Effects of a telework environment intervention on work setup behaviors and somatic symptoms among Japanese teleworkers: a secondary analysis of the TELEWORK cluster randomized controlled trial

OBJECTIVES: Home-workspace ergonomics may influence telework-related somatic symptoms; however, evidence regarding interventions promoting teleworkers' self-directed environment setup remains limited. We examined the effects of a behavioral science-based educational intervention on telework environment setup behaviors and somatic symptoms among Japanese employees. METHODS: This was a secondary analysis of the TELEWORK cluster randomized controlled trial (UMIN000053861). Workplace departments were randomized as clusters (1:1) to intervention/control. The 12-week program comprised educational emails, short videos, individualized feedback sheets, and supportive supervisor messages. The primary and secondary outcomes were the Telework Environment Setup Behavior (12 items) and Somatic Symptom Scale-8 (SSS-8) scores, respectively. Analyses used a modified intention-to-treat approach with mixed-effects models. RESULTS: Twelve clusters from six companies participated (182/188 in the intervention/control groups, respectively). No significant between-group differences were observed in environment setup (difference, 1.34; 95% confidence interval [CI], -1.67 to 4.35; p = .345) or SSS-8 (difference, -1.10; 95% CI, -2.59 to 0.38; p = .129) scores at follow-up. In the process evaluation, over half of intervention participants who completed the follow-up reported satisfaction, nearly 90% read the emails, and approximately 40% viewed the videos. Among video viewers, approximately two-thirds reported adopting recommended behaviors, while > 80% rated the content useful. CONCLUSIONS: This secondary analysis did not detect statistically significant improvements in telework environment setup behaviors or somatic symptoms. Statistical conclusions regarding intervention effects remain inconclusive, underscoring the need for organizationally supported, multifaceted strategies to strengthen telework environments.