Letter by Mittal and McCormick Regarding Article, “Self-Report of Stroke, Transient Ischemic Attack, or Stroke Symptoms and Risk of Future Stroke in the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study”
To the Editor:
We read with great interest the recent article published by Judd et al1 in which a study on risk of future stroke recurrence was described. The authors specifically studied different types of baseline ischemic strokes influencing US patients’ future risk of ischemic stroke in a sample from the south eastern sector of the United States, also known as the stroke belt. This study found a graded association between baseline stroke type and future stroke risk, increasing from patients reporting stroke symptoms only, transient ischemic attack, distant stroke, or recent stroke. This information is clinically relevant as it clearly shows that not all previous strokes are the same, and the risk of recurrent stroke increases as severity of stroke increases and also if the stroke is more recent (defined as <5 years).1 This study had large sample size and had large number of people available at follow-up.
As the authors mentioned, there are methodological concerns about the reliability and validity of the self-reported diagnosis of transient ischemic attack and stroke. Future studies should use a validated screening tool with high sensitivity and specificity to identify patients with ischemic strokes. During the follow-up period of the study, 2 stroke neurologists had reviewed patients’ charts to ascertain the stroke diagnosis; however, it is not mentioned whether the neuroimaging data were used to differentiate ischemic stroke patients from hemorrhagic strokes and stroke mimics.
Another limitation of the study is that the authors used only 2 races and no ethnicity variables in their analysis. Also, the authors intended to recruit 50% blacks in their study but could include only 38.6% blacks.1 The authors did not discuss the reasons of lower recruitment of blacks in their study. Understanding the reasons for a lower recruitment rate is important to improve the recruitment of this community in the future stroke trials. Previous studies have reported potential barriers of low recruitment in blacks, including perceived bias of research benefiting whites only, research not relevant to blacks, lack of information concerning research, lack of compensation, research that does not address a person or his/her family directly, and limited time for healthcare-related activities.2 The authors have also not explained why they only focused on white and black population.
In addition, health disparities within the United States lead to poor outcome for minorities.3 The REGARDS study recruited 50% of their cohort from Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, and Tennessee, consisting of 6.22% Hispanic population.4 People of Hispanic origin currently represent 16.3% of the US population which will be increased to an estimated 25.7% by 2050.5 Previous studies have shown that hypertension, diabetes mellitus, obesity, physical inactivity, and metabolic syndrome are more prevalent in the Hispanic population than white population.3 The authors should have mentioned whether the ethnicity of the study population (white and black) was Hispanic, non-Hispanic, or combined Hispanic and non-Hispanic.
Because race and ethnicity are important demographic factors contributing to healthcare disparity, it is important that National Institutes of Health–funded studies include research participants who are representative of the US population to increase the generalizability of the findings. This is particularly vital in the era of increasing healthcare cost and decreasing National Institutes of Health research dollars.
Manoj K. Mittal, MBBS
Department of Neurology
Jennifer B. McCormick, PhD, MPP
Division of General Internal Medicine
Mayo Biomedical Ethics Reseach Unit
Stroke welcomes Letters to the Editor and will publish them, if suitable, as space permits. Letters must reference a Stroke published-ahead-of-print article or an article printed within the past 3 weeks. The maximum length is 750 words including no more than 5 references and 3 authors. Please submit letters typed double-spaced. Letters may be shortened or edited. Include a completed copyright transfer agreement form (available online at http://stroke.ahajournals.org and http://submit-stroke.ahajournals.org).
The views expressed by Dr Mittal and Dr McCormick do not represent the views of the Mayo Clinic.
- © 2013 American Heart Association, Inc.
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- 4.US Census Bureau, Population Division. Population estimates: April 1, 2010 to July 1, 2011, release date: May 2012 (http://www.Census.Gov/popest/data/index.Html). Accessed January 12, 2013.
- Day JC