RESUMO
A hybrid model based on the positive matrix factorization (PMF) model and the health risk assessment model for assessing risks associated with sources of perfluoroalkyl substances (PFASs) in water was established and applied at Dianchi Lake to test its applicability. The new method contains 2 stages: 1) the sources of PFASs were apportioned by the PMF model and 2) the contribution of health risks from each source was calculated by the new hybrid model. Two factors were extracted by PMF, with factor 1 identified as aqueous fire-fighting foams source and factor 2 as fluoropolymer manufacturing and processing and perfluorooctanoic acid production source. The health risk of PFASs in the water assessed by the health risk assessment model was 9.54 × 10-7 a-1 on average, showing no obvious adverse effects to human health. The 2 sources' risks estimated by the new hybrid model ranged from 2.95 × 10-10 to 6.60 × 10-6 a-1 and from 1.64 × 10-7 to 1.62 × 10-6 a-1 , respectively. The new hybrid model can provide useful information on the health risks of PFAS sources, which is helpful for pollution control and environmental management. Environ Toxicol Chem 2018;37:107-115. © 2017 SETAC.
Assuntos
Fluorocarbonos/análise , Modelos Teóricos , Medição de Risco , Monitoramento Ambiental , Geografia , Humanos , Lagos/química , Regressão Psicológica , Reprodutibilidade dos Testes , Água/química , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Influenza hospitalizations result in substantial morbidity and mortality each year. Little is known about the association between influenza hospitalization and census tract-based socioeconomic determinants beyond the effect of individual factors. OBJECTIVE: To evaluate whether census tract-based determinants such as poverty and household crowding would contribute significantly to the risk of influenza hospitalization above and beyond individual-level determinants. METHODS: We analyzed 33 515 laboratory-confirmed influenza-associated hospitalizations that occurred during the 2009-2010 through 2013-2014 influenza seasons using a population-based surveillance system at 14 sites across the United States. RESULTS: Using a multilevel regression model, we found that individual factors were associated with influenza hospitalization with the highest adjusted odds ratio (AOR) of 9.20 (95% CI 8.72-9.70) for those ≥65 vs 5-17 years old. African Americans had an AOR of 1.67 (95% CI 1.60-1.73) compared to Whites, and Hispanics had an AOR of 1.21 (95% CI 1.16-1.26) compared to non-Hispanics. Among census tract-based determinants, those living in a tract with ≥20% vs <5% of persons living below poverty had an AOR of 1.31 (95% CI 1.16-1.47), those living in a tract with ≥5% vs <5% of persons living in crowded conditions had an AOR of 1.17 (95% CI 1.11-1.23), and those living in a tract with ≥40% vs <5% female heads of household had an AOR of 1.32 (95% CI 1.25-1.40). CONCLUSION: Census tract-based determinants account for 11% of the variability in influenza hospitalization.
Assuntos
Censos , Hospitalização/estatística & dados numéricos , Influenza Humana/epidemiologia , Vigilância da População , Fatores Socioeconômicos , Adolescente , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Idoso , Criança , Pré-Escolar , Características da Família , Feminino , Hospitalização/economia , Humanos , Influenza Humana/mortalidade , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Pobreza , Regressão Psicológica , Estados Unidos/epidemiologia , Adulto JovemRESUMO
The present research aims to more fully explore the issues of performance differences in higher education assessment, particularly in the context of a common measure taken to address them. The rationale for the study is that, while performance differences in written examinations are relatively well researched, few studies have examined the efficacy of anonymous marking in reducing these performance differences, particularly in modern student populations. By examining a large archive (N = 30674) of assessment data spanning a twelve-year period, the relationship between assessment marks and factors such as ethnic group, gender and socio-environmental background was investigated. In particular, analysis focused on the impact that the implementation of anonymous marking for assessment of written examinations and coursework has had on the magnitude of mean score differences between demographic groups of students. While group differences were found to be pervasive in higher education assessment, these differences were observed to be relatively small in practical terms. Further, it appears that the introduction of anonymous marking has had a negligible effect in reducing them. The implications of these results are discussed, focusing on two issues, firstly a defence of examinations as a fair and legitimate form of assessment in Higher Education, and, secondly, a call for the re-examination of the efficacy of anonymous marking in reducing group performance differences.
Assuntos
Avaliação Educacional/métodos , Avaliação Educacional/normas , Estudantes/estatística & dados numéricos , Povo Asiático , População Negra , Feminino , Humanos , Masculino , Regressão Psicológica , Fatores Socioeconômicos , População BrancaRESUMO
Separate literatures have related volunteering to health gains and income gains. We study the association between volunteering, income and health within one statistical framework. A state-of-the-art mediation analysis is conducted on data concerning the health, volunteering and sociodemographic characteristics of 42926 individuals within 29 European countries. We find that volunteering is positively associated to self-rated health. This association is partially mediated by household income.
Assuntos
Nível de Saúde , Renda , Voluntários , Europa (Continente) , Feminino , Humanos , Masculino , Modelos Estatísticos , Regressão Psicológica , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: The aim of the present study was to investigate non-clinical work conducted by Australian doctors. METHODS: This study was an exploratory descriptive study using data from Wave 5 of the Medicine in Australia: Balancing Employment and Life (MABEL) longitudinal survey, collected in 2012 from Australian medical practitioners (2200 general practitioners (GPs), 3455 specialists, 1270 specialists in training and 1656 hospital non-specialists). The main outcome measure was the number of hours worked per week in non-clinical work. Regression analysis was used to determine associations between non-clinical activities (i.e. education-related, management and administration and other) and personal and professional characteristics, including age, gender, job and life satisfaction, total clinical working hours, sector of practice (public or private) and doctor type. RESULTS: Australian doctors spend an average of just under 7 h per week, or 16% of their working time, on non-clinical activities. Doctors who worked more hours on non-clinical activities overall, and in education-related and management and administration specifically, were male, younger, had lower life satisfaction and generally spent fewer hours on clinical work. Lower job satisfaction was associated with longer management and administration hours, but not with time spent in education-related activities. Specialists were more likely to work long non-clinical hours, whereas GPs were more likely to report none. Hospital non-specialists reported relatively high management and administration hours. CONCLUSIONS: Further work is required to better understand the full range of non-clinical activities doctors are involved in and how this may impact future workforce projections.
Assuntos
Pessoal Administrativo , Educação Continuada , Médicos , Ensino , Pessoal Administrativo/estatística & dados numéricos , Adulto , Austrália , Educação Continuada/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Organização e Administração , Satisfação Pessoal , Regressão Psicológica , Inquéritos e Questionários , Ensino/estatística & dados numéricosRESUMO
AIM: Patient perception measures are gaining increasing interest among scholars and practitioners. The aim of this study was to empirically examine a conceptual model of patient-centred care using patient perception survey data. BACKGROUND: Patient-centred care is one of the Institute of Medicine's objectives for improving health care in the 21st century. Patient interviews conducted by the Picker Institute/Commonwealth Fund in the 1980s resulted in a theoretical model and survey questions with dimensions and attributes patients defined as patient-centered. METHOD: The present study used survey data from patients with overnight visits at 142 U.S. hospitals. RESULTS: Regression analysis found significant support for the theoretical model. Perceptions of emotional support had the strongest relationship with overall care ratings. Coordination of care, and physical comfort were strongly related as well. CONCLUSION: Understanding how patients experience their care can help improve understanding of what patients believe is patient-centred, and of how care processes relate to important patient outcomes.
Assuntos
Modelos Teóricos , Assistência Centrada no Paciente/organização & administração , Percepção , Adulto , Idoso , Comunicação , Continuidade da Assistência ao Paciente/organização & administração , Comportamento Cooperativo , Emoções , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/epidemiologia , Satisfação do Paciente , Regressão Psicológica , Reprodutibilidade dos Testes , Fatores Socioeconômicos , Estados UnidosRESUMO
There have been more than 90 hand and upper extremity transplants performed worldwide. Functional and sensory outcomes have been reported in several studies, but little is known about the psychosocial outcomes. A comprehensive systematic literature review was performed, addressing the psychosocial impact of reconstructive hand transplantation. This review provides an overview of psychosocial evaluation protocols and identifies standards in this novel and exciting field. Essentials of the psychosocial assessment are discussed and a new protocol, the 'Chauvet Protocol', representing a standardized assessment protocol for future multicenter psychosocial trials is being introduced.
Assuntos
Transplante de Mão/psicologia , Procedimentos de Cirurgia Plástica/psicologia , Humanos , Qualidade de Vida , Regressão PsicológicaRESUMO
We describe the relationship between immigrant status and self-rated health around the world, both in raw descriptive statistics and in models controlling for individual characteristics. Using the World Values Survey (1981-2005), we analyze data from 32 different countries worldwide. We estimate four regression models per country. The basic model tests mean differences in self-rated health. Additional models add demographic and social class controls. Introduction of control variables (most particularly, age) changes the results dramatically. In the final model, net of controls, only two countries show poorer immigrant health and three countries show better immigrant health. The multivariate regression models net of controls show few differences in health status between immigrants and the native born. The age structure of immigrant populations is an important mediator of differences in health status compared to the native-born population.
Assuntos
Emigrantes e Imigrantes , Inquéritos Epidemiológicos , Internacionalidade , Vigilância da População , Adulto , Feminino , Disparidades nos Níveis de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Regressão Psicológica , Autorrelato , Distribuição por SexoRESUMO
A flexible and simple Bayesian decision-theoretic design for dose-finding trials is proposed in this paper. In order to reduce the computational burden, we adopt a working model with conjugate priors, which is flexible to fit all monotonic dose-toxicity curves and produces analytic posterior distributions. We also discuss how to use a proper utility function to reflect the interest of the trial. Patients are allocated based on not only the utility function but also the chosen dose selection rule. The most popular dose selection rule is the one-step-look-ahead (OSLA), which selects the best-so-far dose. A more complicated rule, such as the two-step-look-ahead, is theoretically more efficient than the OSLA only when the required distributional assumptions are met, which is, however, often not the case in practice. We carried out extensive simulation studies to evaluate these two dose selection rules and found that OSLA was often more efficient than two-step-look-ahead under the proposed Bayesian structure. Moreover, our simulation results show that the proposed Bayesian method's performance is superior to several popular Bayesian methods and that the negative impact of prior misspecification can be managed in the design stage.
Assuntos
Teorema de Bayes , Ensaios Clínicos como Assunto/métodos , Relação Dose-Resposta a Droga , Dose Máxima Tolerável , Projetos de Pesquisa , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Ensaios Clínicos como Assunto/normas , Simulação por Computador , Citotoxinas/administração & dosagem , Citotoxinas/farmacocinética , Teoria da Decisão , Humanos , Modelos Logísticos , Regressão Psicológica , Estatísticas não ParamétricasRESUMO
The federal child-care subsidy program represents one of the government's largest investments in early care and education, but little is known about whether it increases low-income children's access to higher quality child care. This study used newly available nationally representative data on 4-year-old children (N = 750) to investigate whether subsidy receipt elevates child-care quality. Results indicate that subsidy recipients use higher quality care compared to nonrecipients who use no other publicly funded care, but lower quality care compared to nonrecipients who instead use Head Start or public pre-k. Findings suggest that subsidies may have the potential to enhance care quality but that parents who use subsidies are not accessing the highest quality care available to low-income families.
Assuntos
Serviços de Saúde da Criança/economia , Proteção da Criança/economia , Acessibilidade aos Serviços de Saúde/economia , Assistência Pública , Serviços de Saúde da Criança/normas , Pré-Escolar , Escolaridade , Características da Família , Feminino , Humanos , Masculino , Satisfação Pessoal , Pobreza , Pontuação de Propensão , Qualidade da Assistência à Saúde , Regressão Psicológica , Fatores Socioeconômicos , Estados UnidosRESUMO
BACKGROUND: The last decade in Finland has seen a vast increase both in involuntary psychiatric treatment of adolescents and in the numbers of adolescents taken into care under the Child Welfare Act. Moreover, the variation in figures between different hospital districts is remarkable. The reasons for this are not known, but it cannot be due to variation in the epidemiology of mental disorders in minors. AIM: The aim of the study was to explore features associated with compulsory care of adolescents at regional level by comparing two hospital districts clearly differing in this regard. The characteristics of involuntarily treated adolescents and adolescents taken into care, the resources and structures of adolescent psychiatric services and child welfare services, and the environmental factors associated with adolescent well-being and adaptation, such as indicators of social deprivation of families were all considered. MATERIALS AND METHODS: For the present study, 2 out of the 22 hospital districts in Finland were selected, one using compulsory psychiatric care and taking into care of 13-17-year olds above and the other below the average in Finland. Register data on patient characteristics, services, and social deprivation were used. Absolute and population adjusted figures (95% confidence intervals) from the variables are given. The differences in incidences between health care districts were compared using Poisson regression analysis. RESULTS: Proportions of divorces, single parent families, social exclusion and outpatient mental health service use, and detoxification treatment use of adults were higher in the health care district with above average coercion figures than in the area with below average coercion figures. The numbers of adolescent psychiatric outpatient visits were higher in the health care district with coercion figures below average despite the fact that the number of positions in adolescent outpatient services was lower than in the health care district with above average coercion figures. CONCLUSION: Factors other than the characteristics of the adolescents themselves are associated with use of compulsory care on them, although an ecological study design cannot establish causality.
Assuntos
Psiquiatria do Adolescente/estatística & dados numéricos , Serviços de Saúde Mental/organização & administração , Serviços de Saúde Mental/estatística & dados numéricos , Menores de Idade , Sistema de Registros/estatística & dados numéricos , Adolescente , Psiquiatria do Adolescente/organização & administração , Coerção , Internação Compulsória de Doente Mental/estatística & dados numéricos , Relações Familiares , Feminino , Finlândia , Hospitais de Distrito/estatística & dados numéricos , Humanos , Incidência , Masculino , Transtornos Mentais/classificação , Distribuição de Poisson , Carência Psicossocial , Análise de Regressão , Regressão Psicológica , Fatores SocioeconômicosRESUMO
Confidential care is an essential element of quality adolescent primary care. Twenty-one primary care providers tracked provision of confidential care (time alone with adolescent) and sexual health services in clinics serving low-income, primarily minority communities. Over 144 visits attended by a parent, 68% involved time alone with the adolescent. Time alone was 18 times higher for physicals than same day or walk-in visits, and 3 times higher if teen presented a sex complaint. Provision of sexual health services was 3 times higher for those who had time alone with the provider, especially among girls. The results indicate some missed opportunities to deliver needed services to at-risk populations, especially among boys.
Assuntos
Confidencialidade , Grupos Minoritários/estatística & dados numéricos , Relações Médico-Paciente , Áreas de Pobreza , Atenção Primária à Saúde/estatística & dados numéricos , Educação Sexual/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Adolescente , Criança , Centros Comunitários de Saúde , Feminino , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , New York , Exame Físico , Estudos Prospectivos , Regressão Psicológica , Fatores Sexuais , Estatística como AssuntoRESUMO
Errors in nursing practice pose a continuing threat to patient safety. A descriptive, correlational study was conducted to examine the definitions, circumstances, and perceived causes of intraoperative nursing errors; reactions of perioperative nurses to intraoperative nursing errors; and the relationships among coping with intraoperative nursing errors, emotional distress, and changes in practice made as a result of error. The results indicate that strategies of accepting responsibility and using self-control are significant predictors of emotional distress. Seeking social support and planful problem solving emerged as significant predictors of constructive changes in practice. Most predictive of defensive changes was the strategy of escape/avoidance.
Assuntos
Adaptação Psicológica , Atitude do Pessoal de Saúde , Erros Médicos , Recursos Humanos de Enfermagem Hospitalar/psicologia , Enfermagem de Centro Cirúrgico , Aprendizagem da Esquiva , Esgotamento Profissional/etiologia , Esgotamento Profissional/psicologia , Causalidade , Feminino , Humanos , Cuidados Intraoperatórios/enfermagem , Masculino , Erros Médicos/enfermagem , Erros Médicos/prevenção & controle , Pessoa de Meia-Idade , Modelos de Enfermagem , Modelos Psicológicos , Pesquisa Metodológica em Enfermagem , Recursos Humanos de Enfermagem Hospitalar/educação , Recursos Humanos de Enfermagem Hospitalar/organização & administração , Enfermagem de Centro Cirúrgico/educação , Enfermagem de Centro Cirúrgico/organização & administração , Resolução de Problemas , Regressão Psicológica , Gestão de Riscos/organização & administração , Apoio Social , Estatísticas não Paramétricas , Inquéritos e QuestionáriosRESUMO
In a previous study we quantified the effect of multisensory integration on the latency and accuracy of saccadic eye movements toward spatially aligned audiovisual (AV) stimuli within a rich AV-background (Corneil et al. in J Neurophysiol 88:438-454, 2002). In those experiments both stimulus modalities belonged to the same object, and subjects were instructed to foveate that source, irrespective of modality. Under natural conditions, however, subjects have no prior knowledge as to whether visual and auditory events originated from the same, or from different objects in space and time. In the present experiments we included these possibilities by introducing various spatial and temporal disparities between the visual and auditory events within the AV-background. Subjects had to orient fast and accurately to the visual target, thereby ignoring the auditory distractor. We show that this task belies a dichotomy, as it was quite difficult to produce fast responses (<250 ms) that were not aurally driven. Subjects therefore made many erroneous saccades. Interestingly, for the spatially aligned events the inability to ignore auditory stimuli produced shorter reaction times, but also more accurate responses than for the unisensory target conditions. These findings, which demonstrate effective multisensory integration, are similar to the previous study, and the same multisensory integration rules are applied (Corneil et al. in J Neurophysiol 88:438-454, 2002). In contrast, with increasing spatial disparity, integration gradually broke down, as the subjects' responses became bistable: saccades were directed either to the auditory (fast responses), or to the visual stimulus (late responses). Interestingly, also in this case responses were faster and more accurate than to the respective unisensory stimuli.
Assuntos
Atenção , Desempenho Psicomotor , Movimentos Sacádicos , Detecção de Sinal Psicológico , Estimulação Acústica , Adulto , Humanos , Masculino , Estimulação Luminosa , Psicofísica , Tempo de Reação , Regressão Psicológica , Localização de Som , Análise e Desempenho de Tarefas , Fatores de Tempo , Adulto JovemRESUMO
The Personality Assessment Inventory's (PAI's) ability to predict psychopathic personality features, as assessed by the Psychopathy Checklist-Revised (PCL-R), was examined. To investigate whether the PAI Antisocial Features (ANT) Scale and subscales possessed incremental validity beyond other theoretically relevant PAI scales, optimized regression equations were derived in a sample of 281 Canadian federal offenders. ANT, or ANT-Antisocial Behavior (ANT-A), demonstrated unique variance in regression analyses predicting PCL-R total and Factor 2 (Lifestyle Impulsivity and Social Deviance) scores, but only the Dominance (DOM) Scale was retained in models predicting Factor 1 (Interpersonal and Affective Deficits). Attempts to cross-validate the regression equations derived from the first sample on a sample of 85 U.S. sex offenders resulted in considerable validity shrinkage, with the ANT Scale in isolation performing comparably to or better than the statistical models for PCL-R total and Factor 2 scores. Results offer limited evidence of convergent validity between the PAI and the PCL-R.
Assuntos
Transtorno da Personalidade Antissocial/diagnóstico , Crime/psicologia , Inventário de Personalidade , Prisioneiros/psicologia , Psicometria/instrumentação , Psicopatologia/instrumentação , Adolescente , Adulto , Idoso , Transtorno da Personalidade Antissocial/etnologia , Transtorno da Personalidade Antissocial/psicologia , Canadá , Crime/etnologia , Cultura , Geografia , Humanos , Masculino , Pessoa de Meia-Idade , Regressão Psicológica , Fatores de Risco , Estados UnidosRESUMO
The unconscious is implicated in Romantic and liberal discourses of autonomous individuality, and these insinuate themselves in complex ways into Freud's descriptions of the psyche. Focusing on "The Interpretation of Dreams," the paper examines the fortunes of notions such as autonomy and selfhood, beginning with a consideration of Freud's languages of determinism, and moving on to the theory of the wish. In particular it examines ambiguities in the accounts of sexual and egotistical wishes, and in the portrayal of egotism itself. It is suggested that behind such ambiguities lies a deeper ambivalence in Freud's understanding of the I and its autonomy, which is in turn related to indeterminacies in the liberal concept of self. These ambiguities are further explored via the unstable political metaphors Freud attaches to the father-son relationship. The paper argues that such instabilities in the idea of selfhood radically unsettle the terms of the psychoanalytic account.
Assuntos
Antropologia Cultural , Sonhos , Individualidade , Idioma , Autonomia Pessoal , Teoria Psicanalítica , Inconsciente Psicológico , Antropologia Cultural/educação , Antropologia Cultural/história , Autoritarismo , Sonhos/fisiologia , Sonhos/psicologia , Europa (Continente)/etnologia , Teoria Freudiana/história , História do Século XIX , História do Século XX , Metáfora , Teoria da Construção Pessoal , Filosofia/história , Psicanálise/educação , Psicanálise/história , Publicações/economia , Publicações/história , Regressão Psicológica , Repressão PsicológicaAssuntos
Atividades Cotidianas , Adaptação Psicológica , Doença de Alzheimer/complicações , Doença de Alzheimer/psicologia , Idoso , Doença de Alzheimer/fisiopatologia , Ansiedade/etiologia , Atitude Frente a Saúde , Depressão/etiologia , Alucinações/etiologia , Necessidades e Demandas de Serviços de Saúde , Humanos , Memória , Transtornos da Memória/etiologia , Transtornos Mentais/etiologia , Qualidade de Vida , Regressão Psicológica , Comportamento EstereotipadoRESUMO
OBJECTIVE: We performed a retrospective cohort study in South Korea to clarify the role of occupational exposure, especially to welding, in the etiology of Parkinson's disease (PD). METHODS: We constructed a database of subjects classified into an exposure group (blue-collar workers) and a non-exposure group (white-collar workers) in two shipbuilding companies. Jobs of blue-collar workers were categorized into the first group of welding, the second group of fitting, grinding and finishing, cutting, and the other group. To determine new cases of PD during the follow-up period (1992-2003), we used the physician billing claims database of the National Health Insurance Corporation. For the detected PD patients in the physician billing claims database, a neurologist in our research team confirmed the appropriateness of each diagnosis by reviewing medical charts. Based on the review, we confirmed the numbers of new cases of PD and calculated the relative risk (RR) and the 95% confidence intervals (CI) by Cox regression analysis. RESULTS: In a backward selection procedure, 'age' was a significant independent variable but exposure was not. Furthermore, the RR in welders (high exposure group) was also insignificant and less than that in others (very low exposure group). CONCLUSION: This longitudinal study of shipbuilding workers supports our previous case-control studies suggesting that exposure to manganese does not increase the risk of PD.
Assuntos
Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Ocupações/estatística & dados numéricos , Doença de Parkinson/epidemiologia , Doença de Parkinson/etiologia , Idade de Início , Estudos de Coortes , Intervalos de Confiança , Humanos , Seguro de Serviços Médicos/estatística & dados numéricos , Coreia (Geográfico)/epidemiologia , Masculino , Manganês/toxicidade , Doenças Profissionais/epidemiologia , Exposição Ocupacional/análise , Regressão Psicológica , Estudos Retrospectivos , Risco , SoldagemRESUMO
BACKGROUND: Echocardiography combining Doppler and two-dimensional data is recommended for quantitative assessments of valvular regurgitation. We applied a new method to calculate the mitral annulus (MA) area in combination with multiple sample sites. Individuals without regurgitation in whom the valvular and left ventricular stroke volumes (SV) should be identical were investigated in order to evaluate the feasibility in quantitative assessments of valvular regurgitation. METHODS AND RESULTS: Twenty subjects were included. Flow velocity was registered with pulsed Doppler in different positions in the left ventricular outflow tract (LVOT) and in the MA. The MA area was assumed to be either circular, using the diameter from a four-chamber projection, or elliptic, using the major diameter from a parasternal short axis and a minor diameter from an apical long axis. Left ventricular (LV) SV was measured from LV volumes using the biplane method. The overall difference between LVOT SV and mitral SV using one centrally located measurement and elliptic MA was 3.2+/-15.6 ml (P=0.38), 0.9+/-15.7 ml between LVOT SV and LV SV (P=0.80) and -2.2+/-15.2 ml between mitral SV and LV SV (P=0.54). The corresponding standard deviation of the differences as a percentage of the mean value was 24%, 25% and 23%. A circular shaped MA overestimated the mitral SV compared with LVOT SV (P=0.009) and LV SV (P=0.004). Increasing the number of sample sites in the LVOT or MA did not further improve the results. CONCLUSION: Doppler and two-dimensional echocardiography can be used to quantify regurgitation in groups of patients. In individual patients the wide distribution of differences between valves and LV SV implies that the method should be used in conjunction with other Doppler echocardiographic parameters.
Assuntos
Valva Aórtica/diagnóstico por imagem , Ecocardiografia Doppler , Valva Mitral/diagnóstico por imagem , Volume Sistólico/fisiologia , Adulto , Valva Aórtica/fisiopatologia , Feminino , Humanos , Masculino , Valva Mitral/fisiopatologia , Variações Dependentes do Observador , Regressão PsicológicaRESUMO
We developed a simple, non-invasive, and affordable method for estimating net energy expenditure (EE) in children performing activities at high altitude. A regression-based method predicts net oxygen consumption (VO(2)) from net heart rate (HR) along with several covariates. The method is atypical in that, the "net" measures are taken as the difference between exercise and resting VO(2) (DeltaVO(2)) and the difference between exercise and resting HR (DeltaHR); DeltaVO(2) partially corrects for resting metabolic rate and for posture, and DeltaHR controls for inter-individual variation in physiology and for posture. Twenty children between 8 and 13 years of age, born and raised in La Paz, Bolivia (altitude 3,600m), made up the reference sample. Anthropometric measures were taken, and VO(2) was assessed while the children performed graded exercise tests on a cycle ergometer. A repeated-measures prediction equation was developed, and maximum likelihood estimates of parameters were found from 75 observations on 20 children. The final model included the variables DeltaHR, DeltaHR(2), weight, and sex. The effectiveness of the method was established using leave-one-out cross-validation, yielding a prediction error rate of 0.126 for a mean DeltaVO(2) of 0.693 (SD 0.315). The correlation between the predicted and measured DeltaVO(2) was r = 0.917, suggesting that a useful prediction equation can be produced using paired VO(2) and HR measurements on a relatively small reference sample. The resulting prediction equation can be used for estimating EE from HR in free-living children performing habitual activities in the Bolivian Andes.