Working environment at home and mental health in employees working from home in Japan during COVID-19 pandemic: A cross-sectional study

Abstract

Objectives

This cross-sectional study aimed to examine the associations of a poor working environment at home with psychological distress and psychosomatic symptoms in employees working from home in Japan during the COVID-19 pandemic.

Methods

The data obtained in October 2021 from an online cohort of full-time employees (E- COCO- J) were used. Participants who worked from home for at least some days per month were included. The poor working environment at home was assessed using 11 items based on the Japanese Ministry of Health, Labour and Welfare recommended checklist. The score ranged from 0 to 11. Psychological distress and psychosomatic symptoms were measured by the Brief Job Stress Questionnaire (BJSQ). The associations between total scores of poor working environment and outcomes were examined by multiple regression analysis, adjusted by age, sex, education, living with family, frequencies of working from home, company size, job demand, job control, and workplace social support.

Results

Two hundred twenty-six employees who were working at home were included. The mean of the summed scores of poor working environments at home was 2.75. After adjusting the covariates, summed scores of poor working environments were significantly associated with high psychological distress (standardized β = 0.21, P = .003) and with high psychosomatic symptoms (β = 0.19, P = .005). For each poor environment, lack of ventilation and difficulty staying hydrated or resting were significantly associated with both outcomes.

Conclusions

Even after adjusting for job stressors and support, working environments at home were associated with employees’ mental health. Appropriate measures and education may be needed.

INTRODUCTION

Mental health is one of the most critical issues among employees during the coronavirus disease (COVID-19) pandemic. The COVID-19 pandemic has promoted the implementation of working from home and has continued as a part of the standard working style. However, some studies reported that working from home increased job demands and conflicts,¹ and influenced physical and mental health outcomes.² The measures to promote mental wellness at home should be explored further.

Poor environmental factors can influence employees’ mental health. Previous studies examined factors such as noise at home,³ lightning at the office,⁴ and poor air quality in an experimental environment.⁵ Lack of acoustic and visual privacy, inadequate thermal conditions, and lack of control over various environmental factors decreased employees’ environmental satisfaction.⁶ Moreover, the amount of space available for individual work and storage was identified as the most significant determinant of occupant workspace satisfaction.⁷ Although some previous studies reported that working in a personal space (e.g., cell office) was associated with high satisfaction with the environment⁸ and better health outcomes^9,10 than a large open-plan office, the relationship between the working environment “at home” and mental health has not been investigated well.

Working at home can enable employees to exercise autonomy and control of the environment on an individual basis in terms of ambient factors. Still, whether the environment is desirable from the view of occupational health and safety is unknown. The Japanese Ministry of Health, Labour and Welfare published a recommended checklist for the home environment for working (https://www.mhlw.go.jp/seisakunitsuite/bunya/koyou_roudou/roudoukijun/karoushizero/pdf/checklist.pdf). Examining the relevance of these items to benefit the mental health of employees working at home may be important to change employers’ attitudes and promote their support for employees’ home environment.

Thus, this cross-sectional study aims to examine the association of a poor working environment at home with mental health (i.e., psychological distress and psychosomatic symptoms) in employees working from home in Japan during the COVID-19 pandemic.

METHODS

Study design and subjects

This study was designed as a cross-sectional study using the Employee Cohort Study during the COVID-19 pandemic in Japan (E-COCO-J). Full-time employees were recruited from the panel of the Japanese online survey company. The baseline data of the cohort study were obtained in March 2020 (n = 1448), and the survey was repeated for those participants who participated in the baseline. This study retrieved the data in October 2021 (n = 1086). Participants currently working who reported working from home at least some days per month were included in the analysis.

This study was approved by the Research Ethics Committee of the Graduate School of Medicine/Faculty of Medicine, the University of Tokyo No. 10856-(2) (3) (4) (5). This study followed the Strengthening the Reporting of Observational Studies (STROBE) checklist.

Measurement variables

Poor working environments at home

The original 11 items were used to assess the poor working environments at home. Items were developed through discussions with occupational health physicians (NS, RK, and NK) based on the recommended checklist for employees working from home about the working environment, which was publicly released by the Japanese Ministry of Health, Labour and Welfare in March 2021.¹¹ The response option of each item was “Agree” or “Disagree.” While the original items used in the survey were asked positively (e.g., Have enough space for working), the scores were reversed to clarify the negative effects of working environments in this study (e.g., inadequate space for working). Other specific items are listed in Table 1. We calculated the number of “Agree” responses of poor environments to sum, ranging from 0 to 11. The participants who did not live with anyone were required to answer “Disagree” for the item “Family members living with you make it difficult to concentrate on work.”

Psychological distress and psychosomatic symptoms

Psychological distress and psychosomatic symptoms in the last 30 days were assessed by the Brief Job Stress Questionnaire (BJSQ).¹² Psychological distress was comprehensively evaluated in 18 items related to lack of vigor, anger-irritability, fatigue, anxiety, and depression. Psychosomatic symptoms were evaluated in 11 items about various symptoms (e.g., loss of appetite and headache). All items were rated on a four-point Likert scale from 1 (“Never”) to 4 (“Almost always”). The sum of the subscale was calculated as a score, with higher scores indicating greater distress. The reliability and validity of BJSQ among Japanese employees have been established.¹³

Covariates

We selected covariates to use for statistical analysis: age, sex, education (measured in May 2020), living with family (measured in August 2020), frequencies of working from home, company size (measured in March 2020), job demand, job control, supervisor support, and coworkers’ support. Job demand was measured by 3 items of BJSQ (i.e., “I have an extremely large amount of work to do,” “I can’t complete work in the required time,” and “I have to work as hard as I can”). Job control was measured by 3 items of BJSQ (i.e., “I can work at my own pace,” “I can choose how and in what order to do my work,” and “I can reflect my opinions on workplace policy”). The possible score of job demand and job control ranged from 3 to 12. Supervisor support and coworkers’ support were measured by 3 items of BJSQ (i.e., “How freely can you talk with the following people?” “How reliable are the following people when you are troubled?” and “How well will the following people listen to you when you ask for advice on personal matters?”), ranging the score from 3 to 12 each. For participants’ characteristics, we also measured marital status and industry (measured in May 2020).

Statistical analysis

The associations of poor work environment at home with psychological distress and psychosomatic symptoms were examined to compare the answer of “agree” or “disagree” about poor work environment at home using unpaired t-test. Multiple linear regression analyses were conducted to examine the relationship between working environments at home and psychological distress and psychosomatic symptoms, adjusting for age, sex, education, living with family, frequencies of working from home, company size, job demand, job control, supervisor support, and coworkers’ support. In order to identify potential confounders, we drew a directed acyclic graph (DAG) for the association between poor working environment and outcomes by using DAGitty (http://dagitty.net). These covariates were selected to achieve sufficient adjustment (Figure S1). Job stressors potentially impact both the home environment and mental health because stressful work provides employees with less motivation and less time to tidy up the working environment at home. Job demand, job control, and workplace social support were selected as major psychosocial factors at work. Statistical significance was set as a two-sided P < .05. SPSS 28.0. Japanese version (IBM) was used.

RESULTS

A total of 226 employees experiencing working from home at least some days per month were included. Participants’ characteristics are presented in Table S1. The mean age was 43.8 years old. Male (59%), undergraduate educational degree (50%), living with anyone (70%), and company ≥1000 employees (49%) were included. Frequencies of working from home were less than once per week (10%), once per week (15%), 2–3 days per week (36%), 4 days per week (15%), and every day (24%). The mean of summed scores of poor working environments at home was 2.75 (standardized deviation = 2.46).

The mean of psychological distress and psychosomatic symptoms of each poor work environment at home is presented in Table 1. The most frequent poor environments were “Unknown contact information of the person in charge at the company in case of major changes in the work environment at home and in case of physical or mental health problems” (45%), “No measures for earthquake preparedness or to prevent damage to electrical cords and other wiring” (39%), and “Not well-arranged fixtures (e.g., chair, displays) for comfortable and ergonomic posture” (36%).

In crude data, almost all poor environments were significantly associated with high psychological distress, except for “Family members living with you make it difficult to concentrate on work,” “Insufficient light for working,” and “Unknown contact information of the person in charge at the company in case of major changes in the work environment at home and in case of physical or mental health problems.” Six poor environments were significantly associated with psychosomatic symptoms. The result of the regression analysis of crude data showed that the summed scores of poor working environments correlated significantly with psychological distress (B = 1.22, standardized error [SE] = 0.29, standardized β = 0.27, P < .001), and psychosomatic symptoms (B = 0.68, SE = 0.18, β = 0.25, P < .001) (data are not shown in Tables).

The adjusted associations using multiple linear regression analysis are presented in Table 2. The summed scores of poor working environments were significantly associated with psychological distress in the adjusted model (B = 0.99, SE = 0.31, β = 0.22, P = .001) and with psychosomatic symptoms in the adjusted model (B = 0.55, SE = 0.19, β = 0.20, P = .003). University degree (ref. high school), working from home every day (ref. less than once per week), and job control were significantly associated with low psychological distress, and age, job control, and supervisor support were significantly associated with low psychosomatic symptoms (data are not shown in Tables). Regarding each poor environment, lack of ventilation, and difficulty staying hydrated or resting were significantly associated with both outcomes. “No measures for earthquake preparedness or to prevent damage to electrical cords and other wiring” was significantly associated only with high psychological distress. Inadequate space was marginally significantly associated with high psychological distress (P = .055) and was significantly associated with high psychosomatic symptoms. “Noise, odor, etc. that would interfere with the work” was significantly associated only with high psychosomatic symptoms.

DISCUSSION

This study found that the greater number of poor working environments at home was associated with high psychological distress and psychosomatic symptoms. Both outcomes were significantly associated with unavailable ventilation, and difficulty staying hydrated or resting. The present finding showed that home office conditions are essential for employees’ mental health and healthy work at home.

After adjusting covariates, including job demand, job control, and workplace support, the summed scores of poor working environments were significantly associated with high psychological distress and psychosomatic symptoms. This study thus showed that a poor environment at home was associated with deteriorated mental health, independent of job stress. This result was in line with literature that addressed the importance of the environment on mental health during COVID-19.² Physical discomfort leads to feeling stuffy, easily tired, and having difficulty concentrating.¹⁴ Such a failure to perform may lead to distress when working from home because employees are likely to be evaluated based on work products.

As for individual environmental factors, lack of ventilation, no measures for earthquakes, and difficulty in staying hydrated or resting were significantly associated with high psychological distress, while inadequate space with a marginally significant association. Lack of earthquake preparedness and organizing electric cords may cause perceived unsafety, leading to poor mental health, but a previous study reported that poor mental health reduces motivation to prepare for disaster.¹⁵ A causal relationship should be cautioned. Difficulty in staying hydrated or resting may reflect not only the physical limitation of the home layout (e.g., unavailability due to family members’ use) but also a psychosocial work environment, such as a stuffed work schedule, need to respond to a call or chat quickly, and highly monitored by employers. Although this study considered the job stressors (i.e., job quantity and job control) and workplace support, the employees at home may have another job-related stressful situation. Promoting and supporting employees to take something to drink and take rests during work is a meaningful action to improve mental health. Considering the Japanese living condition (e.g., dense, small, and high cost), it may be difficult for some employees to prepare adequate space and ventilation. In such cases, companies may have to provide economic support or another place (such as satellite offices) to work as a mental health measure.

Interference from noise or odor was significantly associated with high psychosomatic symptoms. A previous study during the COVID-19 pandemic among Japanese workers working from home reported that workers with housemates showed high-stress reactions if the noise from housemates interfered with their work.³ In our study, the item related to family members did not show a significant association with outcomes. It may be because the participants who did not live with anyone were required to answer that they do not have such a stressful environment. Although the exact source of the noise in the present findings is unknown, it is not surprising that noise and odor can lead to psychosomatic symptoms, such as loss of appetite, dizziness, and headache, regardless of the source.

In this study, insufficient artificial light for working was not associated with either psychological distress or psychosomatic symptoms, even in the crude model. A recent review about the effects of lightning at workplace on health suggested that the appropriate lighting condition for working from home is still under discussion.⁴ A previous study suggested that employees’ mental health can be affected by screen blue light and daylight exposure at office.⁴ Insufficient artificial lighting at home may impact eye condition, but they may not experience mental health issues if they get an appropriate amount of sunlight and pay less screen time during work hours.

Interference from family was not associated with both outcomes, against the previous study.³ The association may be underestimated because 30% of the participants in this study lived alone. Further study with enough number of employees with family is needed.

The difference in environment factors between related and unrelated outcomes, found in this study, is unclear, but two environment which showed significant associations with both outcomes (i.e., lack of ventilation and difficulty in staying hydrated or resting) seemed to be related to basic physical needs of human for healthy work, and offered individuals less discretion, compared with other environment. Further examination is necessary to confirm the reproducibility of the results.

Nearly half of the respondents did not know the contact information for the work environment at home and health issues, and more than one in three reported a lack of measures for earthquake and electric cord protection and poor arrangement of fixtures for ergonomic posture. Although these factors have a relatively small effect on mental health in this study, they are important and basic environmental factors that should be ensured at home from an occupational health and safety perspective. The checklist for the home environment should be used with education for employees.

The authors focused on the home environment in this study. However, social support at work (e.g., organizational, supervisor, and coworkers) may impact more on mental health in employees working from home.^1,2 In this study, job control largely impacted on mental health, weakening the association of poor working environment with outcomes. Employers should consider that other psychosocial factors are important “environments” for employees working from home.

In this study, participants showed slightly low job demand and high job control compared with the national average of workers (not restricted to employees working from home) before COVID-19 pandemic, while the mean of psychological distress and psychosomatic symptoms were almost the same. Further study using different datasets is needed to reproduce the results.

LIMITATION

This study has several limitations. The participants were recruited from the online survey panel, leading to sampling bias. People with high technology literacy and affinity with Internet use may be likely to participate in this study. Moreover, the proportion of employees working from home among study population was low (20.8%: n = 226/n = 1086). Generalizability thus can be limited. Assessing the outcomes by self-reporting questionnaires can cause reporting bias. Participants may be likely to give socially desirable responses. Some covariates were measured before the data used in the analysis was obtained (e.g., living with family or not). The situation had possibly changed, leading to inaccurate results. The questionnaire on the working environment at home was developed originally and was not validated. Although job demand, job control, and support were adjusted in this study, other job stressors, such as working hours, were not considered. The cross-sectional nature of this study leads to the risk of causal reverse. People with poor mental health may have difficulty arranging the appropriate home environment. A longitudinal study to examine this association is needed in the future.

CONCLUSION

A poor working environment at home was associated with the poor mental health of employees working there. A company should encourage employees to arrange an appropriate environment, such as preparing enough space to work at home, ventilation, and setting conditions to make it easy to drink and rest during work. A governmental published checklist is available and valuable to educate employees. If the appropriate work environment cannot be made available for employees, companies can provide another well-organized place to work instead of home to protect the mental health of employees.

AUTHOR CONTRIBUTIONS

NK was in charge of this study, supervising the process, and providing his expert opinion. NS, YM, and NK organized the study design and analyzed the data. RK created the questionnaires about the working environment at home. Collaborators DN, KT, and KI ensured that questions related to the accuracy or integrity of any part of the work were appropriately investigated and resolved. All authors participated in conducting the survey. NS and NK wrote the first draft of the manuscript, and all other authors critically revised it. All authors approved the final version of the manuscript.

FUNDING INFORMATION

This work was supported by the 2021 Health, Labour and Welfare Policy Research Grants; from the Japan Ministry of Health, Labour, and Welfare and internal funds of the Division for Environment, Health, and Safety, the University of Tokyo.

CONFLICT OF INTEREST STATEMENT

NS reports personal fees from Medilio Co., Ltd., outside the submitted work. DN reports personal fees from Startia, Inc., en-power, Inc., MD.net, and an honorarium from Takeda Pharmaceutical Co., outside the submitted work. NK reports grants from SB AtWork Corp, Fujitsu Ltd, and TAK Ltd, personal fees from the Occupational Health Foundation, SB AtWork Corp, RIKEN, Japan Aerospace Exploration Agency (JAXA), Japan Dental Association, Sekisui Chemicals, Junpukai Health Care Center, Osaka Chamber of Commerce and Industry, outside the submitted work. KI and NK are employed at the Department of Digital Mental Health, an endowment department supported with an unrestricted grant from 15 enterprises (https://dmh.m.u-tokyo.ac.jp/c) outside the submitted work.

DATA AVAILABILITY STATEMENT

The data supporting this study’s findings are available from the corresponding author, NS, upon reasonable request.

DISCLOSURE

Approval of the research protocol: This study was approved by the Research Ethics Committee of the Graduate School of Medicine/Faculty of Medicine, The University of Tokyo, No. 10856-(2) (3) (4) (5). Informed consent: Online informed consent was obtained from all participants with full disclosure and explanation of the purpose and procedures of this study. We explained that their participation was voluntary, and they could withdraw consent for any reason simply by not completing the questionnaire. Registry and registration number of the study/trial: N/A. Animal studies: N/A.

ROLE OF THE FUNDER

The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; in the preparation, review, or approval of the manuscript; and in the decision to submit the manuscript for publication.

REFERENCES