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

During the period from 1990–1991 to 1998–1999, the annual estimated U.S. seasonal influenza-associated deaths averaged about 36,000, and 90% of these deaths occurred in people aged 65 years or older.1 Approximately 200,000 influenza-associated hospitalizations also occurred, with a large proportion among seniors.2 The average annual U.S. cost for pneumonia and influenza-related hospitalizations exceeds $370 million.3 Despite the substantial disease burden from influenza, reported vaccination coverage was 67.2% for people aged ≥65 years, which was consistent with previous studies that have found no significant increases in vaccination coverage over previous seasons, according to the Behavioral Risk Factor Surveillance System from selected states in the 2008–2009 season. Additionally, estimated seasonal influenza vaccination coverage (and 95% confidence intervals [CIs]) varied by race/ethnicity as follows: non-Hispanic white 69.0% (95% CI 67.1, 70.9), non-Hispanic black 56.3% (95% CI 45.0, 66.9), Hispanic 65.8% (95% CI 53.1, 76.6), and other 58.4% (95% CI 46.4, 69.5).4 In fact, racial/ethnic disparities in adult influenza immunization rates have persisted for many years.5–14 One overarching goal of Healthy People 2010 was to eliminate health disparities15 and, within the focus area of immunization and infectious diseases, to increase to 90% the overall proportion of seniors who are vaccinated annually against influenza.16 To achieve these national goals by 2020, significant enhancements in local immunization delivery systems will be required. Although several prior projects in Monroe County, New York, such as the Medicare Influenza Vaccination Demonstration, successfully increased adult influenza vaccine coverage rates in individual practices and across the community,17,18 large racial disparities persisted. For example, in 2002, only 38% of the county's African American seniors received influenza vaccination compared with 71% of white seniors.19 This disparity in rates of vaccination mirrors the patterns found in national and state data. The Task Force on Community Preventive Services20 (hereafter referred to as “Task Force”) disseminated broad categories of evidence-based strategies to improve immunization coverage in communities. These strategies included increasing community demand for vaccinations, enhancing access to vaccination services, and implementing provider- or system-based interventions,21 such as patient reminder/recall and health-care provider prompts about vaccinations.22–25 The Task Force recommended combination strategies, including interventions from more than one of the aforementioned categories. Most studies of immunization strategies have used single interventions and applied the interventions in single practices rather than across a community or network of practices.26–28 To achieve public health goals of raising immunization rates and eliminating disparities across an entire community, it is important to evaluate the effectiveness of interventions across multiple and diverse practice settings, particularly those that serve vulnerable populations. The Racial and Ethnic Adult Disparities in Immunization Initiative (READII) was a two-year project conducted in five U.S. communities to demonstrate promising strategies to increase vaccination rates for African American and Hispanic seniors.29 In Rochester, New York (population 220,000 within Monroe County's total population of 735,000), the READII team developed a two-part program: (1) a community action plan that included a broad-based communication campaign implemented through community organizations along with enhanced vaccine delivery through nontraditional venues, and (2) a practice-based intervention in multiple community health centers and hospital clinics. To study the effectiveness of the latter part of the program, we designed and implemented a randomized controlled trial of this intervention, which involved a stepwise combination of patient tracking and reminder/recall/outreach as well as provider reminders. This combination strategy has been found to improve childhood vaccination rates30 and to reduce community racial/ethnic disparities when implemented across multiple inner-city practices that serve minority children.31 This intervention has not been applied previously to adults across multiple practice settings. The specific study objectives were to evaluate, in a population of seniors served by urban primary care centers (PCCs), the effect of the practice-based intervention on (1) influenza immunization rates and (2) disparities in vaccination rates by race/ethnicity and insurance status.