Chronic respiratory disease disparity between American Indian/Alaska Native and white populations, 2011-2018

Abstract

Background: American Indian/Alaska Native (AI/AN) populations have been disproportionately affected by chronic respiratory diseases for reasons incompletely understood. Past research into disease disparity using population-based surveys mostly focused on state-specific factors. The present study investigates the independent contributions of AI/AN racial status and other socioeconomic/demographic variables to chronic respiratory disease disparity in an 11-state region with historically high AI/AN representation. Using data from the Behavioral Risk Factor Surveillance System (BRFSS) spanning years 2011-2018, this work provides an updated assessment of disease disparity and potential determinants of respiratory health in AI/AN populations.

Methods: This cross-sectional study used data from the BRFSS survey, 2011-2018. The study population included AI/AN and non-Hispanic white individuals resident in 11 states with increased proportion of AI/AN individuals. The yearly number of respondents averaged 75,029 (62878-87,350) which included approximately 5% AI/AN respondents (4.5-6.3%). We compared the yearly adjusted prevalence for chronic respiratory disease, where disease status was defined by self-reported history of having asthma and/or chronic obstructive pulmonary disease (COPD). Multivariable logistic regression was performed to determine if being AI/AN was independently associated with chronic respiratory disease. Covariates included demographic (age, sex), socioeconomic (marital status, education level, annual household income), and behavioral (smoking, weight morbidity) variables.

Results: The AI/AN population consistently displayed higher adjusted prevalence of chronic respiratory disease compared to the non-Hispanic white population. However, the AI/AN race/ethnicity characteristic was not independently associated with chronic respiratory disease (OR, 0.93; 95% CI, 0.79-1.10 in 2017). In contrast, indicators of low socioeconomic status such as annual household income of <$10,000 (OR, 2.02; 95% CI, 1.64-2.49 in 2017) and having less than high school education (OR, 1.37; 95% CI, 1.16-1.63 in 2017) were positively associated with disease. These trends persisted for all years analyzed.

Conclusions: This study highlighted that AI/AN socioeconomic burdens are key determinants of chronic respiratory disease, in addition to well-established risk factors such as smoking and weight morbidity. Disease disparity experienced by the AI/AN population is therefore likely a symptom of disproportionate socioeconomic challenges they face. Further promotion of public health and social service efforts may be able to improve AI/AN health and decrease this disease disparity.

Keywords: American Indian/Alaskan Native; BRFSS; Chronic respiratory disease; Health disparities.

Fig. 1

The AI/AN population experiences higher prevalence of chronic respiratory disease. A Location of federally recognized and statistical American Indian and Alaska Native entities in blue, including reservations. States included in this study are labeled with two-letter abbreviation and were oversampled in 2017 due to historically increased AI/AN representation. The map shown was produced using the tigris package [22] in R with shapefiles publicly available from the US Census Bureau [23]. B Adjusted prevalence of chronic respiratory disease in AI/AN and non-Hispanic white respondents surveyed in years 2011–2018. Comparisons between AI/AN vs white are statistically significant by χ² test for all years except 2015

Fig. 2

Determinants of chronic respiratory disease. Odds ratios with 95% CI are calculated from logistic regression performed on data from survey year 2017 for the 11 oversampled states. The AI/AN variable is not associated with chronic respiratory disease. Only significant covariates are shown. For covariates, closed circles represent variables negatively associated with disease. Open circles indicate variables positively associated with disease. Bars represent 95% CI. Reference levels for covariates are indicated in Table 1