Assessing the effect of portable air purifiers on absences in German daycare centers

Abstract Daycare centers are currently experiencing a high burden due to cases of illness among children and staff, especially since COVID-19 preventive regulations were lifted. As part of a larger research project, portable air purifiers were installed in selected daycare centers in Germany in 2021 to improve air quality and reduce the spread of infections. The value of air purifiers is now in question, therefore an investigation of their benefit for child health beyond the pandemic is needed. Currently the effects of air purifiers on actual absenteeism in daycare centers have rarely been studied. In our study we collected attendance records from 24 daycare centers over a period of two years (2023 and 2024) to assess the effect of portable air purifiers with HEPA filters on the absences of daycare children. The study follows an intervention design, where the intervention daycare centers were equipped with air purifiers. The primary outcome measure was the weekly prevalence of days absent from daycare center per 1,000 children. Results showed a significant difference in absent days between intervention (258 and 213 per 1,000 children in 2023 and 2024) and control groups (278 and 267 per 1,000 children in 2023 and 2024). The effect size is high for both years (2023: 0.60, 2024: 0.78). The results show a reduction in absences by using air purifiers. Thus, a value of the air purifiers beyond COVID-19 is indicated. However, the costs and efforts involved in using air purifiers must be considered individually, especially in daycare settings. Confounding factors in regard to air purifier usage and maintenance as well as perceptions on maintenance costs and efforts were explored in qualitative interviews. Future approaches could investigate the interaction between daycare center specific policies on hygiene, sick-leave and absenteeism and the effectiveness of air purifiers, as well as assess the possible cost saving of reduced daycare staff absences. Key messages • The study shows a significant reduction in days absent from daycare centers in the intervention group by using air purifiers. • The results indicate a value of air purifiers for child health beyond COVID-19.