Increasing Inner-City Adult Influenza Vaccination Rates: A Randomized Controlled Trial

Abstract

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. 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. 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. 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.