Population-based Stroke Surveillance Study Research Articles

Trends Over Time in Stroke Incidence by Race in the Greater Cincinnati Northern Kentucky Stroke Study.

Understanding the current status of and temporal trends of stroke epidemiology by age, race, and stroke subtype is critical to evaluate past prevention efforts and to plan future interventions to eliminate existing inequities. We investigated trends in stroke incidence and case fatality over a 22-year time period. In this population-based stroke surveillance study, all cases of stroke in acute care hospitals within a 5-county population of southern Ohio/northern Kentucky in adults aged ≥20 years were ascertained during a full year every 5 years from 1993 to 2015. Temporal trends in stroke epidemiology were evaluated by age, race (Black or White), and subtype (ischemic stroke [IS], intracranial hemorrhage [ICH], or subarachnoid hemorrhage [SAH]). Stroke incidence rates per 100,000 individuals from 1993 to 2015 were calculated using US Census data and age-standardized, race-standardized, and sex-standardized as appropriate. Thirty-day case fatality rates were also reported. Incidence rates for stroke of any type and IS decreased in the combined population and among White individuals (any type, per 100,000, 215 [95% CI 204-226] in 1993/4 to 170 [95% CI 161-179] in 2015, p = 0.015). Among Black individuals, incidence rates for stroke of any type decreased over the study period (per 100,000, 349 [95% CI 311-386] in 1993/4 to 311 [95% CI 282-340] in 2015, p = 0.015). Incidence of ICH was stable over time in the combined population and in race-specific subgroups, and SAH decreased in the combined groups and in White adults. Incidence rates among Black adults were higher than those of White adults in all time periods, and Black:White risk ratios were highest in adults in young and middle age groups. Case fatality rates were similar by race and by time period with the exception of SAH in which 30-day case fatality rates decreased in the combined population and White adults over time. Stroke incidence is decreasing over time in both Black and White adults, an encouraging trend in the burden of cerebrovascular disease in the US population. Unfortunately, however, Black:White disparities have not decreased over a 22-year period, especially among younger and middle-aged adults, suggesting the need for more effective interventions to eliminate inequities by race.

Abstract WP176: Prior TIAs Among Patients With Ischemic Stroke In The Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS)

Background: TIAs serve as an opportunity to identify and modify risk factors and to prevent future events. Given known epidemiologic differences in strokes by race and sex, our objective was to investigate the rates of prior TIAs among those with incident ischemic stroke (IS) in the GCNKSS. Methods: We included all physician adjudicated, incident IS among adults age ≥20 years in the GCNKSS, a population-based stroke surveillance study in a 5-county region of southern Ohio/ northern Kentucky, in 2005, 2010, and 2015. We calculated the frequency of cases in which a TIA (sudden onset of focal neurologic symptoms lasting ≤ 24 hours) was documented in the 365 days prior to IS. Frequencies and proportions of prior TIA were compared by sex, race, and age, and location at which patients sought care for their TIA was described. Finally, multivariable logistic regression was performed to investigate demographic and clinical predictors of cases in which TIA preceded stroke; covariates were chosen a priori. Results: We included 5310 IS events; mean age was 69.7 (SD 14.8) years, 54.7% were female, and 20.4% were Black. A total of 351 patients (6.6%) had a documented TIA the year preceding their IS. Overall, 42.2% did not seek care for their TIA, 21.6% called 911 and/or came to the ED, 6.0% saw a PCP, and 6.6% sought other care. In 22.5% of cases, location of care was unknown. In adjusted results, older age, female sex, history of hypertension, and CAD were associated with having had a prior TIA, while Black race was not. NIHSS was inversely associated with prior TIA (Table). Prior TIAs were similar between study years. Conclusions: We conservatively estimate that ≥ 6% of patients with first-ever IS had a TIA in the preceding year, though underreporting is likely. Many patients did not report seeking care for the TIA, suggesting missed opportunities for risk factor modification. Further research is needed to understand the implications of sex and race differences in frequencies of prior TIA.

Cognitive recovery trajectories 3 months following stroke in Mexican American and non-Hispanic white adults

ObjectivesWe examined whether cognitive trajectories from 0-3 months after stroke differ between Mexican Americans (MAs) and non-Hispanic white (NHW) adults. Materials and MethodsThe sample included 701 participants with ischemic stroke (62% MA; 38% NHW) from the population-based stroke surveillance study, the Brain Attack Surveillance in Corpus Christi (BASIC) Project, between 2008-2013. The outcome was the modified Mini Mental State Examination (3MSE, range 0-100 lower scores worse). Linear mixed effects models were utilized to examine the association between ethnicity and cognitive trajectories from 0-3 months following stroke, adjusting for confounders. ResultsMAs were younger, had lower educational attainment, and fewer had health insurance than NHWs (all p< 0.01). A smaller proportion of MAs were rated by informants as exhibiting pre-stroke cognitive decline than NHW (p < .0.05). After accounting for confounders, MAs demonstrated lower cognitive performance at post-stroke baseline and at 3-months following stroke (-2.00; 95% CI =-3.92, -0.07). Cognitive trajectories from 0-3 months following stroke were indicative of modest cognitive recovery (increase of 0.034/day, 95% CI =0.030-0.036) and did not differ between MAs and NHWs (p = 0.68). ConclusionWe found no evidence that cognitive trajectories in the first three months following stroke differed between MAs and NHWs. MAs demonstrated lower cognitive performance shortly after stroke and at three months following stroke compared to NHWs. Further research is needed to identify factors contributing to ethnic disparities in cognitive outcomes after stroke.

Acute Stroke Care in Mexico City: The Hospital Phase of a Stroke Surveillance Study.

Background: Acute stroke care has greatly improved in recent decades. However, the increasing stroke mortality in low-to-middle income countries suggests that progress has not been reached completely by these populations. Here we present the analysis of the hospital phase of the first population-based stroke surveillance study. Methods: A daily hospital surveillance method was used to identify adult patients with acute stroke during 18 months in six hospitals. We abstracted data on demographics, vascular risk factors, neuroimaging-confirmed stroke types, and clinical data. Results: A total of 1361 adults with acute stroke were identified (mean age 69.2 years; 52% women) with transient ischemic attack (5.5%), acute ischemic stroke (68.6%), intracerebral hemorrhage (23.1%), cerebral venous thrombosis (0.2%), and undetermined stroke (2.6%). The main risk factors were hypertension (80.7%) and diabetes mellitus (47.6%). The usage rate of thrombolysis was 3.6%, in spite of the fact that 37.2% of acute ischemic stroke patients arrived in <4.5 h. The 30-day case fatality rate was 32.6%, higher in hemorrhagic than ischemic stroke. Conclusion: We identified limitations in acute stroke care in the Mexico City, including neuroimaging availability and thrombolysis usage. The door-to-door phase will help to depict the acute stroke burden in Mexico.

Longitudinal assessment of depression during the first year after stroke: Dimensionality and measurement invariance

ObjectiveRepeated measurement of depression using summative scores of commonly used depression scales assumes that the construct is unidimensional and invariant across time, but little is known about the validity of these assumptions in stroke patients. The study examined the assumptions during the first year after mild to moderate stroke using the 8-item Patient Health Questionnaire (PHQ-8). MethodsData were obtained from the 2014–2016 Brain Attack Surveillance in Corpus Christi project, a population-based stroke surveillance study with longitudinal follow-up in Texas, United States. Depressive symptoms were assessed with the PHQ-8 at 3, 6, and 12 months post-stroke (n = 648, 542, 533, respectively). Dimensionality of the PHQ-8 was examined using exploratory bifactor analysis and confirmatory factor analysis (CFA). Based on a one-factor CFA model, longitudinal measurement invariance was examined by fitting configural, weak, strong and strict invariance models sequentially. ResultsMean age was 65.6 (SD = 11.2), half were women, and 56.7% were Mexican American. Reliability measures suggested a generally unidimensional construct (Omega Hierarchical: 0.79–0.86), good internal consistency (Cronbach's alpha: 0.84–0.88) and good temporal stability (intraclass correlation coefficient: 0.838). Configural invariance for equality of item-factor structure (RMSEA = 0.038, CFI = 0.982, WRMR = 0.970) was supported. Partial weak invariance for equality of factor loadings (p = 0.11) was supported by chi-square difference tests, whereas full longitudinal invariance was supported by changes in comparative fit index and root mean square error of approximation. ConclusionsThe findings suggest the PHQ-8 may be a reasonable tool for repeated measurement of depression in stroke patients, and more research on its longitudinal psychometric properties is needed.

Temporal Trends in Ischemic Stroke Rates by Ethnicity, Sex, and Age (2000-2017): The Brain Attack Surveillance in Corpus Christi Project.

To compare 18-year (2000-2017) temporal trends in ischemic stroke rates by ethnicity, sex, and age. Data are from a population-based stroke surveillance study conducted in Nueces County, Texas, a geographically isolated, biethnic, urban community. Active (screening hospital admission logs, hospital wards, intensive care units) and passive (screening inpatient/emergency department discharge diagnosis codes) surveillance were used to identify cases aged ≥45 (n = 4,875) validated by stroke physicians using a consistent stroke definition over time. Ischemic stroke rates were derived from Poisson regression using annual population counts from the US Census to estimate the at-risk population. In those aged 45-59 years, rates increased in non-Hispanic Whites (104.3% relative increase; p < 0.001) but decreased in Mexican Americans (-21.9%; p = 0.03) such that rates were significantly higher in non-Hispanic Whites in 2016-2017 (p for ethnicity-time interaction < 0.001). In those age 60-74, rates declined in both groups but more so in Mexican Americans (non-Hispanic Whites -18.2%, p = 0.05; Mexican Americans -40.1%, p = 0.002), resulting in similar rates for the 2 groups in 2016-2017 (p for ethnicity-time interaction = 0.06). In those aged ≥75, trends did not vary by ethnicity, with declines noted in both groups (non-Hispanic Whites -33.7%, p = 0.002; Mexican Americans -26.9%, p = 0.02). Decreases in rates were observed in men (age 60-74, -25.7%, p = 0.009; age ≥75, -39.2%, p = 0.002) and women (age 60-74, -34.3%, p = 0.007; age ≥75, -24.0%, p = 0.02) in the 2 older age groups, while rates did not change in either sex in those age 45-59. Previously documented ethnic stroke incidence disparities have ended as a result of declining rates in Mexican Americans and increasing rates in non-Hispanic Whites, most notably in midlife.

Long-Term Trends in the Stroke Prognosis Among Rural Residents in China: A Population-Based Surveillance Study.

ObjectiveAlthough stroke mortality has remained stable over the past decade, the long-term trends of stroke burden are scarce in China, especially in low-income populations. Thus, we aimed to explore the secular trends in the prognosis of stroke in a low-income population in China.MethodsThis was a population-based stroke surveillance study that included all of the participants in the Tianjin Brain Study. Stroke management and outcomes were evaluated for all stroke patients. Trends in the burden of stroke were assessed as annual percentage changes.ResultsOverall, 1462 stroke cases occurred from 1992 to 2018, and 58.7% of patients were male. The rates of diagnosis by neuroimaging and of hospitalization increased noticeably across sexes and ages for all stroke types, and the greatest increases were observed among elderly women; diagnosis by neuroimaging increased by 4.7% and the rate of hospitalization increased by 12.4% (all P<0.001). Stroke fatality decreased by 3.7% annually among those aged <65 years and by 3.1% among patients aged ≥65 years; the corresponding rates were 7.4% and 3.5%, respectively, for women. The recurrence rate of ischemic stroke significantly decreased among all men, by 9.6% for those aged <65 years and by 3.1% for those aged ≥65 years; however, for women, this rate only significantly decreased for those aged ≥65 years.ConclusionOur findings suggest that the allocation of medical resources has improved over the past decades. However, it is crucial to enhance secondary stroke prevention for women aged <65 years by controlling risk factors in low-income populations.

Abstract P597: Growing Prevalence of Post-Stroke Sleep-Disordered Breathing

Introduction: Sleep-disordered breathing (SDB) is common after stroke and is associated with poor functional and cognitive outcomes, and recurrent stroke. Despite increasing prevalence of SDB in the general population, no data are available about trends in post-stroke SDB. We therefore sought to assess changes in post-stroke SDB prevalence over a 10-year period. Methods: Within the Brain Attack Surveillance In Corpus Christi (BASIC) project, a population-based stroke surveillance study in south Texas, participants with acute ischemic stroke were offered assessment of SDB with the ApneaLink Plus device. Medical record abstraction and baseline interviews were conducted and included the Berlin questionnaire to assess SDB status in reference to the prestroke state. SDB testing was performed shortly after stroke presentation (median 12 days (IQR: (6, 21)). Respiratory event index (REI) was calculated as the sum of apneas and hypopneas per hour of overnight recording. SDB was defined as an REI ≥10. SDB assessment procedures remained unchanged throughout (2010-2020). Logistic (SDB) and linear (REI) regression were used to test associations with time (parameterized as years since 2010) adjusted for demographics, and stroke and SDB risk factors including BMI and pre-stroke SDB status. Results: Among the 1,197 participants, median age was 65, 53% were male, and 65% were Mexican American. SDB prevalence was 61% in 2010-2011 and 75% in 2018-2019. Median REI was 19 in 2010-2011 and 23 in 2018-2019. A linear association was identified between time and SDB (REI≥10), with an odds ratio of 1.123 (95% CI: 1.062, 1.187) per year, after adjustment. Similarly, a linear association was identified between time and REI, with an average increase of 0.504 (95% CI: 0.148, 0.860) per year, after adjustment. Based on models with interaction terms added, no differences in time trends were found by sex or ethnicity. Conclusions: Post-stroke SDB prevalence in this population-based sample has increased over the last 10 years. These data highlight the importance of post-stroke SDB and the pressing need to determine whether its treatment improves outcomes.

Abstract 161: Prevalence and Course of Depression During the First Year After Stroke

Introduction: Depression is prevalent and burdensome in stroke survivors, however, information about its longitudinal course following stroke is limited, especially for the early stage of stroke recovery. The study examined changes in the prevalence and patterns of depression during the first year after stroke. Methods: Data were obtained from the Brain Attack Surveillance in Corpus Christi (BASIC) project (2011-2016), a population-based stroke surveillance study in south Texas. Depressive symptoms at 3, 6 and 12 months post-stroke were assessed using the 8-item Patient Health Questionnaire (range: 0-24); scores≥10 classified as having depression. Cross-tabulations were used to estimate prevalence of depression, and latent transition analysis was used to examine changes in symptom patterns. Results: A total of 684, 574 and 563 participants had complete data at 3, 6 and 12 months, respectively. Mean age was 65.9 (SD=11.2), women and men were evenly distributed, and approximately three-fifths were Mexican American. Prevalence of depression after stroke was 35.2% at 3 months, decreased to 24.4% at 6 months, and remained stable at 25.9% at 12 months. Four latent classes of depressive symptom patterns were identified (Table). There were more transitions from the fatigue and sleep predominant and severe symptom groups to mild and slight/no symptom groups between 3 and 6 months than between 6 and 12 months. The majority of the slight/no symptom group retained this pattern over time; whereas a substantial proportion of the mild symptom group developed more severe symptoms, especially after 6 months. Conclusions: Prevalence of depression peaks at 3 months after stroke, declines thereafter but remains stable and high after 6 months. The course of post-stroke depression is heterogeneous and dynamic. Further research should identify the characteristics of group membership in stroke patients to provide evidence for targeted screening and personalized treatment.

Abstract WP409: Heterogeneous Patterns of Depressive Symptoms Among Stroke Survivors: Implications for Screening

Introduction: Although routine screening for post-stroke depression is recommended by the AHA/ASA, the optimal screening method remains unclear. A high rate of false-positives is a potential issue of existing screening tools, as indicated in a recent meta-analysis. This study aims to examine patterns of depressive symptoms that may provide information to improve screening accuracy. Methods: The study sample consists of 613 first-ever stroke patients from the Brain Attack Surveillance in Corpus Christi project (2011-2015), a population-based stroke surveillance study. Depressive symptoms at 90 days after stroke were assessed by the 8-item Patient Health Questionnaire (PHQ-8). Symptom patterns were identified using latent class analysis. Depression status (PHQ-8≥10) by class was examined. Results: The sample was mainly composed of non-Hispanic Whites (38.3%) and Mexican Americans (57.3%), and equally distributed by sex. Mean age was 65.7 (SD=11.0). Prevalence of depression was 26.6% at 90 days after stroke. The best-fitting model yielded 4 classes (Figure). Notably, one class was characterized by symptoms that often overlap between depression and stroke, as opposed to psychological symptoms (termed overlapping symptom class). Percentages of participants classified as having depression were 84.1% in the psychological symptom class, 100.0% in the high-risk class, and 51.7% in the overlapping symptom class. The overlapping symptom class accounted for 28.8% of participants classified as having depression. Conclusion: Existing depression screening tools developed in non-stroke populations may have poor test characteristics in individuals with stroke. Additional research is needed to develop highly sensitive and specific screening tools to identify individuals with post-stroke depression in need of further evaluation and treatment. Understanding symptom patterns may increase our ability to personalize treatment for individual stroke survivors.

Abstract WP357: Prevalence of Pre- and Post-intracerebral Hemorrhage Sleep-disordered Breathing

Background: Sleep-disordered breathing (SDB) is an independent risk factor for stroke. The reported prevalence of SDB after stroke ranges from 60 to &gt;70%, while the pre-stroke prevalence of SDB is less well described. Moreover, much of these data are derived from ischemic stroke or mixed ischemic stroke and intracerebral hemorrhage (ICH) cohorts. Studies that assess the prevalence of SDB before and after ICH are lacking, with only one prior study (n=32) that reported a post-ICH SDB prevalence of 78%. We report herein the results of a second, larger, prospective study that assessed the prevalence of pre- and post-ICH. Methods: Participants enrolled in the population-based stroke surveillance study, the Brain Attack Surveillance in Corpus Christi (BASIC) project, with ICH from 2010-2015 were screened for SDB with the well validated ApneaLink Plus portable monitor (SDB defined as apnea-hypopnea index (AHI) ≥10). The Berlin questionnaire was administered, with reference to the pre-ICH state, to assess for possible pre-stroke SDB. Results: Of the 60 ICH participants screened, the median age was 63 years (interquartile range (IQR): 55.5, 74.5). Twenty-one (35%) were female, 54 (90%) were Mexican American, and 53 (88%) had a history of hypertension. The median Glasgow Coma Scale score was 15.0 (IQR: 15.0, 15.0) and the median NIHSS was 5.5 (IQR: 1.5, 8.0). Post-ICH, the median AHI was 9.5 (IQR: 5.5, 19.0); almost half (46.7%) met criteria for SDB. Thirty-four participants (56.7%) screened as high risk for SDB pre-ICH. Conclusion: Sleep-disordered breathing was highly prevalent after ICH, and also likely common before ICH, in this mostly Mexican American, community-based sample. If SDB increases risk for ICH, the findings suggest a potential new treatment target to prevent ICH and recurrent ICH.

Trends in Age of First-Ever Stroke Following Increased Incidence and Life Expectancy in a Low-Income Chinese Population.

We investigated secular trends in the age of stroke onset and stroke incidence in a low-income population in rural China. The study population was recruited from a population-based stroke surveillance study conducted in a township in Tianjin, China, from 1992 to 2014. The trends in mean age and incidence of first-ever stroke were assessed by sex and stroke subtype. Risk factor surveys were conducted in the same population in both 1991 and 2011. A total of 1053 patients experienced first-ever stroke from 1992 to 2014. The mean age of stroke onset in men significantly decreased by 0.28 years annually overall, by 0.56 years for intracerebral hemorrhage, and by 0.22 years for ischemic stroke (P<0.05). However, a similar trend was not observed in women. The age-standardized first-ever stroke incidence in the same population significantly increased across sex and stroke subtypes, increased by 6.3% overall, 5.5% for men, 7.9% for women, 4.6% for intracerebral hemorrhage, and 7.3% for ischemic stroke (P<0.05) during 1992 to 2014. Concurrently, the prevalence of hypertension, diabetes mellitus, obesity, current smoking, and alcohol consumption increased significantly in young and middle-aged adults from 1991 to 2011. The age of stroke onset tends to be younger among low-income population in China after the dramatic increased incidence of stroke during the gradual extension of life expectancy of population in China. These findings suggested that stroke burden will continue to increase in the long time, unless the risk factors in low-income populations are effectively controlled.

Abstract TP167: Short-Term Exposures to Ambient Air Pollution and Risk of Recurrent Ischemic Stroke

Background: Recurrent strokes are associated with poor outcomes and mortality. Short-term ambient air pollution may be an important environmental risk factor for stroke recurrence. Although associations between air pollution and stroke risk have been observed, the evidence for short-term effects of air pollution on risk of stroke recurrence is in its infancy. We investigated the association between short-term changes in ambient pollution (particulate matter &lt;2.5μm (PM 2.5 ) and ozone (O 3 )) and the risk of recurrent ischemic stroke among individuals living in a bi-ethnic community. Methods: We identified recurrent ischemic stroke cases from the population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project, an ongoing population-based stroke surveillance study in Nueces County, Texas, between 2000 and 2012. Associations between lags of 0 to 3 days PM 2.5 and O 3 levels and odds of ischemic stroke were assessed using a time-stratified case-crossover design. Conditional logistic regression models were used to calculate odds ratios (ORs) for a 10 unit change in exposure. Results: There were 317 recurrent ischemic strokes with mean age of 72 years (SD=12). Median levels of PM 2.5 and O 3 over the study period were 7.7μg/m 3 (IQR: 5.6-10.7μg/m 3 ) and 35.2ppb (IQR: 25.0-46.1ppb), respectively. No associations were observed across the different lagged exposures (0 to 3 days) after adjusting for ambient temperature and relative humidity (Figure). Co-adjustment of both pollutants results did not change the results. Conclusion: No association between PM 2.5 and O 3 and risk of recurrences was observed. Research on the influence of air pollutants on risk of recurrence is still in its infancy, and more research is needed to understand the relation.

The epidemiological transition of first-ever stroke among low-income population in China: a population-based study from 1992 to 2014

BackgroundStroke is the leading cause of death in rural areas and the third cause of death in urban areas in China, but the epidemiological transition of stroke during periods of rapid economic development is unknown in China, especially in rural areas. We aimed to investigate the secular trends in incidence, prevalence, and the 30-day case fatality of first-ever stroke in rural China between 1992 and 2014. MethodsWe assessed the secular trends in the epidemiological transition of stroke in Tianjin, China. The study population was from the Tianjin Brain Study, a population-based stroke surveillance study among low-income residents in a township in Tianjin, China, where stroke events and all deaths have been registered annually from 1992 to 2014. We used data from the Tianjin Brain Study to estimate case-fatality rates, the age-standardised incidence and prevalence of first-ever stroke per 100 000 population with the world standardisation population. Trends in age-standardised incidence and prevalence of stroke were assessed from annual percentage of change by sex and subtypes using the regression model: log(rt)=a+bt, where log denotes the natural logarithm and t is the year, and 100b represents the estimated annual percentage of change. FindingsBetween 1992 and 2014, the age-standardised incidence of first-ever stroke per 100 000 population increased annually by 6·3% overall, by 5·5% in men, and by 7·8% in women (p<0·0001); the case fatality decreased annually by 3·9% overall (p=0·024) and by 6·0% in women (p=0·015), but did not change in men (p=0·072). Simultaneously, the age-standardised prevalence of first-ever stroke per 100 000 population increased annually by 10·6% overall, by 9·9% in men, and by 11·5% in women (p<0·0001). With respect to stroke subtypes, the age-standardised incidence of first-ever stroke from intracerebral haemorrhage increased annually by 4·6% overall (p=0·022), by 3·5% in men (p=0·009), and by 4·8% in women (p=0·016), whereas the incidence of ischaemic stroke increased annually by 7·2% overall, by 6·6% in men, and by 8·3% in women (p<0·0001). The corresponding prevalence of intracerebral haemorrhage increased annually by 8·0% overall, 7·0% in men, and 9·9% in women, whereas the prevalence of ischaemic stroke increased annually by 11·4% overall, by 10·9% in men, and by 12·4% in women. InterpretationThe epidemiological transition of stroke was found among a low-income population in China. The incidence and prevalence of stroke from intracerebral haemorrhage and ischaemic stroke increased rapidly in both men and women. These findings suggest that it is crucial to prevent stroke among low-income population in China to reduce the burden of disease worldwide. FundingThe Ministry of Science and Technology of the People's Republic of China and National Key Project of Clinical Neurology, Tianjin Medical University General Hospital.

Neighborhood Influences on Emergency Medical Services Use for Acute Stroke: A Population-Based Cross-sectional Study

Delay to hospital arrival limits acute stroke treatment. Use of emergency medical services (EMS) is key in ensuring timely stroke care. We aim to identify neighborhoods with low EMS use and to evaluate whether neighborhood-level factors are associated with EMS use. We conducted a secondary analysis of data from the Brain Attack Surveillance in Corpus Christi project, a population-based stroke surveillance study of ischemic stroke and intracerebral hemorrhage cases presenting to emergency departments in Nueces County, TX. The primary outcome was arrival by EMS. The primary exposures were neighborhood resident age, poverty, and violent crime. We estimated the association of neighborhood-level factors with EMS use, using hierarchic logistic regression, controlling for individual factors (stroke severity, ethnicity, and age). During 2000 to 2009 there were 4,004 identified strokes, with EMS use data available for 3,474. Nearly half (49%) of stroke cases arrived by EMS. Adjusted stroke EMS use was lower in neighborhoods with higher family income (odds ratio [OR] 0.86; 95% confidence interval [CI] 0.75 to 0.97) and a larger percentage of older adults (OR 0.70; 95% CI 0.56 to 0.89). Individual factors associated with stroke EMS use included white race (OR 1.41; 95% CI 1.13 to 1.76) and older age (OR 1.36 per 10-year age increment; 95% CI 1.27 to 1.46). The proportion of neighborhood stroke cases arriving by EMS ranged from 17% to 71%. The fully adjusted model explained only 0.3% (95% CI 0% to 1.1%) of neighborhood EMS stroke use variance, indicating that individual factors are more strongly associated with stroke EMS use than neighborhood factors. Although some neighborhood-level factors were associated with EMS use, patient-level factors explained nearly all variability in stroke EMS use. In this community, strategies to increase EMS use should target individuals rather than specific neighborhoods.

Abstract W MP108: Identifying Factors Predictive of Good Outcome among Patients with Severe Ischemic Stroke: the BASIC Project

Background: Utilizing a population-based stroke surveillance study, our objective was to identify possible socio-demographic, cultural and psychological factors that influence outcome among patients with severe stroke who survive at least 3 months. Methods: Ischemic strokes (IS) were identified utilizing the Brain Attack Surveillance in Corpus Christi (BASIC) Project. Severe stroke was defined as the highest quartile of the initial NIH Stroke Scale (NIHSS ≥ 8). Functional outcome was assessed at 90 days using the ADL/IADL score (0-4, higher worse). Good outcome was defined as ADL/IADL &lt;3. Single predictor logistic regression models were used to identify predictors of good outcome among those with severe stroke. Backward elimination was then used to select a final set of predictors. Next, models including selected predictors and pre-stroke social support or pre-stroke depression (PHQ-9) were used to evaluate their association with good outcome among a subset of patients who were asked about these factors. Only patients who were able to answer their own questions were asked about depression and social support. Results: From Feb 2009 to Jun 2012, 646 IS patients completed a baseline interview and subsequent 90-day outcome interview. Of 168 with severe stroke, 68 had a good outcome at 3 months (ADL/IADL &lt;3). One year older age (OR=0.94, 95% confidence interval (CI) 0.91, 0.97), Mexican American ethnicity (OR 0.30, 95%CI: 0.13, 0.68), stroke history (OR 0.27, 95%CI: 0.11, 0.66) and higher pre-stroke modified Rankin of 4-5 (OR 0.28, 95%CI: 0.08, 0.93) were associated with lower odds of good outcome. Among the subset of severe stroke patients (N=93) asked about pre-stroke depression and social support, higher pre-stroke depression score was associated with lower odds of good outcome (OR: 0.89, 95%CI 0.79, 0.99) while greater pre-stroke social support was associated with higher odds of good outcome (OR: 1.45, 95% CI 1.13, 1.86). Conclusion: Among IS survivors with severe stroke, pre-stroke depression and social support are important predictors of good outcome. These factors should be considered in crafting interventions to improve stroke outcome. Mexican American ethnicity and history of prior stroke are strongly negatively associated with good stroke outcome.

Increasing stroke incidence and prevalence of risk factors in a low-income Chinese population.

We investigated secular trends in incidence of first-ever stroke and the prevalence of stroke risk factors within the same population in rural China. In 1985, 15,438 residents from a township of Tianjin, China, were recruited to the Tianjin Brain Study, a population-based stroke surveillance study. Stroke events and all deaths were registered annually. Because imaging technology was first available in 1992, we analyzed the incidence of first-ever stroke over 3 study periods-1992-1998, 1999-2005, and 2006-2012-from 1992 to 2012. Risk factor surveys were conducted in 1991 and 2011. The age-standardized incidence of first-ever stroke per 100,000 person-years increased rapidly from 124.5 in 1992-1998 to 190.0 in 1999-2005 and to 318.2 in 2006-2012; incidence increased annually by 6.5% overall and by 12% among men aged 45-64 years (p < 0.05). From 1992 to 2012, the age at first-ever stroke in men was earlier by 3.3 years overall, but a similar trend was not observed in women. Concurrently, the prevalence of high fasting glucose and alcohol consumption increased significantly in both men and women, especially in men aged <45 years; the prevalence of obesity and high fasting glucose increased by 8.8-fold and 11-fold, respectively, from 1992 to 2012. The incidence of stroke in rural China increased rapidly, particularly among middle-aged adults, along with a concurrent increase in risk factor prevalence. These findings suggest that without controlling these risk factors, stroke incidence will continue to increase over future decades in China.

Ischemic Stroke Subtype and Presence of Sleep-disordered Breathing: The BASIC Sleep Apnea Study

Little is known about the prevalence of sleep-disordered breathing (SDB) across ischemic stroke subtypes. Given the important implications for SDB screening, we tested the association between SDB and ischemic stroke subtype in a population-based study. Within the Brain Attack Surveillance in Corpus Christi Project, ischemic stroke patients were offered SDB screening with the ApneaLink Plus (n = 355). A neurologist assigned Trial of the ORG 10172 in Acute Stroke Treatment subtype (with an additional category for nonlacunar infarctions of unknown etiology) using hospital records. Unadjusted and adjusted (demographics, body mass index, National Institutes of Health Stroke Scale, diabetes, history of stroke/transient ischemic attack) logistic and linear regression models were used to test the association between subtype and SDB or apnea-hypopnea index (AHI). Median age was 65%, and 55% were men; 59% were Mexican American. Median time from stroke onset to SDB screen was 13 days (interquartile range [IQR] 6, 21). Overall, 215 (61%) had SDB (AHI ≥ 10). Median AHI was 13 (IQR 6, 27). Prevalence of SDB by subtype was cardioembolism, 66%; large-artery atherosclerosis, 57%; small-vessel occlusion, 68%; other determined, 50%; undetermined etiology, 58%; and nonlacunar stroke of unknown etiology, 63%. Ischemic stroke subtype was not associated with SDB in unadjusted (P = .72) or adjusted models (P = .91) models. Ischemic stroke subtype was not associated with AHI in unadjusted (P = .41) or adjusted models (P = .62). In this population-based stroke surveillance study, ischemic stroke subtype was not associated with the presence or severity of SDB. Sleep-disordered breathing is likely to be present after ischemic stroke, and the subtype should not influence decisions about SDB screening.

Abstract T P331: Investigating the Association of Traumatic Brain Injury and Ischemic Stroke in a Population-based Study

Background: Recently, two publications, one from California and one from Taiwan, utilizing administrative data have shown an independent, strong association between traumatic brain injury (TBI) and ischemic stroke (IS). The California analysis suggested TBI was a stronger risk factor for IS than hypertension. To begin the process of assessing whether TBI is really associated with IS with more definitive study types, we assessed the feasibility of obtaining TBI information in a population-based stroke study and characterized the history of TBI among IS patients including the time interval from TBI to stroke. Methods: As part of the Brain Attack Surveillance in Corpus Christi Project (BASIC), IS patients (n=439) who completed an interview were asked whether they had ever had a TBI that caused them to lose consciousness. For those IS patients who did have a TBI, we further questioned them as to the number and dates of TBIs and the length of loss of consciousness for the longest event. These questions closely followed the US Department of Defense characterization of TBI. Descriptive statistics were used to summarize history of TBI. Results: From 1/2/12 thru 7/7/13, 101 of the 439 (23%) IS stroke patients reported a history of at least one TBI that caused them to lose consciousness. Among patients with TBI, 67% had one TBI, 21% had 2 TBI’s, 10% had 3 or more TBI’s. The median length of time between the last reported TBI and stroke onset was 32 years (Q1: 7 years, Q3: 46 years); 3% had a TBI within 30 days prior to their IS and 9% had TBI within 1 year prior to their IS. The median NIHSS of IS patients with TBI was 3 (Q1: 1, Q3: 8) compared with a median NIHSS of 4 (Q1: 2, Q3: 9) among IS patients without TBI. Conclusion: It is feasible to obtain TBI information in this population-based stroke surveillance study where a history of TBI is very common in IS patients. The long interval between TBI to IS suggests a lack of association in most cases. A case-control study would be needed to confirm or refute the striking association of TBI and IS previously seen in administrative data. Further, a population-based study with detailed data collection would allow for discovery of associated mechanisms linking TBI to stroke such as dissection, coagulation disorders and intoxications.

Abstract 52: Brainstem Infarction is Associated with Sleep Apnea: The BASIC Sleep Project

Background: Despite hypotheses that brainstem infarction is associated with sleep apnea (SA), no specific site of infarction has been associated with post-stroke SA in existing studies, which have been relatively small. Within a larger, population-based study, we assessed the association between infarction location and SA presence and severity. Methods: Ischemic stroke patients in the Brain Attack Surveillance in Corpus Christi (BASIC) project had SA screening performed (median 13 days after stroke) with a validated portable respiratory monitor (ApneaLink Plus) (n=355). The apnea-hypopnea index (AHI) was used to measure SA severity; SA was defined conservatively as an AHI ≥10. Acute infarction location was determined based on review of CT and MRI reports by board-certified neurologists and dichotomized into brainstem involvement or none. Logistic and linear regression models were used to test the associations between brainstem involvement and SA or AHI in unadjusted and adjusted models. Results: Median age was 65 (IQR: 57, 77); 55% were male. Thirty-eight (11%) had acute infarction involving the brainstem. Of those without brainstem infarction, 59% had SA; the median AHI was 13 (interquartile range (IQR) 6, 26). Of those with brainstem infarction, 84% had SA; median AHI was 20 (IQR 11, 38). In unadjusted analysis, brainstem involvement was associated with over three times the odds of SA (OR 3.71 (95% CI: 1.52, 9.13). In a multivariable model, adjusted for demographics, BMI, stroke risk factors, and stroke severity, results were similar (OR 3.76 (95% CI: 1.44, 9.81)). Similarly, brainstem infarction was associated with AHI in unadjusted (p=0.004) and adjusted models (p=0.004). Conclusion: Acute infarction involving the brainstem was associated with both presence and severity of sleep apnea in this population-based stroke surveillance study.