of mental workload and job stress in employees before and during the coronavirus disease (p<0.05). Conclusion: An examination of peoplechr('39')s mental workload based on the NASA-TLX index revealed that the prevalence of COVID-19 significantly increased the mental workload of the studied staff. It was found that the mean values of the dimensions of mental demand and the frustration level were significantly increased at the time of the outbreak of COVID-19. The findings revealed that the prevalence of COVID-19 had increased the level of mental workload imposed on employees, as well as the level of frustration, insecurity, and stress of employees when performing their duties. It was also found that the COVID-19 epidemic significantly reduced employee performance, making staff less satisfied with their overall performance in the workplace. Previous studies have also shown that the spread of viral diseases can increase a personchr('39')s workload, which is consistent with the results of the present study. The study revealed that occupational stress levels increased during the outbreak of coronavirus. Previous studies have shown that the spread of viral diseases such as Mers and COVID-19 increases the level of anxiety, stress, insomnia, and depression among people. A study by Kim et al. revealed that after the outbreak of viral diseases such as Middle East Respiratory Syndrome (MERS-COV), a personchr('39')s level of burnout and stress increased, which could severely affect a one’s job performance, which is in tandem with the results of the present study. The present study was conducted for the first time to investigate the effect of coronavirus outbreak on physical-psychological components in the industrial sector in Iran. Therefore, the results of the present study can provide a novel insight into the impact of coronavirus epidemic on the components of mental workload and job stress in different work environments. The findings of the present study revealed that the prevalence of coronavirus disease has been able to affect different physical and psychological dimensions of personnel in the workplace. Therefore, psychological intervention is essential to improve the mental health of employees during and after the COVID-19 epidemic.