Search PubMed⌕ Search

Biomedical subjects

Devin L Brown

Publications and source records attributed to Devin L Brown.

At least 19 recordsLinked to original sources
PubMed2006

Defining cause of death in stroke patients: The Brain Attack Surveillance in Corpus Christi Project.

Stroke mortality is an important national health statistic and represents a frequent endpoint for epidemiologic studies. Several methods have been used to determine cause of death after stroke, but their agreement and reliability are unknown. Two hundred consecutive deaths of transient ischemic attack or ischemic stroke patients were identified (January 2000-September 2001) from an ongoing population-based stroke surveillance study in Texas, The Brain Attack Surveillance in Corpus Christi Project. Two neurologists independently recorded the cause of death based on two methods: 1) determining the underlying cause of death as defined by the World Health Organization, and 2) determining whether the death was stroke related. Kappa statistics with 95% confidence intervals were calculated by comparing agreement between methods within reviewers and between reviewers within methods. Agreement between the two cause-of-death-determination methods for each neurologist was 0.41 (95% confidence interval (CI): 0.31, 0.51) and 0.47 (95% CI: 0.38, 0.58), respectively. Agreement between neurologists for the underlying-cause-of-death method was 0.46 (95% CI: 0.32, 0.60); for the stroke-related method, it was 0.63 (95% CI: 0.52, 0.75). Accurate, reliable determinations of cause of death after stroke/transient ischemic attack are not currently feasible. More research is needed to identify a reliable process for coding cause of death from stroke.

Aged↗
PubMed2006

Stroke among patients with dizziness, vertigo, and imbalance in the emergency department: a population-based study.

BACKGROUND AND PURPOSE: Dizziness, vertigo, and imbalance are common presenting symptoms in the emergency department. Stroke is a leading concern even when these symptoms occur in isolation. The objective of the present study was to determine the "real-world" proportion of stroke among patients presenting to the emergency department with these dizziness symptoms (DS). METHODS: From a population-based study, patients >44 years of age presenting with DS to the emergency department, or directly admitted to the hospital, were identified. Demographics, the frequency of new cerebrovascular events, and the frequency of isolated DS (ie DS with no other stroke screening term or accompanying neurologic signs or symptoms) were assessed. Multivariable logistic regression was used to evaluate the association of age, gender, ethnicity, and isolated DS with stroke/transient ischemic attack (TIA). The association of the presenting symptoms with stroke/TIA was also assessed. RESULTS: Stroke/TIA was diagnosed in 3.2% (53 of 1666) of all patients with DS. Only 0.7% (9 of 1297) of those with isolated DS had a stroke/TIA. Patients with stroke/TIA were slightly older than those without stroke/TIA (69.3+/-11.7 vs 65.3+/-12.9, P=0.02). Male gender was associated with stroke/TIA, whereas isolated DS was negatively associated with stroke/TIA. Patients with imbalance (dizziness as referent) were more likely to have stroke/TIA. CONCLUSIONS: The proportion of cerebrovascular events in patients presenting with dizziness, vertigo, or imbalance is very low. Isolated dizziness, vertigo, or imbalance strongly predicts a noncerebrovascular cause. The symptom of imbalance is a predictor of stroke/TIA.

Aged↗
PubMed2006

Increased risk of death in community-dwelling older people with white matter hyperintensities on MRI.

BACKGROUND: Previous studies in subjects with a history of stroke have shown that white matter hyperintensities (WMH) on MRI are associated with increased risk of death. However, it has not been determined whether WMH are independently related to death in community-dwelling older people without stroke. METHODS: In a sample of community-dwelling people over 75 years with no history of stroke or other neurological diseases, WMH on brain MRI T2-weighted sequences were classified as grade 0, grade 1, or grade 2. Grade 2 WMH were identified in 36 subjects. Age- and sex-matched grade 0 and grade 1 WMH groups were selected for comparison to the grade 2 WMH group. All subjects underwent an initial clinical evaluation and were followed for a median of 11.8 years (interquartile range=10.7 to 12.2 years). Cox proportional-hazards analysis was used to determine the independent association between WMH and time to death from any cause. RESULTS: In an unadjusted analysis, grade 2 WMH was associated with death from any cause (hazard ratio=1.98; 95% confidence interval=1.06, 3.70). After adjustment for hypertension, high cholesterol, diabetes, and coronary artery disease, grade 2 WMH remained significantly associated with death (hazard ratio=2.31; 95% confidence interval=1.21, 4.40) in these age- and sex-matched groups. CONCLUSIONS: Severe WMH increase the risk of death, even in community-dwelling elderly without stroke or other neurological disease, independent of other covariates including hypertension, age, and coronary artery disease.

Age Distribution↗
PubMed2006

Stroke information reported on local television news: a national perspective.

BACKGROUND AND PURPOSE: Local television news commonly reports on health. This study aimed to characterize local TV news stroke reporting in America. METHODS: Content analysis of stroke stories reported on 122 US local television stations. All stroke stories were coded for main focus and discussion of risk factors, stroke signs and symptoms, recombinant tissue plasminogen activator, treatment within 3 hours, or recommendation to call 911. RESULTS: Of the 1799 health stories, only 13 stroke stories aired, and the median story length was 24 seconds (interquartile range 21 to 48). Stroke was the 22nd most common health topic. Few stroke stories discussed useful information about prevention or treatment of stroke. CONCLUSIONS: Stroke stories were nearly nonexistent in our sample, and those reported failed to discuss important messages needed to improve stroke prevention and treatment.

Antioxidants↗
PubMed2006

Longitudinal assessment of noninvasive positive pressure ventilation adjustments in ALS patients.

The absence of data guiding optimal titration of noninvasive positive pressure ventilation (NIPPV) over time in ALS patients may contribute to the under-prescribing of NIPPV. We conducted a retrospective, single-center, chart review assessment of NIPPV pressure settings used for symptomatic treatment of ALS patients to determine NIPPV adjustments, and to compare survival between those who were tolerant and intolerant to NIPPV. All subjects were started on nocturnal NIPPV at 8 and 3 cm H2O inspiratory and expiratory pressure, respectively. Of the 18 tolerant subjects identified, 4 (22%) had no NIPPV pressure changes before death; 8 (44%), 1 change; 4 (22%), 2 changes; 1 (6%), 3 changes; and 1 (6%), 5 changes. Most pressure changes occurred during the first year of NIPPV initiation. The maximum pressure needed for comfort by any patient in this study was 19/5 cm H2O, while 4 (22%) found the original 8/3 cm H2O settings to be sufficient until death. Subjects in the tolerant group had better survival, when adjusting for age and site of symptom onset (bulbar versus limb), with a hazard ratio of 0.23 [95% confidence interval: 0.10, 0.54]. The current data suggest that ALS patients who are tolerant to NIPPV typically need at least one upward change in pressure settings. Tolerance to relatively low NIPPV inspiratory pressures is associated with improved survival.

Aged↗
PubMed2006

Ethnic differences in stroke recurrence.

OBJECTIVE: To determine whether stroke recurrence and the effect of recurrence on mortality differ by ethnicity. METHODS: Using methods from the Brain Attack Surveillance in Corpus Christi project, we prospectively identified first-ever ischemic strokes from emergency department logs and hospital admissions (January 2000 to December 2004). Recurrent strokes and deaths were identified for the same period. Cumulative probability of stroke recurrence was estimated. Cox proportional hazards models were used to examine ethnic differences in recurrence and to examine the relation among ethnicity, recurrence, and mortality. RESULTS: During the time interval, 1,345 first-ever ischemic strokes were validated. Median age of patients was 72 years; 53% were Mexican American (MA). There were 126 recurrent strokes. Cumulative risk for recurrence at 30 days and 1 year was 2.6 and 7.5%, respectively. MAs had higher risk for stroke recurrence (risk ratio, 1.57; 95% confidence interval, 1.05-2.34) compared with non-Hispanic white patients, adjusted for demographics, stroke risk factors, and stroke severity. Stroke recurrence was related to mortality to a similar extent across ethnic groups (non-Hispanic white patients: risk ratio, 3.32; 95% confidence interval, 2.07-5.32; MAs: risk ratio, 2.35; 95% confidence interval, 1.42-3.88). INTERPRETATION: MAs had higher stroke recurrence risk compared with non-Hispanic white patients. Stroke recurrence had an important impact on mortality. Efforts to reduce stroke recurrence in MAs are needed.

Age Factors↗
PubMed2006

Sleep disorders and stroke.

Obstructive sleep apnea (OSA) is a very common condition in patients with stroke and is found in over half of stroke patients. There is a complex relationship between OSA and stroke, attributable to shared risk factors. There are numerous mechanisms by which OSA may contribute to increased stroke risk, including promotion of atherosclerosis, hypercoagulability, and adverse effects on cerebral hemodynamics. Obstructive sleep apnea is also a risk factor for hypertension, and likely for atrial fibrillation and diabetes, conditions that in turn are risk factors for stroke. OSA is also associated with poor outcomes following stroke. Further epidemiological studies are needed to assess the relationship between OSA and stroke better. Clinical trials using continuous positive airway pressure as a treatment for OSA in stroke patients are needed to determine whether treatment of this condition alters outcome following stroke.

Humans↗
PubMed2006

Evaluation of sham non-invasive ventilation for randomized, controlled trials in ALS.

Non-invasive positive pressure ventilation (NIV) treatment of advanced respiratory insufficiency prolongs survival in ALS. To investigate the critical question of whether earlier initiation of NIV might provide additional benefit, a randomized trial with an appropriate placebo is needed. This study evaluated sub-therapeutic (sham) continuous positive airway pressure as a potential placebo. In a single-blind design, 40 ALS patients with forced vital capacity>50% were randomized to receive 30 seconds (s) of either active NIV, with 8 cm H2O inspiratory and 4 cm H2O expiratory pressure, or sham NIV with<1 cm of H2O continuous positive airway pressure at the mask. A questionnaire was then used to assess whether subjects thought that they had received a "real" or "pretend" treatment trial. The subjects' median age was 60.5 years, and 38% were female. Twelve of 20 subjects (60%) who received active NIV and 7 (35%) of the 20 subjects who received sham thought that they had tried the active treatment (p = 0.11). Only 8 (20%) of all subjects were confident about their determination that they had received "real" or "pretend" NIV. Thus, sub-therapeutic (sham) continuous positive airway pressure is a promising placebo control for NIV trials in ALS.

Aged↗
PubMed2005

Family history and stroke outcome in a bi-ethnic, population-based stroke surveillance study.

BACKGROUND: The genetic epidemiology of ischemic stroke remains relatively unstudied, and information about the genetic epidemiology of ischemic stroke in populations with significant minority representation is currently unavailable. METHODS: The Brain Attack Surveillance in Corpus Christi project (BASIC) is a population-based stroke surveillance study conducted in the bi-ethnic community of Nueces County, Texas, USA. Completed ischemic strokes were identified among patients 45 years or older seen at hospitals in the county between January 1, 2000-December 31, 2002. A random sample of ischemic stroke patients underwent an in-person interview and detailed medical record abstraction (n = 400). Outcomes, including initial stroke severity (NIH stroke scale), age at stroke onset, 90-day mortality and functional outcome (modified Rankin scale > or = 2), were studied for their association with family history of stroke among a first degree relative using multivariable logistic and linear regression. A chi-square test was used to test the association between family history of stroke and ischemic stroke subtype. RESULTS: The study population was 53.0% Mexican American and 58.4% female. Median age was 73.2 years. Forty percent reported a family history of stroke among a first degree relative. Family history of stroke was borderline significantly associated with stroke subtype (p = 0.0563). Family history was associated with poor functional outcome in the multivariable model (OR = 1.87; 95% CI: 1.14-3.09). Family history was not significantly related to initial stroke severity, age at stroke onset, or 90-day mortality. CONCLUSION: Family history of stroke was related to ischemic stroke subtype and to functional status at discharge. More research is needed to understand whether stroke subtype would be a useful selection criterion for genetic association studies and to hypothesize about a possible genetic link to recovery following ischemic stroke.

Aged↗
PubMed2005

Gender comparisons of diagnostic evaluation for ischemic stroke patients.

BACKGROUND: Sixty-two percent of all stroke deaths in the United States occur in women. We compared diagnostic evaluations by gender in ischemic stroke patients in a biethnic, population-based study. METHODS: A random sample of patients with ischemic stroke identified between 2000 and 2002 by BASIC (Brain Attack Surveillance in Corpus Christi Project) were selected for this study (n = 381). Gender differences in the use of stroke diagnostic tests were assessed. Separate multivariable logistic regression models predicting diagnostic test use were constructed, adjusted for age, ethnicity, hypertension, atrial fibrillation, diabetes, history of stroke, coronary artery disease, having a primary care provider, discharge disposition, modified Rankin Scale score at discharge, and insurance status. RESULTS: The study population consisted of 161 men and 220 women. Median age was 74.3 years. The respective proportions of males and females receiving any carotid artery evaluation were 71% and 62%; brain MRI, 43% and 41%; echocardiography, 57% and 48%; and EKG, 90% and 86%. Multivariable logistic models found that women were less likely to undergo echocardiography (odds ratio [OR] 0.64, CI: 0.42 to 0.98) and carotid evaluation (OR 0.57, CI: 0.36 to 0.91). There was no association of ischemic stroke subtype and gender to explain these results (p = 0.76). CONCLUSIONS: Despite controlling for explanatory variables, women with stroke were less likely to receive standard diagnostic tests vs men. Intervention is needed to increase access to quality stroke care for women.

Aged↗
PubMed2005

The cost-effectiveness of early noninvasive ventilation for ALS patients.

BACKGROUND: Optimal timing of noninvasive positive pressure ventilation (NIPPV) initiation in patients with amyotrophic lateral sclerosis (ALS) is unknown, but NIPPV appears to benefit ALS patients who are symptomatic from pulmonary insufficiency. This has prompted research proposals of earlier NIPPV initiation in the ALS disease course in an attempt to further improve ALS patient quality of life and perhaps survival. We therefore used a cost-utility analysis to determine a priori what magnitude of health-related quality of life (HRQL) improvement early NIPPV initiation would need to achieve to be cost-effective in a future clinical trial. METHODS: Using a Markov decision analytic model we calculated the benefit in health-state utility that NIPPV initiated at ALS diagnosis must achieve to be cost-effective. The primary outcome was the percent utility gained through NIPPV in relation to two common willingness-to-pay thresholds: 50,000 dollars and 100,000 dollars per quality-adjusted life year (QALY). RESULTS: Our results indicate that if NIPPV begun at the time of diagnosis improves ALS patient HRQL as little as 13.5%, it would be a cost-effective treatment. Tolerance of NIPPV (assuming a 20% improvement in HRQL) would only need to exceed 18% in our model for treatment to remain cost-effective using a conservative willingness-to-pay threshold of 50,000 dollars per QALY. CONCLUSION: If early use of NIPPV in ALS patients is shown to improve HRQL in future studies, it is likely to be a cost-effective treatment. Clinical trials of NIPPV begun at the time of ALS diagnosis are therefore warranted from a cost-effectiveness standpoint.

Amyotrophic Lateral Sclerosis↗
PubMed2005

Is it time for a large, collaborative study of pediatric stroke?

BACKGROUND AND PURPOSE: A 2002 report from the National Institute of Neurological Disorders and Stroke cited the critical importance of more childhood stroke studies. We present the incidence rate of pediatric stroke from a biethnic community-based project and calculate the population size required for future prospective studies of pediatric stroke. METHODS: This work is part of the Brain Attack Surveillance in Corpus Christi (BASIC) project. The community of 325,000 is located in southeast Texas and is composed of approximately equal numbers of Mexican Americans (MAs) and non-Hispanic whites (NHWs). Discharge diagnosis codes from all hospitals in the county were used to identify cases of childhood stroke (age >1 month and <20 years) in 2002 and 2003, and stroke cases were validated by source document review. On the basis of the incidence rates, the population size required to complete a case-control study to examine risk factors for pediatric stroke was calculated. RESULTS: Eight cases of pediatric stroke were identified, yielding an annual incidence rate of 4.3 per 100,000 (95% CI, 1.9 to 8.5). There were 5 cases of intracerebral hemorrhage, 1 subarachnoid hemorrhage, 1 ischemic stroke, and 1 transient ischemic attack. All of the events occurred in MAs. Depending on the prevalence of the risk factors of interest, future studies of pediatric stroke would have to draw from a population of up to 59 million children to complete a case-control study within 4 years. CONCLUSIONS: Given the rarity of pediatric stroke, future studies will require multicenter efforts and possibly a national surveillance system.

Adolescent↗
PubMed2005

Stroke burden in Mexican Americans: the impact of mortality following stroke.

PURPOSE: To estimate ethnic-specific all-cause mortality risk following ischemic stroke and to compare mortality risk by ethnicity. METHODS: DATA from the Brain Attack Surveillance in Corpus Christi Project, a population-based stroke surveillance study, were used. Stroke cases between January 1, 2000 and December 31, 2002 were identified from emergency department (ED) and hospital sources (n = 1,234). Deaths for the same period were identified from the surveillance of stroke cases, the Texas Department of Health, the coroner, and the Social Security Death Index. Ethnic-specific all-cause cumulative mortality risk was estimated at 28 days and 36 months using Kaplan Meier analysis. Cox proportional hazards regression was used to compare mortality risk by ethnicity. RESULTS: Cumulative 28-day all-cause mortality risk for Mexican Americans (MAs) was 7.8% and for non-Hispanic whites (NHWs) was 13.5%. Cumulative 36-month all-cause mortality risk was 31.3% in MAs and 47.2% in NHWs. MAs had lower 28-day (RR = 0.58; 95% CI: 0.41, 0.84) and 36-month all-cause mortality risk (RR = 0.79, 95% CI: 0.64, 0.98) compared with NHWs, adjusted for confounders. CONCLUSIONS: Better survival after stroke in MAs is surprising considering their similar stroke subtype and severity compared with NHWs. Social or psychological factors, which may explain this difference, should be explored.

Aged↗
PubMed2005

Screening for obstructive sleep apnea in stroke patients: a cost-effectiveness analysis.

BACKGROUND AND PURPOSE: Obstructive sleep apnea (OSA) is common after acute ischemic stroke and predicts poor stroke recovery, but whether screening for OSA and treatment by continuous positive airway pressure (CPAP) improves neurological outcome is unknown. We used a cost-effectiveness model to estimate the magnitude of benefit that would be necessary to make polysomnography (PSG) and OSA treatment cost-effective in stroke patients. METHODS: A decision tree modeled 2 alternative strategies: PSG followed by 3 months of CPAP for those found to have OSA versus no screening. The primary outcome was the utility gained through OSA screening and treatment in relation to 2 common willingness-to-pay thresholds of $50,000 and $100,000 per quality-adjusted life year (QALY). RESULTS: Screening resulted in an incremental cost-effectiveness ratio of $49,421 per QALY. Screening is cost-effective as long as the treatment of stroke patients with OSA by CPAP improves patient utilities by >0.2 for a willingness-to-pay of $50,000 per QALY and 0.1 for a willingness-to-pay of $100,000 per QALY. CONCLUSIONS: A clinical trial assessing the effectiveness of CPAP in improving stroke outcome is warranted from a cost-effectiveness standpoint.

Cost-Benefit Analysis↗
PubMed2005

Recurrent stroke risk is higher than cardiac event risk after initial stroke/transient ischemic attack.

BACKGROUND AND PURPOSE: Patients with ischemic stroke and transient ischemic attack (TIA) are at risk for recurrent cerebrovascular and cardiac events. Understanding which of these adverse events is more likely to occur next is instructive for preventive therapy planning. METHODS: Subjects (n=1923) were identified from a sample of hospital discharges from administrative claims for the Michigan Medicare population from January 2001 to June 2001 using International Classification of Diseases, 9th Revision codes for ischemic stroke/TIA. Outcomes (cardiac events, myocardial infarction [MI], percutaneous transluminal coronary angioplasty [PTCA], coronary artery bypass grafting [CABG] and ischemic strokes) were identified for 2001 to 2003. Comparison between cardiac and stroke as secondary events were made using cumulative incidence estimates. RESULTS: Over the follow-up period, 172 patients had a cardiac event (62.8% MI, 7.6% CABG, 14.5% PTCA, 9.3% MI and PTCA, and 5.8% MI and CABG) and 239 had a stroke as their first event. Cardiac event at 2 years had occurred in 7.7%, and stroke occurred in 11.8%. CONCLUSIONS: The risk of stroke after initial stroke/TIA is higher than the risk of cardiac events. The propensity after stroke/TIA to have the first recurrent ischemic event in the brain, rather than in the heart, has implications for prophylactic therapy selection.

Aged↗
PubMed2005

Gavestinel does not improve outcome after acute intracerebral hemorrhage: an analysis from the GAIN International and GAIN Americas studies.

BACKGROUND AND PURPOSE: Glycine Antagonist in Neuroprotection (GAIN) International and GAIN Americas trials were prospectively designed, randomized, placebo-controlled trials of gavestinel, a glycine-site antagonist and putative neuroprotectant drug administered within 6 hours of suspected ischemic or hemorrhagic stroke. Both trials reported that gavestinel was ineffective in ischemic stroke. This analysis reports the results in those with primary intracerebral hemorrhage. METHODS: The primary hypothesis was that gavestinel treatment did not alter outcome, measured at 3 months by the Barthel Index (BI), from acute intracerebral hemorrhage, based on pooled results from both trials. The BI scores were divided into 3 groups: 95 to 100 (independent), 60 to 90 (assisted independence), and 0 to 55 (dependent) or dead. RESULTS: In total, 3450 patients were randomized in GAIN International (N=1804) and GAIN Americas (N=1646). Of these, 571 were ultimately identified to have spontaneous intracerebral hematoma on baseline head computerized tomography scan. The difference in distribution of trichotomized BI scores at 3 months between gavestinel and placebo was not statistically significant (P=0.09). Serious adverse events were reported at similar rates in the 2 treatment groups. CONCLUSIONS: These observations from the combined GAIN International and GAIN Americas trials suggest that gavestinel is not of substantial benefit or harm to patients with primary intracerebral hemorrhage. These findings are similar to results previously reported in patients with ischemic stroke.

Acute Disease↗