Increasing inner-city adult influenza vaccination rates: a randomized controlled trial.

Objectives: In a population of seniors served by urban primary care centers, we evaluated the effect of the practice-based intervention on influenza immunization rates and disparities in vaccination rates by race/ethnicity and insurance status.

Methods: A randomized controlled trial during 2003-2004 tested patient tracking/recall/outreach and provider prompts on improving influenza immunization rates. Patients aged > or = 65 years in six large inner-city primary care practices were randomly allocated to study or control group. Influenza immunization coverage was measured prior to enrollment and on the end date.

Results: At study end, immunization rates were greater for the intervention group than for the control group (64% vs. 22%, p < 0.0001). When controlling for other factors, the intervention group was more than six times as likely to receive influenza vaccine. The intervention was effective across gender, race/ ethnicity, age, and insurance subgroups. Among the intervention group, 3.5% of African Americans and 3.2% of white people refused influenza immunization.

Conclusions: Patient tracking/recall/outreach and provider prompts were intensive but successful approaches to increasing seasonal influenza immunization rates among this group of inner-city seniors.