Determinants of adult influenza and pneumonia immunization rates

Objectives: To determine national adult immunization rates for influenza and pneumonia and assess the effect of various predisposing factors on immunization status for both diseases. Design: Retrospective, cross-sectional, random national sample data from the Centers for Disease Control and Prevention's 1999 Behavioral Risk Factor Surveillance System survey. Data extraction and analysis were conducted using SPSS and STATA, with adjustments made for weighted data. Participants: Individuals aged 65 years and older and individuals aged 50 to 64 years (for influenza only). Results: Immunization rates in the 65 and older age group were 66.7% for influenza and 53.8% for pneumonia; immunization rate for influenza in the 50 to 64 age group was 35.6%. Predisposing factors such as race (white) and education (high school and above) positively influenced immunization status. Enabling factors such as income, health insurance, and physician visits and need-related factors such as health status and comorbidities exhibited a strong relationship with influenza and pneumonia vaccination status in both study populations. Health care coverage (odds ratio [OR] = 1.76 for influenza and OR = 1.66 for pneumonia in the 65 years and older group; OR = 1.80 for influenza in the 50 to 64 years age group) and physician visit in the last year (OR = 2.00 for influenza and OR = 1.87 for pneumonia for 65 years and older group; OR = 1.86 for influenza in the 50 to 64 years age group) were strong positive predictors of vaccination status. Individuals with comorbidities and those who perceived their health as being poor had high vaccination rates. Conclusion: Understanding the positive and negative influences on adult immunization status will allow pharmacists to better identify and target prospective recipients of immunization services.