Prevalence grew in hospitalized stroke patients each year
by Kristin Jenkins, Contributing Writer, MedPage Today October 11, 2017
This article is a collaboration between MedPage Today® and: the American Heart Association

Action Points
• Note that this analysis of the National Inpatient Sample found an increasing prevalence of risk factors for stroke among those who had stroke.
• This is not the same as a finding that risk factors have increased in the overall population, as stroke prevention efforts may successfully concentrate the burden of strokes in higher-risk individuals.
Stroke patients have had a rising prevalence of risk factors — including hypertension, dyslipidemia, and smoking — over the last decade, researchers found.
Analysis of the 2004–2014 National Inpatient Sample showed that the proportion of patients with acute ischemic stroke who had at least one risk factor for the disease rose from 88.3% in 2004 to 95% in 2014, according to Fadar Oliver Otite, MD, ScM, from the University of Miami Miller School of Medicine in Florida, and colleagues.
Regression analyses showed that the prevalence of hypertension among these patients rose annually by 1.4%, diabetes by 2%, dyslipidemia by 7%, smoking by 5%, and drug abuse by 7%, they reported online in Neurology. Prevalence of chronic renal failure rose each year by 13%, carotid stenosis by 6%, and coronary artery disease by 1%.
In a statement, Otite said about 80% of all first strokes are caused by preventable risk factors such as hypertension: “Many efforts have been made to prevent, screen for, and treat these risk factors. Yet we saw a widespread increase in the number of stroke patients with one or more risk factors.”
“Focusing on risk factor control is critical for stroke prevention,” he and colleagues wrote in their paper. “Our alarming findings support the call for further concerted action from all stakeholders to more effectively implement evidence-based interventions to reduce stroke risk.”
They looked at data on 922,451 primary acute ischemic stroke admissions from the 2004–2014 National Inpatient Sample. Overall, 92.5% of patients with acute ischemic stroke had at least one risk factor for the disease during that time.
Overall age- and sex-adjusted prevalence of hypertension, diabetes, dyslipidemia, smoking, and drug abuse were 79%, 34%, 47%, 15%, and 2%, respectively. During the same period, the prevalence of carotid stenosis was 13%, chronic renal failure 12%, and coronary artery disease 27%.
Risk factor prevalence varied by age, race, and sex, they noted. While 79.1% of all stroke patients had comorbid hypertension, it was slightly higher in women than in men (80% versus 78.1%, P<0.001), and the prevalence of comorbid diabetes was higher in Hispanic and black patients than in whites (48.7% and 44.4% versus 30.5%). Smoking prevalence increased by 70% between 2004 and 2014, mostly in young and middle-aged patients.
The authors noted that the prevalence of hospital admissions for stroke that had concomitant hypertension, diabetes, and dyslipidemia increased by more than 200%, from 9.4% to 23.7%, during the study period.
In an accompanying editorial, Shyam Prabhakaran, MD, MS, of Northwestern University in Chicago, warned against rushing to judgment about healthcare performance in the U.S. without a more careful inspection of the data.
Factors such as the non-standardized definitions of risk factors within the NIS dataset, and the subsequent lack of data on risk factor management and control “provides little insight” into what’s actually happening, he said.
“Thus, instead of a national crisis of increasing risk factors among stroke patients, these same data could imply improved screening and diagnosis of multiple stroke risk factors prior to or at the time of stroke occurrence.”
The lack of data on duration of exposure to risk factors and incidence of stroke also makes it impossible to assign causality, Prabhakaran said, noting that since more people with multiple risk factors survive longer, increasing prevalence can also be explained by declines in cardiovascular and stroke mortality.
“For these reasons, prevalence, especially in isolation, may not serve as a good marker of the state of public health in the United States,” he wrote. “So, while there should indeed be a call to action to prevent stroke and its negative consequences on society, we should acknowledge important progress that has been made in stroke prevention, even if there is much more work to be done. We should also continue to search for data that measure the health of our society, but remain cautious in interpreting them in a vacuum or without the appropriate context.”

This study received no direct funding. The study authors and the editorialist reported no conflicts of interest.
• Reviewed by F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner
last updated 10.18.2017
• Primary Source
Neurology
Source Reference: Otite FO, et al “Increasing prevalence of vascular risk factors in patients with stroke: A call to action” Neurol 2017.
• Secondary Source
Neurology
Source Reference: Prabhakaran S “Big data trends in stroke epidemiology in the United States: But are they good data?” Neurol 2017.