METHODS: We conducted a case-control investigation using pandemic influenza fatalities from 2009 in Alaska, Arizona, New Mexico, Oklahoma and Wyoming. Controls were outpatients with influenza. We reviewed medical records and interviewed case proxies and controls. We used multiple imputation to predict missing data and multivariable conditional logistic regression to determine risk factors.
RESULTS: We included 145 fatal cases and 236 controls; 22% of cases were AI/AN. Risk factors (p-value < 0.05) included: older age (adjusted matched odds ratio [OR] 3.2, for > 45 years. vs. < 18 years), pre-existing medical conditions (OR 7.1), smoking (OR 3.0), delayed receipt of antivirals (MOR 6.5), and barriers to healthcare access (OR 5.3). AI/AN race was not significantly associated with death.
CONCLUSIONS: The increased influenza mortality among AI/ANs was due to factors other than racial status. AI/AN race is a marker for other risk factors and should lead to a focus on modifiable risk factors that could help address this health disparity. Prevention of influenza could be achieved through smoking cessation and preventing initiative, early antiviral use, improving access to care, and identifying high risk persons for immunization and prompt medical attention.