Caracterización epidemiológica, clínica y cefalométrica del brote anormal de los terceros molares / Epidemiological, clinical and cephalometric characterization of the abnormal eruption of third molars

Introducción: El brote de los terceros molares es un proceso que no está del todo explicado, pero durante su erupción puede provocar diferentes accidentes o complicaciones. Objetivo: Caracterizar el brote anormal de los terceros molares según variables epidemiológicas, clínicas y cefalométricas. Método: Se realizó un estudio observacional, descriptivo y transversal en la Clínica Estomatológica Provincial Docente «Mártires del Moncada», de Santiago de Cuba, desde noviembre de 2019 a febrero de 2020. La población estuvo conformada por jóvenes de 18 a 25 años de edad; la muestra fue seleccionada por muestreo aleatorio simple. Se tuvieron en cuenta las siguientes variables: sexo, color de la piel, brote anormal y otras variables cefalométricas. Resultados: De los 84 dientes incluidos en el estudio, se detectaron 66 terceros molares con brote anormal (78,6 %). El promedio asociado al brote de estos molares de espacio óseo superior insuficiente fue igual para los superiores con medias de 25,9 mm; el de angulación inadecuada resultó obtuso en el superior izquierdo con 128,3º y agudo en los inferiores derechos con 58,8º; asimismo el mayor diámetro mesiodistal inadecuado fue el de los inferiores derechos con 15,7 mm. Conclusiones: El brote anormal de los terceros molares se caracteriza por afectar, de forma importante, a féminas y a individuos mestizos. Su observación se singulariza, fundamentalmente, en molares inferiores con espacios óseos posteriores reducidos, mesioangulaciones y diámetros mesiodistales considerables.

Introduction: eruption of the third molars is a process that is not fully explained in the literature; however it is known that their eruption can cause different complications. Objective: to characterize the abnormal eruption of third molars according to epidemiological, clinical and cephalometric variables. Methods: an observational, descriptive and cross-sectional study was carried out at "Mártires del Moncada" Provincial Teaching Dental Clinic, in Santiago de Cuba, from November 2019 to February 2020. The population consisted of young people aged 18-25 years; the sample was selected by simple random sampling. Gender, skin color, abnormal eruption and other cephalometric variables were taken into account. Results: sixty-six third molars with abnormal eruption were detected from the 84 teeth included in the study (78.6%). The average associated with the eruption of these molars with insufficient upper bone space was the same for the upper ones with means of 25.9 mm; the average with inadequate angulation was obtuse in the upper left third molar with 128.3º and the acute one in the lower right third molars with 58.8º; the lower right third molars likewise had the largest inadequate mesiodistal diameter with 15.7 mm. Conclusions: the abnormal eruption of third molars is characterized by significantly affecting females and mixed-race individuals. Its observation is singled out, fundamentally, in lower molars with reduced posterior bone spaces, mesioangulations and considerable mesiodistal diameters.

Dental caries and depression in pregnant women: The role of oral health self-perception as mediator.

OBJECTIVE: This study investigated the role of oral health self-perception as mediator of association between dental caries and depression among pregnant women from the 2015 Pelotas Birth Cohort Study, Brazil. MATERIALS AND METHODS: Overall, 2,496 pregnant women participated of this oral health sub-study. Data related to demographic and socioeconomic conditions, lifetime and current depression, and oral health self-perception were collected. Participants were also assessed for dental caries (DMF-T index). Depression was assessed using the Edinburgh Postnatal Depression Scale. For analysis, six outcomes related to dental caries experience were considered. Causal mediation analysis was performed using parametric regression models. RESULTS: When it was assumed that all subjects had poor perception about oral health, it was observed that the presence of moderate/severe depressive signals and symptoms was higher in subjects with dental caries experience (OR 1.13; CI 95% 1.06-1.20), with severity of untreated dental caries (OR 2.08; CI 95% 1.16-3.78), untreated dental caries (OR 1.18; 95% CI 1.07-1.29), tooth loss (OR 1.08; 95% CI 1.02-1.14), and filled tooth (OR 1.07; 95% CI 1.02-1.16). CONCLUSIONS: Our findings show the effect of dental caries on depression is mediated by self-perception about oral health in pregnant women.

Comparison of sampling designs from the two editions of the Brazilian National Health Survey, 2013 and 2019 / Comparação de desenhos amostrais das duas edições da Pesquisa Nacional de Saúde, 2013 e 2019 / Comparación entre diseños muestrales de las dos ediciones de la Encuesta Nacional de Salud Brasil, 2013 y 2019

Our objective is to describe the differences in the sampling plans of the two editions of the Brazilian National Health Survey (PNS 2013 and 2019) and to evaluate how the changes affected the coefficient of variation (CV) and the design effect (Deff) of some estimated indicators. Variables from different parts of the questionnaire were analyzed to cover proportions with different magnitudes. The prevalence of obesity was included in the analysis since anthropometry measurement in the 2019 survey was performed in a subsample. The value of the point estimate, CV, and the Deff were calculated for each indicator, considering the stratification of the primary sampling units, the weighting of the sampling units, and the clustering effect. The CV and the Deff were lower in the 2019 estimates for most indicators. Concerning the questionnaire indicators of all household members, the Deffs were high and reached values greater than 18 for having a health insurance plan. Regarding the indicators of the individual questionnaire, for the prevalence of obesity, the Deff ranged from 2.7 to 4.2, in 2013, and from 2.7 to 10.2, in 2019. The prevalence of hypertension and diabetes per Federative Unit had a higher CV and lower Deff. Expanding the sample size to meet the diverse health objectives and the high Deff are significant challenges for developing probabilistic household-based national survey. New probabilistic sampling strategies should be considered to reduce costs and clustering effects.

Nosso objetivo é descrever as diferenças nos desenhos amostrais das duas edições da Pesquisa Nacional de Saúde (PNS 2013 e 2019) e avaliar como suas mudanças afetaram o coeficiente de variação (CV) e o efeito do desenho (Deff) de alguns dos indicadores avaliados. Variáveis de diferentes partes do questionário foram analisadas para avaliar proporções com diferentes magnitudes. A prevalência de obesidade foi incluída na análise uma vez que a medição de antropometria na pesquisa de 2019 foi realizada em uma subamostra. Os valores do estimador pontual, CV e Deff foram calculados para cada indicador considerando a estratificação das unidades amostrais primárias, a ponderação das unidades amostrais, e o efeito do agrupamento. Para a maioria dos indicadores, CV e Deff foram menores nas estimativas de 2019. Em relação aos indicadores para todos os membros familiares, Deffs foram elevados e atingiram valores superiores a 18 para a posse de um plano de saúde. Quanto aos indicadores no questionário individual, Deff variou de 2,7 a 4,2 em 2013 e de 2,7 a 10,2 em 2019 para a prevalência de obesidade. A prevalência de hipertensão arterial e diabetes por Unidade Federativa apresentou CV maior e Deff menor. A expansão do tamanho da amostra para atender aos diversos objetivos de saúde e Deff altos são desafios expressivos para o desenvolvimento de uma pesquisa nacional domiciliar probabilística. Novas estratégias de amostragem probabilística devem ser consideradas para reduzir custos e efeitos do agrupamento.

Nuestro objetivo es describir las diferencias en los diseños muestrales de las dos ediciones de la Encuesta Nacional de Salud (PNS 2013 y 2019) y evaluar cómo sus cambios afectaron el coeficiente de variación (CV) y el efecto de diseño (Deff) de algunos de los indicadores evaluados. Se analizaron variables de diferentes partes del cuestionario para evaluar proporciones con diferentes magnitudes. La prevalencia de obesidad se incluyó en el análisis, ya que la medición de la antropometría en la encuesta de 2019 se realizó en una submuestra. Los valores del estimador puntual, CV y Deff se calcularon para cada indicador considerando la estratificación de las unidades de muestreo primarias, la ponderación de las unidades de muestreo y el efecto de agrupamiento. Para la mayoría de los indicadores, CV y Deff fueron más bajos en las estimaciones de 2019. En cuanto a los indicadores para todos los miembros de la familia, los Deff fueron altos y alcanzaron valores superiores a 18 por tener un plan de salud. En cuanto a los indicadores del cuestionario individual, Deff osciló entre 2,7 y 4,2 en 2013, y entre 2,7 y 10,2 en 2019 para la prevalencia de obesidad. La prevalencia de hipertensión arterial y diabetes por Unidad Federativa tuvo mayor CV y menor Deff. Un mayor tamaño de la muestra para cumplir con los diversos objetivos de salud y un alto valor de Deff son desafíos importantes para el desarrollo de una encuesta nacional domiciliar probabilística. Se deben considerar nuevas estrategias de muestreo probabilístico para reducir los costos y efectos de agrupamiento.

Metodologías Cuantitativas 2: Sesgo de confusión y cómo controlar un confusor / Quantitative Methodologies 2: Confusion bias and how to control a confounding factor

Identificar el sesgo de confusión y cómo controlarlo es uno de los desafíos metodológicos más importantes en el diseño de estudios que buscan identificar la causalidad. Este sesgo está presente en cualquier análisis de la asociación entre una exposición y un resultado de interés, una asociación que puede estar sesgada o no por una tercera variable llamada confusor. Podemos diagnosticar un confusor en todos los casos en los que este crea una asociación espuria entre una variable de exposición o variable independiente y la variable de resultado o variable dependiente. Para controlar el sesgo de confusión, podemos usar diferentes métodos. Estos incluyen aquellas técnicas aplicadas en el diseño del estudio, tales como restricción, aleatorización y coincidencia, y aquellas técnicas empleadas en el análisis de datos, como la estratificación, el análisis multivariado, la estandarización, los puntajes de propensión, el análisis de sensibilidad y el inverso ponderación de probabilidad. En esta revisión, analizamos cómo identificar una variable de confusión y las principales técnicas para controlar el sesgo de confusión.

Addressing confounding bias is one of the challenges when conducting causality studies. This occurs when we report a causal association between an exposure and an outcome, when in fact it could be result of the effect of a third factor called confounding variable. That is, when a confounder variable creates a spurious relationship between the exposure or independent variable and the outcome of interest or dependent variable. By knowing the confounding variables and their association with the exposure of interest, the confounding bias could be controlled. To control for confounding bias, we can use different methods. These include techniques applied in study design, such as restriction, randomization, and coincidence, and techniques used in data analysis, such as stratification, multivariate analysis, standardization, propensity scores, analysis sensitivity and the inverse probability weighting. In this review, we discuss how to identify a confounding variable and the main techniques for controlling for confounding bias.

Serie de Redacción Científica: Estudios Trasversales / Scientific Writing Series: Cross-Sectional studies

Los estudios transversales se caracterizan por la medición simultánea de la exposición y el outcome de interés. Son el diseño idóneo para estimar prevalencias, analizar la precisión diagnóstica de una prueba y validar instrumentos, para lo cual es esencial controlar los sesgos de información, selección y confusión ya sea por diseño o por análisis. Asimismo, es crucial escoger la medida de asociación idónea para cada outcome de interés, llámese el odds ratio para eventos raros y la razón de prevalencias para los eventos frecuentes. Finalmente, para su redacción y publicación se recomienda revisar las guías STROBE y STARD

Cross-sectional studies are characterized by the simultaneous measurement of exposure and the outcome of interest. They are the ideal design to estimate prevalence, analyze the diagnostic accuracy of a test and validate instruments, for which it is essential to control information bias, selection, and confusion either by design or by analysis. It is also crucial to choose the appropriate association measure for each outcome of interest, call the odds ratio for rare events, and the prevalence ratio for frequent events. Finally, for its writing and publication, it is recommended to review the STROBE and STARD guidelines

Metodologías cuantitativas: Cálculo del tamaño de muestra con STATA y R / Quantitative methods: Sample size calculation with STATA and R

El cálculo de tamaño de muestra es un aspecto esencial del diseño de estudios cuantitativos. Un adecuado tamaño de muestra nos permite determinar cuál es la mínima cantidad de participantes necesarios para probar nuestra hipótesis de interés. De esta manera, podemos reducir costos, maximizar el uso de nuestros recursos de investigación y garantizar la factibilidad del estudio. Contradictoriamente, a pesar de su relevancia muy pocos investigadores dominan esta habilidad. Esta revisión tiene por objeto revisar los conceptos básicos para realizar un cálculo de tamaño de muestra y compartir códigos de Stata y R específicamente diseñados para facilitar estos cálculos.

The calculation of sample size is an essential aspect of the design of quantitative studies. An adequate sample size allows us to determine the minimum number of participants necessary to test our hypothesis of interest. Hence, we can reduce costs, maximize the use of our research resources and guarantee the feasibility of the study. Contradictorily, despite its relevance, very few researchers dominate this skill. This review aims to review the basics of sample size calculation and share Stata and R codes specifically designed to facilitate these calculations.

Questionnaire Breakoff and Item Nonresponse in Web-Based Questionnaires: Multilevel Analysis of Person-Level and Item Design Factors in a Birth Cohort.

BACKGROUND: Web-based questionnaires are increasingly used in epidemiologic studies, as traditional methods are facing a decrease in response rates and an increase in costs. However, few studies have investigated factors related to the level of completion of internet-based epidemiologic questionnaires. OBJECTIVE: Our objective was to identify person-level characteristics and item design factors associated with breakoff (not finishing the questionnaire) and item nonresponse in a Web-based questionnaire. METHODS: This study was a cross-sectional analysis of the baseline questionnaire, applied from 2005 to 2016, of the Italian NINFEA (Nascita e Infanzia: gli Effetti dell'Ambiente) birth cohort. The baseline questionnaire was administered to enrolled women, who could register at any time during pregnancy. We used logistic regression to analyze the influence of person-level factors on questionnaire breakoff, and a logistic multilevel model (first level: items of the questionnaire; second level: sections of the questionnaire; third level: study participants) to analyze the influence of person-level and item design factors on item nonresponse. Since the number of applicable items depended on the respondent's characteristics and breakoff, we used inverse probability weighting to deal with missing by design. RESULTS: Of 5970 women, 519 (8.69%) did not finish the questionnaire. Older age (adjusted odds ratio 1.40, 95% CI 1.05-1.88), lower educational level (adjusted odds ratio [OR] 1.53, 95% CI 1.23-1.90), and earlier stage of pregnancy (adjusted OR 3.01, 95% CI 2.31-3.92) were positively associated with questionnaire breakoff. Of the 1,062,519 applicable items displayed for the participants, 22,831 were not responded to (overall prevalence of item nonresponse 2.15%). Item nonresponse was positively associated with older age (adjusted OR 1.25, 95% CI 1.14-1.38), being in the first trimester of pregnancy (adjusted OR 1.18, 95% CI 1.06-1.31), and lower educational level (adjusted OR 1.23, 95% CI 1.14-1.33). Dropdown menu items (adjusted OR 1.77, 95% CI 1.56-2.00) and items organized in grids (adjusted OR 1.69, 95% CI 1.49-1.91) were positively associated with item nonresponse. CONCLUSIONS: It is important to use targeted strategies to keep participants motivated to respond. Item nonresponse in internet-based questionnaires is affected by person-level and item design factors. Some item types should be limited to reduce item nonresponse.

Experiencia en el Foro Global de Bioética en Investigación: desafíos para la revisión ética en Chile / Experience in the global forum of bioethics in research: challenges for the ethical review in Chile

The Global Forum on Bioethics in Research annually convenes a number of researchers, bioethicists and stakeholders with a shared interest in the ethics of conducting research in low and middle-income countries (LMIC). It provides a useful platform to discuss ethical issues that affect research practice in different scenarios, promoting ethically conducted research, global development for health research ethics and partnerships between the global north and south. As participant of the last three meetings, in this article the author analyzes the main ethical issues that were discussed in this forum, namely "Emerging epidemic infections and experimental medical treatments" (Annecy, France, 2015); "Ethics of research in pregnancy" (Buenos Aires, Argentina, 2016), and "The ethics of alternative clinical trial designs and methods in LMIC research" (Bangkok, Thailand, 2017). Local research ethics committees are not well prepared to face the new ethical challenges associated with research conducted in emergency situations or in pregnant women, or to evaluate new methods, such as alternative clinical trial designs (cluster randomized trials, adaptive platforms, or controlled human infection models, among others). According to this scenario, research ethics committees should be trained to carefully assess the risks and benefits of approving this type of research. In this context, it is necessary to harmonize local regulations with the new international standards in research ethics.

Influence of allocation concealment and intention-to-treat analysis on treatment effects of physical therapy interventions in low back pain randomised controlled trials: a protocol of a meta-epidemiological study.

INTRODUCTION: Meta-epidemiological studies examining the influence of methodological characteristics, such as allocation concealment and intention-to-treat analysis have been performed in a large number of healthcare areas. However, there are no studies investigating these characteristics in physical therapy interventions for patients with low back pain. The aim of this study is to investigate the influence of allocation concealment and the use of intention-to-treat analysis on estimates of treatment effects of physical therapy interventions in low back pain clinical trials. METHODS AND ANALYSIS: Searches on PubMed, Embase, Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database (PEDro) and CINAHL databases will be performed. We will search for systematic reviews that include a meta-analysis of randomised controlled trials that compared physical therapy interventions in patients with low back pain with placebo or no intervention, and have pain intensity or disability as the primary outcomes. Information about selection (allocation concealment) and attrition bias (intention-to-treat analysis) will be extracted from the PEDro database for each included trial. Information about bibliographic data, study characteristics, participants' characteristics and study results will be extracted. A random-effects model will be used to provide separate estimates of treatment effects for trials with and without allocation concealment and with and without intention-to-treat analysis (eg, four estimates). A meta-regression will be performed to measure the association between methodological features and treatment effects from each trial. The dependent variable will be the treatment effect (the mean between-group differences) for the primary outcomes (pain or disability), while the independent variables will be the methodological features of interest (allocation concealment and intention-to-treat analysis). Other covariates will include sample size and sequence generation. ETHICS AND DISSEMINATION: No ethical approval will be required for this study. The study findings will be published in a peer-reviewed journal and presented at international conferences. REGISTRATION NUMBER: International Prospective Register of Systematic Reviews (CRD42016052347).

¿Existen los diseños de investigación cuasi cohorte? / Are there any quasi-cohort research designs?

Cuando la población de estudio está integrada por un grupo de pacientes expuestos y se les observa durante un determinado periodo de tiempo para medir la presencia o ausencia de la enfermedad, el diseño se ubica en el contexto de los estudios observacionales, no obstante, no cumple con todos los requisitos de un diseño de cohorte, en consecuencia se podía decir que se trata de un diseño de investigación llamado cuasi cohorte.

When the study population is a group of exposed patients studied over a period of time to measure the presence or absence of disease, the design is placed in the context of observational studies, however, it does not meet all the criteria a cohort design, therefore it could be said that this is a research design quasi cohort.

Quando a população de estudo está integrada por um grupo de pacientes expostos e é observado durante um determinado período de tempo para avaliar a presença ou ausência de uma enfermidade, as características deste estudo são de estudo observacional, no entanto, não cumpre com todos os requisitos de um estudo de coorte, por tanto se poderia dizer que se trata de um estudo epidemiológico chamado quase coorte.

La necesidad de aplicar el método científico en investigación clínica: problemas, beneficios y factibilidad del desarrollo de protocolos de investigación / The scientific method: its relevance in conducting clinical research

La metodología de la investigación científica constituye un conjunto de métodos, leyes y procedimientos que orientan los esfuerzos de la investigación hacia la solución de los problemas científicos con un máximo de eficiencia. El método se basa en el desarrollo de distintas etapas que conducen al establecimiento de una conclusión válida sustentada en la verificación de una hipótesis y supuestos de la investigación realizada. Así, la investigación científica no está exenta a la ocurrencia de errores, los cuales pueden ser originados durante el planteamiento del problema de estudio, el diseño de investigación, el establecimiento de los criterios de elegibilidad, la estimación del tamaño de la muestra, el proceso de medición, durante el seguimiento de los sujetos o debido a la falta de discusión de las limitaciones del estudio. En este contexto, una de las estrategias que permite reducir los potenciales errores en la conducción de un estudio radica en el adecuado desarrollo de un proyecto o protocolo de investigación, el cual, debe ser elaborado en base a un problema de investigación, diseño y método de medición, otorgándole al investigador una serie de ventajas asociadas con la planificación documentada del proceso, reproducibilidad de los protocolos experimentales y facilitación del proceso de divulgación de los resultados. En la presente revisión se discuten los aspectos esenciales referentes al método científico en investigación clínica y se analizan los principales problemas, beneficios y elementos asociados con la factibilidad de desarrollar un protocolo de investigación.

Research methodology is a set of methods, laws and procedures that guide research efforts towards solving scientific problems with maximum efficiency. The method is based on the development of different stages that lead to the establishment of a valid conclusion supported on the verification of a hypothesis and assumptions of the performed research. Thus, scientific research is not exempt from the errors, which can originate during the study issue, research design, establishment of eligibility criteria, sample size estimation, measurement process, during follow-up or due to lack of discussion of study limitations. In this context, one of the strategies to reduce potential errors in conducting a study lies in the proper development of a research project or protocol, which must be elaborated based on a research, design and method problem. This provides the researcher with a number of advantages associated with documented process planning, reproducibility of experimental protocols and facilitation of the results publication. This review aims to discuss the essential aspects regarding the scientific method in clinical research and to analyze the main problems, benefits and elements associated with the feasibility of developing a research protocol.

ORTODOXIA Y FISURAS EN EL DISEÑO Y EJECUCIÓN DE ESTUDIOS DESCRIPTIVOS / ORTHODOXY AND FISSURES IN THE DESIGN AND IMPLEMENTATION OF DESCRIPTIVE STUDIES / ORTODOXIA E FISSURAS NO PROJETO E EXECUÇÃO DE ESTUDOS DESCRITIVOS

Introducción: En diversos contextos se alude la investigación descriptiva en términos peyorativos por endilgarle sesgos e impacto exiguo en el estudio de factores de riesgo. Esto podría atribuirse al desconocimiento de sus fundamentos conceptuales y metodológicos. Objetivo: Recabar las ventajas de los estudios descriptivos a partir de una revisión de sus fundamentos conceptuales y metodológicos. Métodos: Revisión narrativa sobre las ventajas, usos y limitaciones de los estudios descriptivos, sumado al análisis de algunos aspectos metodológicos. Resultados: Se presentan las particularidades de los estudios descriptivos en términos de sus tipologías, usos, ventajas y limitaciones. En relación con la fase conceptual de toda investigación se analizan las características específicas del problema, justificación, objetivos y marco teórico de un estudio descriptivo. En la fase metodológica se contrastan algunos autores que han estudiado temas determinantes para garantizar la validez de la investigación descriptiva como la clasificación y control de sesgos, la identificación de la confusión y el análisis estadístico. Al finalizar, se hace explícito el contenido de un artículo descriptivo a la luz de sus exigencias epidemiológicas y estadísticas. Conclusión: La investigación descriptiva es la que expone de manera más veraz y directa la realidad de un fenómeno de estudio, por ello es necesario conocer sus exigencias conceptuales y operativas para mitigar concepciones erradas sobre su alcance.

Introduction: In some contexts the descriptive researching has been referred with derogatory terms by its biases and low impact in the study of risk factors. This could be attributed to a lack of conceptual and methodological foundations. Objective: To seek the advantages of the descriptive studies from a review of its conceptual and methodological foundations. Methods: Narrative review of the benefits, uses and limitations of descriptive studies, coupled with the analysis of some methodological aspects. Results: the specific items of descriptive studies are presented in terms of their types, uses, advantages and limitations. Regarding the conceptual phase of the research was analyzed the problem, grounds, objectives and theoretical framework. In the methodological phase are presented some determinants to ensure validity of descriptive researching as the classification and control of bias, confounding and statistical analysis. At the end it is showed the content of a descriptive article in the light of their needs and epidemiological statistics. Conclusion: Descriptive researching is exposing more accurate and directly the reality of a phenomenon under study, so it is necessary to understand its conceptual and operational requirements to mitigate misconceptions about its scope.

Introdução: Em muitos contextos se fala pejorativamente da investigação por descritiva impingirlhe sesgos e pouco impacto no estudo de fatores de resgo. Isso pode ser atribuído ao desconhecimento dos fundamentos conceptuais e metodológicos. Objetivo: Coletar as vantagens dos estudos descritivos com uma revisão dos fundamentos conceptuais e metodológicos. Métodos: Revisão narrativa das vantagens, fusos e limitações dos estudos descritivos, mais o análises de alguns aspetos metodológicos. Resultados: Presentam-se as particularidades dos estudos descritivos em términos de suas tipologias, aplicações, vantagens e limitações. Em relação com a fase conceptual de toda investigação, as características específicas do problema, justificação, objetivos e marco teórico dum estudo descritivo foram analisados. Na fase metodológica alguns autores que tem tratado o tema foram contrastados. Eles tem estudado temas determinantes para garantir a validez da investigação descritiva como a classificação y controle de riscos, a identificação da confusão e o análises estadístico. Ao final se fiz claro o conteúdo duma apresentação descritiva guiado pelas exigências epidemiológicas e estadísticas. Conclusão: A investigação descritiva é a que mostra da melhor maneira a realidade dum fenómeno de estudo. Assim é preciso conhecer seus exigências conceptuais e operativas para mitigar conceitos errados no alcance.

Comparação das características de citação entre os relatos de caso/séries de casos versus demais desenhos de estudos nos artigos publicados em periódicos brasileiros de Oftalmologia / Comparison of the citation characteristics between the case reports/cases series versus the other study designs in the articles published in brazilian journals of ophthalmology

Objetivo: Comparar as características de citação entre relatos de caso / séries de casos versus demais desenhos de estudos publicados nos periódicos brasileiros de oftalmologia indexados no Science Citation Index Expanded (SCIE). Métodos: Artigos originais foram identificados a partir da revisão dos documentos publicados nos "Arquivos Brasileiros de Oftalmologia" ou "Revista Brasileira de Oftalmologia". Todos os documentos listados no SCIE, de 01/01/2008 a 31/12/2009, foram incluídos, exceto: "editoriais"; "correções"; "cartas"; e "biografias". Os desfechos foram as distribuições, número de citações, média do número de citações e probabilidade de citação. Resultados: A pesquisa revelou 382 artigos. A distribuição dos artigos segundo desenho do estudo foram relatos de caso 106, séries de casos 50, estudos transversais 92, ensaios clínicos fase I / fase II 40, ensaios clínicos fase III / fase IV 29, revisões não-sistemáticas 33 e estudos experimentais 32. A média do número de citações foi menor (p<0,001) entre relatos de caso / séries de casos (0,55) quando comparados aos outros desenhos de estudos (1,04). A probabilidade de citação foi menor (p<0,001) entre relatos de caso/séries de casos (31,4%) quando comparados aos outros desenhos de estudos (48,7%). Conclusão: Os relatos de caso / séries de casos apresentaram média do número de citações e probabilidade de citação menores que os demais desenhos de estudo. Os resultados deste estudo sugerem que os conselhos editoriais devem publicar apenas relatos de caso / séries de casos originais ou muito raros que tenham repercussão clínica. Este esforço trará benefícios para o pesquisador, para o oftalmologista que estiver em busca ...

Objective: To compare the citation characteristics of the case reports and the case series versus the other study designs of articles published, in 2008-2009, in Brazilian journals of ophthalmology indexed in Science Citation Index Expanded (SCIE). Methods: This study was a systematic review. Original articles were identified by review of documents published at the two Brazilians ophthalmology journals indexed at SCIE ("Arquivos Brasileiros de Oftalmologia" and "Revista Brasileira de Oftalmologia"). All documents ("articles" and "reviews") listed at SCIE from January 1, 2008 to December 31, 2009 were included, except: "editorial materials"; "corrections"; "letters"; and "biographical items". The outcomes were the distributions, the number of citations (through the end of second year after publication date), the mean of the number of citations, and the likelihood of citation (cited at least once vs. no citation), according the study design of the article. Results: The search at the Web of Science revealed 382 articles. The distribution of articles according to study design was: Case Reports 106 articles (27.7%) Case Series 50 (13.1%), Sectional Studies 92 (24.1%), Clinical Trials, Phase I or Phase II 40 (10.5%), Clinical Trials, Phase III or Phase IV 29 (7.6%), Non-Systematic Reviews 33 (8.6%) and Experimental Studies 32 (8.4%). The citation count was statistically lower (P < .001) in the Case Reports/Case Series (0.55 - SD 1.05) compared with the others study designs (1.04 - SD 1.63). The likelihood citation was statistically lower (P < .001) in the Case Reports/Case Series (49/156 - 31.4%) compared with the others study designs (110/226 - 48.7%). Conclusion: Case reports and case series showed lower number of citations and likelihood citation than others study designs. The results of this study suggest that the editorial boards should publish only original or very rare Case Reports / Case Series with clinical significance ...

Plano amostral, ponderacao e efeitos do delineamento da Pesquisa Nacional de Saude Bucal / Prevalencia y extension de la caries dentaria radicular en adultos y ancianos / Sampling plan, weighting process and design effects of the Brazilian Oral Health Survey

OBJETIVO: Apresentar aspectos do plano de amostragem da Pesquisa Nacional de Saúde Bucal (Projeto SBBrasil), com questões teóricas e operacionais que não devem ser ignoradas nas análises dos dados primários. MÉTODOS: A população de estudo compreende cinco grupos demográficos de áreas urbanas brasileiras no ano de 2010. Amostragem por conglomerados em dois ou três estágios foi usada adotando diferentes unidades primárias. Pesos amostrais e efeitos de delineamento (deff) foram as medidas utilizadas para avaliar a consistência das amostras. RESULTADOS: No total, foram alcançados 37.519 indivíduos. Estimativas de deff , embora aceitáveis na sua maioria, apresentaram distorções em alguns domínios. A maioria (90%) das amostras apresentou resultados concordantes com a precisão proposta no plano amostral. As medidas preventivas contra perdas e efeito do processo de conglomerados no tamanho mínimo das amostras mostrou-se efetiva e a maioria das estimativas para deff não ultrapassou o valor 2, mesmo para os resultados decorrentes da ponderação. CONCLUSÕES: As amostras alcançadas no inquérito SBBrasil 2010 se aproximaram das principais proposições de precisão do delineamento. Algumas probabilidades resultaram desiguais entre unidades primárias de um mesmo domínio. Os usuários desse banco de dados devem considerar essa particularidade, introduzindo pesos amostrais nos cálculos das estimativas pontuais, erros padrão, intervalo de confiança e efeitos do delineamento. .

OBJETIVO: Estimar la prevalencia y la extensión de la caries radicular en la población adulta y anciana de Brasil. MÉTODOS: A partir de los datos de la Investigación Nacional de Salud Bucal (SBBrasil 2010) se examinaron 9.564 adultos y 7.509 ancianos en domicilios de las 26 capitales y en el Distrito Federal y de 150 municipios del interior de cada macro región. Se implementaron criterios de diagnóstico establecidos por la Organización Mundial de la Salud. Para estudio de la prevalencia y de extensión se utilizó el índice de caries radicular y el índice de raíces cariadas y obturadas. RESULTADOS: La prevalencia de caries radicular fue de 16,7% en los adultos y 13,6% en los ancianos; el índice de raíces cariadas y obturadas fue de 0,42 y 0,32 respectivamente, siendo la mayor parte compuesta por caries no tratadas. Se observaron diferencias en la experiencia de caries radicular entre capitales y macro regiones, con valores mayores en capitales del Norte y Noreste. El índice de caries radicular en los adultos varió de 1,4% en Aracaju (SE) a 15,1% en Salvador (BA) y en los ancianos de 3,5% en Porto Velho (RO) a 29,9% en Palmas (TO). Se verificó incremento de caries radicular con la edad y mayor expresividad de la enfermedad en hombres de ambos grupos etarios. CONCLUSIONES: Se identificó una gran variación de la prevalencia y extensión de la caries radicular entre y dentro de las regiones de Brasil, tanto en adultos como en ancianos, y la mayor parte de la caries radicular se encuentra no tratada. Se recomienda la incorporación de este agravio al sistema de vigilancia en salud bucal, debido a su tendencia creciente. .

OBJECTIVE: To present aspects of the sampling plan of the Brazilian Oral Health Survey (SBBrasil Project). with theoretical and operational issues that should be taken into account in the primary data analyses. METHODS: The studied population was composed of five demographic groups from urban areas of Brazil in 2010. Two and three stage cluster sampling was used. adopting different primary units. Sample weighting and design effects (deff) were used to evaluate sample consistency.  RESULTS: In total. 37.519 individuals were reached. Although the majority of deff estimates were acceptable. some domains showed distortions. The majority (90%) of the samples showed results in concordance with the precision proposed in the sampling plan. The measures to prevent losses and the effects the cluster sampling process in the minimum sample sizes proved to be effective for the deff. which did not exceeded 2. even for results derived from weighting. CONCLUSIONS: The samples achieved in the SBBrasil 2010 survey were close to the main proposals for accuracy of the design. Some probabilities proved to be unequal among the primary units of the same domain. Users of this database should bear this in mind, introducing sample weighting in calculations of point estimates, standard errors, confidence intervals and design effects. .

Aspectos eticos em estudos longitudinais: o caso do ELSA-Brasil / Ethical issues in longitudinal studies: the case of ELSA-Brasil

Historicamente a discussão acerca da eticidade dos atos em pesquisas com seres humanos privilegiou os estudos experimentais, pelo maior potencial de danos aos sujeitos envolvidos. Todavia, os estudos observacionais também envolvem riscos e suscitam questões relevantes. Neste artigo pretende-se apresentar e discutir aspectos éticos do desenvolvimento do ELSA-Brasil, um estudo longitudinal e multicêntrico, com financiamento público, no qual os sujeitos da pesquisa e pesquisadores pertencem às mesmas instituições. São descritos os procedimentos adotados para atender às exigências e compromissos éticos e a casuística que orientou as ações segundo seus princípios norteadores (beneficência, autonomia e justiça social). São apresentados alguns problemas morais que exigiram ponderação sobre riscos e benefícios na confluência com os objetivos do estudo e comentam-se peculiaridades de um estudo longitudinal e seus potenciais benefícios.

The debate about ethics in research with human beings has historically emphasized experimental studies because of their greater potential to harm the subjects involved. However, observational studies also include risks and relevant questions to be discussed. This article aims to present and discuss the ethical aspects involved in the implementation of ELSA-Brasil, a longitudinal multicenter study, with public funding, in which the research subjects and investigators are employees of the same institutions. The procedures adopted to meet the ethical requirements and commitments are described, as well as the casuistics that guided the actions according to their guiding principles (beneficence, autonomy and social justice). We present some moral problems that required consideration of risks and benefits at the confluence with the study's objectives, and we conclude with comments on the peculiarities and the potential benefits of a longitudinal study.

How to design and write a clinical research protocol in Cosmetic Dermatology* / Como desenhar e escrever um protocolo de pesquisa clínica em Cosmiatria

Cosmetic Dermatology is a growing subspecialty. High-quality basic science studies have been published; however, few double-blind, randomized controlled clinical trials, which are the major instrument for evidence-based medicine, have been conducted in this area. Clinical research is essential for the discovery of new knowledge, improvement of scientific basis, resolution of challenges, and good clinical practice. Some basic principles for a successful researcher include interest, availability, persistence, and honesty. It is essential to learn how to write a protocol research and to know the international and national regulatory rules. A complete clinical trial protocol should include question, background, objectives, methodology (design, variable description, sample size, randomization, inclusion and exclusion criteria, intervention, efficacy and safety measures, and statistical analysis), consent form, clinical research form, and references. Institutional ethical review board approval and financial support disclosure are necessary. Publication of positive or negative results should be an authors' commitment.

Cosmiatria é uma sub-especialidade em grande crescimento. Estudos em ciência básica de alta qualidade têm sido publicados; ao contrário, existem poucos estudos clínicos duplo-cegos, randomizados e controlados, que constituem o maior instrumento para medicina baseada em evidência nessa área. A pesquisa clínica é essencial para a descoberta de novos conhecimentos, melhora das bases científicas, solução de desafios e boa prática clínica. Para ser um pesquisador bem sucedido, os princípios básicos são interesse, disponibilidade, persistência e honestidade. É essencial aprender como escrever um protocolo de pesquisa e conhecer as regras regulatórias nacionais e internacionais. Um protocolo de pesquisa clínica completo deve incluir questão, fundamentos, objetivos, metodologia (desenho, descrição das variáveis, tamanho da amostra, randomização, critérios de inclusão e exclusão, intervenção, parâmetros de eficácia e segurança e análise estatística), termo de consentimento livre e esclarecido, ficha clínica e referências. A aprovação do Comitê de Ética em Pesquisa e a declaração do financiamento são imprescindíveis. A publicação de resultados positivos ou negativos deve ser um comprometimento dos autores.

Os principais delineamentos na epidemiologia / Primary study designs in epidemiology

O presente artigo se propõe a descrever brevemente delineamentos epidemiológicos que são largamente utilizados na pesquisa da área da saúde. Os tipos de estudo abordados nesse artigo são a coorte, o caso controle, os estudos de prevalência, os estudos de teste diagnóstico, os estudos ecológicos, os ensaios clínicos, os estudos de validade, fidedignidade e concordância e os estudos-piloto. Para cada um dos delineamentos são indicadas referências bibliográficas para os leitores poderem obter maior detalhamento dos delineamentos descritos.

This article aims to briefly describe the primary study designs used in epidemiologic research. We discuss the following types of study designs: cohort, case-control, prevalence studies, diagnostic test studies, ecologic studies, clinical trials, pilot studies, and validity, reliability and agreement tests. This article ends with a number of bibliographic references on each type of study so that readers can seek further information.

Drogas en Costa Rica: características y desafíos / Drugs in Costa Rica: characteristics and challenges

Objetivo: Evaluación de las características de las publicaciones sobre drogas realizadas en Costa Rica entre 1966 y 2010. Materiales y Métodos: Análisis bibliométrico de los trabajos compilados en la serie “Investigaciones sobre Alcoholismo y Farmacodependencia” que publica el Instituto sobre Alcoholismo y Farmacodependencia de Costa Rica de publicación quinquenal. Dicha serie se construyó a partir de una hoja de registro con diversas características de interés, tras realizarse una consulta de los catálogos y bases de datos de las bibliotecas y centros de documentación de diferentes instituciones. Resultados: Se estudiaron 491publicaciones. Una tercera parte se publicó en revistas científicas en tanto las publicaciones monográficas y los libros ocuparon, respectivamente, un 33 y un 6 % del total. Cerca de una tercera parte de los trabajos son investigaciones epidemiológicas y la droga mayormente investigada fue el alcohol, en ámbitos poblacionales que comprendieron las evaluaciones en la población general, los sujetos en calidad de pacientes y el sector infancia y juventud. Discusión: Se destaca el papel que ha correspondido a las ciencias sociales en el terreno del conocimiento sobre drogas, la importancia y necesidad de una mayor presencia femenina en la producción de dichos conocimientos y la exploración del fenómeno mediante alternativas que supongan un mayor énfasis tanto en el paradigma cualitativo como en el experimental y cuasi experimental para el abordaje de las complejidades que el tema exige.

Objective: This study analyses the characteristics of the publications on drugs carried out in Costa Rica during the period 1966 - 2010. Methods: Bibliometric analysis of the publications compiled in the serial named “Research publications on drug abuse and drug dependence” which is published by the Costa Rican’s National Institute on Alcoholism and Drug Dependence since 1990. Suchserial has been created using an instrument which allows gathering some bibliometric characteristics of interest in libraries’ catalogues and data bases located in different local institutions. Results: 491 publications have been studied, one third of these publications were published in scientific journals while 33% and 6% were published as monographs and books. About one third of the publications correspond to epidemiologic research. The drug mostly explored was alcohol, which has been studied in the general population as well as in drug affected subjects and in youth and childhood. Discussion: The roll of social sciences on drugs’ knowledge field, the importance and need of a growing feminine participation and the use of qualitative paradigms as well as experimental and quasi experimental research are pointed out and their relevance discussed.

Aproximaciones metodológicas al estudio de la mortalidad infantil en Chile / Methodological approaches to the study of infant mortality study in Chile

Introduction: Infant Mortality Rate (IMR) is still considered a relevant population health indicator. Knowing related factors and implementation of specific policies positively impacts its reduction. Objective: To evaluate the evolution of the studies on infant mortality in Chile in the last three decades. Patients and Methods: A systematic search using Medline, Lilacs and Scielo databases was carried out. Global and component IMR was reviewed. Results: IMR has been reduced considerably since 1980. Sixty-eight papers were found, mostly in national journals and bulletins. Most of them (73.5 percent were descriptive studies, although association studies have increased since 2000. The main data source was National Institute of Statistics (47 percent). The most frequently studied variables were: cause of death (42.6 percent), maternal age (30.9 percent) and site (17.6 percent). Analysis strategies are mostly descriptive, although studies of association most often utilize correlation indices. Conclusion: Infant Mortality continues to be a topic of interest to researchers, who use different strategies. Continued study is encouraged.

Introducción: La tasa de mortalidad infantil (TMI) sigue siendo considerada un indicador relevante de salud poblacional. Su estudio ha permitido conocer factores relacionados e implementar políticas específicas que han impactado positivamente en su reducción. Objetivo: Evaluar la evolución de los estudios sobre mortalidad infantil en Chile en las últimas décadas. Pacientes y Método: Se realizó una búsqueda sistemática en las bases referenciales Medline, Lilacs y Scielo. Se contrastó esta información con la TMI global y por componente. Se detectaron 68 artículos publicados en su mayoría en revistas y boletines nacionales. Resultados: Se observó una reducción de la TMI en el período, en tanto las publicaciones del tema aumentaron. Si bien 73,5 por ciento correspondió a estudios descriptivos, desde 2000 los estudios de asociación han aumentado. La principal fuente de datos corresponde al Instituto Nacional de Estadísticas (47 por ciento) y las variables más estudiadas fueron: causas de muerte (42,6 por ciento), edad materna (30,9 por ciento) y localidad (17,6 por ciento). Las estrategias de análisis en su mayoría se basan en estadística descriptiva mientras los de asociación lo hacen principalmente mediante análisis de correlación. Conclusión: La mortalidad infantil sigue siendo un tópico de interés para investigadores y para su estudio se han intentado distintas aproximaciones. Los sitios disponibles con información al respecto plantean la instancia de continuar focalizando en el tema para ayudar en su comprensión.

Diseños de investigación en epidemiología genética / Genetic epidemiology research designs

Se describen los distintivos de los diseños de investigación epidemiológica que son utilizados con mayor frecuencia en los estudios de asociación genética. Los estudios de casos y controles proporcionan un método eficiente para evaluar asociaciones entre genes candidatos y enfermedad. Los estudios de cohorte, por su parte, si bien aportan un mayor grado de causalidad, no son eficientes para la exploración inicial en la identificación de las asociaciones gen-enfermedad. Los estudios transversales son menos costosos, requieren períodos de tiempo más cortos y son de utilidad para estimar la prevalencia de enfermedades, de factores de riesgo o de variantes genéticas. Los estudios basados en familias han sido exitosos para encontrar alelos que confieren mayor riesgo para el desarrollo de enfermedades de transmisión mendeliana.

This article describes the features of the epidemiologic research designs most commonly used in genetic association studies. Case-control studies are efficient in evaluating associations between candidate genes and disease. Cohort studies, in contrast, yield a greater degree of causality but are not efficient for the initial exploration to identify gene-disease associations. Cross-sectional studies are less expensive, require less time, and are useful for estimating the prevalence of diseases, risk factors, and genetic variants. Family-based studies have been successful in finding alleles that confer greater risk for developing Mendelian inheritance disorders.