Página 1 dos resultados de 257 itens digitais encontrados em 0.003 segundos

Optimum size in grid soil sampling for variable rate application in site-specific management; Tamanho ideal em grades de amostragem de solos para aplicação em taxa variável em manejo localizado

NANNI, Marcos Rafael; POVH, Fabrício Pinheiro; DEMATTÊ, José Alexandre Melo; OLIVEIRA, Roney Berti de; CHICATI, Marcelo Luiz; CEZAR, Everson
Fonte: São Paulo - Escola Superior de Agricultura Luiz de Queiroz Publicador: São Paulo - Escola Superior de Agricultura Luiz de Queiroz
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.26%
The importance of understanding spatial variability of soils is connected to crop management planning. This understanding makes it possible to treat soil not as a uniform, but a variable entity, and it enables site-specific management to increase production efficiency, which is the target of precision agriculture. Questions remain as the optimum soil sampling interval needed to make site-specific fertilizer recommendations in Brazil. The objectives of this study were: i) to evaluate the spatial variability of the main attributes that influence fertilization recommendations, using georeferenced soil samples arranged in grid patterns of different resolutions; ii) to compare the spatial maps generated with those obtained with the standard sampling of 1 sample ha-1, in order to verify the appropriateness of the spatial resolution. The attributes evaluated were phosphorus (P), potassium (K), organic matter (OM), base saturation (V%) and clay. Soil samples were collected in a 100 × 100 m georeferenced grid. Thinning was performed in order to create a grid with one sample every 2.07, 2.88, 3.75 and 7.20 ha. Geostatistical techniques, such as semivariogram and interpolation using kriging, were used to analyze the attributes at the different grid resolutions. This analysis was performed with the Vesper software package. The maps created by this method were compared using the kappa statistics. Additionally...

Tradução para o português e validação de instrumento para triagem de pacientes em serviço de emergência: Canadian Triage and Acuity Scale (CTAS).; Translation into Portuguese and validation of a triage tool to be applied to patients in emergency department: Canadian Triage and Acuity Scale (CTAS).

Pires, Patrícia da Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 10/02/2004 Português
Relevância na Pesquisa
26.45%
A triagem de pacientes em serviços de emergência constitui um campo de atuação para o enfermeiro, entretanto faltam instrumentos que possam ser utilizados para classificar a gravidade do paciente e a adequação de recursos ao seu atendimento. A finalidade deste estudo é obter um instrumento confiável que possa classificar as condições do paciente, melhorando a qualidade da assistência e diminuindo os riscos decorrentes da espera para o atendimento.O presente estudo teve como objetivo validar a escala de classificação de pacientes “Canadian Triage and Acuity Scale” (CTAS). Esta escala classifica o paciente em cinco níveis (1 a 5), respectivamente: situações de risco de vida, emergência, urgência, semi-urgência, não urgência. O instrumento foi submetido à tradução, versão à língua de origem, avaliação semântica, idiomática , cultural e conceitual. Após esta fase de validação, realizou-se a fase de confiabilidade interobservadores, entre a pesquisadora e duas enfermeiras voluntárias. A concordância expressa pelo índice kappa, foi de 0,739. Após esta etapa a pesquisadora avaliou 127 pacientes atendidos em um serviço privado, utilizando a CTAS. Houve predominância de pacientes classificados como nível 4 (46...

Reliability of the interpretation of coronary angiography by the simple visual method

Guimarães,Jorge Augusto Nunes; Victor,Edgar Guimarães; Leite,Maria do Rosário de Britto; Gomes,José Maria Pereira; Victor Filho,Edgar; Reyes Liveras,Jesus
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2000 Português
Relevância na Pesquisa
36.12%
OBJECTIVE: Evaluation of inter and intraobserver reproducibility of by the visual method interpretation of cineangiogram in a clinically based context. METHODS: Five interventional cardiologists analyzed 11 segments of 8 coronary cineangiograms at a two month apart sessions. The percent luminal reduction by the lesions were analyzed by two different classifications: in one (A) the lesions were graded in 0% = absent, 1-50% = mild, 51 - 69 = moderate, and > or = 70% = severe; the other classification (B) was a dichotomic one : <70% = nonsignificant and > or = 70%=significant lesions. The agreement were measured by the kappa (k) index. RESULTS: Interobserver agreement was moderate for classification A (1st measurement, k = 0.36 -- 0.63, k m = 0.49; 2nd measurement, k = 0.39-0.68, k m = 0.52) and good for classification B (1st measurement, k = 0.55-0.73, k m = 0.63; 2nd measurement, k = 0.37-0.82, k m = 0.61). Intraobserver levels of agreement were k = 0.57-0.95 for classification A and 0.62-1.0 for classification B. CONCLUSION: The higher level of reproducibility obtained by adopting the dichotomous criteria usually considered for ischemic limits demonstrates that in the present clinical context, the reliability of the simple visual method is adequate for the identification of patients with clinically significant lesions and candidates for myocardial revascularization procedures.

Optimum size in grid soil sampling for variable rate application in site-specific management

Nanni,Marcos Rafael; Povh,Fabrício Pinheiro; Demattê,José Alexandre Melo; Oliveira,Roney Berti de; Chicati,Marcelo Luiz; Cezar,Everson
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2011 Português
Relevância na Pesquisa
36.12%
The importance of understanding spatial variability of soils is connected to crop management planning. This understanding makes it possible to treat soil not as a uniform, but a variable entity, and it enables site-specific management to increase production efficiency, which is the target of precision agriculture. Questions remain as the optimum soil sampling interval needed to make site-specific fertilizer recommendations in Brazil. The objectives of this study were: i) to evaluate the spatial variability of the main attributes that influence fertilization recommendations, using georeferenced soil samples arranged in grid patterns of different resolutions; ii) to compare the spatial maps generated with those obtained with the standard sampling of 1 sample ha-1, in order to verify the appropriateness of the spatial resolution. The attributes evaluated were phosphorus (P), potassium (K), organic matter (OM), base saturation (V%) and clay. Soil samples were collected in a 100 × 100 m georeferenced grid. Thinning was performed in order to create a grid with one sample every 2.07, 2.88, 3.75 and 7.20 ha. Geostatistical techniques, such as semivariogram and interpolation using kriging, were used to analyze the attributes at the different grid resolutions. This analysis was performed with the Vesper software package. The maps created by this method were compared using the kappa statistics. Additionally...

Kappa statistics as indicators of quality assurance in histopathology and cytopathology.

Cross, S S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1996 Português
Relevância na Pesquisa
36.3%
Kappa statistics are widely-used to assess performance in quality assurance schemes. Low values, however, are difficult to interpret, especially when confidence intervals have not been calculated. A model of a dichotomous decision in pathology (benignancy or malignancy in fine needle aspirates of the breast) was used to calculate kappa statistics (with confidence limits) for increasing false positive rates. It was found that the level at which the upper 95% confidence interval for the kappa statistic fell below 1 was an insensitive method of detecting unsatisfactory performance as at that level the false positive rate was unacceptably high (> 1%) for all populations of specimens less than 800 in number. Either large populations of samples are required in quality assurance schemes which use kappa statistics (which may well be impractical) or other methods of assessing performance, possibly with weighted outcomes, are required.

The need for specialist review of pathology in paediatric cancer.

Parkes, S. E.; Muir, K. R.; Cameron, A. H.; Raafat, F.; Stevens, M. C.; Morland, B. J.; Barber, P. C.; Carey, M. P.; Fox, H.; Jones, E. L.; Marsden, H. B.; Pincott, J. R.; Pringle, J. A.; Reid, H.; Rushton, D. I.; Starkie, C. M.; Whitwell, H. L.; Wright,
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //1997 Português
Relevância na Pesquisa
26.36%
A retrospective histopathological review of 2104 cases of solid tumour was carried out to assess the variability in diagnosis of childhood cancer. Cases were subject to three independent, concurrent opinions from a national panel of specialist pathologists. The conformity between them was analysed using the percentage of agreement and the kappa statistic (kappa), a measure of the level of agreement beyond that which could occur by chance alone, and weighted kappa (w kappa), which demonstrates the degree of variation between opinions. The major groupings of the Birch-Marsden classification were used within which tumours were assigned for kappa analysis according to the clinical significance of the differential diagnoses. The mean agreement for all tumours together was 90%; kappa = 0.82, w kappa = 0.82. Retinoblastoma achieved the highest kappa value (1.0) and lymphoma the lowest (0.66). Of the cases, 16.5% had their original diagnoses amended and the panel confirmed the original diagnosis of paediatric pathologists in 89% of cases compared with 78% for general pathologists. The varying levels of agreement between experts confirm the difficulty of diagnosis in some tumour types, suggesting justification for specialist review in most diagnoses. Specialist training in paediatric pathology is also recommended.

Effect of change of reference standard to NHANES III on interpretation of spirometric ‘abnormality’

Sood, Akshay; Dawson, Beth K; Henkle, Joseph Q; Hopkins-Price, Patricia; Qualls, Clifford
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.5%
The American Thoracic Society has recently recommended the use of NHANES III spirometric reference standard in the United States. The objective of this study was to better quantify the well-known ‘problem’ of the change in interpretation of spirometry, as a consequence of the change from the other commonly used reference standards (Morris, Kory, Crapo, Knudson 1976, and Knudson 1983) to NHANES III. This is a cross-sectional study of spirometries of 1,106 non-Hispanic Caucasian American adults, including 234 subjects with obstructive and 228 subjects with restrictive spirometric ‘abnormalities’. A weighted Kappa statistic was used to evaluate the level of agreement between NHANES III and other commonly used reference standards. The level of agreement in assessing the presence of an ‘abnormality’ was poor to moderate – values of Kappa statistic ranged from 0.13 to 0.46. There was however, good to very good level of agreement in assessing the severity of the ‘abnormality’ – values of Kappa statistic ranged from 0.61 to 0.91. This study better quantifies the well-known differences in the interpretation of spirometric ‘abnormalities’ as a consequence of the recommended change of reference standard to NHANES III, which in turn may cause confusion among patients and their treating physicians.

A study of the test–retest reliability of the self-perceived general recovery and self-perceived change in neck pain questions in patients with recent whiplash-associated disorders

Ngo, Trung; Stupar, Maja; Côté, Pierre; Boyle, Eleanor; Shearer, Heather
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.4%
The objectives of this study were to determine the test–retest reliability of two self-perceived recovery questions in patients with recent whiplash-associated disorders (WAD), and to assess whether remembering previous answers influences reliability. The self-perceived general recovery and self-perceived change in neck pain questions were administered to 46 patients with recent WAD 6 weeks after recruitment and again 3–5 days later. At follow-up, we also asked participants if they remembered their previous answers. We used the intra-class correlation coefficients (ICC) to measure the reliability of the original ordinal response structure and kappa statistics for dichotomized responses. The ICC [95% confidence intervals (CI)] for the general recovery and for the change in neck pain questions were 0.70 (0.60–0.80) and 0.80 (0.72–0.87), respectively. The kappa statistic (95% CI) for the general recovery question was 0.81 (0.64–0.99) when recovery was defined as “completely better” or “much improved”. The kappa statistic (95% CI) for the change in neck pain question was 0.80 (0.62–0.99) when recovery was defined as “very much better” or “better”. Our analysis suggests that the test–retest reliability may be higher for participants who remembered their previous responses. In conclusion...

Reproducibility of IVUS Border Detection for Carotid Atherosclerotic Plaque Assessment

Siewiorek, Gail M.; Loghmanpour, Natasha A.; Winston, Brion M.; Wholey, Mark H.; Finol, Ender A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.4%
Plaque composition is a potentially important diagnostic feature for carotid artery stenting (CAS). The purpose of this investigation is to evaluate the reproducibility of manual border correction in intravascular ultrasound with virtual histology (VH IVUS) images. Three images each were obtained from 51 CAS datasets on which automatic border detection was corrected manually by two trained observers. Plaque was classified using the definitions from the CAPITAL (Carotid Artery Plaque Virtual Histology Evaluation) study, listed in order from least to most pathological: no plaque, pathological intimal thickening, fibroatheroma, fibrocalcific, calcified fibroatheroma, thin-cap fibroatheroma, and calcified thin-cap fibroatheroma. Inter-observer variability was quantified using both weighted and unweighted Kappa statistics. Bland-Altman analysis was used to compare the cross-sectional areas of the vessel and lumen. Agreement using necrotic core percentage as the criterion was evaluated using the unweighted Kappa statistic. Agreement between classifications of plaque type was evaluated using the weighted Kappa statistic. There was substantial agreement between the observers based on necrotic core percentage (κ = 0.63), while the agreement was moderate (κquadratic = 0.60) based on plaque classification. Due to the time-consuming nature of manual border detection...

The validity of questionnaire-based diagnoses: the third Nord-Trøndelag Health Study 2006–2008

Hagen, Knut; Zwart, John-Anker; Aamodt, Anne Hege; Nilsen, Kristian Bernhard; Bråthen, Geir; Helde, Grethe; Stjern, Marit; Tronvik, Erling A.; Stovner, Lars Jacob
Fonte: Springer Milan Publicador: Springer Milan
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.5%
The Nord-Trøndelag Health Study (HUNT 3) performed in 2006–2008 is a replication of the cross-sectional survey from 1995 to 1997 (HUNT 2). The aim of the present study was to assess the sensitivity and specificity of questionnaire-based headache diagnoses using a personal interview by a neurologist as a gold standard. For the questionnaire-based status as headache sufferer, a sensitivity of 88%, a specificity of 86%, and a kappa statistic of 0.70 were found. Chronic headache, chronic tension-type headache (TTH), and medication overuse headache (MOH) were diagnosed with a specificity of ≥99%, and a kappa statistic of ≥0.73. Lower figures were found for the diagnoses of migraine and TTH. For individuals with headache ≥1 day per month, a sensitivity of 58% (migraine) and 96% (TTH), a specificity of 91 and 69%, and a kappa statistic of 0.54 and 0.44 were found, respectively. The specificity for migraine with aura was 95%. In conclusion, the HUNT 3-questionnaire is a valid tool for identifying headache sufferers, and diagnosing patients with chronic headache, including chronic TTH and MOH. The more moderate sensitivity for migraine and TTH makes the questionnaire-based diagnoses of migraine and TTH suboptimal for determining the prevalence. However...

Kappa statistic for the clustered dichotomous responses from physicians and patients

Kang, Chaeryon; Qaqish, Bahjat; Monaco, Jane; Sheridan, Stacey L.; Cai, Jianwen
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.31%
The bootstrap method for estimating the standard error of the kappa statistic in the presence of clustered data is evaluated. Such data arise, for example, in assessing agreement between physicians and their patients regarding their understanding of the physician-patient interaction and discussions. We propose a computationally efficient procedure for generating correlated dichotomous responses for physicians and assigned patients for simulation studies. The simulation result demonstrates that the proposed bootstrap method produces better estimate of the standard error and better coverage performance compared to the asymptotic standard error estimate that ignores dependence among patients within physicians with at least a moderately large number of clusters. An example of an application to a coronary heart disease prevention study is presented.

Interrater reliability: the kappa statistic

McHugh, Mary L.
Fonte: Croatian Society of Medical Biochemistry and Laboratory Medicine Publicador: Croatian Society of Medical Biochemistry and Laboratory Medicine
Tipo: Artigo de Revista Científica
Publicado em 15/10/2012 Português
Relevância na Pesquisa
46.55%
The kappa statistic is frequently used to test interrater reliability. The importance of rater reliability lies in the fact that it represents the extent to which the data collected in the study are correct representations of the variables measured. Measurement of the extent to which data collectors (raters) assign the same score to the same variable is called interrater reliability. While there have been a variety of methods to measure interrater reliability, traditionally it was measured as percent agreement, calculated as the number of agreement scores divided by the total number of scores. In 1960, Jacob Cohen critiqued use of percent agreement due to its inability to account for chance agreement. He introduced the Cohen’s kappa, developed to account for the possibility that raters actually guess on at least some variables due to uncertainty. Like most correlation statistics, the kappa can range from −1 to +1. While the kappa is one of the most commonly used statistics to test interrater reliability, it has limitations. Judgments about what level of kappa should be acceptable for health research are questioned. Cohen’s suggested interpretation may be too lenient for health related studies because it implies that a score as low as 0.41 might be acceptable. Kappa and percent agreement are compared...

Human brain atlas for automated region of interest selection in quantitative susceptibility mapping: application to determine iron content in deep gray matter structures

Lim, Issel Anne L.; Faria, Andreia V.; Li, Xu; Hsu, Johnny T.C.; Airan, Raag D.; Mori, Susumu; van Zijl, Peter C. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.45%
The purpose of this paper is to extend the single-subject Eve atlas from Johns Hopkins University, which currently contains diffusion tensor and T1-weighted anatomical maps, by including contrast based on quantitative susceptibility mapping. The new atlas combines a “deep gray matter parcellation map” (DGMPM) derived from a single-subject quantitative susceptibility map with the previously established “white matter parcellation map” (WMPM) from the same subject’s T1-weighted and diffusion tensor imaging data into an MNI coordinate map named the “Everything Parcellation Map in Eve Space,” also known as the “EvePM.” It allows automated segmentation of gray matter and white matter structures. Quantitative susceptibility maps from five healthy male volunteers (30 to 33 years of age) were coregistered to the Eve Atlas with AIR and Large Deformation Diffeomorphic Metric Mapping (LDDMM), and the transformation matrices were applied to the EvePM to produce automated parcellation in subject space. Parcellation accuracy was measured with a kappa analysis for the left and right structures of six deep gray matter regions. For multi-orientation QSM images, the Kappa statistic was 0.85 between automated and manual segmentation...

Multiple Category-Lot Quality Assurance Sampling: A New Classification System with Application to Schistosomiasis Control

Olives, Casey; Valadez, Joseph J.; Brooker, Simon J.; Pagano, Marcello
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.61%
Background: Originally a binary classifier, Lot Quality Assurance Sampling (LQAS) has proven to be a useful tool for classification of the prevalence of Schistosoma mansoni into multiple categories (≤10%, >10 and <50%, ≥50%), and semi-curtailed sampling has been shown to effectively reduce the number of observations needed to reach a decision. To date the statistical underpinnings for Multiple Category-LQAS (MC-LQAS) have not received full treatment. We explore the analytical properties of MC-LQAS, and validate its use for the classification of S. mansoni prevalence in multiple settings in East Africa. Methodology We outline MC-LQAS design principles and formulae for operating characteristic curves. In addition, we derive the average sample number for MC-LQAS when utilizing semi-curtailed sampling and introduce curtailed sampling in this setting. We also assess the performance of MC-LQAS designs with maximum sample sizes of n = 15 and n = 25 via a weighted kappa-statistic using S. mansoni data collected in 388 schools from four studies in East Africa. Principle Findings Overall performance of MC-LQAS classification was high (kappa-statistic of 0.87). In three of the studies, the kappa-statistic for a design with n = 15 was greater than 0.75. In the fourth study...

Reliability of medical record abstraction by non-physicians for orthopedic research

Mi, Michael Y; Collins, Jamie E; Lerner, Vladislav; Losina, Elena; Katz, Jeffrey N
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
46.45%
Background: Medical record review (MRR) is one of the most commonly used research methods in clinical studies because it provides rich clinical detail. However, because MRR involves subjective interpretation of information found in the medical record, it is critically important to understand the reproducibility of data obtained from MRR. Furthermore, because medical record review is both technically demanding and time intensive, it is important to establish whether trained research staff with no clinical training can abstract medical records reliably. Methods: We assessed the reliability of abstraction of medical record information in a sample of patients who underwent total knee replacement (TKR) at a referral center. An orthopedic surgeon instructed two research coordinators (RCs) in the abstraction of inpatient medical records and operative notes for patients undergoing primary TKR. The two RCs and the surgeon each independently reviewed 75 patients’ records and one RC reviewed the records twice. Agreement was assessed using the proportion of items on which reviewers agreed and the kappa statistic. Results: The kappa for agreement between the surgeon and each RC ranged from 0.59 to 1 for one RC and 0.49 to 1 for the other; the percent agreement ranged from 82% to 100% for one RC and 70% to 100% for the other. The repeated abstractions by the same RC showed high intra-rater agreement...

Studie zur Reliabilität und Validität von Kiefergelenksbefunden im OPT und MRT; Reliability and validity of radiograph findings in the TMJ in rotational panoramic radiogram and magnetic resonance imaging MRI

Seeger, Morten Philipp
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
Português
Relevância na Pesquisa
36.41%
Von 50 Patienten, die in funktionstherapeutischer Behandlung waren, wurden 52 MRT's der Kiefergelenke, als 1,0 Tesla Spinecho-Aufnahmen mit einer Oberflächenspule in angulierter Schichtführung und somit die in der Literatur für die exakte Kiefergelenksbeurteilung genannten Bedingungen erfüllen [21], sowie 51 OPT's im Standardprogramm aufgenommen. Je ein in der Kiefergelenksdiagnostik erfahrener und unerfahrener Radiologe sowie ein erfahrener und unerfahrener Zahnarzt haben diese Aufnahmen befundet. Die Beurteilung des Gelenkkopfes erfolgte in den etablierten knöchernen Kriterien Abflachung, Osteophyt und Erosion [9;13;18-20;27;40;45;50] in je 3 Grade, und die Beurteilung der Struktur sowie Lage des Diskus artikularis wurden in 5 Grade unterteilt. Es wurde die Übereinstimmung der Bewertungen unter den vier Untersucher mit dem Kappa nach Fleiss [13] und für den Vergleich zwischen den verschiedenen Untersuchergruppen das Kappa nach Cohen [7] berechnet. Dabei ergaben sich zwischen den vier Untersuchern am MRT Kappa Werte von 0,28-0,46 und am OPT von 0,35-0,49 , die damit nach der Einteilung von Landis und Koch [29] im geringen bis mäßigen Bereich lagen. Dies entspricht Untersuchungen mit vergleichbarer Bewerterzusammensetzung [9;34;37]. Daraus kann gefolgert werden...

Intraluminal impedance detects failure of pharyngeal bolus clearance during swallowing: a validation study in adults with dysphagia

Szczesniak, M.; Rommel, N.; Dinning, P.; Fuentealba, S.; Cook, I.; Omari, T.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
Relevância na Pesquisa
26.4%
Multichannel intraluminal impedance (MII) detects bolus flow through a healthy pharynx. The aim of this study was to determine whether the technique detects bolus flow and retention in patients with pharyngeal dysphagia; develop appropriate impedance-based criteria for assessing patients and to provide some preliminary insights into the clinical utility of the technique. Pharyngo-oesophageal pressure and impedance were recorded simultaneously with videofluoroscopy (VF) during swallows in six patients with dysphagia. Agreement, as to the presence or absence of bolus material, between the VF and MII was expressed using the Cohen's Kappa statistic. To test whether the impedance criteria for the detection of bolus passage in dysphagia could be improved, a Kappa statistic was calculated in an iterative process for a range of impedance values (100%-0%) defining bolus head entry and bolus tail clearance from the pharynx. Bolus presence according to the MII criteria previously derived by us in healthy controls demonstrated a modest correlation with VF when applied to this dysphagia population [0.37, 0.5 and 0.58 in the hypopharynx, upper oesophageal sphincter (UOS) and proximal oesophagus respectively]. In the patient population, the optimal impedance criteria were 50% for bolus head entry and 20% for bolus tail clearance. Adopting these criteria demonstrated enhanced agreement between VF and impedance; yielding Kappa coefficients of 0.42 in the hypopharynx...

Reliability of the information about the history of diagnosis and treatment of hypertension. Differences in regard to sex, age, and educational level. The pró-saúde study

Faerstein,Eduardo; Chor,Dóra; Lopes,Claudia de S.
Fonte: Sociedade Brasileira de Cardiologia - SBC Publicador: Sociedade Brasileira de Cardiologia - SBC
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2001 Português
Relevância na Pesquisa
26.5%
OBJECTIVE: To assess the intraobserver reliability of the information about the history of diagnosis and treatment of hypertension. METHODS: A multidimensional health questionnaire, which was filled out by the interviewees, was applied twice with an interval of 2 weeks, in July '99, to 192 employees of the University of the State of Rio de Janeiro (UERJ), stratified by sex, age, and educational level. The intraobserver reliability of the answers provided was estimated by the kappa statistic and by the coefficient of intraclass correlation (CICC). RESULTS: The general kappa (k) statistic was 0.75 (95% CI=0.73-0.77). Reliability was higher among females (k=0.88, 95% CI=0.85-0.91) than among males (k=0.62, 95% CI=0.59-0.65).The reliability was higher among individuals 40 years of age or older (k=0.79; 95% CI=0.73-0.84) than those from 18 to 39 years (k=0.52; 95% CI=0.45-0.57). Finally, the kappa statistic was higher among individuals with a university educational level (k=0.86; 95% CI=0.81-0.91) than among those with high school educational level (k=0.61; 95% CI=0.53-0.70) or those with middle school educational level (k=0.68; 95% CI=0.64-0.72). The coefficient of intraclass correlation estimated by the intraobserver agreement in regard to age at the time of the diagnosis of hypertension was 0.74. A perfect agreement between the 2 answers (k=1.00) was observed for 22 interviewees who reported prior prescription of antihypertensive medication. CONCLUSION: In the population studied...

Assessing agreement on classification tasks: the kappa statistic

Carletta, Jean
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/02/1996 Português
Relevância na Pesquisa
46.31%
Currently, computational linguists and cognitive scientists working in the area of discourse and dialogue argue that their subjective judgments are reliable using several different statistics, none of which are easily interpretable or comparable to each other. Meanwhile, researchers in content analysis have already experienced the same difficulties and come up with a solution in the kappa statistic. We discuss what is wrong with reliability measures as they are currently used for discourse and dialogue work in computational linguistics and cognitive science, and argue that we would be better off as a field adopting techniques from content analysis.; Comment: 9 pages

Tamanho ideal em grades de amostragem de solos para aplicação em taxa variável em manejo localizado; Optimum size in grid soil sampling for variable rate application in site-specific management

Nanni, Marcos Rafael; Povh, Fabrício Pinheiro; Demattê, José Alexandre Melo; Oliveira, Roney Berti de; Chicati, Marcelo Luiz; Cezar, Everson
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/06/2011 Português
Relevância na Pesquisa
36.26%
A importância de compreender a variabilidade espacial do solo está conectada ao planejamento do manejo das culturas. Este entendimento faz com que seja possível tratar o solo não como uma entidade uniforme, mas variável, e permite o gerenciamento de sítios específicos para aumentar a eficiência de produção, que é o objetivo da agricultura de precisão. Questões relacionadas com a otimização do intervalo de amostragem do solo se faz necessário para a realização das recomendações de adubações no Brasil. Os objetivos deste estudo foram: i) avaliar a variabilidade espacial dos principais atributos que influenciam as recomendações de adubação, usando amostras de solos georreferenciadas dispostas em padrões de grades de diferentes resoluções; ii) comparar os mapas espaciais gerados com o mapa padrão obtido com amostragem de 1 amostra ha-1, a fim de verificar a adequação da resolução espacial. Os atributos avaliados foram fósforo (P), potássio (K), matéria orgânica (MO), saturação por bases (V%) e argila. As amostras de solos foram coletadas numa grade de 100 × 100 m e georreferenciadas. Um desbaste foi realizado, criando-se uma grade com 1 amostra a cada 2,07, 2,88, 3,75 e 7,20 ha. Técnicas de geoestatística...