ABSTRACT
BACKGROUND: Pattern mining techniques are helpful tools when extracting new knowledge in real practice, but the overwhelming number of patterns is still a limiting factor in the health-care domain. Current efforts concerning the definition of measures of interest for patterns are focused on reducing the number of patterns and quantifying their relevance (utility/usefulness). However, although the temporal dimension plays a key role in medical records, few efforts have been made to extract temporal knowledge about the patient's evolution from multivariate sequential patterns. METHODS: In this paper, we propose a method to extract a new type of patterns in the clinical domain called Jumping Diagnostic Odds Ratio Sequential Patterns (JDORSP). The aim of this method is to employ the odds ratio to identify a concise set of sequential patterns that represent a patient's state with a statistically significant protection factor (i.e., a pattern associated with patients that survive) and those extensions whose evolution suddenly changes the patient's clinical state, thus making the sequential patterns a statistically significant risk factor (i.e., a pattern associated with patients that do not survive), or vice versa. RESULTS: The results of our experiments highlight that our method reduces the number of sequential patterns obtained with state-of-the-art pattern reduction methods by over 95%. Only by achieving this drastic reduction can medical experts carry out a comprehensive clinical evaluation of the patterns that might be considered medical knowledge regarding the temporal evolution of the patients. We have evaluated the surprisingness and relevance of the sequential patterns with clinicians, and the most interesting fact is the high surprisingness of the extensions of the patterns that become a protection factor, that is, the patients that recover after several days of being at high risk of dying. CONCLUSIONS: Our proposed method with which to extract JDORSP generates a set of interpretable multivariate sequential patterns with new knowledge regarding the temporal evolution of the patients. The number of patterns is greatly reduced when compared to those generated by other methods and measures of interest. An additional advantage of this method is that it does not require any parameters or thresholds, and that the reduced number of patterns allows a manual evaluation.
Subject(s)
Data Mining , Humans , Odds Ratio , Data Mining/methods , Time Factors , Pattern Recognition, Automated , Delivery of Health Care , Electronic Health RecordsABSTRACT
BACKGROUND: It is important to exploit all available data on patients in settings such as intensive care burn units (ICBUs), where several variables are recorded over time. It is possible to take advantage of the multivariate patterns that model the evolution of patients to predict their survival. However, pattern discovery algorithms generate a large number of patterns, of which only some are relevant for classification. OBJECTIVE: We propose to use the diagnostic odds ratio (DOR) to select multivariate sequential patterns used in the classification in a clinical domain, rather than employing frequency properties. METHODS: We used data obtained from the ICBU at the University Hospital of Getafe, where 6 temporal variables for 465 patients were registered every day during 5 days, and to model the evolution of these clinical variables, we used multivariate sequential patterns by applying 2 different discretization methods for the continuous attributes. We compared 4 ways in which to employ the DOR for pattern selection: (1) we used it as a threshold to select patterns with a minimum DOR; (2) we selected patterns whose differential DORs are higher than a threshold with regard to their extensions; (3) we selected patterns whose DOR CIs do not overlap; and (4) we proposed the combination of threshold and nonoverlapping CIs to select the most discriminative patterns. As a baseline, we compared our proposals with Jumping Emerging Patterns, one of the most frequently used techniques for pattern selection that utilizes frequency properties. RESULTS: We have compared the number and length of the patterns eventually selected, classification performance, and pattern and model interpretability. We show that discretization has a great impact on the accuracy of the classification model, but that a trade-off must be found between classification accuracy and the physicians' capacity to interpret the patterns obtained. We have also identified that the experiments combining threshold and nonoverlapping CIs (Option 4) obtained the fewest number of patterns but also with the smallest size, thus implying the loss of an acceptable accuracy with regard to clinician interpretation. The best classification model according to the trade-off is a JRIP classifier with only 5 patterns (20 items) that was built using unsupervised correlation preserving discretization and differential DOR in a beam search for the best pattern. It achieves a specificity of 56.32% and an area under the receiver operating characteristic curve of 0.767. CONCLUSIONS: A method for the classification of patients' survival can benefit from the use of sequential patterns, as these patterns consider knowledge about the temporal evolution of the variables in the case of ICBU. We have proved that the DOR can be used in several ways, and that it is a suitable measure to select discriminative and interpretable quality patterns.
ABSTRACT
The objective of the study was the construction of a generic curriculum development model for the use of biomedical physics (BMP) educators teaching the non-physics healthcare professions (HCP) in Europe. A comprehensive, qualitative cross-sectional Europe-wide survey of the curricula delivered by BMP in Faculties of Medicine and Health Sciences (FMHS) was carried out. Curricular content was collected from faculty web-sites, curricular documents and textbooks. The survey data was supplemented with semi-structured interviews and direct observation during onsite visits. The number of faculties studied was 118 from 67 universities spread all over Europe, whilst the number of onsite visits/interviews was 15 (geographically distributed as follows: Eastern Europe 6, North Western Europe 5, and South Western Europe 4). EU legislation, recommendations by European national medical councils, educational benchmark statements by higher education quality assurance agencies, research journals concerning HCP education and other documents relevant to standards in clinical practice and undergraduate education were also analyzed. Best practices and BMP learning outcomes were elicited from the curricular materials, interviews and documentation and these were subsequently used to construct the curriculum development model. A structured, comprehensive BMP learning outcomes inventory was designed in the format required by the European Qualifications Framework (EQF). The structures of the inventory and curriculum development model make them ideally suited for use by BMP involved in European curriculum development initiatives for the HCP.
Subject(s)
Curriculum , Physics , Cross-Sectional Studies , Delivery of Health Care , EuropeABSTRACT
Objective. To test a software application for the quantification of metabolic heterogeneity and to evaluate its superiority in relation to visual interpretation. To investigate if a quantitative analysis adds information to the interpretation of 18F-FDG-PET/CT. Material and methods. The study analyzed 215 patients with a 18F-FDG-PET/CT done for the initial staging of lung cancer between March 2011 and December 2015. The study included 57 (26.5%) women and 158 (73.5%) men, with ages ranging from 34 to 88 years (mean±SD: 67.23±10.04). There were 82 surgical stages (I, II, IIIA), and 133 non-surgical stages (IIIB, IV). The primary tumour was analyzed quantitatively by obtaining the following parameters: SUVmax, metabolic active tumour volume (MATV), total lesion glycolysis (TLG), and the entropy heterogeneity index (ET). Heterogeneity was assessed visually. Death dates and/or the follow-up time were registered, ranging from 0.70 to 67.60 months (mean±SD: 23.20±17.68). Results. In multivariate analysis, ET emerged as a better predictor of survival than visual analysis of heterogeneity that was not statistically significant. The C-index determination demonstrated that all quantitative parameters were statistically-significant predictors of survival. Cut-offs were obtained in order to compare survival times. A multivariate analysis was performed. In the total population, the best predictor was the TNM stage, but MATV, ET, and male gender were statistically significant and independent predictors of survival. In stages without surgical indication, the best predictor was the TNM stage, but the MATV and male gender were statistically significant and independent predictors of survival. In the surgical stages, ET was the only statistically significant and independent predictor of survival. Conclusions. Quantification adds prognostic information to the visual analysis of 18F-FDG-PET/CT (AU)
Objetivo. Valorar un software para cuantificar la heterogeneidad metabólica e investigar su superioridad en relación con la interpretación visual. Analizar si el análisis cuantitativo ofrece información adicional en la interpretación de los estudios 18F-FDG-PET/TC. Material y métodos. Se valoraron retrospectivamente 215 estudios 18F-FDG-PET/TC para estatificación inicial de cáncer de pulmón entre marzo de 2011 y diciembre de 2015; se incluyeron 57(26,5%) mujeres y 158(73,5%) hombres, con edades de 34 a 88 años (media±DE: 67,23±10,04); hubo 82 estadios quirúrgicos (I, II, IIIA) y 133 no quirúrgicos (IIIB, IV). El tumor primario fue analizado obteniendo los parámetros SUVmax, metabolic active tumour volume (MATV), total lesion glycolisys (TLG) y el índice de heterogeneidad entropía (ET). La heterogeneidad fue valorada visualmente. Se registró la fecha de fallecimiento y/o el tiempo de seguimiento, que osciló entre 0,70 y 67,60 meses (media±DE: 23,20±17,68). Resultados. En el análisis multivariante, la ET se mostró mejor predictor de supervivencia que el análisis visual de heterogeneidad, el cual no fue estadísticamente significativo. La determinación del C-index demostró que todos los parámetros cuantitativos fueron predictores de supervivencia estadísticamente significativos. Se obtuvieron puntos de corte para comparar los tiempos de supervivencia. En el análisis multivariante, el mejor predictor fue el TNM, pero el MATV, el ET y el género masculino demostraron ser predictores de supervivencia independientes estadísticamente significativos. En los estadios no quirúrgicos, el mejor predictor fue el TNM, pero el MATV y el género masculino demostraron ser predictores de supervivencia estadísticamente significativos e independientes. En los estadios quirúrgicos, la ET fue el único predictor de supervivencia estadísticamente significativo e independiente. Conclusiones. La cuantificación ofrece información pronóstica adicional al análisis visual del 18F-FDG-PET/TC (AU)
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Fluorodeoxyglucose F18/administration & dosage , Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung , Positron-Emission Tomography/methods , 24960/methods , Retrospective Studies , Neoplasm Staging/statistics & numerical data , Multivariate Analysis , 28599 , Kaplan-Meier EstimateABSTRACT
OBJECTIVE: To test a software application for the quantification of metabolic heterogeneity and to evaluate its superiority in relation to visual interpretation. To investigate if a quantitative analysis adds information to the interpretation of 18F-FDG-PET/CT. MATERIAL AND METHODS: The study analyzed 215 patients with a 18F-FDG-PET/CT done for the initial staging of lung cancer between March 2011 and December 2015. The study included 57 (26.5%) women and 158 (73.5%) men, with ages ranging from 34 to 88 years (mean±SD: 67.23±10.04). There were 82 surgical stages (I, II, IIIA), and 133 non-surgical stages (IIIB, IV). The primary tumour was analyzed quantitatively by obtaining the following parameters: SUVmax, metabolic active tumour volume (MATV), total lesion glycolysis (TLG), and the entropy heterogeneity index (ET). Heterogeneity was assessed visually. Death dates and/or the follow-up time were registered, ranging from 0.70 to 67.60 months (mean±SD: 23.20±17.68). RESULTS: In multivariate analysis, ET emerged as a better predictor of survival than visual analysis of heterogeneity that was not statistically significant. The C-index determination demonstrated that all quantitative parameters were statistically-significant predictors of survival. Cut-offs were obtained in order to compare survival times. A multivariate analysis was performed. In the total population, the best predictor was the TNM stage, but MATV, ET, and male gender were statistically significant and independent predictors of survival. In stages without surgical indication, the best predictor was the TNM stage, but the MATV and male gender were statistically significant and independent predictors of survival. In the surgical stages, ET was the only statistically significant and independent predictor of survival. CONCLUSIONS: Quantification adds prognostic information to the visual analysis of 18F-FDG-PET/CT.
Subject(s)
Fluorodeoxyglucose F18 , Lung Neoplasms/diagnostic imaging , Positron Emission Tomography Computed Tomography , Radiopharmaceuticals , Adult , Aged , Aged, 80 and over , Female , Humans , Lung Neoplasms/mortality , Male , Middle Aged , Retrospective Studies , Survival RateABSTRACT
Objectives. In 2009-2010 a Portuguese consortium was created to implement the methodologies proposed by the Dose Datamed II (DDM2) project, aiming to collect data from diagnostic X-ray and nuclear medicine (NM) procedures, in order to determine the most frequently prescribed exams and the associated ionizing radiation doses for the Portuguese population. The current study is the continuation of this work, although it focuses only on NM exams for the years 2011 and 2012. Material and methods. The annual frequency of each of the 28 selected NM exams and the average administered activity per procedure was obtained by means of a nationwide survey sent to the 35 NM centres in Portugal. Results. The results show a reduction of the number of cardiac exams performed in the last two years compared with 2010, leading to a reduction of the annual average effective dose of Portuguese population due to NM exams from 0.08 mSv ± 0.017 mSv/caput to 0.059 ± 0.011 mSv/caput in 2011 and 0.054 ± 0.011 mSv/caput in 2012. Portuguese total annual average collective effective dose due to medical procedures was estimated to be 625.6 ± 110.9 manSv in 2011 and 565.1 ± 117.3 manSv in 2012, a reduction in comparison with 2010 (840.3 ± 183.8 manSv). Conclusions. The most frequent exams and the ones that contributed the most for total population dose were the cardiac and bone exams, although a decrease observed in 2011 and in 2012 was verified. The authors intend to perform this study periodically to identify trends in the annual Portuguese average effective dose and to help to raise awareness about the potential dose optimization (AU)
Objetivo. En 2009 y 2010 un consorcio portugués ha sido creado para implementar las metodologías propuestas por el proyecto europeo Datamed II (DDM2), con el objetivo de coleccionar datos de procedimientos de radiología de diagnóstico y medicina nuclear (MN) más frecuentes, así como la dosis asociada en la población portuguesa. Este estudio es una continuación del trabajo, que se centrará en los datos de MN para los años de 2011 y 2012. Material y Métodos. La frecuencia anual de cada uno de los 28 exámenes de MN seleccionados y la actividad media administrada por procedimiento se obtuvieron a través de una encuesta enviada a los 35 departamentos de MN en Portugal. Resultados. Los resultados muestran una reducción drástica en el número de procedimientos cardiacos en los últimos dos años, lo que tiene como consecuencia una reducción de la dosis efectiva anual en la población portuguesa derivado de procedimientos de MN de 0,08mSv±0,017 mSv/caput en 2010, a 0,059±0,011 mSv/caput in 2011 y 0,054±0,011 mSv/caput in 2012. La dosis efectiva colectiva media en la población portuguesa es estimada en 625.6 ± 110.9 manSv en 2011, y 565.1 ± 117.3 manSv en 2012. Conclusiones. Los exámenes cardiacos y óseos fueron más frecuentes y los que más contribuyeron para la dosis total de la población, aunque se verificó una disminución en 2011 y en 2012. Los autores de este trabajo pretenden realizar este tipo de estudios periódicamente para identificar tendencias en los diferentes procedimientos de MN y ayudar a aumentar la conciencia de los profesionales de MN sobre este asunto (AU)
Subject(s)
Humans , Male , Female , Nuclear Medicine/instrumentation , Nuclear Medicine/methods , Nuclear Medicine/organization & administration , Dose-Response Relationship, Radiation , Nuclear Medicine/statistics & numerical data , Nuclear Medicine/standards , Nuclear Medicine/trends , Portugal/epidemiology , Myocardial Perfusion Imaging/methods , Surveys and QuestionnairesABSTRACT
OBJECTIVES: In 2009-2010 a Portuguese consortium was created to implement the methodologies proposed by the Dose Datamed II (DDM2) project, aiming to collect data from diagnostic X-ray and nuclear medicine (NM) procedures, in order to determine the most frequently prescribed exams and the associated ionizing radiation doses for the Portuguese population. The current study is the continuation of this work, although it focuses only on NM exams for the years 2011 and 2012. MATERIAL AND METHODS: The annual frequency of each of the 28 selected NM exams and the average administered activity per procedure was obtained by means of a nationwide survey sent to the 35 NM centres in Portugal. RESULTS: The results show a reduction of the number of cardiac exams performed in the last two years compared with 2010, leading to a reduction of the annual average effective dose of Portuguese population due to NM exams from 0.08 mSv ± 0.017 mSv/caput to 0.059 ± 0.011 mSv/caput in 2011 and 0.054 ± 0.011 mSv/caput in 2012. Portuguese total annual average collective effective dose due to medical procedures was estimated to be 625.6 ± 110.9 manSv in 2011 and 565.1 ± 117.3 manSv in 2012, a reduction in comparison with 2010 (840.3 ± 183.8 manSv). CONCLUSIONS: The most frequent exams and the ones that contributed the most for total population dose were the cardiac and bone exams, although a decrease observed in 2011 and in 2012 was verified. The authors intend to perform this study periodically to identify trends in the annual Portuguese average effective dose and to help to raise awareness about the potential dose optimization.
Subject(s)
Radiation Dosage , Radiation Exposure , Radiation, Ionizing , Radionuclide Imaging , Adult , Bone and Bones/diagnostic imaging , Child , Dose-Response Relationship, Radiation , Health Care Surveys , Humans , Myocardial Perfusion Imaging/adverse effects , Myocardial Perfusion Imaging/statistics & numerical data , Nuclear Medicine Department, Hospital/statistics & numerical data , Portugal , Positron-Emission Tomography/adverse effects , Positron-Emission Tomography/statistics & numerical data , Radionuclide Imaging/adverse effects , Radionuclide Imaging/statistics & numerical data , Radiopharmaceuticals/adverse effects , Surveys and QuestionnairesABSTRACT
A method based upon the application of mathematical techniques of deconvolution on the classical compartmental model for the quantitative study of liver function from hepatobiliary scintigraphy using 99mTc-mebrofenin data is proposed. The theory in which the method is based upon is presented and a comparison with a published methodology of obtaining the hepatic extraction after scintigraphic sudies has been performed using the results on 36 rats studies obtained with the two methods. A highly significant correlation between the two techniques was verified. The characteristics of the two methodologies, the proposed one based upon a theoretical approach and the other one on an empirical approximation are discussed. Comments are made on the interest and limitations of the presented technique that may be an useful tool for the evaluation of hepatic insufficiency.
Subject(s)
Biliary Tract/diagnostic imaging , Imino Acids , Liver/diagnostic imaging , Organotechnetium Compounds , Radiopharmaceuticals , Aniline Compounds , Animals , Bile/metabolism , Biliary Tract/physiopathology , Cholestasis/diagnostic imaging , Glycine , Hepatocytes/metabolism , Imino Acids/pharmacokinetics , Ligation , Liver/physiopathology , Liver Function Tests , Male , Models, Biological , Organotechnetium Compounds/pharmacokinetics , Radionuclide Imaging , Radiopharmaceuticals/pharmacokinetics , Rats , Rats, Sprague-DawleyABSTRACT
Se propone un método basado en la aplicación de técnicas matemáticas de deconvolución sobre el modelo compartimental clásico para el estudio cuantitativo de la función hepática con datos de gammagrafía hepatobiliar con 99mTc-mebrofenina. Se presenta la teoría sobre la cual se basa el método y se hace una comparación con una metodología publicada para la obtención de la extracción hepática después de hacer estudios grammagráficos utilizando los resultados de 36 estudios en ratas, obtenidos con los dos métodos. Se comprobó una correlación altamente significativa entre las dos técnicas. Se discuten las características de las dos metodologías, la propuesta basada en un enfoque teórico y la otra en un enfoque empírico. Se comenta el interés y limitaciones de la técnica presentada que puede ser una herramienta útil para la evaluación de la insuficiencia hepática. (AU)
Subject(s)
Rats , Animals , Male , Organotechnetium Compounds , Rats, Sprague-Dawley , Radiopharmaceuticals , Models, Biological , Hepatocytes , Biliary Tract , Bile , Cholestasis , Liver , Ligation , Imino Acids , Liver Function TestsABSTRACT
Se presentan 10 niños estudiados en el servicio desde mayo de 1991 a mayo de 1992 con hepatitis por citomegalovirus, con una edad promedio al diagnóstico entre 1 y 3 meses. Se realizaron determinaciones bioquímicas para la evaluación de la colestasis y/o hepatitis: serológicas (sífilis, Chagas, toxoplasmosis, hepatitis A y B, citomegalovirus); alfa 1 antitripsina, test del sudor. La permeabilidad de la vía biliar fue evaluada con ecografía abdominal y cámara gamma TcPipida. Además se estudió la configuración histológica. El seguimiento bioquímico mostró a los seis meses de evolución que normalizaron 7/10 la bilirrubina, 8/10 las transaminasas y sólo 3/10 la fosfatasa alcalina. En la totalidad se detectó IgM anti CMV positiva por ELISA. Las alteraciones histológicas encontradas en los pacientes fueron variadas desde triaditis leve, colestasis, hepatitis neonatal, fibrosis portal e interlobulillar y metamorfosis grasa. Se concluye que la remisión de nuestros 10 pacientes no planteó diferencias con respecto a la evolución habitual pero subraya la necesidad de investigar esta etiología en lactantes de corta edad con hepatomegalia y/o síndrome colestático o hepatitis (AU)
Subject(s)
Humans , Male , Female , Infant , Hepatitis, Viral, Human/etiology , Clinical Evolution , Cytomegalovirus Infections/complications , Hepatitis, Viral, Human/diagnosis , Hepatitis, Viral, Human/blood , Alkaline Phosphatase/blood , Prospective StudiesABSTRACT
Se presentan 10 niños estudiados en el servicio desde mayo de 1991 a mayo de 1992 con hepatitis por citomegalovirus, con una edad promedio al diagnóstico entre 1 y 3 meses. Se realizaron determinaciones bioquímicas para la evaluación de la colestasis y/o hepatitis: serológicas (sífilis, Chagas, toxoplasmosis, hepatitis A y B, citomegalovirus); alfa 1 antitripsina, test del sudor. La permeabilidad de la vía biliar fue evaluada con ecografía abdominal y cámara gamma TcPipida. Además se estudió la configuración histológica. El seguimiento bioquímico mostró a los seis meses de evolución que normalizaron 7/10 la bilirrubina, 8/10 las transaminasas y sólo 3/10 la fosfatasa alcalina. En la totalidad se detectó IgM anti CMV positiva por ELISA. Las alteraciones histológicas encontradas en los pacientes fueron variadas desde triaditis leve, colestasis, hepatitis neonatal, fibrosis portal e interlobulillar y metamorfosis grasa. Se concluye que la remisión de nuestros 10 pacientes no planteó diferencias con respecto a la evolución habitual pero subraya la necesidad de investigar esta etiología en lactantes de corta edad con hepatomegalia y/o síndrome colestático o hepatitis
Subject(s)
Humans , Male , Female , Infant , Clinical Evolution , Cytomegalovirus Infections/complications , Hepatitis, Viral, Human/etiology , Alkaline Phosphatase/blood , Hepatitis, Viral, Human/blood , Hepatitis, Viral, Human/diagnosis , Prospective StudiesABSTRACT
The authors study aggression with the "Instrument I to measure aggression of Ledesma Jimeno, Rodrigues Isidoro and Izquierdo de la Torre" in a sample of teachers (N = 48) made up of 15 university professors and 33 non-university professors (primary school, secondary school and professional training). The teacher sample is compared with a control sample of 479 men. The group of non-university professors showed more self-aggression and less aggression toward others than the control sample and university sample did. Both groups of teachers showed high levels of "technical intelligence". The aggression of the university professors was very similar to the control group and showed special peculiarities giving high values of intrapsychic incoherence that made their conduct more unforeseeable, with higher creative dispositions and a higher risk to their mental health than the other two groups studied.