Self-reported indoor climate in shared vs. private offices and its effects on headache and respiratory symptoms in Norwegian office workers

This two-wave cross-sectional study analyzed data from 7,968 Norwegian office workers collected in 2016 and 2019 to investigate associations among self-reported indoor climate, headaches, and respiratory symptoms across six office types. Interaction effects between office type, indoor climate, and health outcomes were assessed, alongside a mediation analysis examining indoor climate as a mediator between office type and health outcomes. Adjusted generalized linear models (GLMs) revealed that shared offices had significantly poorer indoor climate conditions than private offices, with the highest odds reported in flexible spaces (OR = 1.72, 95% CI: 1.41–2.09) and offices with over 24 occupants (OR = 1.57, 95% CI: 1.27–1.93). Self-reported poor indoor climate was associated with respiratory symptoms (OR = 2.17, 95% CI: 1.74 - 2.27) and headaches (OR = 1.66, 95% CI: 1.48 – 1.86). No direct association was found between office type and health outcomes; however, mediation analysis demonstrated a significant indirect effect of office type on health outcomes via indoor climate. Interaction analysis further revealed that the association between poor indoor climate and respiratory symptoms was stronger in shared offices compared to cell offices for both respiratory symptoms (OR = 2.32 vs. OR = 1.80) and headaches (OR = 1.69 vs. OR = 1.44). In conclusion, this study demonstrates notable associations between office type, perceived indoor climate, and self-reported health outcomes. While the cross-sectional design limits the ability to determine the direction or underlying mechanisms of these associations, the results emphasize the relevance of both office layout and indoor climate quality in evaluating workplace health. • Perceived indoor climate was poorer in shared offices than in private cell offices. • Dry air, draught and poor ventilation raised the risk of respiratory symptoms. • Dry air and poor ventilation raised the risk of headaches. • Joint exposure to shared offices and poor indoor climate increases the health risk. • Indoor climate mediates the relationship between office type and health outcomes.