Factors Associated with Receipt of 2009 Influenza A (H1N1) Monovalent and Seasonal Influenza Vaccination Among Adults Living with School-Aged Children — Maricopa County, Arizona, 2009–2010 Influenza Season

Background: In the US, annually >200,000 hospitalizations and ~24,000 deaths are influenza-associated. Although annual influenza vaccination is recommended for persons who are or live with others at increased risk for influenza-related complications, influenza vaccination coverage remains low.

Objectives: To determine factors associated with receipt of 2009 influenza A (H1N1) monovalent and seasonal influenza (SI) vaccination among Maricopa County adult respondents living with school-aged children.

Methods: Random-digit telephone dialing was used to identify and survey 600 households with school-aged children and a willing adult (aged ≥18 years) participant. Two multivariate logistic regression models were used to identify factors associated with adult influenza vaccination.

Results: To survey 600 (21%) eligible households, 2,843 were contacted. In 186 (31%) households, at least one adult received H1N1 vaccination. Of these households, 54 (29%) and 73 (39%) had a child or adult with a high-risk condition, respectively. In 257 (43%) households, at least one adult received SI vaccination. Of these households, 73 (28%) and 95 (37%) had a child or adult with a high-risk condition, respectively. After adjusting for race/ethnicity and health insurance in two separate models, factors independently associated with adult H1N1 or SI vaccination included high-risk medical condition in a child (H1N1 vaccination adjusted odds ratio [HAOR]: 1.8; 95% confidence interval [CI]: 1.1–2.8; SI vaccination adjusted odds ratio [SAOR]: 1.6; 95% CI: 1.0–2.6); high-risk medical condition in any adult (HAOR: 2.3; 95% CI: 1.4–3.7; SAOR: 2.7; 95% CI: 1.7–4.5); and college degree attainment (versus nonattainment) of respondent (HAOR: 2.1; 95% CI: 1.4–3.1; SAOR: 1.9; 95% CI: 1.3–2.7).

Conclusions: The association of adult influenza vaccination was stronger for adults living in a household with any adult with a high-risk condition compared to living with a child with a high-risk condition. Additional studies are needed to better understand these differences.