This supplementary information is presented as submitted by the corresponding author. It has not been copy-edited by NTvG.
Seasonal vaccination of health care workers against influenza virus can reduce the transmission of the virus to frail hospitalised patients and inhabitants of long-term care facilities. In the current study, we assessed the influenza vaccine coverage in Dutch hospitals in the fourth quarter of 2012.
Observational questionnaire study.
In August 2013 we informed 62 hospitals, affiliated with a sick leave registration office, about the intended study. This is the majority of the 87 general hospitals in the Netherlands. Hospitals willing to participate were asked to report the number of employees that received seasonal influenza vaccination in the fourth quarter of 2012. They were also asked to complete a questionnaire with respect to the vaccination policy in their hospital (i.e. which employees were eligible for vaccination, was information about the benefits, indication and adverse effects of vaccination provided, and did the employees receive a personal invitation for vaccination). Vaccination coverage per hospital was calculated as the number employees who received the vaccine via the employer divided by the total number of employees.
Forty-five of the 62 hospitals were willing to participate, giving a response rate of 73%. In 43 of these 45 hospitals, all employees were eligible for influenza vaccination, while in the other two hospitals only employees directly in contact with patients were eligible. Vaccine coverage ranged from 2% to 33%, with median vaccine coverage of 13%. Vaccine uptake was higher in the oldest age groups. Information about vaccination was given in 43 of the 45 hospitals (96%). This concerned information on the benefits (31/43; 72%), possible side effects (17/43; 40%) and contraindications of vaccination (10/43; 23%).
In 2012 a maximum of one third of the employees in 45 Dutch hospitals had been vaccinated against influenza at work. Since it is likely that seasonal vaccination of health care workers can reduce the transmission of influenza to vulnerable patients, higher vaccine uptake is recommended, as advised by the Dutch Health Council. Because we found no evidence that a more active approach of health care workers, for example through a personal invitation for vaccination at a time that suits the employee, did increase the vaccination coverage, it is important to explore how this can be accomplished properly.