摘要：Objectives. We compared pneumonia and influenza death rates among American Indian/Alaska Native (AI/AN) people with rates among Whites and examined geographic differences in pneumonia and influenza death rates for AI/AN persons. Methods. We adjusted National Vital Statistics Surveillance mortality data for racial misclassification of AI/AN people through linkages with Indian Health Service (IHS) registration records. Pneumonia and influenza deaths were defined as those who died from 1990 through 1998 and 1999 through 2009 according to codes for pneumonia and influenza from the International Classification of Diseases, 9th and 10th Revision , respectively. We limited the analysis to IHS Contract Health Service Delivery Area counties, and compared pneumonia and influenza death rates between AI/ANs and Whites by calculating rate ratios for the 2 periods. Results. Compared with Whites, the pneumonia and influenza death rate for AI/AN persons in both periods was significantly higher. AI/AN populations in the Alaska, Northern Plains, and Southwest regions had rates more than 2 times higher than those of Whites. The pneumonia and influenza death rate for AI/AN populations decreased from 39.6 in 1999 to 2003 to 33.9 in 2004 to 2009. Conclusions. Although progress has been made in reducing pneumonia and influenza mortality, disparities between AI/AN persons and Whites persist. Strategies to improve vaccination coverage and address risk factors that contribute to pneumonia and influenza mortality are needed. Although infectious disease rates have fallen dramatically in the United States, 1 infectious disease continues to be a significant health problem, and substantial racial and ethnic disparities for some such diseases remain. 2,3 American Indian and Alaska Native (AI/AN) people are at higher risk for many chronic and infectious diseases, have a higher prevalence of certain health risk behaviors, and experience higher infectious disease hospitalization rates compared with the general US population. 4–13 Lower respiratory tract infections are a leading cause of infectious disease hospitalizations for AI/AN people, 10 and previous studies have found significant disparities in lower respiratory tract infection hospitalization rates for AI/AN people compared with the US population in some regions, especially for infants (children aged < 1 year). 12 Hospitalization and death rates for overall lower respiratory tract infections are significantly higher for AI/AN infants compared with other US infants. 14–16 Pneumonia is a common cause of lower respiratory tract infection, 14 and influenza is one of the leading causes of pneumonia. Pneumonia and influenza together are one of the top 10 leading causes of death in the United States. In 2010, pneumonia and influenza ranked ninth as the leading cause of death for all races in the United States. 17 Pneumonia and influenza also ranks among the top 10 causes of death for AI/AN populations; elevated rates of pneumonia and influenza mortality compared with other races have been documented since the early 1990s. 18–21 In 2010, pneumonia and influenza ranked 10th as a leading cause of death for the AI/AN population. 17 Among the AI/AN population, hospitalization and disease rates for the leading causes of pneumonia (e.g., respiratory syncytial virus, influenza, and Streptococcus pneumoniae ) are higher compared with other US population groups. For example, respiratory syncytial virus hospitalization rates are significantly higher for AI/AN infants, particularly in the Southwest and Alaska, compared with other US infants 22 ; respiratory syncytial virus hospitalizations for Alaska Native infants in the Alaskan Yukon-Kuskokwim Delta are 5 times higher than rates for the general US infant population. 23 Before the introduction of pneumococcal vaccines, rates of invasive pneumococcal disease in AI/AN adults and children in Alaska and some tribes in the Southwest were higher than rates for the general US population. 3,24–26 Although rates of invasive pneumococcal disease declined significantly in US children and adults and among AI/AN children 3,26–33 after the introduction of pneumococcal vaccines, invasive pneumococcal disease rates among certain AI/AN populations remain elevated compared with the general US population. 3,26,29,32 Influenza, a leading cause of pneumonia, has also been found to disproportionately affect AI/AN populations. In the last 100 years, numerous reports have described the high rates of influenza-associated morbidity and mortality in AI/AN communities. 34,35 More recently, during the 2009 H1N1 influenza A pandemic, several studies found higher influenza mortality and hospitalization rates among AI/AN people compared with the general population, 36–38 as well as a higher prevalence of self-reported influenza-like illness and influenza-associated hospitalizations compared with non-Hispanic Whites. 39 Racial misclassification has been found to contribute to an underestimation of death rates for AI/AN people, who are often misclassified as non-AI/AN persons in death certificate data. 40,41 In 1 evaluation of the validity of racial classification in death certificates, only 55% of self-identified AI/AN decedents were correctly classified on their death certificates from 1990 to 1998. 40 In another study, included in this supplement, misclassification of AI/AN race in mortality data was 17.7%. 41 Although it is clear that pneumonia and influenza are significant health burdens for AI/AN people, racial misclassification in previous studies that relied on death certificate data likely underestimated the death rate for AI/AN persons. 40 To provide more accurate estimates of the true burden of pneumonia and influenza mortality among AI/AN people, we used data from the National Death Index linked to Indian Health Service (IHS) patient registration data to improve AI/AN racial classification. Using these data, we compared pneumonia and influenza death rates for AI/AN populations to those for Whites. We described pneumonia and influenza related deaths among AI/AN people from 1990 to 2009, examined geographic differences in pneumonia and influenza death rates for AI/ANs, compared overall and age-specific pneumonia and influenza death rates among AI/AN people with rates among Whites, and described progress in addressing disparities in pneumonia and influenza mortality.
