Perception of adverse-effect risks and receipt of influenza vaccination among hospital personnel

Abstract number: 1732_229

Ehrenstein B.P., Hanses F., Blaas S., Mandraka F., Audebert F., Salzberger B.

Objectives: Hospital personnel (HP) are at risk for contracting influenza and may transmit influenza to patients. Although, influenza vaccination of HP significantly reduces the overall mortality of patients, vaccination rates in many hospitals remain low. Surveys among HP delineated fear of adverse effects (AE) as an important reason for HP not to get vaccinated. We surveyed HP to delineate their appraisal of influenza vaccine AE rates and to correlate correct knowledge of AE rates with the receipt of influenza vaccination.

Methods: In February 2006, we distributed anonymous self-administered, multiple-choice paper questionnaires to the 637 physicians and final-year medical students (FYMS), 994 nurses, and 267 hospital administrators at a university tertiary care hospital. Questions pertained to the incidence and complication rates of influenza, to the general knowledge about, and the indications for influenza vaccination, and to the rates of twelve possible influenza-vaccination AE. We also retrieved demographic data, the receipt of influenza vaccination in the current season (2005/2006), and the most important reason to get or not get vaccinated.

Results: 647/1898 (34%) surveys were returned. 345/647 (53%) respondents had received influenza vaccination in 2005/2006. 127/302 (42%) 2005/06 non-vaccinated HP stated that vaccine AE were the most important reason not to get vaccinated. Overall, respondents underestimated the incidence rates of non-severe AE (headache, muscle aches, fever, chills, painful injection site, and >2 days absenteeism) and overestimated severe AE rates (skin necrosis, severe hepatitis, acute renal failure, encephalitis, Guillain-Barré syndrome, permanent neurological damage). In a multivariate analysis among physicians and FYMS, receipt of influenza vaccination 2005/06 was independently associated with above-average knowledge about influenza vaccine (OR 2.4) and correct appraisal of severe AE rates (OR 3.7), among nurses with above-average knowledge about the influenza vaccine (OR 2.1) and an underestimation of non-severe AE rates (OR 3.6).

Conclusion: HP overestimated the severe AE rates and underestimated the non-severe AE rates of influenza vaccination. The appraisal of these AE rates appears to be very important in the decision of HP to get vaccinated. A better mediation of the actual very low rates of severe adverse effects may improve the influenza-vaccination rates among HP.