Participants and data collection
The present cross-sectional study was conducted from March 5th to April 5th, 2020. We targeted all of the health care workers such as nurses, doctors, emergency medical service staff, clinical, and public health technicians working in Iran ministry of health and medical education. We aimed for a convenience sample of participants. Informed written consent was obtained from all the participants included. Afterward, the anonymous online questionnaires were distributed among them. Accordingly, each health worker was allowed to fill the questionnaire for only one time.
This questionnaire included the subjects’ sociodemographic information such as age, marital status, sex, job title, shift working (fixed morning, fixed evening, fixed night or rotational), type of employment (contractual or permanent), over times per month (hrs.), duration of employment (in years), educational level (diploma, bachelor's, master's, doctoral, and higher), Governmental workplace (yes or no), having contact with COVID- 19 patients at workplace (yes or no), interest in job (yes or no), the increased working hours due to COVID-19 prevalence (yes or no), ward of work ( ICU, operating room, laboratory, emergency, radiology, nursing station, COVID-19 service center, or others).
To assess workload, we applied the NASA-TLX (NASA -Task Load Index) technique. Correspondingly, this technique was developed by the Human Performance Group at NASA Ames Research Center, which involved 6 subscales as follows: mental pressure, physical pressure, temporal pressure, performance, effort, and frustration. 20-step bipolar scales were then used to obtain ratings for these subscales. In this regard, the score of each scale was from 0 to 100. NASA-TLX score was also calculated by multiplying each subscale rate to its weight. Afterward, the overall workload was obtained by summing across scales and dividing by 15[9, 10]. Mohammedi et al. in their study indicated the acceptable reliability of the NASA-TLX among health workers, with Cronbach’s alpha = 0.897.
General Health Questionnaire (GHQ-12)
To evaluate the mental health (the psychosocial well-being), the General Health Questionnaire-12 (GHQ-12) was applied. Accordingly, GHQ was developed by Goldberg & Williams in 1972. Although this instrument initially had 60 items, currently there is a range of brief versions of the questionnaire including the GHQ-30, the GHQ-28, the GHQ-20, and the GHQ-12. Out of them, the GHQ-12 is short and easy to complete, and its application is appropriate in research settings. The GHQ-12 comprises of 12 items (six of which were positively phrased and six others were negatively phrased). Each item is rated on a 4-point scale (less than usual, no more than usual, rather more than usual, or much more than usual). Correspondingly, we used Goldberg's original scoring method (0, 0, 1, and 1). This method supplies scores ranging from 0 to 12. Also, the appropriate reliability of Persian translation of the GHQ-12 was shown in a study by Montazeri et al. with Cronbach's alpha = 0.87.
All statistical analyses were performed using IBM SPSS Statistics software. The normality of variables was confirmed using the Kolmogorov- Smirnov test. Moreover, chi-square test was used to compare the categorical data between the studied groups. The comparisons of the variables’ difference between the groups were performed using the independent Student's t-test and ANOVA. Linear regression analysis in 3 models (Model 0: linear regression analysis without adjustment; Model I: linear regression analysis with adjustment for the encounter to coronavirus; and Model II: linear regression analysis with the correction of the encounter to the coronavirus, age, gender, marital status, job, experience, type of employment, shift, educational level, governmental, interested, and ward of work) was used for the determination of the association between overtimes of total Task Load score and GHQ score. Moreover, Spearman- test was used to indicate the correlation among overall Task Load score and NASA-TLX questionnaire components’ GHQ scores and age, educational level, and experience. A p-value of less than 0.05 was considered to be statistically significant.