Relationship Between Companies' Responses to Near-Miss Reports and Turnover Intentions of Workers: A Nationwide Cross-Sectional Study.

Background: Effective near-miss management is important in preventing workplace accidents. A company's inadequate response to near-miss reports can lead workers to feel insecure and dissatisfied with the company. We investigated the relationship between companies' responses to near-miss reports and turnover intentions of workers. Methods: We conducted a cross-sectional study using online self-administered questionnaire survey to workers aged ≥20 years in Japan in March 2022. The analysis included 5,071 participants who had near-miss experiences and reported them to their companies. The independent variable was companies' responses to near-miss reports, classified into three categories: adequate response group, inadequate response group, and no response group. The dependent variable was turnover intentions. We calculated the odds ratio and 95% confidential interval (CI) using multilevel logistic regression analyses nested for industries and adjusted for covariates. Results: Of the 5,071 participants, 3,058 (60.3%) were adequate response group, 1,484 (29.3%) were inadequate response group, and 529 (10.4%) were no response group. In multivariable adjusted model, compared with adequate response group, the odds ratio of inadequate response group and no response group were 1.80 (95% CI: 1.56-2.08) and 2.63 (95% CI: 2.15-3.22), respectively. Conclusion: Our results suggested that there was a relationship between companies' responses to the near-miss reports and turnover intentions of workers. It is important not only to collect near-misses but also to respond appropriately to the reports and provide feedback to workers.

Role of Supervisor Consultation Toward Work Engagement: A Prospective Cohort Study.

Background: We examined the association between supervisor consultation, as an actual practice representing supervisor support, and work engagement. Methods: This was a prospective cohort study in Japan, involving 14,026 participants who met the requirement for a one-year follow-up. Supervisor consultation was measured using a single question, and work engagement was defined using the Japanese version of the nine-item Utrecht Work Engagement Scale (UWES-9). Associations were examined using linear regression analysis. Results: Supervisor consultation was positively associated with work engagement after adjusting for gender, age, education, income, and industry (ß = 3.474; p < 0.001). The relationship remained significant after adjustment for perceived supervisor support, although the coefficient decreased (ß = 1.315; p < 0.001). Conclusion: Supervisor consultation probably acted on work engagement in different ways than perceived supervisor support.

Association Between Telecommuting Preference-frequency mismatch and Insomnia among Japanese Workers in the COVID-19 Pandemic: A Prospective Cohort study.

OBJECTIVE: We hypothesized that telecommuting's impact on sleep varied based on preference-frequency mismatch. Here, we evaluated this relationship in a large cohort of Japanese workers. METHODS: We collected data from 33,302 Japanese workers through an online survey, and analyzed participant preferences and frequency of telecommuting in 9,425 individuals who responded to a follow-up survey. We evaluated sleep using the Athens Insomnia Scale, and estimated odds ratios of insomnia using multilevel logistic regression. RESULTS: Workers preferring telecommuting had a higher risk of insomnia as telecommuting frequency decreased. OR for insomnia was 1.87 (p < 0.001) in those who telecommuted less than once per week. CONCLUSION: Telecommuting's impact on workers' sleep depends on preference mismatch, with a higher risk of insomnia among those who prefer telecommuting but are unable to utilize it.

Effect of side jobs and psychological distress on employee turnover in Japanese employees: A nationwide prospective cohort study.

OBJECTIVES: We investigated the impact of engaging in side jobs on turnover and its interaction with psychological distress among Japanese employees. METHODS: A prospective cohort study was conducted using a questionnaire-based survey. We investigated 2783 full-time employees in companies permitting side jobs. Multiple logistic regression analyses were used to examine the relationship between side jobs and turnover, and its relationship stratified by psychological distress. RESULTS: Employees engaging in side jobs had higher odds ratios (ORs) for turnover after adjusting for covariates, included psychological distress (OR = 1.54, 95% confidence interval: 1.22-1.93). Among those under psychological distress, ORs for turnover were significantly higher (OR = 1.96, 95% confidence interval: 1.39-2.76). Conversely, in employees without distress, no significant difference was observed. CONCLUSIONS: Side job engagement correlates with higher turnover, particularly among employees under psychological distress.

The Individual and Work-Related Factors Associated with the Occupational Future Time Perspective: A Cross-Sectional Study of Older Workers in Japan.

OBJECTIVES: Occupational future time perspective (OFTP) is important concept for the successful career in older workers. The purpose of this study was to examine the associations between individual and work-related factors and OFTP. METHODS: We conducted a cross-sectional study via an online questionnaire survey. Respondents were stratified sampled according to the distribution of workers across Japan. To assess OFTP, we used the Japanese version of the OFTP scale. We included the factors such as sex, age, education, marital status, subjective health status, personal income, length of employment, industry, size of company, employment status, working days per week, and night shift. Multiple regression analysis was employed to calculate the regression coefficients for each factor, with OFTP serving as the dependent variable. RESULTS: We totally included 1,484 respondents. Our findings indicated that higher OFTP was associated with higher education, better subjective health status, higher personal income, and smaller size of company. Compared to the manufacturing, certain industries such as agriculture and forestry, transportation and postal services, and healthcare showed lower OFTP. In contrast to permanent workers, contract and part-time workers demonstrated lower OFTP, whereas owners of non-family businesses exhibited higher OFTP. Furthermore, individuals working 1-4 days per week showed lower OFTP compared to those working 5 days per week. CONCLUSIONS: Older workers facing limitations in resources, such as educational background, personal income, precarious employment, and health status, tend to have lower OFTP. Such individuals should be given priority for support and assistance.

Determinants of job continuity among older workers: a mixed-methods research in Japan.

This study aims to determine the factors that encourage older workers to continue working. This study had an exploratory sequential design using a mixed-methods approach, including interviews and questionnaire surveys. In the interview survey, we targeted 30 workers aged between 60-65 across three manufacturing companies. After using the results of the content analysis in the interviews, we conducted an online questionnaire survey with 1,500 workers aged between 60-89 across the country. We analyzed whether the 15 factors were related to intention to continue working using logistic regression analysis. We identified factors affecting job continuity from three perspectives: individual, company, and life. We determined several factors: health condition, job performance, self-esteem, conservatism, employment system, workload, medical insurance and welfare programs, monetary and non-monetary rewards, relationships, attachment to the organization, distance between living and work, social support, economic situation, and employment policy. In the questionnaire survey, some factors had no relationship with job continuity, including conservatism, employment systems, monetary rewards, and the distance between living and work. Employers and policymakers can use the findings to consider appropriate ways of supporting older workers.

Occupational health staff's involvement contributes to supervisor's perceived organizational support in Japanese workforce: a prospective cohort study.

OBJECTIVES: Enhancing employees' perceived organizational support (POS) is crucial for organization, and one effective approach is enhancing supervisors' POS. However, there is limited research focusing specifically on enhancing supervisors' POS. We aimed to investigate the influence of occupational health staff's involvement for supervisors on their POS. METHODS: A prospective cohort study was conducted using an online survey targeting supervisors in various industries across Japan. We assessed supervisors' POS using an effective 8-items of the Japanese version of the Survey of Perceived Organizational Support. Data on the involvement of occupational health staff in providing occupational health staff's involvement in providing supervisors with training on workplace health management and guidance on addressing specific subordinates with health concerns were collected. The association between these involvement and POS was assessed through multiple regression analyses. RESULTS: The study involved 541 supervisors with occupational health staff at their workplace in the final analysis. Training from occupational health staff was significantly associated with an increase in POS at follow-up after adjustment for potential confounders, including demographic variables and POS at baseline. Similarly, guidance from occupational health staff was also significantly associated with an increase POS. This effect was particularly notable in small workplaces. CONCLUSIONS: Our study indicates that occupational health staff's involvement in supporting supervisors can contribute to enhancing supervisors' POS, especially in small workplaces. These findings suggest that by developing structured systems and establishing specific roles for occupational health staff, organizations may effectively enhance supervisors' POS.

Reliability and Validity of the Japanese Version of the Survey of Perceived Organizational Support.

OBJECTIVES: This study aimed to examine the reliability and validity of the Japanese version of the Survey of Perceived Organizational Support (SPOS-J) for the Japanese workforce. METHODS: The translation of the SPOS into Japanese followed the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Task Force guidelines. An online baseline survey with 6,220 Japanese workers assessed the SPOS-J and related scales, followed by a follow-up survey with 452 respondents two weeks later. We developed the SPOS-J and evaluated its factorial, convergent, and known-group validities, as well as its internal consistency, test-retest reliability, and interpretability. RESULTS: Exploratory and confirmatory factor analysis (EFA and CFA) indicated that the SPOS-J, diverging from the original version's one-factor structure, adopted a two-factor structure comprising two subscales: the SPOS-J (Sufficiency of Positive Aspects (SPA)) and the SPOS-J (Minimality of Negative Aspects (MNA)). The final version of the SPOS-J, consisting of eight items selected by the item response theory analysis, demonstrated acceptable model fit in the CFA. Cronbach's alphas for SPOS-J (SPA) and SPOS-J (MNA) were .92 and .84; intra-class coefficients were .72 and .55, respectively. The correlations between SPOS-J (SPA) and related variables, as well as the score distributions by demographic characteristics, supported the convergent and known-group validity of SPOS-J (SPA). In contrast, SPOS-J (MNA) showed lower correlation coefficients with all related variables and did not support known-group validity. CONCLUSIONS: The SPOS-J (SPA), a subscale of the eight-item SPOS-J, is a reliable and valid measure for assessing perceived organizational support among Japanese workers.

A prospective cohort study of perceived organizational support and occupational accidents and near-miss events among Japanese workers.

INTRODUCTION: Preventing occupational accidents is a major global challenge, and employee safety practices play a crucial role in accident prevention. Although perceived organizational support (POS) is related to safety practices, there is currently insufficient evidence supporting a relationship between POS and occupational accidents. We investigated the relationships between POS and both occupational accidents and near-miss events that can lead to accidents in the following year among workers in various industries in Japan. METHOD: This prospective cohort study was conducted from March 2022 to March 2023 using a questionnaire survey. In total, 9916 participants who completed the follow-up survey and met our inclusion criteria were analyzed. The follow-up survey asked participants about both occupational accidents and near-miss events experienced in the year following the baseline assessment. POS was evaluated at baseline using the eight-item version of the Survey of Perceived Organizational Support. Odds ratios (ORs) for the relationships between POS and occupational accidents and near-miss events were estimated using multilevel logistic regression analyses nested by industries. RESULTS: The ORs for self-reported occupational accidents were significantly higher for the moderate (OR = 1.41, 95% confidence interval [CI]: 1.10-1.82), low (OR = 1.49, 95%CI: 1.18-1.89), and very low (OR = 2.03, 95%CI: 1.61-2.56) POS groups compared with the very high group. The ORs for self-reported near-miss events were also significantly higher for the moderate (OR = 1.21, 95%CI: 1.03-1.43), low (OR = 1.20, 95%CI: 1.03-1.40), and very low (OR = 1.56, 95%CI: 1.34-1.82) groups than the very high group. CONCLUSIONS: Our findings suggest lower POS is related to a higher occurrence of occupational accidents and near-miss events in the following year. Organizations should consider enhancing employees' POS to reduce occupational accidents and near-miss events. PRACTICAL APPLICATIONS: To enhance employees' POS, organizations should address identified antecedents of POS (e.g., fairness, supervisor support, rewards, favorable job conditions, and human resource practices).

Faecalibacterium taiwanense sp. nov., isolated from human faeces.

Two Gram-stain-negative, straight rods, non-motile, asporogenous, catalase-negative and obligately anaerobic butyrate-producing strains, HLW78T and CYL33, were isolated from faecal samples of two healthy Taiwanese adults. Phylogenetic analyses of 16S rRNA and DNA mismatch repair protein MutL (mutL) gene sequences revealed that these two novel strains belonged to the genus Faecalibacterium. On the basis of 16S rRNA and mutL gene sequence similarities, the type strains Faecalibacterium butyricigenerans AF52-21T(98.3-98.1 % and 79.0-79.5 % similarity), Faecalibacterium duncaniae A2-165T(97.8-97.9 % and 70.9-80.1 %), Faecalibacterium hattorii APC922/41-1T(97.1-97.3 % and 80.3-80.5 %), Faecalibacterium longum CM04-06T(97.8-98.0% and 78.3 %) and Faecalibacterium prausnitzii ATCC 27768T(97.3-97.4 % and 82.7-82.9 %) were the closest neighbours to the novel strains HLW78T and CYL33. Strains HLW78T and CYL33 had 99.4 % both the 16S rRNA and mutL gene sequence similarities, 97.9 % average nucleotide identity (ANI), 96.3 % average amino acid identity (AAI), and 80.5 % digital DNA-DNA hybridization (dDDH) values, indicating that these two strains are members of the same species. Phylogenomic tree analysis indicated that strains HLW78T and CYL33 formed an independent robust cluster together with F. prausnitzii ATCC 27768T. The ANI, AAI and dDDH values between strain HLW78T and its closest neighbours were below the species delineation thresholds of 77.6-85.1 %, 71.4-85.2 % and 28.3-30.9 %, respectively. The two novel strains could be differentiated from the type strains of their closest Faecalibacterium species based on their cellular fatty acid compositions, which contained C18 : 1 ω7c and lacked C15 : 0 and C17 : 1 ω6c, respectively. Phenotypic, chemotaxonomic and genotypic test results demonstrated that the two novel strains HLW78T and CYL33 represented a single, novel species within the genus Faecalibacterium, for which the name Faecalibacterium taiwanense sp. nov. is proposed. The type strain is HLW78T (=BCRC 81397T=NBRC 116372T).

Key issues in Japan's public health centers to prepare for future pandemics: a text mining study using a topic model.

BACKGROUND: In Japan, over 450 public health centers played a central role in the operation of the local public health system in response to the COVID-19 pandemic. This study aimed to identify key issues for improving the system for public health centers for future pandemics. METHODS: We conducted a cross-sectional study using an online questionnaire. The respondents were first line workers in public health centers or local governments during the pandemic. We solicited open-ended responses concerning improvements needed for future pandemics. Issues were identified from these descriptions using morphological analysis and a topic model with KHcoder3.0. The number of topics was estimated using Perplexity as a measure, and Latent Dirichlet Allocation for meaning identification. RESULTS: We received open-ended responses from 784 (48.6%) of the 1,612 survey respondents, which included 111 physicians, 330 nurses, and 172 administrative staff. Morphological analysis processed these descriptions into 36,632 words. The topic model summarized them into eight issues: 1) establishment of a crisis management system, 2) division of functions among public health centers, prefectures, and medical institutions, 3) clear role distribution in public health center staff, 4) training of specialists, 5) information sharing system (information about infectious diseases and government policies), 6) response to excessive workload (support from other local governments, cooperation within public health centers, and outsourcing), 7) streamlining operations, and 8) balance with regular duties. CONCLUSIONS: This study identified key issues that need to be addressed to prepare Japan's public health centers for future pandemics. These findings are vital for discussions aimed at strengthening the public health system based on experiences from the COVID-19 pandemic.

Bridging perceived organizational support with learning motivation and work engagement: the mediating role of focus on opportunity.

OBJECTIVES: Perceived organizational support (POS) represents the extent to which employees believe their organization values their contributions and well-being. Although higher POS is associated with increased work engagement and learning motivation, the intricacies of this relationship, especially the mediation by occupational future time perspective (OFTP), are not well understood. METHODS: We conducted an online survey of 2046 working individuals aged 20-69 to assess the relationships between POS and 2 outcome variables, learning goal orientation (LGO) and work engagement, with multiple regression analyses for all ages and in the younger age group (under 45). Then, the mediating effects of focus on opportunity (FOO)-a primary component of OFTP-on these relationships were examined. RESULTS: Of 2046 participants, 887 were younger than 45 years. Younger participants, predominantly more educated and inclined toward professional jobs, exhibited higher LGO but lower work engagement compared with their older counterparts. POS showed positive correlations with LGO, and FOO significantly mediated the relationship, especially in the young group. Furthermore, a positive relationship between POS and work engagement was noted, with FOO as a partial mediator. CONCLUSIONS: POS correlates positively with both LGO and work engagement across various age demographics, with FOO critically mediating this relationship. To enhance employee engagement and learning motivation, organizations should emphasize bolstering both POS and FOO.

Association Between Workaholism and Headaches Causing Presenteeism: A Cross-sectional Study in Japan.

OBJECTIVES: This study investigates the association between workaholism and headaches causing presenteeism among Japanese employees. METHODS: Used data from self-reporting questionnaire and annual health checkups. Workaholism was assessed using the Dutch Workaholic Scale and headaches causing presenteeism were identified as the symptom hindering work. We performed a logistic regression analysis adjusted for covariates. RESULTS: Among 5802 respondents, 3.7% cited headaches as the symptom hindering work. We found an association between workaholism and such headaches (odds ratios [OR]: 1.05, 95% confidence intervals [CI]: 1.03-1.08). Both working excessively (OR: 1.08, 95% CI: 1.04-1.12) and working compulsively (OR: 1.10, 95% CI: 1.05-1.15) subscales were also related. CONCLUSIONS: Workaholism may lead to productivity loss due to headaches, and addressing workaholism can prevent this loss. Combining health examination data with work hours data may enable the early detection of workaholism.

Relationship Between Firm Size and Perceived Organizational Support and the Moderating Role of Supervisor Support: A Nationwide Cross-sectional Study.

OBJECTIVE: The study aims to explore the relationship between firm size and perceived organizational support (POS) and to investigate how supervisor support might moderate this relationship. METHODS: The study involved a cross-sectional questionnaire survey in Japan with 25,648 participants. Assessing POS through eight-question. Firm size was categorized into small (2-49 employees), medium (50-999), and large (1000 or more). Coefficients were estimated using multiple regression analyses. RESULTS: The analysis revealed that medium and large firms had lower POS compared to small firms, with the difference being more pronounced in medium firms. A positive interaction between firm size and supervisor support was observed for POS. CONCLUSIONS: This study found that although POS is more likely to be lower in medium and large firms than in small firms, the effect of supervisor support on improving POS is stronger.

Relationship between diabetes treatment status and occupational accidents.

AIMS: To evaluate the relationship between diabetes treatment status and occupational accidents. METHODS: A cross-sectional study was conducted using an online questionnaire survey completed in March 2022 among workers aged 20 years or older. The questionnaire included questions about diabetes treatment status and occupational accidents. The association between the treatment status of diabetes and occupational accidents was examined using a logistic regression analysis. RESULTS: The study included 25,756 participants with no diabetes, 1,364 participants receiving diabetes treatment, 177 participants who had interrupted diabetes treatment, and 396 participants who needed diabetes treatment but had not seen a doctor. Compared with those with diabetes treatment, the odds ratio of occupational accidents among participants without diabetes was 0.40 (95% CI: 0.32-0.49), the odds ratio among participants with interrupted diabetes treatment was 4.15 (95% CI: 2.86-6.01), and the odds ratio among participants who needed diabetes treatment but had not seen a doctor was 1.25 (95% CI: 0.89-1.77). CONCLUSIONS: This study showed that diabetes treatment status was related to occupational accidents, and it may be important for workers with diabetes to be supported to balance their diabetes management and their work commitments.

Treatment status of psychiatric disorders and falls in the workplace among Japanese workers: a nationwide cross-sectional study.

OBJECTIVES: In Japan, the most common injury requiring sick leave is a fall in the workplace; therefore, it is very important to prevent falls. Most measures to prevent falls involve aspects of the workplace environment and safety. However, few measures consider the perspective of individual health. We investigated the relationship between psychiatric disorders and falls in the workplace and whether treatment status for a psychiatric disorder is associated with workplace falls. METHODS: We conducted a cross-sectional study among workers aged 20 years or older in Japan from February 28 to March 3, 2022. In total, the data of 27 693 participants were analyzed. We used a questionnaire to query participants' status of treatment for any psychiatric disorder and whether they had experienced a fall in the workplace. The association between treatment for a psychiatric disorder and workplace falls was examined using logistic regression analysis. RESULTS: Compared with participants receiving appropriate treatment for a psychiatric disorder, the odds ratio (OR) of a workplace fall was significantly lower among participants who did not require treatment for a psychiatric disorder, at 0.56 (95% CI: 0.47-0.66; P < .001); the OR of a workplace fall was significantly higher among participants whose treatment for a psychiatric disorder was interrupted, at 1.47 (95% CI: 1.21-1.78; P < .001), after adjusting for age, sex, household income, number of workplace employees, sleeping hours, exercise habits, and psychological distress. CONCLUSIONS: Our findings suggest that receiving appropriate treatment for psychiatric disorders may contribute to preventing falls in the workplace.

Association between exposure to technological advances in the workplace and work engagement: a prospective cohort study.

OBJECTIVES: The study objective was to measure the association between exposure to technological advances and work engagement, adjusting for personal and workplace factors. METHODS: We conducted a nationwide online longitudinal survey study in Japan. The sample was stratified to represent Japanese workforce conditions. Work engagement was measured using the Japanese version of the Utrecht Work Engagement Scale-9. Exposure to technological advances was measured using a single question with Likert scale responses. Industry characteristics that were more/less likely to be replaced by automation were also measured. Linear regression was used for statistical analysis. RESULTS: There were 16 629 participants. We found that exposure to technological advances was associated with work engagement after adjustment for age, sex, education, income, and industry characteristics. We observed a significant interaction between age and exposure to technological advances (coefficient 0.891, P < .001), and conducted an age-stratified linear regression analysis. The significant association between age and exposure to technological advances reduced as age increased, and disappeared after adjustment for baseline work engagement. CONCLUSIONS: Longitudinal observations showed that exposure to technological advances was not significantly associated with work engagement.

Health and productivity management initiatives to promote worker health and improve the workplace environment at the Fukushima Daiichi nuclear power plant.

BACKGROUND: Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, measures have been taken to address occupational health risks, such as heat illness and infectious diseases, and ensure fitness for duty with the Tokyo Electric Power Company and its contractors. However, with the decommissioning operations set to span several decades and an aging workforce, there arose a need for proactive occupational health strategies that not only addressed these risks but also promoted employee health and created a comfortable work environment. With the Japanese government's promotion of health and productivity management (HPM) for corporations, an HPM-based initiative was launched at the FDNPP in 2019. CASE: We designed an HPM questionnaire tailored to the unique conditions at the FDNPP for contractors in 2019. Subsequently, we adjusted the questionnaire annually in light of evolving societal contexts and insights derived from contractors' feedback. This initiative also involved the annual recognition of outstanding contractors. These efforts have led to a steady increase in the number of contractors participating in the HPM survey, with respondents' scores continually improving. We also emphasized dissemination of HPM practices from contractors to their subcontractors due to the complex subcontracting structure at FDNPP, and our results showed that more contractors have been extending these efforts to their subcontractors. CONCLUSIONS: Our findings suggest that individual contractors are steadily enhancing their HPM efforts. We are committed to continually offering support to advance HPM throughout the FDNPP.

Work engagement among older workers: a systematic review.

OBJECTIVES: Given current labor force conditions, including population aging, keeping older workers engaged in work and motivated is important. Aging may alter the effects that psychological and environmental factors have on work engagement. We conducted a systematic review to understand the features of work engagement among older workers. METHODS: A systematic search was conducted in July 2022 using 4 databases. The review included relevant articles that focused on participants aged 40 years and older. RESULTS: Fifty articles were selected for our review, which were grouped into 5 categories: (1) studies examining the relationship between chronological age and work engagement, (2) studies investigating the moderating effects of age on the relationship between job-related psychological factors and work environment factors and work engagement, (3) studies comparing the relationship of job-related psychological factors and work environment factors with work engagement across different age groups, (4) studies exploring the relationship between work engagement and retirement intentions or continued employment beyond retirement age, and (5) other studies discussing work engagement in the context of older workers. Most articles focused on workers in Europe and the United States and used observational study designs. CONCLUSIONS: Work engagement increases with age, and is mainly mediated by increased emotional regulation. In addition, age moderates the relationships between various job-related psychological and work-environmental factors and work engagement. Work engagement is associated with working beyond retirement age. Organizations should understand the characteristics of work engagement among older workers and make age-conscious efforts to support them in adapting to social changes.

Sociodemographic factors affecting not receiving COVID-19 vaccine in Japan among people who originally intended to vaccinate: a prospective cohort study.

Objective: Vaccine hesitancy is a major issue for acquiring herd immunity. However, some individuals may go unvaccinated owing to inhibitory factors other than vaccine hesitancy. If there is even a small number of such people, support is needed for equitable vaccine distribution and acquiring herd immunity. We investigated sociodemographic factors that affected not undergoing COVID-19 vaccination in Japan among individuals who had strong intention to vaccinate before beginning the vaccination. Methods: We conducted this prospective cohort study on workers aged 20-65 years from December 2020 (baseline), to December 2021 using a self-administered questionnaire survey. There were 27,036 participants at baseline and 18,560 at follow-up. We included 6,955 participants who answered yes to this question at baseline: "Would you like to receive a COVID-19 vaccine as soon as it becomes available?" We applied multilevel logistic regression analyses to examine the association between sociodemographic factors and being unvaccinated at follow-up. Results: In all, 289 participants (4.2%) went unvaccinated. The odds ratios (ORs) for being unvaccinated were significantly higher for participants aged 30-39 and 40-49 than those aged 60-65 years. Being divorced, widowed, or single, having low income, and having COVID-19 infection experience also had higher ORs. Discussion: We found that some participants who initially had strong intention to vaccinate may have gone unvaccinated owing to vaccine side effects and the financial impact of absenteeism due to side effects. It is necessary to provide information repeatedly about the need for vaccination as well as social support to ensure that those who intend to vaccinate are able to do so when aiming for acquiring herd immunity through vaccination against COVID-19 as well as other potential infection pandemics in the future.