viral disease that originated in Wuhan city of China called coronavirus 2019 (Covid-19) emerged in December 2019 and soon became a worldwide pandemic due to its asymptomatic transmission ability and highest transmission rate.¹ The first confirmed case of COVID-19 in Iran was officially reported on 19 February 2020. ² According to the World Health Organization, more than 248 million people have been infected with Covid-19 since the disease began to November 5, 2021 worldwide, and more than 5 million people have died; Also, more than 5.9 million people have been infected and more than 126 thousand people have died in Iran to November 5, 2021. ³ The prevalence of Covid-19 is very high and the probability of transmission from person to person is high in closed places. ⁴
Covid-19 can affect people's mental health in addition to physical health. ⁵ It can also have a negative impact on the economy, social relationships and public health of people around the world. In order to fight the emerging coronavirus, governments in different countries use physical distancing, quarantine, the use of face masks and hand washing as temporary measures. However, these measures have increased anxiety and decreased quality of life among people around the world. ^4,6,7 Fear and anxiety have also increased among the public due to the social and electronic media that cover the Covid-19 news with daily increases in morbidity and mortality. ⁸
Human Resource (Employees) Is the Most Important Asset of any Country, ⁹ which should pay attention to their health, which is one of the signs of quality of life. Quality of life (QOL) is a multidimensional concept, including functional ability, physical health and mental status of individuals, which is influenced by many important factors such as physical and mental condition, personal beliefs and social relationships. ^10,11 Numerous factors can have a significant impact on a person's health, one of which is anxiety. Nowadays, anxiety caused by the COVID-19 spread is one of the most important anxieties, which can lead to a decrease in quality of life. ^{11, 12}
Therefore, there is a need for a comprehensive understanding of the prevalence of mental health problems during the COVID-19 pandemic in different populations to enable policymakers to take effective countermeasures. Although many studies have assessed the prevalence of these psychological problems, but, most recent studies have focused on one to three different populations ¹³. There are few studies on anxiety and quality of life among workers and industry personnel during the Covid-19 pandemic. Published studies on the Covid-19 pandemic have focused primarily on the status of nurses and health care workers. Therefore, the present study was carried out aimed to investigate the effect of anxiety on the quality of life of employees in the industrial sector.
 
Methods
This study was a descriptive cross-sectional research conducted in the egg processing and packaging plant in 2021. In this study, the statistical population included 212 administrative staff and workers working in the industrial sector, selected by multi-stage random sampling according to inclusion criteria. The questionnaires were completed in person and individually, in approximately 30 minutes. During the time of completing the questionnaire, the researcher was present at the workplace to clear up the ambiguity and answer the questions accurately and completely. Inclusion criteria included having at least one year of work experience, not taking sedatives, not having more than 1 month off due to illness in the past year, no history of high blood pressure, no physical disability, no history of depression and other chronic diseases. The exclusion criterion included improper completion of questionnaires. ¹⁴
In the present study, data was collected by self-report method using demographic information questionnaires, Corona Disease Anxiety Scale (CDAS) and WHOQOL-BREF questionnaire.
Demographic information questionnaire included items such as gender, marital status, age, work experience (year), (BMI), job position, education, family member with chronic illness (diabetes, hypertension, etc.) and having a family member over 65 years old.
The Corona Disease Anxiety Scale (CDAS) validated by Alipour et al. in Iran was used to measure anxiety. This tool has 18 items and two components. Items 1 to 9 measure psychological symptoms and items 10 to 18 measure physical symptoms. This questionnaire is scored in a 4-point Likert scale (never = 0, sometimes = 1, most of the time = 2 and always = 3) and finally the total anxiety intensity score range is from 0 to 54.
Higher scores indicate higher levels of anxiety in individuals. The cut-off point of this questionnaire in Iran is determined and is divided into 3 domains of non-anxiety or mild (0-16), moderate (17-29) and severe (54-30). The reliability of this questionnaire is 0.91 which was obtained using Cronbach's alpha method. ¹⁵
The World Health Organization quality of Life (WHOQOL-BREF) questionnaire is a 26-item multidimensional self-report instrument consisting of four domains: This questionnaire contains a total of 26 questions. Questions 1 and 2 assess general health and overall quality of life. Also, 24 other questions in four domains included physical health (7 questions), mental health (6 questions), social relationships (3 questions) and environmental health (8 questions). Participants score from 1 to 5 on each item on a Likert scale. The total score of each domain can be converted to a scale of 0 to 100 points. Quality of life increases with increasing scores. ^16,17
WHOQOL-BREF has acceptable psychometric properties and can replace WHOQOL-100 to measure quality of life without significant loss of information. WHOQOL-BREF is a reliable and valid assessment and offers a brief overview of quality of life and has excellent psychometric properties with high reliability. ^18,19 The Persian version of this questionnaire has been validated by Nejat et al. with Cronbach's alpha above 0.70. ²⁰ The questionnaires were anonymous and confidential. Data was entered into SPSS software version 24 and analyzed by independent t-test, one-way ANOVA and Pearson correlation coefficient. Significance level in the current study was considered less than 0.05.
 
Results
In this study, 212 workers and administrative staff participated, 167 (78.8%) of whom were male and 45 (21.2%) were female with mean and standard deviation of age and work experience, respectively 33.27±6.6 and 7.24±5.6. Table 1 reflects other data related to the contextual and demographic variables of the study participants.
The mean and standard deviation of anxiety and quality of life scores of participants were 11.60±8.2 and 64.66±10.8, respectively. The highest and lowest quality of life scores were related to social relationships and mental health, respectively. Also, the score of psychological symptoms of anxiety was higher than physical symptoms. Other information is listed in Table 2.
Independent t-test was used to compare anxiety and quality of life scores by gender, marital status, job position, having a chronic illness in the family and having a person over 65 in the family. There was a statistically significant difference between gender with anxiety (P = 0.002) and quality of life (P = 0.008). The Women had higher anxiety scores and lower quality of life than men. Also, the anxiety score in the group of single and married people was statistically significant, so that married people had higher anxiety than single people (P = 0.012). But there was no statistically significant difference between marriage and quality of life score (P = 0.519). There was also a statistically significant difference between the anxiety scores and the quality of life of people over 65 or having a family member with a chronic illness. There was no statistically significant difference between the mean score of anxiety (P = 0.252) and quality of life (P = 0.813) in the group of workers and administrative staff. Table 3 shows more detailed information.
One-way analysis of variance (ANOVA) compared anxiety scores and quality of life in people with different levels of education. The results show that people with lower education had more anxiety than people with higher education. So that people with education middle school had the highest score of anxiety and the lowest score of quality of life. Table 4 shows the other results.
Pearson correlation test was established between anxiety and quality of life with age, work experience and BMI variables. The results show that a significant inverse correlation was observed between age and work experience with quality of life and a significant direct correlation between age and work experience with anxiety. But no significant correlation was observed between BMI with anxiety and quality of life. Table 5. 
The results of Pearson correlation test show that there was a significant inverse correlation between anxiety and quality of life (P <0.001 and r = -0.656). A significant inverse relationship was observed between the components of these two variables after Pearson correlation test between anxiety and quality of life dimensions. Table 6 shows the other information.
 
Discussion
Most research has been done on health's medical staff during the Covid-19 pandemic crisis, and less attention has been paid to the industrial staff, a large percentage of each country's population. Therefore, this study was conducted to investigate the relationship between anxiety and quality of life in employees working in the industrial sector. The results of this study show that the dimension of social relationships and mental health dimension of quality of life had the highest and lowest scores among individuals, respectively, which were consistent with the results of the study by Woon et al. ¹⁹ Contrary to the results of this study, the dimension of social relationships had the lowest score among the dimensions of quality of life in the study of Vitorino et al. ²¹ Also, the results of the study of psychological and physical symptoms of anxiety in this study, showed that psychological symptoms had a higher score than physical symptoms, which psychological symptoms scored higher than physical symptoms in a study by Alipour et al., Which was performed on people aged 18 to 60 years. ²²

 
Table 1. Demographic information of the participants (n=212)

 

 
Table 2. Mean and standard deviation of anxiety, quality of life scores and its dimensions among participants (n=212)

Table 3. Comparison of the quality of life and anxiety scores of participants  )n=212)

Table 4. Comparison of the quality of life and anxiety scores by the education of the participants )n=212)

Table 5. Pearson correlation coefficients between anxiety and quality of life with variables of age, work experience and
BMI among participants (n=212)

^*p <0.05; ^**p <0.01

 
Table 6. Pearson correlation coefficient between anxiety and quality of life dimensions in participants (n = 212)

^* p <0.05; ^** p <0.01