Eficacia del midazolam contra la ansiedad en niños de 1-3 años sometidos a cirugía / Effectiveness of midazolam against anxiety in children aged 1 to 3 years old who underwent surgery

Cualquier acto quirúrgico crea ansiedad, sobre todo en niños, a lo que se añade la ansiedad parental por separación a la entrada al salón de operaciones.Demostrar la eficacia del midazolam jarabe para controlar la ansiedad en niños de 1-3 años que fueron sometidos a cirugía que requería anestesia general en el Hospital Provincial Pediátrico Docente Pepe Portilla de Pinar del Río, en el período 2008-2009.Se realizó estudio de cohorte, longitudinal y prospectivo de casos y controles en niños. Treinta recibieron dosis de 0.5 mg/kg de peso, y 60 controles que no lo recibieron, previo consentimiento informado de los padres. Se midió tiempo de sedación, signos vitales, reacciones adversas y grado de satisfacción de padres y personal del salón de operaciones. Se calcularon frecuencias que fueron comparadas mediante X2.La muestra resultó homogénea por sexo, edades y el tipo de cirugía a realizarse (p> 0,05). La sedación se obtuvo desde los 10 minutos en (24 niños/30). La bradipnea fue el único efecto adverso observado en 7 niños. Los controles (100 por ciento taquipneicos y llorosos). El 76.7 por ciento de los padres y el 100 por ciento del personal estuvo satisfecho con los efecto sedativos del midazolam.Es la primera vez que se usa esta droga como premedicación anestésica en niños 1-3 años, y se demuestra la eficacia y efectiva, con escasas reacciones adversas y gran aceptabilidad y satisfacción por padres y personal de salud(AU)

Any surgical procedure creates anxiety, especially in children, and also parental separation anxiety is added at the entrance to the operating room.The objective was to determine the effectiveness of midazolam syrup against anxiety in children aged 1 to 3 years old who were undergoing surgery and requiring general anesthesia, in Pepe Portilla Provincial Pediatric Teaching Hospital of Pinar del Rio, in the period 2008-2009.A prospective, longitudinal and cohort study of cases and control was carried out in children (ASA I or II). Thirty received the syrup by drops, in a dose of 0.5 mg/kg, and 60 controls who did not receive it, under informed parental consent. Sedation period, vital signs, adverse reactions and degree of satisfaction of parents and staff of the operating room were measured. Frequencies compared using the chi-square test also calculated.The sample was homogeneous by sex, age and type of surgery performed (p> 0.05). Sedation was obtained from 10 minutes on in 24 out of 30 children. Bradypnea was the only adverse effect observed with midazolam syrup in 7 children. The controls (100 percent tachypneic and crying children). 76.7% of the parents and 100 percent of the medical staff were satisfied with the sedative effect of midazolam.This is the first time this drug has been used as a premedication in children aged 1 to 3 years old, and the effectiveness and efficacy has been proved, with few adverse and wide acceptability and satisfaction by the parents and the medical staff.

Percepción de la mujer gestante sobre su función sexual / The pregnant woman's knowledge about her sexual function

Para comprender la conducta sexual humana durante el embarazo es necesario valorar áreas sumamente extensas como las de tipos anatómicas, fisiológicas y socioculturales. Identificar la percepción que tienen las mujeres gestantes sobre su función sexual.Investigación longitudinal, prospectiva y analítica en el Policlínico Universitario Hermanos Cruz de la provincia de Pinar del Río, entre abril de 2009 y febrero de 2010. El universo quedó conformado por todas las mujeres embarazadas captadas precozmente de los grupos básicos de trabajo 1, 2 y 3 (n = 218); para la selección de la muestra se escogieron al azar 21 consultorios, y de ellos, se seleccionaron las primeras siete gestantes captadas antes de las 13 semanas de embarazo (n = 147); se empleó un cuestionario el que fue aplicado en los tres trimestres del embarazo, para la validación de los resultados se empleó la prueba de ji cuadrado con nivel de significación de p<0,05.La edad promedio de las mujeres fue de 28,6 años, el 46,26 por ciento eran trabajadoras, con predominio del preuniversitario como escolaridad, la primigesta y un promedio de 2,8 años de tiempo de matrimonio. La mediana de la frecuencia del coito fue de 1 en el primero y tercer trimestre, existiendo una disminución de dicha frecuencia en ambos trimestre, también en estos períodos disminuyó la percepción del deseo y la excitación sexual, así como la apreciación cualitativa del orgasmo.Las mujeres perciben su función sexual muy perturbada durante el proceso de gestación(AU)

To understand the human sexual behavior during pregnancy it is required to assess broadly comprehensive areas such as anatomical, physiological and sociocultural. The objetive was to identify the pregnant women´s knowledge about their sexual behavior. Material and Analytical, prospective, longitudinal research in Hermanos Cruz Outpatient Polyclinic in Pinar del Río Province, between April 2010 and February 2011. The universe was made up of all pregnant women early caught from the basic work groups 1, 2 and 3 (n=218). To choose the sample 21 doctor´s offices were randomly chosen, and from these the first 7 pregnant women caught within the first 13 weeks of pregnancy (n=147). A questionnaire made up by the authors was used in three trimesters. To evaluate the statistical significance ALIGN="JUSTIFY">the Gamma and Friedman chi-square test was used at 95 percent of accuracy.The mean age of women was 28.6 years, 46.26 percent were workers, predominantly with pre-university schooling, primigravida and an average time of 2.8 years of marriage. Median coital frequency was 1 in the first and third quarters, and there is a decrease in the frequency in both quarters, even in these periods perception of desire and arousal decreased, and so did the qualitative assessment of orgasm, by which variations are shown in the various terms (p <0.05).During gestation changes in coital frequency occurred, and so did sexual desire and arousal and orgasm phases of the sexual response.

Influencia de la gestación en la sexualidad de la mujer / Influence of pregnancy in the woman's sexuality

Rsulta impostergable considerar la sexualidad en el contexto de la salud integral de la mujer, por la recuperación que tiene en el estilo de vida, y el proceso de gestación puede afectar el comportamiento sexual de la pareja. Determinar la influencia que tiene la gestación en la sexualidad de la mujer. Investigación longitudinal, prospectiva y analítica en el policlínico Hermanos Cruz de la provincia de Pinar del Río, entre abril de 2010 y febrero de 2011. El universo quedó conformado por todas las mujeres embarazadas captadas precozmente de los grupos básicos de trabajo (GBT) 1, 2 y 3 (n = 218); para la selección de la muestra se escogieron al azar 21 consultorios, y de ellos se seleccionaron las primeras siete gestantes captadas antes de las 13 semanas de embarazo (n = 147); se empleó un cuestionario el que fue aplicado en los tres trimestres del embarazo, para la validación de los resultados se empleó la prueba de ji cuadrado con nivel de significación de p < 0,05. Se obtuvo una mediana de 2, 3 y 2 coitos semanales según los trimestres del embarazo, en cuanto al deseo sexual, la excitación sexual, el orgasmo y la satisfacción sexual tuvieron una relación altamente significativa con el primero y tercer trimestre de la gestación. El embarazo es un proceso que lleva aparejado un trastorno en la sexualidad de la mujer(AU)

It is timely to consider sexuality in the context of the woman's comprehensive health, for the recovery in the lifestyle, and the pregnancy process can affect the couple's sexual behavior. The objective was to determine the influence of pregnancy in the woman's sexuality. Longitudinal, prospective and analytic research carried out in Pinar del Río Hermanos Cruz Outpatient Polyclinic, from April 2010 to February 2011. The target group was made up of all the pregnant women early caught from the basic work groups 1, 2 and 3 (n=128), for choosing the sample 21 medical family offices were randomly chosen, and from them the first seven pregnant women were caught before the 13 weeks of pregnancy (n=147). A questionnaire was applied in the first three trimesters during the pregnancy. For validating the result we used the chi-square test, with signification level of p < 0.05. A media of 2, 3 or 4 coituses weekly was obtained according the pregnancy's trimesters. Regarding sexual desire, sexual arousal, orgasm, and sexual satisfaction, they had a highly significant relation in the pregnancy's first and third trimesters. Pregnancy is a process entailing disorders in the woman's sexuality(AU)

Power analysis on the time effect for the longitudinal Rasch model.

Statistics literature in the social, behavioral, and biomedical sciences typically stress the importance of power analysis. Patient Reported Outcomes (PRO) such as quality of life and other perceived health measures (pain, fatigue, stress,...) are increasingly used as important health outcomes in clinical trials or in epidemiological studies. They cannot be directly observed nor measured as other clinical or biological data and they are often collected through questionnaires with binary or polytomous items. The Rasch model is the well known model in the item response theory (IRT) for binary data. The article proposes an approach to evaluate the statistical power of the time effect for the longitudinal Rasch model with two time points. The performance of this method is compared to the one obtained by simulation study. Finally, the proposed approach is illustrated on one subscale of the SF-36 questionnaire.

Thyroglobulin in lymph node fine-needle aspiration washout: a systematic review and meta-analysis of diagnostic accuracy.

CONTEXT: The thyroglobulin measurement in the needle washout after fine-needle aspiration (FNA) has been reported to increase the sensitivity of FNA in identifying lymph node (LN) metastases from differentiated thyroid cancer (DTC). OBJECTIVE: The aim of the study was to estimate the diagnostic accuracy of this technique. DATA SOURCES: To identify eligible studies, we searched electronic databases for original articles in English from 1975 through 2013. STUDY SELECTION: Studies that enrolled participants with suspicious neck LNs during thyroid nodule workup or thyroid cancer follow-up were included. DATA EXTRACTION: Working independently, authors used a standard form to extract data. For quality assessment, QUADAS2 guidelines were applied. DATA SYNTHESIS: Including all the selected studies (24 studies, 2865 LNs) in the pooled analysis, overall sensitivity was 95.0% (95% confidence interval [CI], 93.7-96.0%), specificity was 94.5% (95% CI, 93.2-95.7%), and diagnostic odds ratio (DOR) was 338.91 (95% CI, 164.82-696.88) with significant heterogeneity (inconsistency [I(2)] = 65.7%; heterogeneity, P < .001). Stratifying different populations and including only patients with thyroid gland (410 LNs), pooled sensitivity was 86.2% (95% CI, 80.9-90.5%), specificity was 90.2% (85.1-94.0%), and DOR was 56.621 (22.535-142.26; I(2) = 37.3%; heterogeneity, P = .121). Including only patients after thyroidectomy (1007 LNs), pooled sensitivity was 96.9% (95% CI, 94.9-98.2%), specificity was 94.1% (91.7-96.0%), and DOR was 407.65 (198.67-836.46; I(2) = 0.0%; heterogeneity, P = .673). CONCLUSIONS: Thyroglobulin measurement in washout from LN FNA has high accuracy in early detection of nodal metastases from DTC. The technique is simple, but a better standardization of criteria for patient selection, analytical methods, and cutoff levels is required.

Selectivity of attrition in longitudinal studies of cognitive functioning.

OBJECTIVES: Identify characteristics distinguishing people who do and do not continue to participate in a longitudinal study and determine whether the longitudinal changes for people who continue are representative of the changes that would have occurred had longitudinal data been available from all of the initial participants. METHOD: Moderately large samples of returning (N = 2,082) and nonreturning (N = 1,698) participants across a wide age range (i.e., 18-97 years of age) performed a battery of cognitive tests and completed personality and mood questionnaires. Differences between the groups were examined with multiple regression analyses with age, returner status, and their interaction as predictors. RESULTS: Compared with participants who did not return, returning participants at the initial occasion had higher levels of each cognitive ability and of certain personality characteristics (e.g., agreeableness and openness), but many of the differences were only apparent among adults older than 50 years of age. Importantly, there was no evidence that the longitudinal change for nonreturning participants would have been different from that among the participants who did return. DISCUSSION: The phenomenon of selective attrition is more complex than often assumed, and it may not necessarily limit the generalizability of longitudinal comparisons.

Missing data in longitudinal studies: cross-sectional multiple imputation provides similar estimates to full-information maximum likelihood.

PURPOSE: The aim of this research was to examine, in an exploratory manner, whether cross-sectional multiple imputation generates valid parameter estimates for a latent growth curve model in a longitudinal data set with nonmonotone missingness. METHODS: A simulated longitudinal data set of N = 5000 was generated and consisted of a continuous dependent variable, assessed at three measurement occasions and a categorical time-invariant independent variable. Missing data had a nonmonotone pattern and the proportion of missingness increased from the initial to the final measurement occasion (5%-20%). Three methods were considered to deal with missing data: listwise deletion, full-information maximum likelihood, and multiple imputation. A latent growth curve model was specified and analysis of variance was used to compare parameter estimates between the full data set and missing data approaches. RESULTS: Multiple imputation resulted in significantly lower slope variance compared with the full data set. There were no differences in any parameter estimates between the multiple imputation and full-information maximum likelihood approaches. CONCLUSIONS: This study suggested that in longitudinal studies with nonmonotone missingness, cross-sectional imputation at each time point may be viable and produces estimates comparable with those obtained with full-information maximum likelihood. Future research pursuing the validity of this method is warranted.

Satisfacción con el tratamiento antidepresivo. Validación del cuestionario "ESTA" / Validation of Questionnaire “ESTA”, designed to assess the satisfaction with antidepressant treatment. Spain

Fundamento: No existen cuestionarios para evaluar la satisfacción con el tratamiento antidepresivo, el cual repercute en la calidad de vida relacionada con la salud. El objetivo fue desarrollar y validar un instrumento específico para valorar la satisfacción con el tratamiento antidepresivo, determinando su validez convergente respecto a su efectividad clínica, cumplimiento de expectativas, adherencia terapéutica y tolerabilidad. Métodos: Estudio observacional longitudinal donde 168 pacientes iniciaron tratamiento antidepresivo y fueron evaluados durante un año. Las variables incluyeron efectos adversos, cumplimiento e intensidad de síntomas depresivos. En el cuestionario para la Evaluación de la Satisfacción con el Tratamiento Antidepresivo (ESTA), de 11 ítems respondidos mediante escala Likert, se evaluó su fiabilidad, validez de construcción y concurrente con mediciones relacionadas conceptualmente con dicho constructo. Resultados: El α de Cronbach osciló entre 0,936 y 0,951. En el análisis factorial un solo factor explicó el 63,76% de la varianza. La puntuación media del cuestionario ESTA osciló entre 40,0 y 44,7 puntos, observándose una correlación negativa respecto a las escalas de Hamilton (-0,321/-0,601) y Montgomery-Asberg (-0,491/-0,307). La satisfacción con el tratamiento antidepresivo al cabo de un mes fue 39,5 en incumplidores y 44,3 en cumplidores. En quienes presentaron efectos adversos fue 39,2 frente a 43,3 de quienes no los presentaron. En la primera visita (15 días) la puntuación fue 40,0; al mes 42,6; a los 3 meses 44,4 y a los 6 meses 44,5. Estas diferencias fueron estadísticamente significativas para p<0,05. En el análisis de fiabilidad test-retest el coeficiente de correlación intraclase fue 0,908. Conclusiones: El cuestionario ESTA, diseñado para evaluar la satisfacción con el tratamiento antidepresivo, es válido y fiable, constituyendo un instrumento de medición centrado en el paciente complementario a la valoración clínica de la efectividad del tratamiento antidepresivo (AU)

Background: We have no questionnaires to assess satisfaction with antidepressant treatment, which affects the health related quality of life. The objective was to develop and validate a specific instrument to assess satisfaction with antidepressant treatment, determining convergent validity regarding clinical effectiveness, fulfillment of expectations, adherence and tolerability. Methods: Longitudinal observational study where 168 patients started antidepressant treatment and were followed for one year. The variables included adverse effects, compliance and intensity of depressive symptoms. The questionnaire for the Evaluation of Antidepressant Treatment Satisfaction (ESTA) consists of 11 items answered using Likert scale. We evaluated its reliability, construct validity and concurrent validity with conceptually related measures with the construct assessed. Results: The Cronbach's alpha statistic ranged between 0.936 and 0.951. In the factor analysis one factor accounted for 64.11% of the variance. The average score of the questionnaire ranged from 40.0 to 44.7 points, showing a negative correlation regarding the Hamilton scale (-0.321 / - 0.601) and Montgomery-Asberg scale (-0.491 / -0.307). After a month, the antidepressant treatment satisfaction was 39.5 points in noncompliant patients and 44.3 in compliers. In those who had adverse effects was 39.2 versus 43.3 for those who had not. At the first visit (15 days) the score was 40.0, in a month 42.6, in 3 months 44.4 and in 6 months 44.5. These differences were statistically significant (p <0.05). In test-retest analysis, intraclass correlation coefficient was 0.908. Conclusions: The questionnaire, designed to assess satisfaction with antidepressant treatment, is valid and reliable, and provides a patient-centered instrument which is complementary to the clinical assessment of the effectiveness of antidepressant treatment (AU)

Incidencia de lesiones cervicales asociadas a fracturas mandibulares aisladas causadas por agresión física / Incidence of cervical spine injuries associated with isolated mandibular fractures caused by physical aggression

Los traumatismos suprclaviculares que se asocian a las fracturas de la mandíbula pueden ser generadores de lesiones cervicales, si estas no son diagnosticadas en la evaluación integral del paciente policontundido pueden pasar desapercibidas causando complicaciones neurológicas, musculares o la muerte. Objetivo. Determinar la presentación e incidencia de las lesiones cervicales asociadas a las fracturas mandibulares. Material y métodos. Estudio tipo cohorte, observacional, prospectivo-longitudinal, donde se incluyeron 25 pacientes con diagnóstico de fractura mandibular aislada durante el periodo de mayo de 2010 a febrero de 2011, que acudieron al servicio de cirugía maxilofacial del Hospital Central «Dr. Ignacio Morones Prieto» en San Luís Potosí. Resultados. De los 25 pacientes, fueron 24 hombres y una mujer, con una edad media de 26,4 años. Los estudiantes fueron los más involucrados. El tipo de agresión física que destacó fue la violencia interpersonal por riña. El 44% de los pacientes identificó los efectos del uso de alcohol en sus agresores. Ninguno de los pacientes presentó alteraciones de sensibilidad y tuvieron una fuerza muscular normal. El tipo de lesión cervical predominante fue la anterolistesis. Radiográficamente, la dimensión de los tejidos blandos prevertebrales correspondió a las cifras promedio de los tejidos sanos, la inestabilidad cervical máxima fue de 3 mm. El diámetro de la columna de aire, fue en promedio de C1:13,28 mm, C3:11,52 mm y C6:22,04 mm. Conclusiones. Las lesiones cervicales en pacientes con fractura mandibular causada por agresión física son comunes pero suelen cursar de manera subclínica por lo que es muy importante la inspección clínica y radiográfica(AU)

Supraclavicular trauma associated with fractures of the mandible may lead to cervical spine injuries if they are not diagnosed in the comprehensive evaluation of the multiple trauma patient, and may cause subclinical or unnoticed neurological and muscular complications, and even death. Objective: To determine the presentation and incidence of cervical spine injuries associated with mandibular fractures. Material and methods: A prospective, longitudinal and observational study was performed on a 25 patient cohort diagnosed with isolated mandibular fracture during the period from May 2010 to February 2011, and who were seen in the “Dr. Ignacio Morones Prieto” hospital in San Luis Potosi (Mexico) Results: The majority of the 25 patients were students with a mean age of 26.4 years of whom 24 were male and 1 was female. The most frequent type of physical aggression was a violent interpersonal violence. The effects of alcohol on their assailants were identified by 44% of the patients. None of the patients showed any changes in sensitivity and had normal muscle strength. The type of cervical spine lesion was predominantly anterolisthesis. The prevertebral soft tissue was radiographically within normal limits and the, the dimension of the corresponded to the average figures for normal tissue, maximum cervical instability was 3mm. The mean diameters of the air column were, C1: 13.28mm, C3: 11.52mm, and C6: 22.04mm. Conclusions: Cervical spine lesions in patients with mandibular fractures caused by physical assault are common and often have subclinical course, so a clinical and radiographic evaluation is very importan(AU)

¿Neurodesarrollo o neurodegeneración? Estado actual / Neurodevelopment or neurodegeneration? An update

La esquizofrenia es una enfermedad que se caracteriza por un curso crónico y a menudo incapacitante. A pesar de los avances en el conocimiento de esta enfermedad, todavía hay aspectos poco claros, como son los determinantes del curso y pronóstico. Las 2 hipótesis etiopatogénicas principales que intentan responder a estas preguntas son la hipótesis del neurodesarrollo y la hipótesis neurodegenerativa, no mutuamente excluyentes. Gracias al avance en diferentes técnicas, entre ellas la neuroimagen, en los últimos años se ha podido profundizar en el estudio de estas hipótesis. El presente trabajo revisa críticamente el estado actual de su conocimiento (AU)

Schizophrenia is a characterised by its chronic and often incapacitating course. Despite the advances in the knowledge of this disease, some aspects are still unclear, such as the factors determining its course and prognosis. The two main aetiopathological hypotheses, which try to answer these questions, are the neurodevelopment hypothesis and the neurodegenerative hypothesis, not mutually exclusive. Due to the advances in different techniques, neuroimaging among them, it has made it possible to study these hypotheses in greater detail. The present article critically reviews the current state of its knowledge (AU)

Risk of attrition in a longitudinal study of skin cancer: logistic and survival models can give different results.

OBJECTIVES: Longitudinal studies are a major tool for public health research, but their value can be undermined by attrition. Identification of factors associated with attrition through modeling depends on the efficient use of data and is conditional on modeling assumptions being met. The primary aim of this study was to compare the performance of four models in analyzing attrition risk. STUDY DESIGN AND SETTING: Data from participants who were lost to follow-up from The Nambour Skin Cancer Study between 1992 and 2000 were analyzed using logistic and survival models, for all-cause and nondeath attritions. RESULTS: During follow-up, 321 (19.8%) of 1,621 participants were lost to follow-up; 70 (4.3%) because of death and 251 (15.5%) for other reasons. Using survival models showed skin cancer diagnosis to be associated with increased all-cause attrition (hazard ratio: 2.3; 95% confidence interval [95% CI]: 1.5, 3.4) and nondeath attrition (subhazard ratio: 1.9; 95% CI: 1.0, 3.3). Using logistic regression resulted in inverse associations being observed for both all-cause attrition (odds ratio [OR]: 0.7; 95% CI: 0.5, 1.1) and nondeath attrition (OR: 0.5; 95% CI: 0.3, 1.0). CONCLUSION: These results demonstrate the relative inadequacy of a logistic as opposed to a survival approach when analyzing attrition risk in the presence of time-varying covariates and multiple timepoints.

Evaluation of time-varying and cumulative effects in nursing in a longitudinal study.

BACKGROUND: Traditional statistics in longitudinal data analysis are likely to be insufficient in nursing studies, in which the time varying characteristics of explanatory variables and cumulative effects require additional consideration. OBJECTIVES: The aims of this study were to introduce alternative longitudinal approaches for incorporating time-varying variables and cumulative effects, to discuss their strengths, and to highlight key issues that nursing researchers should recognize before and while undertaking such analyses. RESULTS: The three alternative models provide differing analytical outcomes based on the research focus. The baseline tracking model was used to estimate the stability effect of an intervention program, detecting risk factors early. The temporal sequence of potential cause and effect was incorporated further in the time-dependent model. The cumulative model was used to explore whether cumulative intervention effects existed. CONCLUSION: Nurse researchers should incorporate alternative methods into the longitudinal data analysis tools they commonly use when facing explanatory variables with time variations or cumulative effects on the variable being measured.

Assessing possible selection bias in a national voluntary MS longitudinal study in Australia.

BACKGROUND: Surveying volunteer members of a multiple sclerosis registry is a very cost-effective way of assessing the impact of the disease on life outcomes. However, whether the data from such a study can be generalised to the whole population of persons living with MS in a country or region is unclear. METHODS: Here we compare the demographic and disease characteristics of participants in one such study, the Australian Multiple Sclerosis Longitudinal Study (AMSLS), with two well-characterised MS prevalence studies with near-complete ascertainment of MS in their study regions. RESULTS: Although some differences were found, these largely represented the effects of geography (sex ratios) and local factors (national immunomodulatory therapy prescribing requirements), and the cohorts were otherwise comparable. Overall, despite comprising only 12-16% of MS cases in Australia, the AMSLS is highly representative of the MS population. CONCLUSIONS: Therefore with some minor caveats, the AMSLS data can be generalised to the whole Australasian MS population. Volunteer disease registries such as this can be highly representative and provide an excellent convenience sample when studying rare conditions such as MS.

Flexible marginalized models for bivariate longitudinal ordinal data.

Random effects models are commonly used to analyze longitudinal categorical data. Marginalized random effects models are a class of models that permit direct estimation of marginal mean parameters and characterize serial correlation for longitudinal categorical data via random effects (Heagerty, 1999). Marginally specified logistic-normal models for longitudinal binary data. Biometrics 55, 688-698; Lee and Daniels, 2008. Marginalized models for longitudinal ordinal data with application to quality of life studies. Statistics in Medicine 27, 4359-4380). In this paper, we propose a Kronecker product (KP) covariance structure to capture the correlation between processes at a given time and the correlation within a process over time (serial correlation) for bivariate longitudinal ordinal data. For the latter, we consider a more general class of models than standard (first-order) autoregressive correlation models, by re-parameterizing the correlation matrix using partial autocorrelations (Daniels and Pourahmadi, 2009). Modeling covariance matrices via partial autocorrelations. Journal of Multivariate Analysis 100, 2352-2363). We assess the reasonableness of the KP structure with a score test. A maximum marginal likelihood estimation method is proposed utilizing a quasi-Newton algorithm with quasi-Monte Carlo integration of the random effects. We examine the effects of demographic factors on metabolic syndrome and C-reactive protein using the proposed models.

The evolution of a clinical registry during 25 years of experience with Gamma Knife radiosurgery in Pittsburgh.

OBJECT: The first North American 201 cobalt-60 source Gamma Knife surgery (GKS) device was introduced at the University of Pittsburgh Medical Center in 1987. The introduction of this innovative and largely untested surgical procedure prompted the desire to study patient outcomes and evaluate the effectiveness of this technique. The parallel advances in computer software and database technology led to the development of a registry to track patient outcomes at this center. The purpose of this study was to describe the registry's evolution and to evaluate its usefulness. METHODS: A team was created to develop a software database and tracking system to organize and retain information on the usage of GKS. All patients undergoing GKS were systematically entered into this database by a clinician familiar with the technology and the clinical indications. Information included patient demographics and diagnosis as well as the anatomical site of the target and details of the procedure. RESULTS: There are currently 11,738 patients in the database, which began to be used in August 1987. The University of Pittsburgh Medical Center has pioneered the evaluation and publication of the GKS technique and outcomes. Data derived from this computer database have facilitated the publication of more than 400 peer-reviewed manuscripts, more than 200 book chapters, 8 books, and more than 300 published abstracts and scientific presentations. The use of GKS has become a well-established surgical technique that has been performed more than 700,000 times around the world. CONCLUSIONS: The development of a patient registry to track and analyze the use of GKS has given investigators the ability to study patient procedures and outcomes. The future of clinical medical research will rely on the ability of clinical centers to store and to share information.

Influencia de la práctica clínica en la presencia de puntos gatillo miofasciales en el músculo trapecio de estudiantes de enfermería. Estudio longitudinal descriptivo / Influence of clinical practice in trapezius muscle myofascial trigger points in nursing students: longitudinal descriptive study

Objetivo: Observar si la práctica clínica de estudiantes de enfermería influye en el estado de PGM en el trapecio. Participantes y métodos: Estudio longitudinal descriptivo en el que se evaluaron 30 estudiantes de tercero de la Escuela Universitaria de Enfermería de Alcalá de Henares. Criterios de inclusión: iniciar su primer período de prácticas tras la primera sesión de valoración. Criterios de exclusión: presentar alteración muscular sensitiva o trófica, estar realizando o iniciar algún tratamiento influyente. Se pasó un cuestionario sobre tareas desempeñadas en sus prácticas clínicas y otros factores sociodemográficos y del entorno académico-laboral. Se valoraron: la presencia de puntos gatillo miofasciales (activos y latentes) en el trapecio según criterios diagnósticos, el umbral de dolor a la presión (con algómetro), y los rangos de movimiento cervical activo. Todas las medidas se tomaron antes y después de un mes de prácticas. En el análisis estadístico se compararon los datos recopilados en el cuestionario con el estado de los PGM en los dos momentos, considerando una p<0.05 y el intervalo de confianza del 95%. Resultados: Todos los participantes fueron mujeres, que tras el período de prácticas clínicas, registraron una puntuación 1.8 superior en la escala analógica visual, mostraron un incremento medio de 1,55º en los rangos de movimiento cervical, salvo en la flexión; y el umbral de dolor a la presión aumentó de media 0.139 kg/cm2. Los PG 1 y 2 cambiaron de estado latente a activo en un 6,7% de sujetos, y el PG 5 en un 3,3%. Al final del período el PG6 apareció en el 6,7%. Conclusiones: Se han observado tendencias en las variables analizadas que permiten plantear el estudio más específico de factores biológicos y sociolaborales influyentes en la presencia de PGM, para establecer estrategias fisioterápicas eficientes antes de la incorporación al ámbito profesional (AU)

Aim: To observe whether the tasks performed by nursing students during their third year of nursing degrees have an influence on the state of MTP of their trapezius muscle. Participants and Methods: 30 third-year students from Alcalá de Henares University College of Nursing were evaluated. Exclusion criteria: to suffer any sense or trophic muscular disorder, to have begun or be receiving any influential treatment. A questionnaire about the types of tasks they carry out and other sociodemographic and academical work factors were done. Students were assessed to check the presence of some MTP in their trapezius, describing its active or dormant state through diagnostic criteria, their pressure pain threshold (measured with an algometer) and active ranges of cervical movements were also recorded. All measurements were taken before and after one month of the experiment. Through the statistical analysis the data collected in the questionnaire was compared with the state of the MTP in both moments, with a p<0.05 and a 95% confidence interval. Results: all the subjects were women who over the course of the experiment recorded a 1.8- upper scoring on the visual analogue scale, they showed an average increase of 1.55º in the cervical ranges of motion, except flexion; and the pressure pain threshold rose an average 0.139 kg/cm2. Trigger points (TP) 1 and 2 changed from dormant to active state on 6,7% of the subjects, and the TP5 on 3,3%. At the end of the experiment the TP6 appeared as 6,7% of them. Conclusions: tendencies have been observed among the analyzed variables which allow the proposition of more specific studies about biological and socio-labour factors linked to MTPs in order to establish physio-therapeutic efficient strategies for incorporation into the professional world (AU)

Continuous time modelling with individually varying time intervals for oscillating and non-oscillating processes.

When designing longitudinal studies, researchers often aim at equal intervals. In practice, however, this goal is hardly ever met, with different time intervals between assessment waves and different time intervals between individuals being more the rule than the exception. One of the reasons for the introduction of continuous time models by means of structural equation modelling has been to deal with irregularly spaced assessment waves (e.g., Oud & Delsing, 2010). In the present paper we extend the approach to individually varying time intervals for oscillating and non-oscillating processes. In addition, we show not only that equal intervals are unnecessary but also that it can be advantageous to use unequal sampling intervals, in particular when the sampling rate is low. Two examples are provided to support our arguments. In the first example we compare a continuous time model of a bivariate coupled process with varying time intervals to a standard discrete time model to illustrate the importance of accounting for the exact time intervals. In the second example the effect of different sampling intervals on estimating a damped linear oscillator is investigated by means of a Monte Carlo simulation. We conclude that it is important to account for individually varying time intervals, and encourage researchers to conceive of longitudinal studies with different time intervals within and between individuals as an opportunity rather than a problem.

Dynamic semiparametric Bayesian models for genetic mapping of complex trait with irregular longitudinal data.

Many phenomena of fundamental importance to biology and biomedicine arise as a dynamic curve, such as organ growth and HIV dynamics. The genetic mapping of these traits is challenged by longitudinal variables measured at irregular and possibly subject-specific time points, in which case nonnegative definiteness of the estimated covariance matrix needs to be guaranteed. We present a semiparametric approach for genetic mapping within the mixture-model setting by jointly modeling mean and covariance structures for irregular longitudinal data. Penalized spline is used to model the mean functions of individual quantitative trait locus (QTL) genotypes as latent variables, whereas an extended generalized linear model is used to approximate the covariance matrix. The parameters for modeling the mean-covariances are estimated by MCMC, using the Gibbs sampler and the Metropolis-Hastings algorithm. We derive the full conditional distributions for the mean and covariance parameters and compute Bayes factors to test the hypothesis about the existence of significant QTLs. We used the model to screen the existence of specific QTLs for age-specific change of body mass index with a sparse longitudinal data set. The new model provides powerful means for broadening the application of genetic mapping to reveal the genetic control of dynamic traits.