BACKGROUND:
The ACIP recommends influenza vaccination for about 104 million adults between the ages of 18 and 64, about 15% of whom are uninsured. Many more do not have insurance benefits that cover the cost of vaccination, while people who seek care in emergency departments (ED) are more likely to be underinsured. Previous studies have found vaccine acceptance to be associated with age, gender, income and race.

OBJECTIVE:
To analyze the influence of cost as a deterrent to vaccine acceptance among adult patients in an urban ED.

METHOD:
Patients between the ages of 18 and 65 years who were uninsured or Medicaid-enrolled seeking care for non-life threatening health problems in an ED in Baton Rouge, LA were assessed to determine if influenza vaccine was recommended. In a convenience sample, 104 patients were presented a vignette illness with influenza, then randomized to one of four groups and hypothetically asked if they would accept the vaccine in the ED if its cost to them were $0, $4, $11, or $30. Logistic regression was used to analyze the effects of vaccine cost, age, monthly income, gender, and race on acceptance.

RESULT:
Complete data were available for 52 (50%) of the 104 patients. Median monthly income was $550 (range $0 to $3500, mean $643). Willingness to accept influenza vaccine decreased from 83% when the vaccine was free to 31% when the vaccine cost $30 (P=0.01). Acceptance was not related to age (P=0.31), monthly income (P=0.70), gender (P=0.34), or race (P=0.46).

CONCLUSION:
Cost to patient was found to have a statistically significant effect on acceptance of influenza vaccination. However, even when vaccine was free, about 20% of patients refused vaccine.

LEARNING OBJECTIVES:
List one factor that does and two factors that do not influence acceptance of vaccination in an inner city emergency department.