Using the National Health Interview Survey: time trends in influenza vaccinations among targeted adults

Abstract

Context. Influenza and its complications result in significant morbidity and mortality each year. Certain groups are at increased risk for influenza and influenza-related complications. They, and others who are in close contact with them, are target groups to receive a yearly influenza immunization according to recommendations from the Advisory Committee on Immunization Practices (ACIP). Objective. To estimate the proportions of adults in selected target groups who received influenza vaccination in 1995 and 1998 and to identify characteristics associated with vaccination receipt. Data Source. The National Health Interview Survey (NHIS), a nationally representative survey of civilian noninstitutionalized persons conducted annually by the Centers for Disease Control's National Center for Health Statistics. We used data for adults (> 18 years of age) from the 1995 and 1998 NHIS. Outcome Measure. Proportions of persons in target groups self-reporting influenza vaccination in the 12 months before the NHIS interview. Results. Between 1995 and 1998, influenza vaccination increased for persons aged 65 and older (58.2% to 63.3%; P<0.05) and for adults under 65 belonging to selected ACIP target groups (27.5% to 30.1%; P<0.05). Examination of 1998 data shows that regardless of age, the likelihood of influenza vaccination is strongly influenced by having health coverage or a regular source of care. For example, 66% of the elderly with private fee- for-service health care coverage were vaccinated, compared with 23% of the elderly with no insurance (adjusted odds ratio [OR], 3.9; 95% CI, 1.6 to 9.3). For persons aged 18 to 64 years belonging to an ACIP target group, the corresponding figures are 32% vs. 16% (adjusted OR, 1.8; CI, 1.4 to 2.3). The likelihood of vaccination also varied by race and ethnicity: For age 65 and older, 66% of non-Hispanic whites were vaccinated compared with 46% of non-Hispanic blacks (adjusted OR, 2; CI, 1.6 to 2.4). Conclusions. The use of influenza vaccination among adults at high risk for influenza and influenza-related complications increased between 1995 and 1998. Younger individuals at high risk, people without insurance or a regular source of care, and nonwhites still have low vaccination rates.