key: cord-0711461-71xxol2m
authors: Kawakami, Norito; Sasaki, Natsu; Asaoka, Hiroki; Kuroda, Reiko; Tsuno, Kanami; Imamura, Kotaro
title: Effects of workplace measures against COVID-19 and employees' worry about them on the onset of major depressive episodes: A 13-month prospective study of full-time employees
date: 2022-04-16
journal: J Affect Disord
DOI: 10.1016/j.jad.2022.04.040
sha: 4b03c171b37559d1e5de9d27558d875c217672ae
doc_id: 711461
cord_uid: 71xxol2m

BACKGROUND: Workplace measures against COVID-19 may prevent the onset of major depressive episode (MDE) in the working population. This 13-month prospective study aimed to investigate the association of the number of workplace measures against COVID-19 and employees' worry about the measures on the onset of MDE during COVID-19 outbreaks in Japan. METHODS: Data were collected from employees by using online questionnaires at baseline (May 2020) and the 7th survey (June 2021). The onset of MDE during the follow-up was retrospectively measured at the 7th survey, with a self-report scale based on the Mini-International Neuropsychiatric Interview according to the DSM-IV/DSM-5 criteria. Participants were asked to report the number of workplace measures against COVID-19 in their companies/organizations and their worry about these measures (scored 0–3). Multiple logistic regression was conducted of MDE on the number of workplace measures and worry about these, adjusting for demographic and work-related covariates and psychological distress at baseline. RESULTS: Among 968 respondents employed in May 2020, 827 completed the 7th survey in June 2021 (80%). We excluded 75 respondents who reported they had an MDE in May 2020 or earlier. Worry about workplace measures was significantly associated with the onset of MDE after adjusting for the covariates (OR for 1 score increase, 1.53; 95% CI, 1.02–2.32; p = 0.042). No significant association was found between the number of workplace measures and the onset of MDE. CONCLUSIONS: Worrying about workplace measures taken by company/organization may be a risk factor for the onset of an MDE among employees during the COVID-19 pandemic.

Deteriorated mental health status in the community and working populations has been recognized as a major public health concern during the global pandemic of the novel coronavirus disease since late 2019 (Giorgi et al. 2020; Abbott 2021) . Studies during the epidemic have consistently reported a higher prevalence of psychiatric symptoms, such as depression, anxiety, post-traumatic stress symptoms, and insomnia (Cenat et al. 2021; Vizheh et al. 2020; Wu et al. 2021; Xiong et al. 2020) in these populations during the COVID-19 epidemic, and found that these symptoms actually increased along with the COVID-19 epidemic compared to the pre-epidemic era (Bierman and Schieman 2020; Kwong et al. 2020; Niedzwiedz et al. 2021; Pierce et al. 2020) , although the impact may vary among subgroups such as people with less education and health care workers Sasaki et al. 2020a ). Diagnosed common mental disorders such as major depressive episode (MDE) may also increase under such stressful conditions. However, no previous study has examined the onset of MDE and associated factors in the COVID-19 epidemic.

A review conducted in an early phase of the COVID-19 pandemic suggested that taking hand hygiene and wearing face masks, and organizational measures such as improvement of workplace hygiene and expressions of concern from the company were associated with less severe psychiatric symptoms in employees who returned to work after a COVID-19 outbreak (Tan et al. 2020 ). We have also found that the number of workplace measures against significantly and negatively correlated with psychological distress in a cross-sectional study of full-time employees in Japan in an early phase of COVID-19 epidemic (Sasaki et al. 2020b ).

Workplace measures against COVID-19 may prevent not only psychiatric symptoms, but also the onset of MDEs during the epidemic. However, workers may still worry about insufficiency or ineffectiveness of preventive measures taken against COVID-19 by their companies/organizations, depending on the employees' perceived needs and the characteristics of companies/organizations, such as type of industry, location, structures, and work content (ILO 2020). Employees' perceptions on effectiveness of implemented workplace preventive measures may be another good indicator of the quality of those preventive efforts. Workers' worry about workplace measures may also be associated with the onset of an MDE in the COVID-19 epidemic.

To date, no study has been conducted on the impact of workplace measures against COVID-19 and employees' worry about these on the onset of MDEs in the working population.

This 13-month prospective study aimed to investigate the effect of workplace measures against COVID-19 and worry about the workplace measures taken, both reported by employees,

This study was a 13-month prospective study from May 2020 until June 2021, embedded in a repeated panel survey of full-time workers of Japan during the COVID-19 epidemic, the E-COCO-J study (Sasaki et al. 2020a (Sasaki et al. , 2020b Sasaki, Imamura, et al. 2021; Sasaki, Kuroda, et al. 2021; Hidaka et al. 2021) . A total of 1,448 full-time employees were recruited for the 1st survey in March 2020, during the initial, small COVID-19 epidemic in Japan, from participants of another larger survey conducted in 2019 by an Internet survey company from a large pool of preregistered community-dwelling residents across Japan. After the recruitment, seven (1st to 7th) consecutive surveys were conducted of the respondents between March 2020 and June 2021. We used the 2nd wave survey that was conducted in May 2020 to collect baseline data. This was because workplace measures against COVID-19 substantially changed between the 1st and 2nd wave surveys ) and we could obtain data of stable measurement of the workplace measures by using the 2nd wave survey. We limited the subjects to those currently employed, excluding those who were unemployed, temporarily laid-off, on maternity-, childcareor nursing care-leave, or on a long-term sick leave. The 7th survey used a self-rated version of M.I.N.I to ask participants' experience of major depressive episode (MDE) according to DSM-5 during the previous 13 months, as well as the month and year of the onset of the MDE if they experienced it. Based on the information collected, we excluded those who reported having had an MDE in May 2020 or earlier.

The experience of an MDE was measured with a self-report scale developed based on the Mini-International Neuropsychiatric Interview (M.I.N.I.) (Sheehan et al. 1998; Otsubo et al. 

The degree of implementation of workplace measures for prevention against and control of COVID-19 was assessed by using a 23-item original scale, which was developed based on workplace measures in a past outbreak of novel influenza and a discussion by occupational health professionals Sasaki et al. 2020b) . Briefly, the items covered the surveys (intraclass correlation coefficient [ICC], 0.748). The score 0-23 was used as a continuous variable in the main analysis; a categorization of the score into the tertiles (low, moderate, and high implementation) was made for supplemental analyses. The same scale was used in the 3rd, 4th, 5th, and 6th surveys.

A single item question asked if a respondent worried about the insufficiency of workplace measures taken by his/her company/organization. The 4-point responses (strongly agree, somewhat agree, somewhat disagree, and strongly disagree) were scored 3, 2, 1, and 0, respectively. The concordance between the 2nd and 3rd surveys was 0.505 in intraclass correlation coefficient (ICC). The same scale was asked in the 3rd, 4th, 5th, and 6th surveys. The score was used as a continuous variable in the main analysis, while the four categories were used for supplementary analyses. The worry (or a concern) is theoretically defined as a psychological threat (a stressor) rather than a stress response, such as anxiety.

All covariates were measured at baseline (the 2nd survey). The demographic covariates included sex (male or female), age (20-34 years, 35-49 years, or 50+ years), marital status (single or married), and living in areas with the governmental emergency call in May 2020 (yes or no).

Job-related covariates included occupation (managers, non-manual workers, manual workers, or health care workers), remote work (no or any type of remote work). Health-related covariates included chronic physical condition (any of 10 predetermined physical conditions) and psychological distress (depression and anxiety) in the last 30 days, measured by using the Kessler 6 (K6) scale (Kessler et al. 2003; Furukawa et al. 2008) , and used as a continuous score (0-24).

Fear of COVID-19 was measured using a single item scale, -Do you worry about COVID-19?‖; the 6-point Likert-type response was scored from 0 to 5 (Hidaka et al. 2021 ).

The numbers and proportions of participants were tabulated by groups, classified based on the baseline covariates. The averages of the number of workplace measures and the score of worry about workplace measures were compared between the onset cases of MDE and the other respondents (t-test). Multiple logistic regression was conducted for the onset of MDEs on the number of workplace measures against COVID-19 and the score of worry about workplace measures, adjusting for the other covariates (sex, age groups, marital status, occupation, remote work, living in emergency call areas, fear of COVID-19, chronic condition, and psychological distress).

As supplemental analyses, we used the Cox proportional hazard model. This was because the Cox proportional hazard model is able to (1) use information from censored cases, (2) consider the timing of onset of MDE, and also (3) incorporate information of time-dependent change of exposure variables (i.e., the number of and worry about the measures). However, it should be noted that, in this study, the first merit may be small because the sample was limited to respondents who completed both baseline and last follow-ups surveys; the second merit may be offset by unviable reporting of the onset month of MDE by respondents. First, the Cox 

A total of 1,032 responded to the 2nd survey of May 2020 (Figure 1) . We excluded those who were unemployed (n=17), temporarily laid-off (n=28), on maternity-, childcare-or nursing care-leave (n=17), or on a long-term sick leave (n=2 

The numbers (proportions) of MDE cases by the tertiles of the number of workplace measures were: 19 (7.9%) for the lowest (0-12) group (N=241); 16 (6.7%) for the middle (13-17) group (N=240); and 17 (6.3%) for the highest (18-23) group (chi-square=0.5, DF=2, p=0.760). The numbers (proportions) of MDE cases by worry about workplace measures were: 16 (16.7%) for strongly agree (N=96); 19 (6.7%) for somewhat agree (N=284); 13 (4.2%) for somewhat disagree (N=310); and 4 (6.5%) for strongly disagree (N=62) (chi-square=17.8, DF=3, p<0.001).

In a multiple logistic regression adjusting the covariates (Supplemental table 2) 

The present study found that worry about workplace measures was significantly associated with the onset of MDE during the 13-month follow-up, in the multiple logistic regression after J o u r n a l P r e -p r o o f Journal Pre-proof adjusting for the covariates (OR for 1 score increase, 1.53; 95%CI, 1.02-2.32; p=0.042). In the supplemental analyses, Findings of the supplemental analyses using Cox proportional hazard models were also in line with this: the association was not statistically significant, but qualitatively similar to findings with the multiple logistic regression model. The number of workplace measures implemented by companies/organizations of the respondents was not significantly associated with the onset of an MDE.

Worrying about workplace measures taken by company/organization was associated with the onset of an MDE in the multiple logistic regression after adjusting for the covariates including psychological distress and fear of COVID-19 at baseline. The estimated odds ratio for 1 score change was 1.5. The association was not significant in the supplemental analyses applying Cox proportional hazard models. This may be due to the lack of the statistical power and/or an unreliable reporting of the onset month of MDE by respondents. However, the magnitude of the associations (hazard ratios for 1 score change) was similar to one observed with the multiple logistic regression that showed statistical significance. Worrying about workplace measures against COVID-19 may be a risk factor of MDE among employees in the COVID-19 pandemic.

Further research needs to replicate the finding. An additional multiple logistic regression also showed a significant association between the four categories of worry about workplace measures and MDE onset: compared to respondents who strongly agreed about their worry about workplace measures, respondents who somewhat agreed and somewhat disagreed had significantly lower risks (odds ratios, 0.39 and 0.26, respectively). Cox proportional hazard models yielded similar findings. Respondents in the last category who strongly disagreed also showed a non-significantly but lower risk of MDE than that of respondents who strongly agreed (odds ratio, 0.56), which was greater than that of respondents who somewhat agreed. The relationship between the degree of worry about workplace measures and MDE may be U-shaped. However, this may be by chance J o u r n a l P r e -p r o o f Journal Pre-proof due to the small number of respondents in the last category. Further studies are needed to confirm this non-linear association with a larger sample.

The findings suggest that respondents with strong worry about workplace measures are more likely to develop MDE. These respondents may keep working with this feeling in the COVID-19 pandemic, with little say to change the top-down policy of workplace measures. The situation may provoke learned helplessness of the participants, which is known as a risk factor for an MDE (Maier & Seligman, 2016) . The finding is also in line with studies showing that job satisfaction has been associated with depression (Faragher et al, 2005) . Worry about workplace measures may reflect lack of satisfaction on a specific aspect of work, i.e., workplace measures against COVID-19, which may lead to the onset of MDE. However, it is possible that some respondents may express excessive worry about workplace measures because of other reasons. For instance, neurotic traits that may exist behind worrying about workplace measures could increase the risk of MDE, although we tried to minimize this bias by adjusting for fear of COVID-19 and psychological distress. Respondents expressing strong worry about workplace measures may also be dissatisfied with other aspects of their work, such as the interpersonal relationship at work or salary, which may increase the risk of an MDE. Lack of communication at work may underlie worry about workplace measures, which has been associated with poor mental health of workers in the COVID-19 pandemic (Giorgi et al., 2020) . Further careful research is needed to conclude the causal association between worry about workplace measures against COVID-19 and MDE.

The number of workplace measures against COVID-19 was not significantly associated with the onset of an MDE and odds ratio was very small. This contradicts our previous cross-sectional finding of the association between the number of workplace measures and psychological distress in the same sample (Sasaki et al. 2020b ). Since the reported effect was small (Sasaki et al. 2020b ), it may not exist for a longer-term period. The effect of workplace measures on better mental J o u r n a l P r e -p r o o f health may not apply to an MDE, a more severe form of psychopathology. The number of workplace measures may be too simple to be a good judge of sufficiency or effectiveness for prevention of COVID-19. Some workplace measures, such as forced social distancing, may rather increase stress among employees (Hamouche, 2020) . Some of the measures may not be relevant to some industries or workplace structures; the quality, not the number of workplace measures may be more important. It would be interesting to investigate if any specific item of the scale is associated with the onset of an MDE. Further research is also required using a scale of quantity and quality of workplace measures against COVID-19.

The present study implies that focusing on worry about workplace measures may be more important for preventing MDE than just increasing the number of workplace measures, while there was a weak negative association between these two. Implementing workplace measures against COVID-19 meeting employees' concerns and needs may be essential. Communication only moderate stability between the surveys, which may lead to the underestimation of the association with MDE. The number of workplace measures was self-reported, and may be unreliable because employees may not be fully informed of the measures or able to exactly recall measures taken. Since the scale was developed in Japan, it may not be applicable to other countries that have a different system for occupational health and safety. Workplace responses to the COVID-19 pandemic varied among industrial sectors and occupations ; Risks of COVID-19 infection (Yoshikawa & Kawachi, 2021) and fear of COVID-19 and psychological distress (Midorikawa et al., 2021) also varied among industrial sectors. While we adjusted for major occupational categories including health care workers, industry and occupation may confound the findings. Moreover, it is not clear if the observed association may be different among types of industry or occupation. Type of employment contract, such as represented in the study sample compared to the whole employed population of Japan (23% vs 15%, respectively), while sex and age distribution of the sample was close to it (Sasaki et al., 2020a) . The findings may more reflect the situations in this occupation. The self-report M.I.N.I.

was not fully validated to measure an MDE. The measurement errors may result in the underestimation of the association with the onset of an MDE. The sample size was small, with only 52 cases developing MDE. The study may not be statistically powerful enough, which may lead to a non-significant association between worry about workplace measures and MDE onset in supplementary Cox proportional hazard analyses. The present findings should be replicated with a larger sample with established measures of worry about workplace measures and MDE onset, considering occupational differences and adjusting for possible confounders. 

COVID's mental-health toll: how scientists are tracking a surge in depression

Diagnostic and Statistical Manual of Mental Disorders

Social estrangement and psychological distress before and during the COVID-19 pandemic: patterns of change in Canadian workers

Prevalence of symptoms of depression, anxiety, insomnia, posttraumatic stress disorder, and psychological distress among populations affected by the COVID-19 pandemic: A systematic review and meta-analysis

The relationship between job satisfaction and health: a meta-analysis

The performance of the Japanese version of the K6 and K10 in the World Mental Health Survey Japan

COVID-19-related mental health effects in the workplace: a narrative review

COVID-19, physical distancing in the workplace and employees' mental health: implications and insights for organizational interventions -narrative review

Changes in fears and worries related to COVID-19 during the pandemic among current

Screening for serious mental illness in the general population

Learned helplessness at fifty: insights from neuroscience

Demographics associated with stress, severe mental distress, and anxiety symptoms during the COVID-19 pandemic in Japan: nationwide cross-sectional web-based survey

Mental health and health behaviours before and during the initial phase of the COVID-19 lockdown: longitudinal analyses of the UK Household Longitudinal Study

Reliability and validity of Japanese version of the Mini-International Neuropsychiatric Interview

Mental health before and during the COVID-19 pandemic: a longitudinal probability sample survey of the UK population. Environmental and Occupational Health Practice

Deterioration in mental health under repeated COVID-19 outbreaks greatest in the less educated: a cohort study of Japanese employees

The deterioration of mental health among healthcare workers during the COVID-19 outbreak: a population-based cohort study of workers in Japan

Workplace responses to COVID-19 associated with mental health and work performance of employees in Japan

The Mini-International Neuropsychiatric Interview (MINI): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10

Is returning to work during the COVID-19 pandemic stressful? a study on immediate mental health status and psychoneuroimmunity prevention measures of Chinese workforce

The mental health of healthcare workers in the COVID-19 pandemic: a systematic review

Prevalence of mental health problems during the COVID-19 pandemic: a systematic review and meta-analysis

Impact of COVID-19 pandemic on mental health in the general population: a systematic review

Association of socioeconomic characteristics with disparities in COVID-19 outcomes in Japan