Occupational health service Arbo Unie predicts a steep increase in employee sick leave during September. An analysis of company data from 2020 through 2025 shows that sick leave notifications rise by an average of 69 per cent in September compared to August. The organization identifies September as the official start of the annual sickness season.
Increased contact and seasonal illnesses drive spike
Arbo Unie emphasizes that the sudden increase does not stem from a lack of workplace motivation. Occupational physician Corné Roelen explained that workloads increase in September as staff return, leading to frequent physical contact among colleagues. Concurrently, cold and flu viruses begin circulating more widely, driving up infection rates across workplaces.
Short-term absences dominate despite long-term risks
The vast majority of September sick leave instances remain brief. Almost three-quarters of reported absences last less than a week, with a median duration of four days. However, Arbo Unie warns that a notable proportion of these short absences eventually develop into long-term leave, with work-related stress and psychological issues serving as the primary cause.
Winter months represent peak absence period
While September marks the start of the upward trend, total sick leave reaches its annual peak during the winter months of January, February, and March. Persistent seasonal respiratory viruses, including influenza and common colds, drive the highest volumes of absence during that period.
@ anp | NEWS BRAINPORT
