BACKGROUND:
Determinants of low influenza vaccination coverage among minority groups aged 65+ years remain poorly understood. Without new insight into the environment in which preventive care is delivered, further advances to improve influenza immunization rates are unlikely.

OBJECTIVE:
To describe the organizational context in which racial and ethnic disparities in adult influenza immunizations occur.

METHOD:
We conducted a multimethod comparative case study of three family medicine offices in New Jersey: one urban academic practice, one suburban private practice, one urban community health clinic. We analyzed ethnographic observations, surveys and interviews, and 60 medical charts from each clinic. Three main outcomes were measured: (1) Influenza immunization rates among patients age 65 and older, (2) Staff, physician, and patient knowledge, attitudes and beliefs regarding influenza immunizations, and (3) Organizational culture.

RESULT:
Adult influenza immunizations rates varied widely among the three practices (32%, 33%, and 67% respectively for academic, private, and community clinics). Rates were highest in the community clinic where there was a concerted effort to promote flu shots and where the head nurse and medical director strongly supported vaccination. Overall coverage was highest among Hispanics (71%), who primarily attended the community clinic, compared to 34% among African Americans and 44% among Whites. Race and ethnicity of providers did not affect practices' influenza vaccine rates.
Conclusions: Influenza immunization in the primary care environment is influenced by practice culture, office systems, and health care workers' and patients' knowledge, attitudes and beliefs. These data support the need for more systematic investigation of how these factors may affect population level immunization disparities. Improving immunization rates may be best accomplished through practice based interventions that involve entire practice teams.

CONCLUSION:
Influenza immunization in the primary care environment is influenced by practice culture, office systems, and health care workers' and patients' knowledge, attitudes and beliefs. These data support the need for more systematic investigation of how these factors may affect population level immunization disparities. Improving immunization rates may be best accomplished through practice based interventions that involve entire practice teams.

LEARNING OBJECTIVES:
1) to understand factors affecting primary care practice immunization rates
2) to compare patient and staff vaccination in clinics with different organizational cultures and immunization strategies