Occupational health nurse involvement and bright 500 certification among Japanese small- and medium-sized enterprises: A repeated cross-sectional analysis of four annual Health and Productivity Management Survey waves.

OBJECTIVE: To investigate the association between occupational health nurse (OHN) involvement and Bright 500 certification, an indicator of high-performing health and productivity management (HPM), among Japanese small- and medium-sized enterprises (SMEs) using multi-year survey data. METHODS: This observational study used secondary data from the 2021-2024 HPM Survey. Each annual response was analyzed as a corporation-year observation, and within-corporation correlation was handled with a random intercept for corporations. OHN involvement was defined as the appointment of public health nurses and/or nurses as health promotion officers. Bright 500 certification, obtained from publicly available certification records, was used as an indicator of more advanced HPM. The association was examined using a mixed-effects logistic regression model. RESULTS: The analytical sample comprised 12 847 (2021), 14 401 (2022), 17 316 (2023), and 20 267 (2024) SMEs. OHN involvement increased from 5.1% (2021) to 5.8% (2024). Bright 500 certification was consistently higher in corporations with OHN involvement (10.8% in 2021, 8.4% in 2024) than in those without (2-3% across years). After adjustment for survey year, region, insurer category, industry type, employee size, internal and external dissemination of HPM initiatives, and occupational physician involvement, OHN involvement was independently associated with certification (odds ratio: 2.35, 95% confidence interval: 1.21-4.54, p = 0.011). CONCLUSIONS: Across the four survey waves, OHN involvement was positively associated with Bright 500 certification among SMEs. These findings suggest that OHNs may be relevant to advanced HPM implementation in this setting. Future studies should capture OHN staffing arrangements, intensity and roles, and initiative timing to clarify mechanisms and potential causality.