Kotaro Imamura

Dr. Kotaro Imamura

orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 October 2016 in BMC Psychology
Verified
Journal Article
Open access
PDF file
ASAsuka Sakuraya
Asuka Sakuraya
Akihito ShimazuAkihito Shimazu
Akihito Shimazu
KIKotaro Imamura
Kotaro Imamura
KNKatsuyuki Namba
Katsuyuki Namba
NKNorito Kawakami
Norito Kawakami
Job crafting, an employee-initiated job design/redesign, has become important for employees’ well-being such as work engagement. This study examined the effectiveness of a newly developed job crafting intervention program on work engagement (as primary outcome), as well as job crafting and psychological distress (as secondary outcomes), using a pretest-posttest study design among Japanese employees. Participants were managers of a private company and a private psychiatric hospital in Japan. The job crafting intervention program consisted of two 120-min sessions with a two-week interval between them. Outcomes were assessed at baseline (Time 1), post-intervention (Time 2), and a one-month follow-up (Time 3). The mixed growth model analyses were conducted using time (Time 1, Time 2, and Time 3) as an indicator of intervention effect. Effect sizes were calculated using Cohen’s d. The program showed a significant positive effect on work engagement (t = 2.20, p = 0.03) in the mixed growth model analyses, but with only small effect sizes (Cohen’s d = 0.33 at Time 2 and 0.26 at Time 3). The program also significantly improved job crafting (t = 2.36, p = 0.02: Cohen’s d = 0.36 at Time 2 and 0.47 at Time 3) and reduced psychological distress (t = −2.06, p = 0.04: Cohen’s d = −0.15 at Time 2 and −0.31 at Time 3). The study indicated that the newly developed job crafting intervention program was effective in increasing work engagement, as well as in improving job crafting and decreasing psychological distress, among Japanese managers. UMIN Clinical Trials Registry UMIN000024062 . Retrospectively registered 15 September 2016.

1 August 2020 in Journal of Affective Disorders
Verified
Journal Article
Closed access
NYNaonori Yasuma
Naonori Yasuma
ZNZui Narita
Zui Narita
NSNatsu Sasaki
Natsu Sasaki
EOErika Obikane
Erika Obikane
JSJunpei Sekiya
Junpei Sekiya
Daisuke NishiDaisuke Nishi
Daisuke Nishi

16 September 2022 in Psychiatry and Clinical Neurosciences
Verified
Journal Article
Open access
Daisuke NishiDaisuke Nishi
Daisuke Nishi
KIKotaro Imamura
Kotaro Imamura
KWKazuhiro Watanabe
Kazuhiro Watanabe
EOErika Obikane
Erika Obikane
NSNatsu Sasaki
Natsu Sasaki
NKNorito Kawakami
Norito Kawakami
Background: Prevention of perinatal depression beginning from the antenatal period is essential. Therefore, this study aimed to investigate the effectiveness of recently developed internet‐delivered cognitive behavioral therapy (iCBT) for preventing the onset of a major depressive episode (MDE) in the third trimester and at 3 months postpartum.Methods: This is a two‐arm, parallel‐group, general‐information controlled, randomized controlled trial. Participants were 5017 pregnant women at 16–20 weeks' gestation without MDE at baseline. They were randomly assigned to an iCBT (intervention; n = 2509) or general‐information (control; n = 2508) group, stratified by psychological distress at baseline. The primary outcomes were the numbers of new MDE onsets, measured using the World Health Organization Composite International Diagnostic Interview 3.0, at 32 weeks' gestation and at 3 months postpartum.Results: New MDE onset was reported by 59 participants (2.35%) in the intervention group and 73 (2.91%) in the control group during follow‐up. Compared with the control group, the hazard ratio (HR) of MDE in the intervention group was 0.85 (95% CI 0.61–1.20), which was not significantly different. Among participants who scored between 5 and 8 on K6 at baseline, 10 (1.37%) in the intervention group reported new onset of MDE, compared with 28 (3.81%) in the control group, and the HR of MDE was 0.38 (95%CI 0.19–0.79).Conclusions: No intervention effect was found for iCBT in preventing new onset of perinatal MDE. iCBT might prevent perinatal depression only among pregnant women with subthreshold depressive symptoms. Trial registration: UMIN000038190.

NSNatsu Sasaki
Natsu Sasaki
AIAkiomi Inoue
Akiomi Inoue
HAHiroki Asaoka
Hiroki Asaoka
YSYuki Sekiya
Yuki Sekiya
Daisuke NishiDaisuke Nishi
Daisuke Nishi
KIKotaro Imamura
Kotaro Imamura
Objectives: This study validated the Japanese version of O’Donovan et al.’s (2020) composite measure of the psychological safety scale and examined the associations of psychological safety with mental health and job-related outcomes. Methods: Online surveys were administered twice to Japanese employees in teams of more than three members. Internal consistency and test–retest reliability were tested using Cronbach’s α and intra-class correlation coefficient (ICC), respectively. Structural validity was examined using confirmatory factor analysis (CFA) and exploratory factor analysis (EFA). Convergent validity was tested using Pearson’s correlation coefficients. Multiple linear regression analyses were conducted to examine the relationship between psychological safety and psychological distress, work engagement, job performance, and job satisfaction. Results: Two hundred healthcare workers and 200 non-healthcare workers were analyzed. Internal consistency, test–retest reliability, and convergent validity were acceptable. CFA demonstrated poor fit, and EFA yielded a two-factor structure, with team leader as one factor and peers and team forming the second factor. The total score showed significant and expected associations with all outcomes in the adjusted model for all workers. Conclusions: The Japanese version of the measure of the psychological safety scale presented good reliability and validity. Psychological safety is important for employees’ mental health and performance.

23 November 2021 in JMIR Formative Research
Verified
Journal Article
Open access
NSNatsu Sasaki
Natsu Sasaki
EOErika Obikane
Erika Obikane
AVAsha Vedanthan
Asha Vedanthan
KIKotaro Imamura
Kotaro Imamura
PCPim Cuijpers
Pim Cuijpers
Daisuke NishiDaisuke Nishi
Daisuke Nishi
Background: Digital mental health interventions are being used more than ever for the prevention and treatment of psychological problems. Optimizing the implementation aspects of digital mental health is essential to deliver the program to populations in need, but there is a lack of validated implementation outcome measures for digital mental health interventions. Objective: The primary aim of this study is to develop implementation outcome scales of digital mental health for different levels of stakeholders involved in the implementation process: users, providers, and managers or policy makers. The secondary aim is to validate the developed scale for users. Methods: We developed English and Japanese versions of the implementation outcome scales for digital mental health (iOSDMH) based on the literature review and panel discussions with experts in implementation research and web-based psychotherapy. The study developed acceptability, appropriateness, feasibility, satisfaction, and harm as the outcome measures for users, providers, and managers or policy makers. We conducted evidence-based interventions via the internet using UTSMeD, a website for mental health information (N=200). Exploratory factor analysis (EFA) was conducted to assess the structural validity of the iOSDMH for users. Satisfaction, which consisted of a single item, was not included in the EFA. Results: The iOSDMH was developed for users, providers, and managers or policy makers. The iOSDMH contains 19 items for users, 11 items for providers, and 14 items for managers or policy makers. Cronbach α coefficients indicated intermediate internal consistency for acceptability (α=.665) but high consistency for appropriateness (α=.776), feasibility (α=.832), and harm (α=.777) of the iOSDMH for users. EFA revealed 3-factor structures, indicating acceptability and appropriateness as close concepts. Despite the similarity between these 2 concepts, we inferred that acceptability and appropriateness should be used as different factors, following previous studies. Conclusions: We developed iOSDMH for users, providers, and managers. Psychometric assessment of the scales for users demonstrated acceptable reliability and validity. Evaluating the components of digital mental health implementation is a major step forward in implementation science.

12 January 2021 in JMIR Mental Health
Verified
Journal Article
Open access
NKNorito Kawakami
Norito Kawakami
NSNatsu Sasaki
Natsu Sasaki
RKReiko Kuroda
Reiko Kuroda
Kanami TsunoKanami Tsuno
Kanami Tsuno
KIKotaro Imamura
Kotaro Imamura
Background: Downloading a COVID-19 contact tracing app may be effective in reducing users’ worry about COVID-19 and psychological distress. Objective: This 2.5-month prospective study aimed to investigate the association of downloading a COVID-19 contact tracing app, the COVID-19 Contact Confirming Application (COCOA), released by the Japanese government, with worry about COVID-19 and psychological distress in a sample of employed adults in Japan. Methods: A total of 996 full-time employed respondents to an online survey conducted May 22-26, 2020 (baseline), were invited to participate in a follow-up survey August 7-12, 2020 (follow-up). A high level of worrying about COVID-19 and high psychological distress were defined by baseline and follow-up scores on a single-item scale and the Kessler 6 (K6) scale, respectively. The app was released between the two surveys, on June 17. Participants were asked at follow-up if they downloaded the app. Results: A total of 902 (90.6%) of 996 baseline participants responded to the follow-up survey. Among them, 184 (20.4%) reported that they downloaded the app. Downloading of the contact tracing app was significantly negatively associated with psychological distress at follow-up after controlling for baseline variables, but not with worry about COVID-19. Conclusions: This study provides the first evidence that using a government-issued COVID-19 contact tracing app may be beneficial for the mental health of employed adults during the COVID-19 pandemic.