Regarding "Preprocedural risk stratification: identifying an appropriate population for carotid stenting".
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Angioplasty, Balloon, Coronary↗
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Regarding "Preprocedural risk stratification: identifying an appropriate population for carotid stenting".
Explore the source record for details and available documents.
Carotid Stenosis↗
Toxicity in a water column following the stratification of a cyanobacterial population development in a calm lake.
Cyanobacteria, including the genera Anabaena, Aphanizomenon, Microcystis, and Oscillatoria, are known to release or have the potential to release phycotoxins into the water. Indeed, there are documented cases of both animal and human intoxication. Data obtained from field observations and laboratory experiments demonstrate a correlation between the development of the cyanobacterial population and the level of phycotoxin present in the water, though it should be noted that not all cyanobacterial blooms are toxic. The development of cyanobacterial populations is described by a dynamical model which accounts for factors that include algal growth, degradation, and light-driven buoyancy under the assumption of an isothermal, calm, and nutrient-abundant lake. A semiempirical mathematical model for water-column toxicity is developed and is used in conjunction with an improved result for the density of the cyanobacteria population obtained from the dynamical model. Light transfer through the water column, light absorption, the implication of the differentiated attenuation of light by the water, and its diurnal effect on the cyanobacteria population is considered. The result of which is a plausible description of the seasonal development of cyanobacteria populations and of the toxicity within the water body.
Animals↗
DM firm enlists prediction tools, risk stratification to focus on population health.
Redefining pregnancy as a 'disease' may sound strange, but it brings pregnancy into the disease management arena. Check out how one DM program is documenting lower costs and better outcomes in an aggressive effort to help prospective mothers and their babies.
Disease Management↗
Prognostic value of clinical variables at presentation in patients with non-ST-segment elevation acute coronary syndromes: results of the Proyecto de Estudio del Pronóstico de la Angina (PEPA).
Patients with suspected non-ST-segment elevation acute coronary syndromes (NSTEACS) constitute a heterogeneous population with variable outcomes. Risk stratification in this population of patients is difficult due to the complexity in patient risk profile. We conducted this study to characterize the value of clinical and electrocardiographic variables for risk stratification in an unselected population of consecutive patients with NSTEACS on admission. Thirty-five clinical and electrocardiographic variables at presentation in the emergency room of 18 hospitals were prospectively analyzed in 4,115 patients with NSTEACS and related with the outcomes at 90 days. We also developed a risk score using the variables found to be independent predictors of ischemic events to facilitate risk stratification. Cardiovascular mortality was 4.3% and the rate for the outcome of either cardiovascular death or nonfatal myocardial infarction was 6.9%. The only independent predictors of mortality were age, diabetes, peripheral vascular disease, postinfarction angina, Killip class > or = 2, ST-segment depression, and elevation of cardiac markers. A risk profile using the variables found to be independent predictors of events was calculated for cardiovascular mortality and for the combination of either death or nonfatal myocardial infarction. Event rates increased significantly in all subgroups of patients based on the number of independent risk factors as the risk score increased. Using these factors, 90-day mortality ranged from as low as 0.4% in patients with no risk factors to 21.1% for those with more than 4 risk factors. In conclusion, simple clinical and electrocardiographic data obtained at hospital admission allow an accurate risk stratification of patients with NSTEACS. In the PEPA registry, simple variables easy to obtain at admission appear to be a valuable tool in discerning between patients at very low and very high risk according to the cluster of factors for each patient. The risk score developed was obtained from an unselected population, representative of the whole spectrum of patients with NSTEACS, allowing identification of patients at different risks for adverse outcomes, and, therefore, permitting optimization of therapy.
Adult↗
Cardiovascular disease risk stratification and comparison in a California population.
This study was designed to identify the need for primary prevention of cardiovascular disease in an HMO population and to develop appropriate interventions for individuals in different risk groups, based on risk stratification and comparison. The analysis is based on a cross-sectional survey of the HMO members of a large employer group. Respondents (n=17,878) were stratified based on the Framingham model; 34% of respondents without cardiovascular disease were classified as moderate to high attributable risk for the disease, and 66% were classified as low attributable risk. Results of logistic regression analyses suggest that, compared with respondents with pre-existing cardiovascular disease, moderate- to high-risk respondents are more likely to smoke, have unhealthy diets, and be overweight, hypertensive, and hypercholesterolemic. More low-risk respondents had unhealthy diets than did those with pre-existing cardiovascular disease. There were no differences between these groups for physical activity and stress. Respondents had fewer modifiable risk factors and healthier lifestyles than did those who were at risk. These findings suggest that primary prevention should be enhanced, especially among those with significantly increased risk for the disease. Moreover, the approaches of this project-population-based risk assessment, stratification, and comparison-were instrumental in identifying the target population and designing appropriate interventions. (c) 2001 by CHF, Inc.
Journal Article↗
Prognostic value of dobutamine stress technetium-99m-sestamibi single-photon emission computed tomography myocardial perfusion imaging: stratification of a high-risk population.
OBJECTIVES: This work was undertaken to define the intrinsic cardiac risk of the patient population referred for dobutamine stress perfusion imaging and to determine whether dobutamine technetium-99m ((99m)Tc)-sestamibi single-photon emission computed tomography (SPECT) imaging is capable of risk stratification in this population. BACKGROUND: In animal models, dobutamine attenuates the myocardial uptake of (99m)Tc-sestamibi resulting in underestimation of coronary stenoses. Therefore, we hypothesized that the prognostic value of dobutamine stress (99m)Tc-sestamibi SPECT myocardial perfusion imaging might be impaired, owing to reduced detection of coronary stenoses. METHODS: We reviewed the clinical outcome of 308 patients (166 women, 142 men) who underwent dobutamine stress SPECT (99m)Tc-sestamibi imaging at our institution from September 1992 through December 1996. RESULTS: During an average follow-up of 1.9 +/- 1.1 years, there were 33 hard cardiac events (18 myocardial infarctions [MI] and 15 cardiac deaths) corresponding to an annual cardiac event rate of 5.8%/year, which is significantly higher than the event rate for patients referred for exercise SPECT imaging at our institution (2.2%/year). Event rates were higher after an abnormal dobutamine (99m)Tc-sestamibi SPECT study (10.0%/year) than after a normal study (2.3%/year) (p < 0.01), even after adjusting for clinical variables. In the subgroup (n = 29) with dobutamine-induced ST-segment depression and abnormal SPECT imaging, the prognosis was poor, with annual cardiac death and nonfatal MI rates of 7.9% and 13.2%, respectively. CONCLUSIONS: Patients referred for dobutamine perfusion imaging are a high-risk population, and dobutamine stress (99m)Tc-sestamibi SPECT imaging is capable of risk stratification in these patients.
Aged↗
Mortality caused by sepsis in patients with end-stage renal disease compared with the general population.
BACKGROUND: In the United States, infection is second to cardiovascular disease as the leading cause of death in patients with end-stage renal disease (ESRD), and septicemia accounts for more than 75% of this category. This increased susceptibility to infections is partly due to uremia, old age, and comorbid conditions. Although it is intuitive to believe that mortality caused by sepsis may be higher in patients with ESRD compared with the general population (GP), no such data are currently available. METHODS: We compared annual mortality rates caused by sepsis in patients with ESRD (U.S. Health Care Financing Administration 2746 death notification form) with those in the GP (death certificate). Data were abstracted from the U.S. Renal Data System (1994 through 1996 Special Data request) and the National Center for Health Statistics. Data were stratified by age, gender, race, and diabetes mellitus (DM). Sensitivity analyses were performed to account for potential limitations of the data sources. RESULTS: Overall, the annual percentage mortality secondary to sepsis was approximately 100- to 300-fold higher in dialysis patients and 20-fold higher in renal transplant recipients (RTRs) compared with the GP. Mortality caused by sepsis was higher among diabetic patients across all populations. After stratification for age, differences between groups decreased but retained their magnitude. These findings remained robust despite a wide range of sensitivity analyses. Indeed, mortality secondary to sepsis remained approximately 50-fold higher in dialysis patients compared with the GP, using multiple cause-of-death analyses; was approximately 50-fold higher in diabetic patients with ESRD compared with diabetic patients in the GP, when accounting for underreporting of DM on death certificates in the GP; and was approximately 30-fold higher in RTRs compared with the GP, when accounting for the incomplete ascertainment of cause of death among RTRs. Furthermore, despite assignment of primary cause-of-death to major organ infections in the GP, annual mortality secondary to sepsis remained 30- to 45-fold higher in the dialysis population. CONCLUSIONS: Patients with ESRD treated by dialysis have higher annual mortality rates caused by sepsis compared with the GP, even after stratification for age, race, and DM. Consequently, this patient population should be considered at high-risk for the development of lethal sepsis.
Adult↗
[Serotypical stratification of HIV-1 in populations of intravenous drug users in the south/southwestern Ukraine].
A total of 101 HIV-1 positive sera from intravenous drug users (IVDU) in Southern and South-Eastern Ukraine were serotyped using V3-mimicking peptides. Serotype B circulates in Nikolaev and type A/C in Odessa and Donetsk. Prevalence of A/C serotype in the population of IVDU is a characteristic feature of the epidemic situation in this region, in contrast to the USA and Western Europe, where subtype B circulates. Serotypical stratification indicates that routes of HIV-1 dissemination in the Ukraine differ from those in the USA and Western Europe, which should be borne in mind when planning the strategy of epidemic control.
Amino Acid Sequence↗
[Epidemiology and social determinants of health inequalities].
BACKGROUND: The general approach of social epidemiology is based on the observation of a strong social stratification of health outcomes within populations: a similar stratification of factors associated with health must therefore also exist according to social status. To explain social differences in health, the natural approach for epidemiologists is to consider an imbalanced distribution of established risk factors according to the social position of individuals. As this approach has largely failed, two main other research areas were recently explored: (i) identification of "new" social risk factors; (ii) research of possible mechanisms of social differences in health. METHODS AND RESULTS: Identification of social risk factors: early events and life course, occupational factors, social relationships (social networks and support, discrimination, neighborhood characteristics), health care. Research of possible mechanisms of social differences in health in the context of specific theoretical frameworks: the materialist model, the psychosocial model and the eco-social model integrating the interaction between individuals'characteristics and their environment. COMPLEX METHODOLOGICAL PROBLEMS: definition and measurement of variables characterizing the social situation of individuals; quantification of social inequalities at population level. Observational methods must often rely on very long-lasting cohorts, and imply statistical methods that account for longitudinal data or are able to manage simultaneously individual and contextual data.
Cohort Studies↗
[Application of risk stratification scores in acute myocardial infarction. Results of RICO (observation of infarction in the Ivory Coast)].
Several risk stratification scores for myocardial infarction have been developed in recent years, based on clinical trials. The object of this study was to assess the application of these scores in an unselected population of myocardial in farction in a French department. One thousand and fifty-four patients with acute myocardial infarction were included in the RICO observatory in the Côte d'Or. Those with ST elevation (SST), N = 746, had 30 day-mortality rates which increased with the TIMI and GUSTO scores (khi2 tendency, p < 0.001). There was a good discriminatory power of both these scores (correlations of 0.71 and 0.69 respectively). Similarly, logistic regression analysis showed a significant relationship between TIMI and GUSTO scores and 30 day mortality (p < 0.001). No correlation was observed between mortality and increased TIMI score in cases of infarction without ST elevation, N = 308, p = 0.344. Moreover, this score had a low discriminatory value in the study population with a correlation of 0.54. On the other hand, regression analysis showed a strong predictive value of the PURSUIT score in infarction without ST elevation for mortality. In addition, there was a correlation between death and the value of this score (p < 0.05). This score also showed a good discriminatory power with a correlation of 0.71. This study shows that, in an unselected population, risk stratification scores may be used as a routine in myocardial infarction, especially in cases with ST elevation.
Aged↗
Relationship of the delta-opioid receptor gene to heroin abuse in a large Chinese case/control sample.
Pharmacological and electrophysiological evidence has shown that opioid receptors are involved in the mechanism of heroin dependence. Thus, opioid receptors are appropriate candidate genes for case-control association studies of heroin dependence. Previously, two single nucleotide polymorphisms (SNPs), OPRD1 921T > C and 80G > T, of the human delta opioid receptor gene were used in population-based studies of heroin dependence. One study in a German population found that OPRD1 921T > C was associated with heroin dependence. This finding, however, was not replicated in a different German sample. To test the hypothesis that OPRD1 or a closely linked gene is associated with heroin dependence, we used 5' nuclease assays to genotype both OPRD1 SNPs in 450 Chinese heroin dependent patients and 304 unaffected controls from the same population. In addition, five SNPs distributed in four other genes: ADH2, ALDH2, OPRM1, and DRD1, were used as genomic control loci to test the case and control populations for stratification bias. Genotype and allele frequencies at OPRD1 921T > C were not significantly different, and the OPRD1 80G was absent from both Chinese opioid dependence patients and controls. Based on the genotype and allele frequencies of the genomic control loci, there was no evidence for stratification bias capable of masking an association of OPRD1 to heroin dependence in this large and homogenous Chinese sample. Therefore, these data do not support an association between the OPRD1 gene and heroin dependence in the Chinese population.
Adult↗
Oral health status in an adult Swedish population. Prevalence of caries. A cross-sectional epidemiological study in the Northern Alvsborg county.
The aim of the present epidemiological study was to describe prevalence, distribution and type of caries in an adult Swedish population. After stratification with respect to age (20-29, 30-39,.....greater than 79 years of age), sex and location of residence (city, village, rural region), a random sample of 967 individuals was drawn (0.75% of the total adult population greater than 19 years). The results were based on radiographic and clinical examination of 919 individuals, of whom 750 were dentate (participation rate: 95%). The examinations were carried out from November 1983 to December 1984. The caries registrations distinguished between enamel caries and root caries, subdivided into manifest and initial caries. Despite lower number of remaining teeth in older ages, the mean number of surfaces with manifest caries (DS) was relatively even in all age groups (4.1-5.1 DS), except for the youngest age group ("20-29 years": mean 3.1 DS). When the number of decayed teeth (DT) were expressed as a percentage of remaining teeth, the ratio (%) was markedly higher in the older age groups than in the younger age groups. Initial caries was more frequent in the younger age groups. In the age groups above forty years the majority of the observed carious lesions involved root surfaces. In the oldest age group ("greater than 79 years of age"), 95% of the lesions were root caries. The mean number of filled surfaces (FS) was higher among women than men, while untreated caries (DS) showed a tendency of higher values for men. No significant differences in caries prevalence related to location of residence could be demonstrated.
Adult↗
Prevalence of the metabolic syndrome in drug-treated hypertensive patients and control subjects.
OBJECTIVES: To determine the prevalence of the metabolic abnormalities associated with hypertension and to define the predictors of the metabolic syndrome by different definitions in random population-based samples. DESIGN: A cross-sectional epidemiological study of hypertensive patients and controls. SETTING: The participating study subjects visited the research laboratory of the Department of Internal Medicine, University of Oulu, Oulu, Finland. SUBJECTS: Six hundred treated male and female hypertensives aged 40-59 years and 600 age- and sex-matched controls were randomly selected by age stratification from population registers. MAIN OUTCOME MEASURES: A wide range of laboratory analyses were conducted. After fasting blood had been drawn, the subjects were given a 75 g glucose load except previously known insulin-treated diabetics. Both 1 h and 2 h glucose and insulin concentrations were determined. During the same visit, a standardized health questionnaire covering the past medical history, current and former medication use, physical activity, smoking habits, alcohol consumption and family history was completed. Ten different definitions of the metabolic syndrome were applied to achieve a wide perspective of the prevalence of the different combinations. RESULTS: The prevalence of the metabolic syndrome in different samples varied depending on the definition from 0.8 to 35.3%, being lowest in the control men and women and highest in the hypertensive men. Three-quarters of a random, middle-aged, urban population show at least one cardiovascular risk factor and 91.3% of all the hypertensive subjects show at least one cardiovascular risk factor in addition to hypertension itself. The independent predictors of the metabolic syndrome were waist circumference, uric acid, total cholesterol and gamma-glutamyl transpeptidase in logistic analysis after adjustment for age, measure of obesity and gender. CONCLUSIONS: This cross-sectional, epidemiological study shows that the magnitude of the prevalence rates of the metabolic syndrome is at the same level in various populations, being less than one-third in population-based samples in spite of the different definitions. The cluster of several cardiovascular risk factors, especially in the hypertensives, leads to an increased relative risk of cardiovascular diseases.
Adult↗
[Unidentified arteriopathy: an epidemiological study. The preliminary results].
The importance of the social and medical impact of arteriosclerotic disease fully justifies a series of studies focused on improving knowledge of this pathology before symptoms become manifest, so as to orientate treatment increasingly towards prevention. The aim of this study-of which the authors now report the preliminary results-was to establish the incidence of unidentified lower limb arteriopathy in the general population and to evaluate the relations between this and the possible presence of risk factors. The authors therefore decided to evaluate patients attending outpatient General Surgery clinic for symptoms manifestly not related to lower limb vascular pathology (arterial or venous). Patients suffering from any arterial disease were likewise excluded from the study. The importance of performing a large-scale epidemiological study (sample size, stratification of population studied, vast geographic area, etc.) persuaded the authors to adopt a multi-centre structure. Twelve General Surgery departments at hospitals in the Veneto area were involved: each was required to evaluate an average of 150 patients, giving a total of 1950 subjects. The method of study chosen was the residual pressure index (RPI) measured using Doppler velocimetry. Patients were divided into two study groups: patients in Group A (with pathological RPI) were re-evaluated after correction for risk factors, integrated or not by medical treatment. Preliminary results relating to 46% of the total sample show that 26.7% of the subjects present pathological RPI. The evaluation of risk factors and the comparison of their presence in the two groups (A--pathological patients, B--non-pathological subjects) reveals significant differences regarding diabetes and hypertension.
Adult↗
Gastrointestinal stromal tumors in Iceland, 1990-2003: the icelandic GIST study, a population-based incidence and pathologic risk stratification study.
Gastrointestinal stromal tumor (GIST) is a newly defined clinical and pathologic entity. This study examines the whole population-based incidence of GIST as well as pathologic risk stratification schemes. All patients diagnosed in Iceland with a gastrointestinal mesenchymal tumor over the years 1990-2003 were evaluated with an immunohistochemical panel including staining for c-kit. The age-adjusted incidence of GIST was calculated. Size, mitotic rate per 50 HPF and various other pathologic parameters were evaluated. Each tumor was categorized into 1 of 4 recently defined NIH risk stratification categories. Fifty-seven of the mesenchymal gastrointestinal tumors were positive for c-kit and therefore categorized as GIST. The annual incidence for the study period is 1.1 per 100,000. The median age of patients was 65.8 years and median tumor size was 4.6 cm. Only 2 of 35 gastric tumors fall into the NIH high-risk category while half of the nongastric tumors (11 of 22) fall into this high-risk category. Eight of the 57 tumors (14%) metastasized, 7 of which were nongastric. The positive predictive value for malignant behavior of the high-risk category is 46%. The negative predictive value of low- and very-low-risk NIH category is 100%. Pathologic predictors of malignant behavior are tumor size, mitotic rate, mucosal disruption, necrosis and high cellularity. Nongastric GISTs are clearly at much higher risk of a malignant behavior than gastric GISTs. This population-based GIST study estimates the incidence of GISTs at 1.1 per 100,000 and furthermore supports the NIH consensus categories for the prediction of malignant behavior of GISTs.
Age Factors↗
Analysis of T cell receptor V alpha polymorphisms in rheumatoid arthritis.
OBJECTIVE: To test for association of T cell receptor (TCR) V alpha polymorphisms and rheumatoid arthritis (RA) in British and Swiss white populations. METHODS: TCRAV polymorphisms were analysed in RA patients and controls by single strand conformational polymorphism (SSCP) analysis. Associations were sought between defined genotypes and RA, and the effect of HLA-DR4 status analysed. Putative associations were then retested further in new groups of patients and controls. Overall, 360 RA patients and 197 controls were studied. RESULTS: No association between TCRAV5S1, V6S1, V8S1, V17S1 or V21S1 polymorphisms and RA were observed in the initial population screened. Stratification for DR4 status showed an increase of V5S1*01/*01 in DR4 positive versus DR4 negative patients (chi 2 = 7.19, p = 0.028 (2df), p = 0.14 after correction for multiple comparisons). This putative association was tested in three further patient groups, none of which showed significant increase of V5S1*01/*01 in DR4 positive patients, although an overall trend towards an increase in V5S1*01/*01 was observed. CONCLUSION: No evidence was found for a strong association of TCRAV genes and RA in a white population. However, these results suggest a weak association of V5S1*01/*01 with DR4 positive RA, although this requires confirmation using larger groups of patients and controls.
Arthritis, Rheumatoid↗
Spatial variability in the abundance and composition of the free-living bacterioplankton community in the pelagic zone of Lake Bourget (France).
Spatial variations in the abundance and diversity of the free-living bacterioplankton community of a large Alpine lake, Lake Bourget (France), were investigated in the pelagic zone by means of two two-dimensional samplings taken in 2003. Lake-water samples were collected in winter during water mixing, and in early summer during stratification. The population abundance in each sample was determined by flow cytometry. Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments from organisms measuring less than 2 mum was used to assess eubacterioplankton community composition. In winter, no obvious differences were observed in either the abundance or the diversity of the bacterial community, on either the horizontal or the vertical scales. The only influence detected was that of river water input, but this was at a very minor scale relative to the surface area of the lake. In early summer, changes were found in the community composition on the vertical scale related to the thermal stratification of the water column. There were also marked differences on the horizontal scale at 15 m depth due to internal waves. The implications of these findings for sampling strategies are very important from the perspective of comparative studies of free-living bacterial community diversity and functioning in large and deep lakes.
Animals↗