Objectives: This study examined the relationship between the status of infection control efforts against COVID-19 in the workplace and workers' mental health using a large-scale Internet study .
Methods: This cross-sectional study was based on an Internet monitoring survey conducted during the third wave of the COVID-19 epidemic in Japan . Of the 33,302 people who participated in the survey , 27,036 were included in the analyses . Participants answered whether or not each of 10 different infection control measures were in place at their workplace (e.g . wearing masks at all times during working hours). A Kessler 6 (K6) score of [≥] 5 was defined as mild psychological distress . The odds ratios (ORs) of psychological distress associated with infection control measures at the workplace were estimated using a multilevel logistic model nested in the prefectures of residence .
Results: The OR of subjects working at facilities with 4 or 5 infection control measures was 1.15 (95% confidence interval [CI]: 1.02-1.29, p=0.025), that in facilities with 2 or 3 infection control measures was 1.32 (95% CI : 1.15-1.50, p <0.001), and that in facilities with 1 or no infection control measures was 1.48 (95% CI : 1.30-1.68, p <0.001) compared to subjects whose workplaces had [≥] 6 infection control measures . Conclusion: Our findings suggest that proactive COVID-19 infection control measures can influence the mental health of workers.