Effective Use of Employee Vaccination Data to Improve Healthcare Workers' Seasonal influenza Vaccination Rates

Influenza is a global health problem annually resulting in excess mortality and morbidity.  Vaccination is a well-established preventative measure for influenza and is especially encouraged in healthcare workers to prevent passing disease to patients. The objective of this study was to use employee vaccination data to assess factors associated with vaccination uptake (the percentage immunized) among workers at a large, healthcare institution in California during the 2006/2007 through 2011/2012 seasons. A combined cohort/cross sectional study design was utilized. Basic descriptive analyses were used to describe vaccination rates and reasons for vaccination declination by important subgroups.  A logistic regression model was fit to examine factors (i.e., age, gender, job category, and work department) associated with vaccination uptake. The vaccination rates increased from 48% in 2006/2007 to 74.9% in 2011/2012. During the 2009 influenza pandemic, 72% of employees were vaccinated with the seasonal flu vaccine versus 68% who were vaccinated with the 2009 H1N1 vaccine. The most common reason for declination across all job categories was “personal reasons” (58%), followed by “I get ill from the flu vaccine” (16%). Data from the 2011/2012 season showed that vaccination rates varied by age (OR=1.005) and employee type (nursing assistants versus nurses, OR =1.408), and location (working in a procedure area compared with working in medical surgical units, OR= .840). Although statistical differences were found, there were no real clinical differences seen as evidenced by small differences in percentage vaccination rates. The identification of factors related to vaccination uptake is an important step in developing targeted strategies to increase compliance with vaccination recommendations.