An opt-out influenza vaccination policy improves immunization rates in primary care

During the 2007-08 influenza season 36% of outpatients seen at our urban family medicine center received an influenza immunization. We explored the expected increase in vaccinations from an opt-out policy using standing orders in a lower-income population.

A comparison of vaccination rates during the periods 10/1/2007 to 3/31/2008 (P1) versus 10/1/2008 to 3/31/2009 (P2) with adjustments for cohort non-independence.

The overall P2 vaccination rate increased to 49% [p<.000001]. P2 rates were significantly higher for those with diabetes, both genders, African American and European American patients from 3 to 64 years old, and in all insurance groups. The vaccination rates for patients with Medicaid insurance (37% and 54%) were higher than the rates for patients with commercial insurance (31% and 43%).

The opt-out policy is associated with a moderate (1.4 fold) increase in the vaccination rate. Primary care resource constraints may limit further improvement.