Neurological Care within the Indian Health Service

American Indians and Alaska Natives (AI/AN) are the Indigenous peoples of the United States. According to the U.S. Census Bureau, approximately 9.7 million people self-identified as AI/AN (alone or in combination with other races), representing 2.9% of the total U.S. population. These people represent diverse groups of discrete Tribes, each with their language, culture, and geographic home. As part of the conquest and settlement of North America, some Indigenous peoples signed treaties with the U.S. government, surrendering their lands in return for various government commitments, including health care. The Indian Health Service (IHS) was born out of these agreements. The IHS is an agency in the U.S. Department of Health and Human Services under the U.S. Public Health Service. The IHS provides a comprehensive health service delivery system for approximately 2.7 million AI/AN who belong to 574 federally recognized Tribes/nations in 37 states. The aim of this paper is to make recommendations regarding the initiation of sustainable neurology care in marginalized or underserved populations by reviewing 40 years of neurology care provision within the IHS. We will discuss (1) the IHS, (2) neurological care provided within the IHS, including midlevel provider extension of neurology care and traditional medical care, and (3) select neurological diagnoses within AI/AN populations. Marginalized populations, including those in the United States that are rural, remote, or low socioeconomic status, lack access to specialty neurology care. This includes many AI/AN. The IHS has developed novel solutions to promote specialty care, including neurology. Notably, initial IHS investments in full-time neurology providers have led to more robust neurology care, often receiving attention from university programs. This suggests that an initial investment in stable on-site full-time neurology services provides a path to potential sustainable care for marginalized populations.

Ascertainment of Alaska Native Stroke Incidence, 2005-2009: Lessons for Assessing the Global Burden of Stroke

BACKGROUND

Stroke is a critical public health issue in the United States and globally. System models to optimally capture stroke incidence in rural and culturally diverse communities are needed. The epidemiological transition to a western lifestyle has been associated with an increased burden of vascular risk factors among Alaska Native (AN) people. The burden of stroke in AN communities remains understudied.

METHODS

The Alaska Native Stroke Registry (ANSR) was designed to screen and capture all stroke cases between 2005 and 2009 through its integration into the existing single-payer Alaska Tribal Health System infrastructure. Registry staff received notification each time stroke International Classification of Diseases, Ninth Revision codes (430-436) were initiated anywhere in the system. Trained chart abstractors reviewed medical records to document incident strokes among AN patients, which were adjudicated.

RESULTS

Between October 2005 and October 2009, over 2100 alerts were screened identifying 514 unique stroke cases, of which 372 were incident strokes. The average annual incidence of stroke (per 100,000) among AN adults was 190.6: 219.2 in men and 164.7 in women. Overall, the ischemic stroke incidence rate was 148.5 per 100,000 with men (184.6) having higher ischemic rates per 100,000 than women (118.3). Men have higher rates of ischemic stroke at all ages, whereas older women experienced higher rates of hemorrhagic strokes over the age of 75 years.

CONCLUSIONS

We report a high rate of overall stroke, 190.6 per 100,000. The ANSR methods and findings have implications for other indigenous populations and for global health populations currently undergoing similar epidemiological transitions.

All-cause, cardiovascular, and cancer mortality in western Alaska Native people: western Alaska Tribal Collaborative for Health (WATCH)

OBJECTIVES

We determined all-cause, cardiovascular disease (CVD), and cancer mortality in western Alaska Native people and examined agreement between death certificate information and adjudicated cause of deaths.

METHODS

Data from 4 cohort studies were consolidated. Death certificates and medical records were reviewed and adjudicated according to standard criteria. We compared adjudicated CVD and cancer deaths with death certificates by calculating sensitivity, specificity, predictive values, and κ statistics.

RESULTS

Men (n = 2116) and women (n = 2453), aged 18 to 95 years, were followed an average of 6.7 years. The major cause of death in men was trauma (25%), followed by CVD (19%) and cancer (13%). The major cause of death in women was CVD (24%), followed by cancer (19%) and trauma (8%). Stroke rates in both genders were higher than those of US Whites. Only 56% of deaths classified as CVD by death certificate were classified as CVD by standard criteria; discordance was higher among men (55%) than women (32%; κs = 0.4 and 0.7).

CONCLUSIONS

We found lower rates for coronary heart disease death but high rates of stroke mortality. Death certificates overestimated CVD mortality; concordance between the 2 methods is better for cancer mortality. The results point to the importance of cohort studies in this population in providing data to assist in health care planning.

Racial-ethnic disparities in stroke care: the American experience: a statement for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

Our goal is to describe the effect of race and ethnicity on stroke epidemiology, personal beliefs, access to care, response to treatment, and participation in clinical research. In addition, we seek to determine the state of knowledge on the main factors that may explain disparities in stroke care, with the goal of identifying gaps in knowledge to guide future research. The intended audience includes physicians, nurses, other healthcare professionals, and policy makers.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council Scientific Statement Oversight Committee and represent different areas of expertise in relation to racial-ethnic disparities in stroke care. The writing group reviewed the relevant literature, with an emphasis on reports published since 1972. The statement was approved by the writing group; the statement underwent peer review, then was approved by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

There are limitations in the definitions of racial and ethnic categories currently in use. For the purpose of this statement, we used the racial categories defined by the US federal government: white, black or African American, Asian, American Indian/Alaskan Native, and Native Hawaiian/other Pacific Islander. There are 2 ethnic categories: people of Hispanic/Latino origin or not of Hispanic/Latino origin. There are differences in the distribution of the burden of risk factors, stroke incidence and prevalence, and stroke mortality among different racial and ethnic groups. In addition, there are disparities in stroke care between minority groups compared with whites. These disparities include lack of awareness of stroke symptoms and signs and lack of knowledge about the need for urgent treatment and the causal role of risk factors. There are also differences in attitudes, beliefs, and compliance among minorities compared with whites. Differences in socioeconomic status and insurance coverage, mistrust of the healthcare system, the relatively limited number of providers who are members of minority groups, and system limitations may contribute to disparities in access to or quality of care, which in turn might result in different rates of stroke morbidity and mortality. Cultural and language barriers probably also contribute to some of these disparities. Minorities use emergency medical services systems less, are often delayed in arriving at the emergency department, have longer waiting times in the emergency department, and are less likely to receive thrombolysis for acute ischemic stroke. Although unmeasured factors may play a role in these delays, the presence of bias in the delivery of care cannot be excluded. Minorities have equal access to rehabilitation services, although they experience longer stays and have poorer functional status than whites. Minorities are inadequately treated with both primary and secondary stroke prevention strategies compared with whites. Sparse data exist on racial-ethnic disparities in access to surgical care after intracerebral hemorrhage and subarachnoid hemorrhage. Participation of minorities in clinical research is limited. Barriers to participation in clinical research include beliefs, lack of trust, and limited awareness. Race is a contentious topic in biomedical research because race is not proven to be a surrogate for genetic constitution.

CONCLUSIONS

There are limitations in the current definitions of race and ethnicity. Nevertheless, racial and ethnic disparities in stroke exist and include differences in the biological determinants of disease and disparities throughout the continuum of care, including access to and quality of care. Access to and participation in research is also limited among minority groups. Acknowledging the presence of disparities and understanding the factors that contribute to them are necessary first steps. More research is required to understand these differences and find solutions.

Stroke in minorities

Minorities in the United States have higher stroke risks, stroke occurrence at an earlier age, and for some groups, more severe strokes than non-Hispanic whites. Factors contributing to these disparities are explored. Characteristics of African American, Hispanic, and Native American stroke risk and incidence are reviewed. The authors describe recent interventions to raise the awareness of stroke risk factors and symptoms in minorities. The importance of the problem is highlighted, and the authors suggest ways that stroke in minorities may be reduced.

Brain tissue pH and ventilatory acclimatization to high altitude

31P nuclear magnetic resonance spectroscopy (31P-NMRS) was performed on brain cross sections of four human subjects before and after 7 days in a hypobaric chamber at 447 Torr to test the hypothesis that brain intracellular acidosis develops during acclimatization to high altitude and accounts for the progressively increasing ventilation that develops (ventilatory acclimatization). Arterial blood gas measurements confirmed increased ventilation. At the end of 1 wk of hypobaria, brain intracellular pH was 7.023 +/- 0.046 (SD), unchanged from preexposure pH of 6.998 +/- 0.029. After return to sea level, however, it decreased to 6.918 +/- 0.032 at 15 min (P less than 0.01) and 6.920 +/- 0.046 at 12 h (P less than 0.01). The ventilatory response to hypoxia increased [from 0.35 +/- 0.11 (l/min)/(-%O2 saturation) before exposure to 0.69 +/- 0.19 after, P = 0.06]. Brain intracellular acidosis is probably not a supplemental stimulus to ventilatory acclimatization to high altitude. However, brain intracellular acidosis develops on return to normoxia from chronic hypoxia, suggesting that brain pH may follow changes in blood and cerebrospinal fluid pH as they are altered by changes in ventilation.

Divergent effects of suramin on in vitro and in vivo assays of cartilage degradation

Proteinases are thought to be responsible for cartilage and bone erosion noted in chronic inflammatory conditions. Suramin [8-(3-benzamindo-4-meta-1-benzamindo)naphthalene-1,3,5-trisulfonic acid], 10(-5) and 10(-4) M, inhibited the release of a mouse macrophage-derived cartilage proteoglycan-degrading enzyme. At 10(-5) M it antagonized the activity of beta-glucuronidase and cathepsin D derived from the mouse macrophage, as well as similar enzymes secreted by rat macrophages in vivo. When cultured at 10(-4) M with rabbit knee cartilage, it antagonized the autolytic release of proteoglycan, indicating an inhibitory activity against a chondrocyte-derived neutral proteinase. After in vivo treatment at 10 mg/kg/day s.c., it was ineffective in preventing the cartilage and bone erosion noted in the adjuvant arthritic rat.

Release of cartilage proteoglycan degrading enzyme activity by thioglycollate stimulated mouse peritoneal macrophages in culture

Media from cultured mouse peritoneal macrophages were tested for cartilage proteoglycan degrading activity using S35-labelled rabbit ear cartilage. Media samples collected at 2-day intervals contained increasing amounts of activity between days two and six. This activity was activated by trypsin and antagonized by chelating agents. The macrophage products induced release of the proteoglycan component of cartilage as determined by biochemical and histological methods without affecting the collagen component. Media from cells incubated with hydrocortisone were devoid of proteoglycan degrading activity.