Introduction
Deaths from diabetes have increased significantly in the past two decades, impacting every state, age group, sex, and racial and ethnic group in the USA.1 However, some regions and populations carry a disproportionate burden of diabetes. Diabetes was the fourth leading cause of death among American-Indians (AIs) and Alaska Natives (ANs) between 1999 and 2010 and the seventh leading cause of death in the US population.2 Diabetes was the second leading cause of death for AIs in North Dakota, South Dakota, Iowa, and Nebraska in 2010;3 however, these rates may be 15–25% higher because death certificates often under-report diabetes as the underlying cause of death.4 To address mortality differences, public health officials, tribes, and policymakers must first document tribal-specific disparities. However, this task is often difficult to complete due to the lack of tribal-specific data, small populations, and confidentiality issues. In addition, there is a lack of substantial data and poor surveillance infrastructure in tribal communities. No known published study has examined mortality rate differences in diabetes among AIs and Caucasians residing in the same reservation areas in the Great Plains Region (GPR), (Montana, Wyoming, South Dakota, North Dakota, Iowa, and Nebraska).
Persons with diabetes often experience comorbidities such as heart disease, stroke, and kidney failure. Many patients with diabetes experience increased mortality from pneumonia and influenza.4 AIs experience more comorbidities and more severe complications from diabetes that lead to premature mortality. A recent study in South Dakota compared AI adults with diabetes and the US adult population with diabetes and found a higher prevalence of hypertension, cerebrovascular disease, lower extremity amputations, mental health disorders, and liver disease among the AI adults.5
Often, AIs experience additional risk factors for diabetes complications than other racial and ethnic groups. AIs over the age of 25 years are less likely to have a college degree or high school diploma and 77% of them have a high school diploma compared with 91% of Caucasians.6 AIs report higher rates of smoking, obesity, and unhealthy diets, all of which increase the risk of diabetes and death from diabetes.7 ,8 AIs also report significantly lower income than Caucasians. In 2010, the median income for AIs in the USA was $39 664 compared with $67 892 for Caucasians.9 Low income is linked with persistent poverty conditions. Lower income and persistent poverty are associated with higher mortality from all causes in the general US population.10 ,11
AI communities experience segregation, oppression, and discrimination, often linked to colonization,12 ,13 and these factors may contribute to differences in diabetes mortality and inequalities in health outcomes across tribal nations. As a racial minority, AIs may experience racial oppressions that contribute to health differences.14 AIs may experience more discrimination from healthcare providers than Caucasians15 and this may influence how they seek care, prevent or manage diabetes, and cope with complications from diabetes. Healthcare service and delivery for AIs are often described by geographic region.
In the GPR, AIs represent a relatively small percent of the population as a racial minority. However, AIs are an important group to study because of mounting evidence that they experience extreme health disparities and premature mortality.16–18 Similarly, in the USA, racial and ethnic minorities have poorer health than Caucasians19–21 and report higher mortality from diabetes.
The purpose of this study was to document diabetes mortality among AIs and Caucasians in the GPR and describe the differences observed. One unique contribution of this study is the use of a tribally recommended approach for calculating reservation-specific mortality rates.