Análisis factorial confirmatorio de la Escala verbal de fusión de identidad en una muestra chilena / Confirmatory factor analysis of the Verbal Identity Fusion Scale in a Chilean sample

Resumen La fusión de identidad consiste en un sentimiento de unión con un grupo, en el que el individuo experimenta una mezcla entre su identidad personal y la social; y es un buen predictor de la conducta extrema progrupo. El presente estudio analizó la estructura factorial de la Escala verbal de fusión de identidad elaborada por Gómez et al. (2011), en una muestra chilena. Se utilizó una muestra universitaria seleccionada por conveniencia de 411 participantes (66% mujeres) con una edad media de 24.45 años (DT = 5.89). Se analizó el ajuste unifactorial y bifactorial de la Escala a través del análisis factorial, y las respectivas confiabilidades. Los resultados indicaron un buen y mejor ajuste del modelo bifactorial (χ 2/gl = 3.34, p < .001, CFI = .975, TLI = .957, SRMR = .030, y RMSEA = .085), por sobre el unifactorial, que no mostró un buen ajuste (χ 2/gl = 5.26, p < .001, CFI = .946, TLI = .919, SRMR = .042, y RMSEA = .116). Ambos modelos contaron con altas confiabilidades (> .800). Se discutió sobre el mejor ajuste de la estructura bifactorial en relación con estudios realizados en Estados Unidos, España y población inmigrante en Chile. Se proyecta la necesidad de futuros estudios que incorporen otros análisis de validez y superen la limitación del presente estudio asociada al uso de una muestra no representativa.

Abstract Identity fusion consists in a form alignment with a group and is a significant predictor of extreme pro-group behavior. The present study analyzed the factor structure of the verbal scale of identity fusion developed by Gómez et al. (2011), in a Chilean sample. A Chilean university sample by convenience of 411 participants (66% women) with a mean age of 24.45 years (SD = 5.89) was used. One-factor and two-factor fit of the scale was analyzed through factor analysis, and the respective reliabilities. The results indicated a good and better fit of the two-factor (χ2/gl = 3.34, p < .001, CFI = .975, TLI = .957, SRMR = .030, and RMSEA = .085), than the one-factor model, which did not show a good fit (χ2/gl = 5.26, p < .001, CFI = .946, TLI = .919, SRMR = .042, and RMSEA = .116). Both models had high reliabilities (> .800). The better fit of the two-factor structure was discussed in relation to studies conducted in the United States, Spain, and an immigrant population in Chile. The need for future studies incorporating other validity analyses and overcoming the limitation of the present study associated with the use of a non-representative sample is projected.

Mexican Validation of the MOS Questionnaire on Perceived Social Support in the Context of the COVID-19 Pandemic

Introduction: The COVID-19 pandemic has had a very negative impact on people's overall mental health and psychosocial well-being, but the study of available social support to cope with such an adverse situation has received hardly any attention. Objective: To examine the psychometric properties of the MOS Perceived Social Support Questionnaire among the Mexican population in the context of the COVID-19 pandemic. Method: Non-experimental cross-sectional study. A sociodemographic questionnaire and the Medical Outcomes Study were applied in a non-probabilistic sample. A total of 898 people from different regions in Mexico, 258 males and 640 females, participated in the study in the context of the COVID-19 pandemic. Results: The analysis yielded a bi-factor model with two factors, Emotional/informational support and Tangible support, with satisfactory goodness of fit indices. Reliability was adequate with a high hierarchical omega coefficient, as well as in the factors. Likewise, the H coefficient was adequate in the general factor and its dimensions. Conclusions: Results showed that the scale is a valid and reliable measure of perceived social support among the Mexican population.

Introducción: La pandemia de COVID-19 ha tenido un impacto muy negativo en la salud mental y el bienestar psicosocial general de las personas, pero el estudio del apoyo social disponible para hacer frente a una situación tan adversa como esta ha recibido muy poca atención. Objetivo: Examinar las propiedades psicométricas del Cuestionario MOS de Apoyo Social Percibido en población mexicana en contexto de pandemia por COVID-19. Método: Diseño no experimental transversal. Se aplicó un cuestionario sociodemográfico y el Medical Outcomes Study en una muestra no probabilística por conveniencia. Participaron 898 personas de diferentes regiones de México, 258 hombres y 640 mujeres, durante el contexto de la pandemia por COVID-19. Resultados: El análisis arrojó un modelo Bi-factor de dos factores Apoyo emocional/ informacional y Apoyo tangible, con índices de bondad que se ajustaron a los datos. La fiabilidad fue adecuada con un coeficiente de omega jerárquico alto, así como en los factores. Asimismo, el coeficiente H fue adecuado en el factor general y sus dimensiones. Conclusiones: La escala presenta validez y confiabilidad para medir el apoyo social percibido en población mexicana.

How to use χ2 test correctly——χ2 distribution and the related contents / 四川精神卫生

The purpose of this article was to introduce the χ2 distribution and related contents， including χ2 distribution and non-central χ2 distribution. It focused on showing the definition of two χ2 distributions， the graph and the main properties of the probability density function. Among them， the two most important properties were： first， the limiting distribution of the χ2 distribution was the normal distribution； second， n-1s2σ2followed the χ2 distribution with n-1 degrees of freedom.In addition， it also explained the relationship between the χ2 distribution and the normal distribution， the relationship between χ2 test statistic and Z test statistic. Finally， it illustrated the computational approaches of the χ2 distribution based on the two SAS functions in SAS software.

How to use χ2 test correctly—— the goodness of fit tests and the implementation of the SAS software / 四川精神卫生

The purpose of this article was to introduce the goodness of fit test and its SAS implementation. The main contents included the following four aspects： ① Pearson΄s goodness of fit test； ② deviance or likelihood ratio goodness of fit test； ③ Hosmer-Lemeshow goodness of fit test； ④ goodness of fit test for the sparse data. In the aforementioned “fourth aspect”， there were six specific test approaches， namely “information matrix test” “information matrix diagonal test” “Osius-Rojek test” “unweighted residual sum of squares test” “Spiegelhalter test” and “Stukel test”. The paper implemented the four types of the goodness of fit tests mentioned above with the help of the SAS software through an example， explained the output results， and made statistical and professional conclusions.

Power divergence test statistics for testing Hardy–Weinberg equilibrium

The Hardy–Weinberg equilibrium (HWE) model states that allele and genotype frequencies in a population will remain constant for generations in the absence of evolutionary effects. A goodness-of-fit test can be used to test if a population is significantly different from the expectations of HWE. Pearson statistics are commonly used in goodness-of-fit tests for testing the HWE. In this paper, a simulation study is carried out to evaluate the performance of power divergence statistics under different sample sizes, effect sizes and minor allele frequencies. A real genotype dataset is also analysed to compare the results of several power divergence test statistics.

Investigation and Analysis of Familial Aggregation of Helicobacter pylori Infection / 胃肠病学

Background: Helicobacter pylori (Hp) infection is an important public health problem, and the transmission mode of Hp is not yet fully understood, however, human-to-human transmission route has been widely recognized, thus familial aggregation may occur for Hp infection. Aims: To explore the Hp infection in family members of Hp-positive patients and to analyze the familial aggregation of Hp infection. Methods: A total of 976 patients who underwent 14C-urea breath test (14C-UBT) from January 2018 to January 2019 were enrolled. According to Hp infection, the subjects were divided into Hp-positive group (case group) and Hp-negative group (control group), and all family members of all the subjects were encouraged to detect Hp infection. The Hp infection of family members in the two groups, the consistence of Hp infection between husband and wife, and the relationship between Hp-positive parents and Hp infection of children in case group were analyzed, and the goodness-of-fit test for binomial distribution was used to explore familial aggregation of Hp infection. Results: Among the 493 complete families who completed the survey, Hp-positivity rate in parents, spouses, children in case group were 70.6%, 62.1%, 65.9%, respectively, and were significantly higher than those in parents, spouses, children in control group (63.2%, 54.4%, 56.7%, respectively) (P0.05). Among 548 children in case group, 361 children were Hp positive, and the infection rate was increased with the increase of parental infection (P<0.05). The goodness-of-fit test showed that there were statistically significant differences in the actual households distribution and theoretical households distribution of Hp infection (P<0.05). Conclusions: There is a certain familial aggregation of Hp infection. When a member of the family is infected, the risk of Hp infection of parents, spouses and children may increase.

Survival analysis: part II – applied clinical data analysis / 대한마취과학회지

As a follow-up to a previous article, this review provides several in-depth concepts regarding a survival analysis. Also, several codes for specific survival analysis are listed to enhance the understanding of such an analysis and to provide an applicable survival analysis method. A proportional hazard assumption is an important concept in survival analysis. Validation of this assumption is crucial for survival analysis. For this purpose, a graphical analysis method and a goodness-of-fit test are introduced along with detailed codes and examples. In the case of a violated proportional hazard assumption, the extended models of a Cox regression are required. Simplified concepts of a stratified Cox proportional hazard model and time-dependent Cox regression are also described. The source code for an actual analysis using an available statistical package with a detailed interpretation of the results can enable the realization of survival analysis with personal data. To enhance the statistical power of survival analysis, an evaluation of the basic assumptions and the interaction between variables and time is important. In doing so, survival analysis can provide reliable scientific results with a high level of confidence.

Autopercepción y satisfacción corporal de la población adulta mexicana por estados: una modelación probabilística con base en la Encuesta Nacional de Salud y Nutrición de México (ENSANUT) 2012 / Autoperception and satisfaction on adult mexican´s body by states: a probabilistic model based on the Mexican National Health and Nutrition Survey (ENSANUT) 2012

RESUMEN Objetivo:inferir el modelo probabilístico que represente a nivel estatal las discrepancias entre percepción y aspiración de la población mexicana en cuanto a su figura, a través de las denominadas siluetas de Stunkard, Sorenson y Schulsinger. Metodología: con muestras representativas a nivel estatal provenientes de la Encuesta Nacional de Salud y Nutrición (ENSANUT) 2012, se estimaron discrepancias entre distintos Índices de Masa Corporal (IMC): el medido y el autoreportado. Se utilizaron pruebas de bondad de ajuste y, con modelos ajustados de normalidad estadística, se calcularon probabilidades. Se aplicaron clusters jerárquicos a variables vinculadas con las discrepancias para identificar similitudes entre las muestras de los estados. Resultados: con la prueba Kolmogorov-Smirnov (KS), la Anderson-Darling (AD) y la Ji cuadrada (χ2) con una significancia del 1%, se ajustaron las discrepancias por sexo y estados, y en su mayoría se obtuvo una distribución normal. Se realizaron algunas estimaciones de probabilidades y se aplicó la regla empírica, con lo que se dimensionó la magnitud del posible conocimiento del IMC medido y de la satisfacción existente. Se identificaron grupos de estados que comparten similitudes en sus poblaciones en relación a variables estimadas. Conclusiones: se constató una percepción equivoca y una aspiración sistemática, permeadas de heterogeneidad ante un escenario de obesidad y sobrepeso que posee la mayor parte de la población mexicana.

ABSTRACT: Objective: to infer the probabilistic model of the discrepancy between how Mexicans perceive and aspire to be in their figure through the so-called Stunkard, Sorenson and Schulsinger silhouettes at state level. Methodology: we estimate discrepancies between different Body Mass Indexes (BMI): the measured and the auto reported. Then state samples are employed coming from the Mexican National Health and Nutrition Survey (ENSANUT) 2012. Goodness-of-fit tests are used, and, with adjusted normal models, specific probabilities are calculated. Some variables linked to discrepancies are taken into account for applying hierarchical clusters to identify similarities between states. Results: the Kolmogorov-Smirnov (KS), Anderson-Darling (AD) and Chi-square (χ2) tests were employed to model discrepancies by sex and state. The Normal distribution was recognized as appropriate. Some estimates of probabilities are made and the Empirical Rule is applied, which measures the magnitude of the possible knowing of the real BMI and the existing satisfaction. We identify groups of states that share similarities in their populations in relation to estimated variables. Conclusions: there is an erroneous perception and a systematic aspiration, permeated by heterogeneity in the face of a scenario of obesity or overweight in most mexicans.

Protocolo de observación de la función de explicación (PROFE): un instrumento para operacionalizar la transmisión de contenidos por parte del profesorado / Observation Protocol of the Explanation Function (OPEF): An Instrument to Operationalize the Transmission of Contents by Teachers

Resumen La calidad de la docencia universitaria es fundamental dentro del proceso educativo, lo que exige la evaluación del profesorado, prefiriéndose la metodología observacional cuando se evalúa la conducta de este. El objetivo de este estudio consistió en el análisis pormenorizado de la función docente de explicación, de especial relevancia dentro el escenario educativo, lo que hace importante su análisis. Para ello, se utilizó el instrumento observacional PROFE, para medir los recursos y estrategias utilizados durante la explicación. Se ha puesto a prueba la bondad psicométrica del instrumento mediante fiabilidad, homogeneidad y se ha optimizado el número de sesiones y el tiempo, para posteriormente analizar la conducta de cinco profesores de la Universidad de La Laguna.

Abstract The quality of university teaching is a very important aspect inside the educational process. This aspect makes it necessary the evaluation of teaching professionals. The observational methodology is the one used for evaluation. The objective of this study is the detailed analysis of one teaching function, the explanation. It is a function of particular relevance in the educational setting, so it is very important to analyze it. For that, the instrument PROFE was utilized. It allows the measurement of the resources and strategies used during the explanation. The instrument psychometric goodness has been tested calculating reliability and homogeneity. The number of sessions and time have been optimized. For later the behavior of five professors of La Laguna University has been analyzed.

Propuesta de evaluación del procesamiento sensorial de recién nacidos de pretérmino: favoreciendo el goodness of fit con sus padres y la autorregulación / Sensory processing assessment proposal for preterm new born: enhancing self regulation and goodness of fit with their parents

En este artículo se muestra el desarrollo de un instrumento para evaluar el procesamiento sensorial a través de la observación y registro de las conductas de recién nacidos de pretérmino en las unidades de neonatología. Este es un cuestionario que contiene 21 preguntas que se responden en conjunto con los padres. El principal objetivo de esta evaluación es poder facilitar las habilidades de éstos para observar y reconocer las conductas de sus hijos. Lo que podría llevarnos a facilitar un mejor calce entre la madre – padre y el bebé.Este buen calce o Goodness of Fit entre los padres y sus hijos hace referencia a que los padres puedan reconocer e interpretar las conductas de sus hijos o hijas y que de esta forma puedan responder de manera más atingente a sus necesidades. Esto tendría un importante impacto en las capacidades del bebé para regularse y también sobre los padres para desarrollar una mayor sensación de eficacia en su rol de cuidador.

This article presents an instrument for assessing the sensory processing through the observation and record of preterm babies behavior. This instrument has 21 questions that must be answered with the babies’ parents. The main goal of this measure is to favor the parents’ abilities to observe and recognize their babies’ behaviors. This could favor the Goodness of Fit between the mother father and the new born. This Goodness of Fit between the parents and the baby refers to the ability to recognize and read their babies’ cues and being able to answer in a satisfactory way to their new born needs. This could have an important effect on their babies’ regulation and on the parents feeling of efficacy in their role.

Effect of Number of Measurement Points on Accuracy of Muscle T2 Calculations

PURPOSE: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. MATERIALS AND METHODS: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long (“phantom”) and short T2 (“polyvinyl alcohol gel”). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ± standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. RESULTS: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. CONCLUSION: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.

Pruebas de bondad de ajuste en distribuciones simétricas, ¿qué estadístico utilizar? / Goodness of Fit Tests for Symmetric Distributions, which Statistical Should I Use?

El uso de pruebas no paramétricas resulta recomendable cuando los datos a analizar no cumplen los supuestos de normalidad y homocedasticidad. Sin embargo, la suposición de la normalidad de los datos o el empleo de pruebas de bondad de ajuste que no son adecuadas para el tamaño muestral empleado son aspectos habituales. Este hecho implica, en muchas ocasiones, el uso de pruebas estadísticas no ajustadas al tipo de distribución real y, consecuentemente, el establecimiento de conclusiones erróneas. Por ello, en el presente estudio se ha analizado el poder de detección de cinco pruebas de bondad de ajuste (Kolmogorov-Smirnov, Kolmogorov-Smirnov-Lilliefors, Shapiro-Wilk, Anderson-Darling y Jarque-Bera) en distribuciones simétricas con seis tamaños muestrales entre 30 y 1000 participantes generados mediante una simulación Monte Carlo. Los resultados muestran una tendencia conservadora generalizada a medida que se incrementa el tamaño muestral. En cuanto a los tamaños muestrales, las pruebas con un mejor poder de detección de la no normalidad son Kolmogorov-Smirnov-Lilliefors y Anderson-Darling para muestra pequeñas, la prueba de Kolmogorov-Smirnov si se emplean tamaños muestrales medios (200 participantes) y la prueba de Shapiro-Wilk cuando se analizan muestras superiores a 500 participantes. Además, la prueba clásica de Kolmogorov-Smirnov se considera absolutamente ineficaz independientemente del tamaño muestral.

The use of nonparametric tests is recommended when the data do not meet the assumptions of normality and homoscedasticity. However, the assumptions of normality of the data or the use of goodness of fit tests that are not appropriate for the assessed sample are common aspects. In many cases, this implies the use of statistical tests unadjusted for the real data distribution and, consequently, the establishment of inaccurate conclusions. Therefore, in this paper the detection power of five tests of goodness of fit (Kolmogorov-Smirnov-Lilliefors, Kolmogorov-Smirnov, Shapiro-Wilk, Anderson-Darling and Jarque -Bera) in symmetric distributions is analysed in six sample sizes between 30 and 1000 participants generated by Monte Carlo simulation. Results show a marked conservative tendency as the sample size becomes larger. Regarding sample sizes to detect non-normality: analysing small samples the best results are provided by Kolmogorov-Smirnov-Lilliefors and Anderson-Darling tests, if the sample is medium-sized (200 participants) the Kolmogorov-Smirnov, and when samples are over 500 participants the Shapiro-Wilk test is recommended. In addition, the classic test of Kolmogorov-Smirnov is considered absolutely ineffective regardless the sample size.

Total knee arthroplasty:Goodness-of-fit analysis of intraoperative knee society score of Peking Union Medical College / 中国组织工程研究

BACKGROUND:Knee society score of Peking Union Medical Col ege has been promoted and used in the 306th Hospital of PLA for 2 years and we have accumulated some clinical data. OBJECTIVE:To analyze the stability and feasibility for suitable clinical medical practice of knee society score of Peking Union Medical Col ege. METHODS:Fifty-five patients with osteoarthritis of the knee were included, and the patients were divided into three groups:the preoperative group;3 months postoperative fol ow-up group;6 months postoperative fol ow-up group. The measurement results obtained by the application of the scale were compared to those of the Western Ontario and McMaster Universityies Ostroarthritis Index, visual analog scale, and hospital for special surgery score, and then knee society score goodness-of-fit analysis was performed based on the structural equation model. RESULTS AND CONCLUSION:Knee society score performance assessment of the signs and symptoms of osteoarthritis of the knee patients was positively correlated with the pain severity of visual analog scale score;the overal knee society score of the patients after 6-month fol ow-up was significantly improved compared with that before treatment. The knee society score after 3-and 6-month fol ow-up was significantly higher than that before treatment, and the score was quite with the hospital for special surgery score. The overal assessment of the knee society score after treated for 3 and 6 months was improved for more than grade Ⅰ, the visual analog scale score was decreased for more than 30%. The pain assessment items and physiological functional assessment items of Western Ontario and McMaster Universityies Ostroarthritis Index after 6-month fol ow-up were significantly better than those before treatment (Pgoodness-of-fit analysis showed that the scale had good goodness which had scientific nature and application value.

Analysis of the rocuronium-vecuronium interaction on tetanic fade based on a generalized response surface model with varying relative potencies / 대한마취과학회지

BACKGROUND: Some studies have shown that rocuronium and vecuronium have additive, or synergistic effects on muscle relaxation based on the Loewe additivity. Therefore, we performed a fit of tetanic fade data to a generalized response surface model with varying relative potencies proposed by Kong and Lee (KLGRS) to evaluate the usefulness of KLGRS for capturing the interspersed drug interactions and to characterize the interaction between the two drugs. METHODS: Left phrenic nerve-hemidiaphragms (Male Sprague-Dawley rats, 150-250 g) were mounted in Krebs solution. Supramaximal electrical stimulation (0.2 ms, rectangular) of 50 Hz for 1.9 s to the phrenic nerve evoked tetanic contractions that were measured with a force transducer. Each preparation was exposed to one of 4 vecuronium concentrations (0.0, 1.5, 2.5, and 3.0 microM), or one of 4 rocuronium concentrations (0.0, 3.0, 4.5, and 5.5 microM). Subsequently the adequate amount of rocuronium was added to a vecuronium bath and that of vecuronium was added to a rocuronium until an 80-90% increase in tetanic fade was achieved. We then fitted the modified KLGRS models to the above data, after which we selected the best model, based on 5 methods for determining goodness of fit. Using this method, we obtained the response surface, as well as contour plots for the response surface (i.e. isoboles), the polynomial function and the interaction index. RESULTS: The model with the constant relative potency ratio and 8 parameters was found to best describe the results, and this model reflected well the characteristics of the raw data. In addition, the two drugs showed a synergistic interaction in almost every area and an antagonistic one in a very narrow area. CONCLUSIONS: KLGRS was found to be a useful method of analyzing data describing interspersed drug interactions. The interaction between rocuronium and vecuronium was found to be synergistic.

An Application of Discrete Probability Models to the Number of Outpatient Visits

It is hypothesized that the number of outpatient visits can be represented by three different probability models: the truncated Poisson distribution, the Zeta distribution and the logarithmic series distribution. Maximum likelihood estimates of parameters of the above distributions were obtained by using grouped data according to the number of visits. A goodness-of-fit test was also made to compare the fit of the three distributions and the value of this statistic was classified and compared according to the types of medical care facilities. Based on the likelihood ratio statistic as a test criterion, both the truncated Poisson and Zeta distributions were not appropriate for the model of the number of outpatient visits. However, the logarithmic series distribution provides a good fit to data in the case of university hospitals, general hospitals and hospitals. When we apply this distribution in the 10 most common diseases, the estimates of the parameter vary from 0.39567 to 0.54176 for university hospitals, from 0.45329 to 0.65387 for general hospitals, and from 0.55104 to 0.77625 for hospitals. On the other hand in the case of clinics, even the logarithmic series distribution cannot be fitted to the data well. A characteristic of clinic utilization with almost homogeneous treatment patterns, in spite of the fact that there are a great many clinics, could be the reason for the above results.