A Validation of the Essen Stroke Risk Score in Outpatients with Ischemic Stroke.

BACKGROUND: Little is known about the predictive accuracy of the Essen Stroke Risk Score (ESRS) for Chinese stroke outpatients. Our goal was to perform an external validation of the ESRS using a large multicenter cohort of outpatients with ischemic stroke (IS). METHODS: We estimated the 1-year cumulative event rates for both recurrent stroke and combined vascular events for patients in different ESRS categories using data from a prospective cohort of 3316 outpatients with IS admitted to 18 hospitals in China. In addition, we evaluated the predictive accuracy of the ESRS for both recurrent stroke and combined vascular events using C statistic. RESULTS: In the nonatrial fibrillation IS outpatients, the cumulative 1-year event rate was 2.47% (95% confidence interval [CI], 1.97%-3.06%) for recurrent stroke and 4.32% (95% CI, 3.65%-5.06%) for combined vascular events. The event rates were significantly higher in patients in higher ESRS categories. The ESRS had a predictive accuracy of .63 (.57-.69) for recurrent stroke and .63 (.58-.68) for combined vascular events. CONCLUSION: Among the Chinese outpatients with IS, the ESRS was able to stratify the risk of both recurrent stroke and combined vascular events equally well. A prediction model suitable for Chinese IS populations is needed.

Validation of the Essen Stroke Risk Score in different subtypes of ischemic stroke.

OBJECTIVE: Predictive scores are important tools for stratifying patients based on their risk of future vascular events and for selecting preventive therapies. The aim of this study is to validate the Essen Stroke Risk Score (ESRS) for stratifying stroke recurrence in different subtypes of non-atrial fibrillation ischemic stroke in a large Chinese cohort. METHODS: Data were derived from the Blood pressure and clinical Outcome in Stroke Survivors registry, which includes a cohort of 2204 stroke patients. All patients were further classified according to the TOAST (Trial of Org 10 172 in Acute Stroke Treatment) criteria. We stratified one-year cumulative rates for stroke and composite vascular events using the ESRS. The predictive power of the ESRS was assessed using the area under the receiver-operator curves (AUC). RESULTS: Among 1699 patients included in the study, the AUC of ESRS was 0.58 (95% CI: 0.52-0.64) for recurrent stroke, whereas 0.59 (95% CI: 0.53-0.64) for composite vascular events at 1 year. In patients with large-artery atherosclerosis (LAA) subtype of stroke, the AUC of ESRS was both 0.61 (95% CI: 0.54-0.68) for recurrent stroke and composite vascular events. However, no significant AUC was observed in patients with small-artery occlusion subtype of stroke. CONCLUSIONS: In patients with LAA subtype of non-atrial fibrillation stroke, the ESRS has moderate accuracy in stratifying the risk of both recurrent strokes and major vascular events within the first year. However, the ESRS couldn't accurately stratify the risk of recurrent strokes in patients with small-artery atherosclerosis subtype of non-atrial fibrillation stroke.

Particulate Matter and Hospital Admissions for Stroke in Beijing, China: Modification Effects by Ambient Temperature.

BACKGROUND: The impact of particulate matter (PM) on stroke may vary by particle size, stroke subtype, and patient characteristics and temperature. We examined the association of stroke admissions with PM in different subgroups in Beijing, China, during 2013-2014. METHODS AND RESULTS: A time-stratified case-crossover design was used to assess the relation between PM of different particle sizes and hospital admissions for ischemic and hemorrhagic stroke. Stratified analyses were performed by age, sex, and temperature. In total, there were 147 624 stroke admissions during the study period. In the whole-period analysis, both PM2.5 and PM10 were positively associated with ischemic stroke admissions on the day of hospital admission and negatively associated with ischemic stroke at lag2 and lag3 day. In warm days (>13.5°C), the odds ratios of ischemic stroke admissions were 2.071 (95% CI 1.959-2.190), 1.470 (95% CI 1.391-1.554), and 1.590 (95% CI 1.493-1.694) per IQR increase in the same-day PM2.5 (82.0 µg/m(3)), PM2.5-10 (36.6 µg/m(3)), and PM10 (93.5 µg/m(3)), respectively. For hemorrhagic stroke, the corresponding values were 1.941 (95% CI 1.658-2.273), 1.590 (95% CI 1.366-1.851), and 1.527 (95% CI 1.278-1.826). The positive associations were also observed in the other lag structures and were higher than in cold days (≤13.5°C). CONCLUSIONS: This study suggests that the associations of PM2.5, PM2.5-10, and PM10 with stroke admissions differed across levels of temperature. Short-term exposure to PM2.5, PM2.5-10, and PM10 was positively associated with hospital admissions for ischemic and hemorrhagic stroke on warm days (>13.5°C).

A Novel Risk Score to the Prediction of 10-year Risk for Coronary Artery Disease Among the Elderly in Beijing Based on Competing Risk Model.

The study aimed to construct a risk prediction model for coronary artery disease (CAD) based on competing risk model among the elderly in Beijing and develop a user-friendly CAD risk score tool. We used competing risk model to evaluate the risk of developing a first CAD event. On the basis of the risk factors that were included in the competing risk model, we constructed the CAD risk prediction model with Cox proportional hazard model. Time-dependent receiver operating characteristic (ROC) curve and time-dependent area under the ROC curve (AUC) were used to evaluate the discrimination ability of the both methods. Calibration plots were applied to assess the calibration ability and adjusted for the competing risk of non-CAD death. Net reclassification index (NRI) and integrated discrimination improvement (IDI) were applied to quantify the improvement contributed by the new risk factors. Internal validation of predictive accuracy was performed using 1000 times of bootstrap re-sampling. Of the 1775 participants without CAD at baseline, 473 incident cases of CAD were documented for a 20-year follow-up. Time-dependent AUCs for men and women at t = 10 years were 0.841 [95% confidence interval (95% CI): 0.806-0.877], 0.804 (95% CI: 0.768-0.839) in Fine and Gray model, 0.784 (95% CI: 0.738-0.830), 0.733 (95% CI: 0.692-0.775) in Cox proportional hazard model. The competing risk model was significantly superior to Cox proportional hazard model on discrimination and calibration. The cut-off values of the risk score that marked the difference between low-risk and high-risk patients were 34 points for men and 30 points for women, which have good sensitivity and specificity. A sex-specific multivariable risk factor algorithm-based competing risk model has been developed on the basis of an elderly Chinese cohort, which could be applied to predict an individual's risk and provide a useful guide to identify the groups at a high risk for CAD among the Chinese adults over 55 years old.

The design, rationale, and baseline characteristics of a nationwide cohort registry in China: blood pressure and clinical outcome in TIA or ischemic stroke.

BACKGROUND: The relationship between poststroke blood pressure (BP) and clinical outcomes in ischemic stroke (IS) is still controversial. However, there is no large BP database for IS or transient ischemic attack (TIA) in China. This study aims to describe the rationale, study design, and baseline characteristics of a nationwide BP database in IS or TIA patients in China. MATERIALS AND METHODS: The BOSS (blood pressure and clinical outcome in TIA or ischemic stroke) study was a hospital-based, prospective cohort study aiming to assess BP parameters and clinical outcome in IS/TIA patients. BP parameters were based on office BP, ambulatory BP, and home BP. Clinical outcomes included stroke recurrence, combined vascular events, and disability. Electronic case-report forms were used to record baseline and follow-up data. The patients were followed up for clinical outcomes at 3 months through face-to-face interview and at 12 months by telephone. RESULTS: Between October 2012 and February 2014, the BOSS registry recruited 2,608 patients from 61 hospitals, with a mean age of 62.5 years, 32.4% of whom were female, 88.9% with an entry diagnosis of IS, and 86% diagnosed with hypertension. The rates of patients lost-to-follow-up were 3.1% at 3 months and 5.1% at 1 year; 93% of patients completed ambulatory BP monitoring during hospitalization and 94.7% finished a 3-month BP diary. CONCLUSION: The BOSS registry will provide important evidence about BP management in the acute phase and secondary prevention for IS/TIA patients.

An association of platelet indices with blood pressure in Beijing adults: Applying quadratic inference function for a longitudinal study.

The quadratic inference function (QIF) method becomes more acceptable for correlated data because of its advantages over generalized estimating equations (GEE). This study aimed to evaluate the relationship between platelet indices and blood pressure using QIF method, which has not been studied extensively in real data settings.A population-based longitudinal study was conducted in Beijing from 2007 to 2012, and the median of follow-up was 6 years. A total of 6515 cases, who were aged between 20 and 65 years at baseline and underwent routine physical examinations every year from 3 Beijing hospitals were enrolled to explore the association between platelet indices and blood pressure by QIF method. The original continuous platelet indices were categorized into 4 levels (Q1-Q4) using the 3 quartiles of P25, P50, and P75 as a critical value. GEE was performed to make a comparison with QIF.After adjusting for age, usage of drugs, and other confounding factors, mean platelet volume was negatively associated with diastolic blood pressure (DBP) (Equation is included in full-text article.)in males and positively linked with systolic blood pressure (SBP) (Equation is included in full-text article.). Platelet distribution width was negatively associated with SBP (Equation is included in full-text article.). Blood platelet count was associated with DBP (Equation is included in full-text article.)in males.Adults in Beijing with prolonged exposure to extreme value of platelet indices have elevated risk for future hypertension and evidence suggesting using some platelet indices for early diagnosis of high blood pressure was provided.

Technology Resource, Distribution, and Development Characteristics of Global Influenza Virus Vaccine: A Patent Bibliometric Analysis.

Influenza virus vaccine (IVV) is a promising research domain that is closely related to global health matters, which has been acknowledged not only by scientists and technology developers, but also by policy-makers. Meanwhile, patents encompass valuable technological information and reflect the latest technological inventions as well as the innovative capability of a nation. However, little research has examined this up-and-coming research field using patent bibliometric method. Thus, this paper (a) designs the technology classification system and search strategy for the identification of IVV; and (b) presents a longitudinal analysis of the global IVV development based on the European Patent Office (EPO) patents. Bibliometric analysis is used to rank countries, institutions, inventors and technology subfields contributing to IVV technical progress. The results show that the global trends of IVV are a multi-developing feature of variety but an uneven technical resource distribution. Although the synthetic peptide vaccine is a comparatively young field, it already demonstrates the powerful vitality and the enormous development space. With the worldwide competition increasing, all nations especially China should be looking to increase devotion, enhance capability and regard effectiveness of technological innovation.

PM2.5 Spatiotemporal Variations and the Relationship with Meteorological Factors during 2013-2014 in Beijing, China.

OBJECTIVE: Limited information is available regarding spatiotemporal variations of particles with median aerodynamic diameter < 2.5 µm (PM2.5) at high resolutions, and their relationships with meteorological factors in Beijing, China. This study aimed to detect spatiotemporal change patterns of PM2.5 from August 2013 to July 2014 in Beijing, and to assess the relationship between PM2.5 and meteorological factors. METHODS: Daily and hourly PM2.5 data from the Beijing Environmental Protection Bureau (BJEPB) were analyzed separately. Ordinary kriging (OK) interpolation, time-series graphs, Spearman correlation coefficient and coefficient of divergence (COD) were used to describe the spatiotemporal variations of PM2.5. The Kruskal-Wallis H test, Bonferroni correction, and Mann-Whitney U test were used to assess differences in PM2.5 levels associated with spatial and temporal factors including season, region, daytime and day of week. Relationships between daily PM2.5 and meteorological variables were analyzed using the generalized additive mixed model (GAMM). RESULTS: Annual mean and median of PM2.5 concentrations were 88.07 µg/m3 and 71.00 µg/m3, respectively, from August 2013 to July 2014. PM2.5 concentration was significantly higher in winter (P < 0.0083) and in the southern part of the city (P < 0.0167). Day to day variation of PM2.5 showed a long-term trend of fluctuations, with 2-6 peaks each month. PM2.5 concentration was significantly higher in the night than day (P < 0.0167). Meteorological factors were associated with daily PM2.5 concentration using the GAMM model (R2 = 0.59, AIC = 7373.84). CONCLUSION: PM2.5 pollution in Beijing shows strong spatiotemporal variations. Meteorological factors influence the PM2.5 concentration with certain patterns. Generally, prior day wind speed, sunlight hours and precipitation are negatively correlated with PM2.5, whereas relative humidity and air pressure three days earlier are positively correlated with PM2.5.

Risk factors of CVD mortality among the elderly in Beijing, 1992 - 2009: an 18-year cohort study.

Few researchers have examined the effects of multiple risk factors of cardiovascular disease (CVD) mortality simultaneously. This study was to determine the associations of combined lifestyle and other factors with CVD mortality among the elderly (n = 3,257), in Beijing, China, through data mining of the Beijing Longitudinal Study of Aging (BLSA). BLSA is a representative cohort study from 1992 to 2009, hosted by Xuan Wu Hospital. Competing risk survival analysis was conducted to explore the association between risk factors and CVD mortality. The factors focused mainly on lifestyle, physical condition, and the model was adjusted for age and gender. There were 273 of the 1,068 recorded deaths caused by CVD among the 2010 participants. Living in a suburban area (HR = 0.614, 95% CI: 0.410-0.921) was associated with lower CVD mortality. Increasing age (66-75: HR = 1.511, 95% CI: 1.111-2.055; ≥ 76: HR = 1.847, 95% CI: 1.256-2.717), high blood pressure (HR = 1.407, 95% CI: 1.031-1.920), frequent consumption of meat (HR = 1.559, 95% CI: 1.079-2.254) and physical inactivity (p = 0.046) were associated with higher CVD mortality. The study provides an instructional foundation for the control and prevention of CVD in Beijing, China.

Risk factors for cerebrovascular disease mortality among the elderly in Beijing: a competing risk analysis.

OBJECTIVE: To examine the associations of combined lifestyle factors and physical conditions with cerebrovascular diseases (CBVD) mortality, after accounting for competing risk events, including death from cardiovascular diseases, cancers and other diseases. METHODS: Data on 2010 subjects aged over 55 years were finally analyzed using competing risk models. All the subjects were interviewed by the Beijing Longitudinal Study of Aging (BLSA), in China, between 1 January 1992 and 30 August 2009. RESULTS: Elderly females were at a lower risk of death from CBVD than elderly males (HR = 0.639, 95% CI = 0.457-0.895). Increasing age (HR = 1.543, 95% CI = 1.013-2.349), poor self-rated health (HR = 1.652, 95% CI = 1.198-2.277), hypertension (HR = 2.201, 95% CI = 1.524-3.178) and overweight (HR = 1.473, 95% CI = 1.013-2.142) or obesity (HR = 1.711, 95% CI = 1.1754-2.490) was associated with higher CBVD mortality risk. Normal cognition function (HR = 0.650, 95% CI = 0.434-0.973) and living in urban (HR = 0.456, 95% CI = 0.286-0.727) was associated with lower CBVD mortality risk. Gray's test also confirmed the cumulative incidence (CIF) of CBVD was lower in the 'married' group than those without spouse, and the mortality was lowest in the 'nutrition sufficient' group among the 'frequent consumption of meat group' and the 'medial type group' (P value<0.001). CONCLUSIONS: CBVD mortality was associated with gender, age, blood pressure, residence, BMI, cognitive function, nutrition and the result of self-rated health assessment in the elderly in Beijing, China.