Vascular Risk Factor Prevalence and Trends in Native Americans With Ischemic Stroke - A National Inpatient Sample Analysis

Abstract

AbstractIntroductionNative Americans have a higher incidence and prevalence of stroke and the highest stroke-related mortality among race-ethnic groups in the United States. We aimed to analyze trends in the prevalence of vascular risk factors among Native Americans with ischemic stroke over the last two decades along with a comparison to the other race-ethnic groups.MethodsNational/Nationwide Inpatient Sample (NIS) database was used to explore the prevalence of risk factors among hospitalized ischemic stroke patients during 2000 - 2016. Ischemic stroke and risk factors of interest were identified using validated ICD-9/10 codes. The race-ethnic groups of interest were Native American, White, Black, Hispanic, Asian/Pacific Islanders, and others. Crude and age-and sex-standardized prevalence estimates were calculated for each risk factor within each race-ethnic group in 6 time periods: 2000-02, 2003-05, 2006-08, 2009-11, 2012-14, and 2015-16. We explored linear trends over the defined time periods using linear regression models, with differences in trends between the Native American group and each of the other race-ethnic groups assessed using interaction terms. The analysis accounted for the complex sampling design, including hospital clusters, NIS stratum, and trend weights for analyzing multiple years of NIS data.ResultsOf the 1,278,784 ischemic stroke patients that were included in the analysis, Native Americans constituted 5472. The age-and-sex-standardized prevalence of hypertension (trend slope = 2.24, p < 0.001), hyperlipidemia (trend slope = 6.29, p < 0.001), diabetes (trend slope = 2.04, p = 0.005), atrial fibrillation/flutter (trend slope = 0.80, p = 0.011), heart failure (trend slope = 0.73, p = 0.036) smoking (trend slope = 3.65, p < 0.001), and alcohol (slope = 0.60, p = 0.019) increased during these time periods among Native Americans, while coronary artery disease prevalence remained unchanged. Similar upward trends of several risk factors were noted across other race-ethnic groups with Native Americans showing larger increases in hypertension prevalence compared to Blacks, Hispanics, and Asian/Pacific Islanders and in smoking prevalence compared to Hispanics and Asian/Pacific Islanders. By the year 2015-2016, Native Americans had the highest overall prevalence of diabetes, coronary artery disease, smoking, and alcohol among all the race-ethnic groups.ConclusionThe prevalence of most vascular risk factors among ischemic stroke patients has increased in Native Americans and other race-ethnic groups over the last two decades. Significantly larger increases in the prevalence of hypertension and smoking were seen in Native Americans compared to other groups along with them having the highest prevalence in multiple risk factors in recent years.