Reliability and validity of the Japanese version of the psychological safety scale for workers

Abstract

Although an increasing number of studies on psychological safety at workplaces has been conducted in both western and eastern countries, there are few empirically validated measures in Japan. Our purpose was to investigate the validity and reliability of the Japanese version of the Psychological Safety Scale. Japanese workers were invited to participate in online surveys at baseline and at one-month follow-up (N=320).The Psychological Safety Scale was translated into Japanese according to international guidelines. Social support at workplace, work engagement, organization-based selfesteem, organizational justice, and job satisfaction were measured. Cronbach's alphas and intra-class correlation coefficient (ICC) were examined for reliability, and its validity was tested by confirmatory factor analysis and correlational analyses. The results of the survey showed that respondents were 287 at baseline and 236 at followup. Cronbach's alphas of the Psychological Safety Scale were 0.91 (baseline) and 0.88 (follow-up), and ICC was 0.87. Confirmatory factor analysis demonstrated a marginally acceptable fit. Overall, the Japanese Psychological Safety Scale had moderate to strong correlations with other scales. In conclusion, the Japanese version of the Psychological Safety Scale had acceptable levels of reliability and validity, and may be applicable for use in Japanese workers.

The Survey Measure of Psychological Safety and Its Association with Mental Health and Job Performance: a Validation Study and Cross-Sectional Analysis

“…showing the positive association of PS with supervisor support, co-workers' support, and organizational factors 6 . A supportive work environment may make workers feel safe in taking interpersonal risks.…”

“…In non-HCWs, a previous study suggested that being allowed to express opinions and actually doing so were different experiences among Japanese workers 6 . Leaders' willingness to allow and encourage employees to speak up and employees' perceptions of doing so may both be required PS in non-HCWs.…”

“…We then performed 15 , focusing on the workers' speaking out 9 . The Japanese version of the scale was translated by Ochiai et al 6 . It had five items on a five-point Likert scale.…”

“…To assess structural validity, confirmatory factor analysis (CFA) assuming three factors was conducted to test the goodness of fit for the existing structure of PS, and an exploratory factor analysis (EFA) was conducted if the CFA showed a poor fit. As a hypothesis test for convergent validity, Pearson's correlation coefficients (r) were calculated between each score of the PS scale and PS scale for workers developed by Liang et al, social support at work, servant leadership, organization-based self-esteem, and organizational justice, which was considered to have moderate to high positive correlations with PS scale (r > 0.40) 6 .…”

“…(2020) was tailored to healthcare settings, the survey measure of PS could also be useful for measuring PS in nonhealthcare workers (HCWs). Several scales with fewer than 10 items can measure PS in non-HCWs 3,[6][7][8] , including the Japanese version of the PS scale 6 developed by Liang et al 9 . However, a systematic review has suggested that scales with few items could not fully capture the state of PS at work and needed holistic, objective measuring instruments 10 .…”