El modelo Clinical outcomes, healthcare resource utilization, and related costs (COHERENT). Aplicación en pacientes con insuficiencia cardiaca / The Clinical outcomes, healthcare resource utilization, and related costs (COHERENT) model. Application in heart failure patients

Introducción y objetivos: Los resultados combinados se utilizan ampliamente, pero tienen diversas limitaciones. El modelo Clinical outcomes, healthcare resource utilization and related costs (COHERENT) es una aproximación nueva para presentar y comparar visualmente todos los componentes de los resultados combinados (incidencia, tiempo, duración) y los costes relacionados. El objetivo es evaluar su utilidad en una cohorte de pacientes. Métodos: Se diseñó un sistema de colores que representa gráficamente el porcentaje de pacientes en cada situación clínica (estado vital y ubicación: domicilio, urgencias, hospital), codificada jerárquicamente, en cada momento del seguimiento. Se aplicó a 1.126 pacientes con insuficiencia cardiaca aguda de 25 hospitales seguidos durante 30 días tras su visita a urgencias, y se calculó el tiempo en cada situación clínica y sus costes sanitarios. Resultados: El modelo ilustra visualmente los componentes del objetivo combinado a los 30 días (el 2,12% en urgencias, el 23,6% en hospitalización índice, el 2,7% en reingresos, el 65,5% vivo en casa y el 6,02% fallecido) y muestra diferencias significativas entre grupos de pacientes, hospitales o sistemas sanitarios. El instrumento también calcula y muestra los costes diarios y acumulados (total, 4.895.070 euros; media, 144,91 euros/paciente/día). Conclusiones: El modelo COHERENT es un nuevo método para mostrar visualmente resultados combinados y sus costes que permite comparar grupos de pacientes y cohortes. El nuevo sistema puede ser útil como un nuevo criterio de valoración para ensayos clínicos o estudios observacionales, y un instrumento para la evaluación comparativa, la planificación clínica, el análisis económico y la implementación de la atención sanitaria basada en valor (AU)

Introduction and objectives: Composite endpoints are widely used but have several limitations. The Clinical outcomes, healthcare resource utilization and related costs (COHERENT) model is a new approach for visually displaying and comparing composite endpoints including all their components (incidence, timing, duration) and related costs. We aimed to assess the validity of the COHERENT model in a patient cohort. Methods: A color graphic system displaying the percentage of patients in each clinical situation (vital status and location: at home, emergency department [ED] or hospital) and related costs at each time point during follow-up was created based on a list of mutually exclusive clinical situations coded in a hierarchical fashion. The system was tested in a cohort of 1126 patients with acute heart failure from 25 hospitals. The system calculated and displayed the time spent in each clinical situation and health care resource utilization-related costs over 30 days. Results: The model illustrated the times spent over 30 days (2.12% in ED, 23.6% in index hospitalization, 2.7% in readmissions, 65.5% alive at home, and 6.02% dead), showing significant differences between patient groups, hospitals, and health care systems. The tool calculated and displayed the daily and cumulative health care-related costs over time (total, €4 895 070; mean, €144.91 per patient/d). Conclusions: The COHERENT model is a new, easy-to-interpret, visual display of composite endpoints, enabling comparisons between patient groups and cohorts, including related costs. The model may constitute a useful new approach for clinical trials or observational studies, and a tool for benchmarking, and value-based health care implementation (AU)

Sensitivity analysis and literature review of parameters controlling local biodegradation processes in municipal solid waste landfills.

The local gas production rate in municipal landfills is influenced by a large number of processes, which have been modelled by a local mechanistic reaction model based on Monod kinetics. This type of model, however, requires over 40 input parameters. The aim of this research was to review published values for these input parameters, and to analyse the sensitivity of the model to changes in each of them. Included were rate constants based on Monod kinetics, general rate-controlling variables, and parameters that influence the local pH and temperature of the waste. Mathematical functions that describe the influence of water content, temperature, and pH on biodegradation rates were calibrated on the basis of literature data. The results of the sensitivity analysis suggest that the parameters with the largest impact on model output are the hydrolysis constant k(Hy), the kinetic constants mu(max,X(me,1), b(X)(me), Y (ac,X(me,1), K(i,ac,Hy), and Y(CO(2),X(me,2),) the water content, temperature, pH, initial concentration of X(me), the enthalpy of formation of the original organic matter, as well as the protein content and buffering capacity of the waste. These parameters, therefore, should be carefully selected when similar modelling studies are performed.

Modelling and experimental investigation of environmental influences on the acetate and methane formation in solid waste.

An anaerobic reaction model is represented and used for simulation of the biodegradation of organic compounds and the generation of biogas. The model is based on fundamental relationships among physical, chemical, thermodynamic and microbial processes occurring in municipal landfills. Local microbially mediated degradation processes occurring in municipal landfills are simulated in terms of hydrolysis of readily and inherently degradable organic matter, the formation of acetate as surrogate for intermediary low-molecular carbon substrates, and the generation of the biogases CH4 and CO2. Thus, the overall decomposition of the organic matter has been assumed to follow three sequential anaerobic reactions steps: hydrolysis, acetogenesis and methanogenesis. In order to study the impact of environmental factors on the biological decomposition processes, experiments have been conducted to investigate the effect of temperature and water content. In the degradation model, the impact of temperature and water content was defined as reaction rate influencing factors. Further, waste samples have been taken from four drill holes on a municipal landfill near Wolfsburg (Germany) and used to analyze and to describe the waste composition and prevailing environmental conditions dependent on the depth of the drill hole. The data and waste samples obtained from the landfill have also been used for model development and validation.

Experimental investigation and modelling of the effect of sulfate on anaerobic biodegradation processes in municipal solid waste.

The experimental investigations have been carried out in two parts. First, the biodegradation of the organic compounds in the municipal solid waste has been investigated with focus on different sulfate concentrations influencing the methane formation. Second, the inhibition effect of hydrogen sulfide in solution (H2S(aq)) on the acetate, and methane formation, respectively, has been studied at different pH and temperature values. In solution the equilibrium of hydrogen sulfide (H2S(aq)) and the hydrogen sulfide anion (HS-(aq)) mainly depends on pH. At pH 6.3 the favoured species is H2S(aq) whereas at pH 7.7 the HS-(aq) species is favoured. Additionally, the experiments have been carried out at two different temperatures (35 degrees C and 55 degrees C). According to the acetate and methane formation the H2S(aq) species is observed to have an inhibitory effect. All simulations based on a biodegradation model represented are in good agreement with the experimental data obtained.

Interobserver agreement of perceived intelligibility of magnitude of r in children.

This study was designed to test whether independent listeners could correctly classify 162 stimuli (words) that started with a multiple trill, magnitude of r, followed by a vowel magnitude of a. The sounds were from 27 Spanish children between the ages of 3.0 and 6.6 years, pronouncing Spanish words current in their vocabulary. Twelve listeners were presented with the recordings of the children's magnitude of r production and were instructed to rate the intelligibility of the pronounced sound as high, medium, or low. Inter-rater agreement ranged from 85 to 96%. Analyses of variance for each of the three production categories showed that there were significant differences, so it seems possible to classify the words starting with a trilled magnitude of r based on auditory-perceptual features into three broad categories according to intelligibility.

The long-term average spectrum as a measure of voice stability.

This paper aims at providing a methodological answer to the topic of voice stability. Seventeen experimental subjects read a standard text 5 times during a 2-week period. The data were obtained through the Long-Term Average Spectrum and were analyzed with a twofold procedure: (i) analysis of the absolute energy values at different frequency points throughout the length of the spectrum, and (ii) analysis of the relative values obtained by subtraction of each of two consecutive frequency values analyzed. The results obtained with the first procedure indicate that the differences that exist between the various sessions are centered mainly in the frequencies below 0.6 kHz and in the area of 4 kHz, following a linear tendency. The fact that the differences between sessions disappear when employing relative measures may indicate that the utilization of these measures eliminates the sources of systematic or aleatoric error can be introduced during a recording or in the period of time between two consecutive recording sessions.

High-frequency components of normal and dysphonic voices.

The analysis of high-frequency energy levels can presently be considered as being more influenced by the characteristics of the speaker than by the phonetic material, serving as an indicator of the quality of the voice. In this study the energy levels in the frequency intervals of 6-10 and 10-16 kHz were evaluated, both in dysphonic voices and in subjects with no voice problems. The material consisted of consonant-vowel syllables formed by stop phonemes and the basic Spanish vowels, analyzing the vocal segment. The results indicate that the energy, found from the power spectrum average, in both frequency areas, is significantly bigger in the group with dysphonic voices. The analysis in the 10-16 kHz regions shows additional significant differences of energy between the vowels, progressively decreasing from front to back vowels.

[Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia]. / Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia.

The objective of this study was to evaluate the technical quality of sputum microscopy carried out for diagnostic purposes in the Network of Tuberculosis Bacteriology Laboratories in Colombia. The National Central Reference Laboratory received 6,529 slides for reexamination from the network of 513 sectional, regional, and local laboratories, which contributed 33.2%, 27.6%, and 39.2%, respectively, of the slides. These included all the positive (3,283) and negative (3,246) smears processed during a 4-month period. The reexamination was carried out by six laboratory workers who did not know the origin of the slides or the original diagnosis. When qualitative problems were detected, a second reexamination was done, which significantly increased the percentage of agreement for both the positive results (93.9%) and the negative (98.7%). Overall, the level of agreement was 96.3%. A significant correlation was found (P < 0.05) between good slide preparation and staining and agreement in the readings, as well as between thin smears, presence of fuchsin precipitates, and deficient coloration and conflicting readings (P < 0.05). The highest percentages of agreement were associated with laboratories that performed the largest number of sputum examinations each month (96.5%), and with readings done by experienced, university-trained bacteriologists (96.6%). It is concluded that indirect technical supervision and ongoing training of laboratory personnel are important determinants of the impact of the tuberculosis control program.

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis

Calidad de la baciloscopia de esputo en la red de laboratorios de bacteriología de tuberculosis en Colombia / Quality of sputum microscopy in the network of tuberculosis bacteriology laboratories in Colombia

El objetivo fue evaluar la calidad técnica de la baciloscopia de esputo realizada con fines diagnósticos en la Red de Laboratorios de Bacteriología de la tuberculosis en Colombia. En el Laboratorio Central Nacional de Referencia se recibieron para relectura 6 529 láminas provenientes de la red de 513 laboratorios seccionales, regionales y locales, los cuales contribuyeron 33,2, 27,6 y 39,2 por ciento de las láminas, respectivamente. Estas representaron todas las baciloscopias positivas (3 283) y la siguiente negativa (3 246) procesadas durante un período de cuatro meses. La relectura estuvo a cargo de seis lectores que desconocían la procedencia de las láminas y el diagnóstico original. Cuando se detectaron discordancias cualitativas, se hizo una segunda relectura que aumentó significativamente las concordancias, tanto de los resultados positivos ((3,9 por ciento) como de los negativos (98,7 por ciento), con una concordancia total de 96,3 por ciento. Se hallo una correlación significativa (P0,05) entre buen extendido y buena coloración y las lecturas concordantes, así como entre extendidos delgados, presencia de precipitados de fucsina y decoloración deficiente y las lecturas discordantes (P0,05). Los porfcentajes de concordancia más altos se relacionaron con los laboratorios que realizan mensualmente el mayor número de baciloscopias (96,5 por ciento), y con las lecturas por bacteriólogos universitarios experimentados (96,6 por ciento). Se concluyed que la supervisión técnica indirecta y la continua capacitación del personal de laboratorio son factores determinantes del impacto del Programa de Control de la Tuberculosis

Respuesta tensional al ejercicio dinámico e isométrico en hipertensos tratados con labetolol o acebutolol / Arterial pressure response to dynamic exercise in hypertensives treated with labetalol or acebutolol

En el presente estudio de diseño simple-ciego, placebo-control, cruzado y randomizado, evaluamos la respuesta tensional y las modificaciones hemodinámicas causadas por el tratamiento oral y durante dos semanas con un agente bloqueador beta-adrenérgico selectivo con efecto simpático-mimético intríseco (Acebutolol, 400 mg/día) o con un agente bloqueador alfa y beta-adrenérgico (Labetalol, 400 mg/día). A tal efecto, 25 pacientes hipertensos leves fueron sometidos a ejercicio isométrico al 30% de su capacidad máxima y a ejercicio dinámico hasta un máximo de 75W, bajo monitoreo con electrograma de impedancia y durante ciclos de tratamiento con placebo, Acebutolol o Labetalol en forma cruzada, La efectividad terapéutica de ambas drogas fue similar en reposo, pero el Labetalol indujo una menor respuesta hipertensiva al ejercicio isométrico que el Acebutolol, la cual parece deberse a un menor incremento de las resistencias periféricas. Durante el ejercicio dinámico se observó una atención de la respuesta hipertensiva similar con ambos medicamentos; el labetalol, sin embargo, permitió un incremento del gasto cardíaco mayor que el tratamiento con Acebutolol. Estos efectos diferenciales del Labetalol se atribuyen a su efecto bloqueador alfa-adrenérgico, y lo hacen particularmente útil en pacientes hipertensos con actividad física moderada o intensa

Use of reduced silver staining to show loss of connections in aged rat brain.

A variation of the Fink-Heimer reduced silver technique was used to show the extent of axonal degeneration in the brains of aged rats. Degeneration product was extensive throughout the white matter of the old brains, being most dense in the optic tract, but substantial in fornix, corpus callosum, cingulum, and anterior commissure. There was selective impregnation of hippocampal strata, suggesting that there may be differential atrophy of connections as a function of age.