Evaluating influenza vaccination campaigns beyond coverage: a before-after study among health care workers

Influenza vaccination campaigns based on educational interventions do not seem to increase coverage in the hospital setting, and their impact on educational goals is not usually evaluated. This study describes the campaign implemented in a university hospital and assesses the achievement of the strategic objectives, which were to increase health care workers (HCW) perceptions of the risk of influenza and of their role as promoters of influenza vaccination among their colleagues and to increase knowledge about influenza.

A before-after study was conducted using a self-administered survey in a randomized sample of HCW during the 2010-2011 influenza vaccination campaign. The Wilcoxon paired measures test was used to assess attainment of the strategic objectives.

The campaign had a positive impact on the strategic objectives (Wilcoxon test, P value <.05 in all cases). The reach of the campaign was high (91.9%), and HCW rated it as positive (7.19 [standard deviation, 2.3] out of 10) but did not achieve increased coverage (34%; 95% confidence interval: 33.8-36.4).

Evaluation of the campaign shows that its effect responded to the strategic objectives. However, it seems that increasing the information provided to HCW and heightening their risk perception do not necessarily lead to greater acceptance of influenza vaccination.