ABSTRACT The inventory of the vascular flora in the area of forest fragments along the Transistmican highway, Boyd - Roosevelt produced the following results: 52 families of vascular plants (43 dicotyledonous and 9 monocotyledonous) with 136 genera, 152 species. The best represented families in terms of species number are: Fabaceae (18), Arecaceae (10), Malvaceae (9), Rubiaceae (8), Annonaceae, Apocynaceae, Bignoniaceae, Euphorbiaceae and Poaceae (6). 19% of the species are herbaceous, 29% are shrubs and 52% trees.

RESUMEN El estudio florístico realizado en el área de los fragmentos boscosos a lo largo de la carretera Transístmica, Boyd - Roosevelt registró la presencia de 52 familias de plantas vasculares (43 dicotiledóneas y 9 monocotiledóneas), 136 géneros, 152 especies. Las familias mejor representadas son: Fabaceae (18), Arecaceae (10), Malvaceae (9), Rubiaceae (8), Annonaceae, Apocynaceae, Bignoniaceae, Euphorbiaceae y Poaceae (6). El 19% de las especies corresponden a la forma de vida herbácea, 29% son arbustos y 52% árboles.

Foundation: cytological study in the most important of the programs for early detection of cervical uterus cancer. The most frequently atypia found was squamous cells of undetermined significance. Objective: to determine the incidence of squamous cells of undetermined significance in the consultation of Cervix Pathology at the Gyneco-Obstetric University Hospital Mariana Grajales. Method: it was a cross-sectional study in a universe constituted by the 206 patients referred to the cervix pathology consultation during the year 2011. The sample was 120 women from the organic cytology registration book at the pathological anatomy department of the Hospital, who had all the required data with a report of atypical squamous cells of undetermined significance. The studied variables were: age in years completed at the time of diagnosis, age in years of the first sexual relations and the number of births. A data file was created in Excel where the necessary calculations were made. Absolute numbers and percentages were used to summarize the qualitative and average variables, standard deviation, minimum and maximum values for the quantitative variables. Results: an incidence of atypical squamous cells of undetermined significance of 0.37 % was obtained, it predominated in women older than 40 and younger than 50 years old and most of them started their sexual relations before the age of 20 and had 2 children. Conclusion: the report incidence of atypical squamous cells during the studied period of time was low; it predominated in middle-aged women, in those who had an early sexual relation and in multiparous women.

Fundamento: el estudio citológico es el más importante en los programas de detección precoz de cáncer cervicouterino, siendo la atipia de células escamosas de significado indeterminado la anomalía más frecuente encontrada. Objetivo: determinar la incidencia de atipia de células escamosas de significado indeterminado en la consulta de patología de cuello del Hospital Universitario Ginecobstétrico Mariana Grajales de la provincia Villa Clara. Método: se realizó un estudio de tipo transversal en el que el universo estuvo constituido por las 206 pacientes remitidas a la consulta de patología de cuello durante el año 2011, la muestra fue de 120 mujeres que en el libro de registro de citologías orgánicas del departamento de anatomía patológica del Hospital, contaban con la totalidad de los datos requeridos con un reporte de células escamosas atípicas de significado indeterminado. Las variables estudiadas fueron: edad en años cumplidos al momento del diagnóstico, la edad en años de las primeras relaciones sexuales y el número de partos. Se confeccionó un fichero de datos en Excel donde se realizaron los cálculos necesarios. Se emplearon números absolutos y porcentajes para resumir las variables cualitativas y media, desviación estándar, valores mínimos y máximos para las cuantitativas. Resultados: se obtuvo una incidencia de células escamosas atípicas de significado indeterminado de un 0,37 %, predominó en las mujeres mayores de 40 y menores de 50 años, la mayoría inició sus relaciones sexuales antes de los 20 años y tuvieron 2 hijos. Conclusión: la incidencia de reportes de células escamosas atípicas durante el período de tiempo estudiado fue baja, predominó en mujeres de mediana edad, en aquellas que iniciaron sus primeras relaciones sexuales de manera precoz y en las multíparas.

ABSTRACT Statistical modeling is commonly used in both predictive and explanatory studies in health research. Its use in Cuba continues to grow, although it is sometimes employed inappropriately, which can lead to errors that imperil validity. This article attempts to shed light on faulty practices in statistical modeling by examining and discussing the main differences between explanatory and predictive models, with reference to the following: study objectives, theoretical considerations in model-building, aspects requiring assessment, variable and algorithm selection, analysis of confounders, treatment of multicollinearity, and reporting results.

Introduction: predictive models are support tools when it comes to decision making in public health. We should count on a specific form of internal validation, as a part of the development of these models, which allows us to quantify any optimism in their predictive performance. For this validation, the same group of study employed for its performance is used, and results are reproducible to the underlying population.Objective: to validate an index of orthodontic treatment need, created by means of a methodology, that uses the values of Cramer's V of each predictor in order to build the multivariate model. Methods: the model created with the training sample was applied to 181 students from a primary school of Santa Clara, and measures of discriminatory performance were calculated, such as, area under the receiver operating characteristic curve, as well as, parameters were calculated from the confusion matrices. Models obtained by means of the new method and the logistic regression were also compared. Results: the new model exceeds logistic regression in all calculated parameters with values of sensitivity, specificity and validity of 79,3 %, 84,3 % and 81,2 %, respectively. Area under the curve was of 0,886. Conclusions: these results support the obtained index through Cramer ` V in order to be used in the underlying target population. The easiness of calculation and comprehension of this methodology are arguments in favor of its use for health decision - makers in primary care

Introducción: los modelos predictivos sirven de apoyo a la toma de decisiones en salud pública. Como parte del desarrollo de estos modelos, se debe contar con alguna forma de validación interna que permita cuantificar el optimismo en su desempeño predictivo. Para esta validación, se utiliza el mismo grupo de estudio empleado para su desarrollo y los resultados son reproducibles a la población subyacente. Objetivo: validar un índice de necesidad de tratamiento ortodóntico, creado mediante una metodología que utiliza, para construir el modelo multivariante, los valores del estadígrafo V de Cramer de cada predictor. Métodos: el modelo creado con la muestra de entrenamiento, se aplicó a 181 estudiantes de una escuela primaria de Santa Clara y se calcularon medidas del desempeño discriminatorio; estas fueron: área bajo la curva Receiver Operating Characteristic y parámetros calculados a partir de las matrices de confusión. Fueron comparados los modelos obtenidos mediante el nuevo método y la regresión logística. Resultados: el nuevo modelo superó en todos los parámetros calculados a la regresión logística, con valores de sensibilidad, especificidad y validez de 79,3 %, 84,3 % y 81,2 %, respectivamente. El área bajo la curva fue de 0,886. Conclusiones: estos resultados avalan el índice obtenido mediante V de Cramer, para su utilización en la población diana subyacente. La facilidad de cálculo y comprensión de esta metodología son argumentos a favor de su uso por decisores del sector en la atención primaria de salud

The aim of this article was approaching the usage of the statistical method in health researches beginning from the critical analysis of the reviewed literature. Emphasis was made in the necessity of recognizing the importance of the continuous training of the health care professionals in themes of descriptive, inferential and health statistics as essential elements for the development of professional activities as teaching, health assistance and research, beginning from pre-graduated studies and during the post-graduated ones. We itemized some recommendations on the usage of the statistical methods in health, resulting in a contribution to the successful development of health research from its design.

El objetivo de este artículo fue abordar, a partir del análisis crítico de la literatura revisada, el uso de los métodos estadísticos en las investigaciones en salud. Se enfatizó en la necesidad de reconocer la importancia de la superación continua desde el pregrado y durante el postgrado del profesional de la salud, en temas de estadística descriptiva, inferencial y de salud, como elementos esenciales para el desarrollo de la docencia, la asistencia y en la investigación. Se relacionaron algunas recomendaciones sobre el uso de los métodos estadísticos en salud, que resultan en una contribución al desarrollo exitoso de la investigación en salud desde su diseño.

INTRODUCTION: EKG remains a highly valuable tool for heart disease management. Corrected QT interval dispersion is a useful EKG parameter to assess prognosis in ischemic heart disease and specifically acute coronary syndrome. Understanding QT interval physiopathology helps assess importance of QT measurement in this context. Although increased QT dispersion is an ominous prognostic marker, its utility has not been evaluated for all types of acute coronary syndrome, even though in many circumstances it is the only tool available for diagnosing patients with equivocal EKG signs and/or atypical symptoms. OBJECTIVE: Describe corrected QT interval dispersion in acute coronary syndrome in three groups of patients-with ST elevation, without ST elevation, and without ST elevation with equivocal EKG signs-admitted to the intensive care unit of Celestino Hernández Robau University Hospital in Santa Clara, Cuba, from January 2010 through June 2011. METHODS: A descriptive retrospective study was conducted in 194 patients admitted with diagnosis of acute coronary syndrome. QT interval was measured and its dispersion calculated for the first EKG after symptom onset. Patterns were assessed for typical and atypical clinical presentations, and unequivocal and equivocal EKG signs. RESULTS: Nonclassifiable acute coronary syndrome was found in 6.7% of patients (13/194), the majority of whom had increased QT dispersion (76.9%, 10/13). There were significant differences in QT dispersion patterns between patients with typical and atypical presentations and between patients with equivocal and unequivocal EKG findings. In non-ST elevation acute coronary syndrome and nonclassifiable acute coronary syndrome with increased dispersion, atypical presentation was the most common (65.5%, 19/29; and 90%, 9/10, respectively). CONCLUSIONS: Corrected QT interval dispersion is a useful diagnostic tool for acute coronary syndrome, especially when patients present with atypical symptoms and equivocal EKG findings. Thus, it is a low-cost alternative in management of acute coronary syndrome in resource-poor settings.

Statistical classification models are used every day in health care as evaluation systems allowing building homogeneous groups to help in prognostics, diagnostics, therapy choosing and any other situation. The usefulness of them is not only evident in the medical surroundings, but many of them tribute directly to the performance and policies improvement in the Public Health area. As part of the health technologies, they require a continuous assessment in the different environments they are performed. On the other hand, using them mechanically, without a critical mentality, could bring about more risks than benefits, so their predictive or explanatory power does not justify the usage of their outcomes in an unquestioned way.

Los modelos estadísticos de clasificación se emplean cotidianamente en salud como sistemas de evaluación que permiten construir grupos homogéneos en la ayuda de pronósticos, diagnósticos, elección de terapias y cuantas situaciones requieran la discretización como herramienta para la toma de decisiones más acertadas. Su utilidad no solo se evidencia en el ámbito médico sino que muchos de ellos ayudan a mejorar actuaciones y políticas en el sector de la salud pública. Como parte de las tecnologías sanitarias, requieren de una evaluación continua en los diferentes escenarios donde se ejecuten. Por otra parte, emplearlos de manera mecánica, sin una mentalidad crítica, puede traer más riesgos que beneficios, por lo que su poder predictivo o explicativo no justifica que sus resultados se empleen de manera incuestionada.