Clinical and non-clinical staff differences in sick leave: flu effect

Background: Although healthcare workers have been at risk for work-related illness during recent SARS and avian influenza outbreaks, no consensus exists on the current degree of hazard from clinical care delivered to patients during seasonal or pandemic influenza

Objective: The authors sought to document relationships between sick leave usage and evolution of the epidemic among clinical and non-clinical staff in the Veterans Health Aministration

Methods: Sick leave usage for all employees was identified by two-week pay periods for three years, 2007 to 2009.  Average and 95% confidence intervalls were calculated for 2007 and 2008.  Usage in 2009 was compared with usage during 2007 and 2008.  In addition, the ratio of sick leave usage between clinical and non-clinical staff was plotted and calcuated (figure 1).

Results: Leave usage showed wide variability in each year.  Although there was no "bump" during the first wave of the epidemic, in May and June, leave usage increased signficantly compared to prior years beginning in in April, 2009, overall leave usage showed a significant increase beginning in September.  More importantly, the ratio of sick leave usage of clinical to non-clinical staff, usually .97, showed significant "bumps" in May and then again beginning in early Septmeber.

Conclusions: Clinical staff may be at greater risk for influenza than non-clinical staff suggesting transmission at work.  Exploration of leave ratios may be a sensitive indicators of novel influenza illness.