Influenza vaccination: impact on absenteeism among nursing and medical staff in a metropolitan teaching hospital

Abstract

During the 1998 pre-winter season, an influenza 'needles on wheels' campaign was promoted among health-care workers at a 250-bed paediatric and a 250-bed women's teaching hospital in Western Australia. Approximately 720 staff accepted the offer of influenza vaccination across both hospitals. A study was undertaken to compare the incidence of sick leave between the vaccinated and non-vaccinated groups. Medical officers and nurses were considered to have the most clinical contact; therefore, a randomised retrospective study of 1300 of these staff was conducted. Of the study subjects, 46 vaccinated and 47 non-vaccinated staff were noted to be absent from duty for a period of 20 hours or longer with a 'flu-like illness'. A telephone interview utilising the Australian Sentinel Practice Research Network case definition was used as a diagnostic tool. Chi-square analysis revealed a significant reduction in the incidence of 'flu-like illness' in the vaccinated group (32.6 per cent versus 59.6 per cent (chi square = 6.8; p = 0.009). Staff who received the influenza vaccination reduced their chance of developing a 'flu-like illness' by 67 per cent. As a result of this study, it was recommended that influenza vaccination be offered free to all hospital employees each year, prior to commencement of the winter season.