Lower respiratory tract infection hospitalizations among American Indian/Alaska Native children and the general United States child population

BACKGROUND: The lower respiratory tract infection (LRTI)-associated hospitalization rate in American Indian and Alaska Native (AI/AN) children aged <5 years declined during 1998–2008, yet remained 1.6 times higher than the general US child population in 2006–2008. PURPOSE: Describe the change in LRTI-associated hospitalization rates for AI/AN children and for the general US child population aged <5 years. METHODS: A retrospective analysis of hospitalizations with discharge ICD-9-CM codes for LRTI for AI/AN children and for the general US child population <5 years during 2009–2011 was conducted using Indian Health Service direct and contract care inpatient data and the Nationwide Inpatient Sample, respectively. We calculated hospitalization rates and made comparisons to previously published 1998–1999 rates prior to pneumococcal conjugate vaccine introduction. RESULTS: The average annual LRTI-associated hospitalization rate declined from 1998–1999 to 2009–2011 in AI/AN (35%, p<0.01) and the general US child population (19%, SE: 4.5%, p<0.01). The 2009–2011 AI/AN child average annual LRTI-associated hospitalization rate was 20.7 per 1,000, 1.5 times higher than the US child rate (13.7 95% CI: 12.6–14.8). The Alaska (38.9) and Southwest regions (27.3) had the highest rates. The disparity was greatest for infant (<1 year) pneumonia-associated and 2009–2010 H1N1 influenza-associated hospitalizations. CONCLUSIONS: Although the LRTI-associated hospitalization rate declined, the 2009–2011 AI/AN child rate remained higher than the US child rate, especially in the Alaska and Southwest regions. The residual disparity is likely multi-factorial and partly related to household crowding, indoor smoke exposure, lack of piped water and poverty. Implementation of interventions proven to reduce LRTI is needed among AI/AN children.