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

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 self-esteem, 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 follow-up. 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.