Introducción: Un estudio de casos y controles es un estudio en el que se compara individuos que tuvieron un desenlace de interés o outcome (casos) versus individuos que no tuvieron dicho resultado (controles) con respecto a la exposición de interés, potencialmente un "factor de riesgo" o “factor de protección”. El objetivo de un estudio de casos y controles es primariamente determinar si existe asociación entre una exposición (o varias) y un desenlace de interés. Esta asociación debe ser cuantificada y reportada como un odds ratio o razón de momios teniendo en cuenta sus fortalezas y limitaciones. En general, este tipo de estudios ofrece como ventajas su relativo bajo costo y rapidez con la que es posible realizarlos. Sin embargo, no son idóneos si lo que se quiere investigar son desenlaces de interés frecuente o con periodos de latencia largos. En el presente artículo s...

Introduction: A case-control study is a study comparing individuals who had an outcome of interest (cases) versus individuals who had no such outcome (controls) with respect to the exposure of interest, potentially a "risk factor "or" protection factor." The objective of a case-control study is primarily to determine if there is an association between one exposure (or several) and an outcome of interest. This association must be quantified and reported as an odds ratio or odds ratio taking into account its strengths and limitations. In general, this type of study offers as advantages its relatively low cost and speed with which it is possible to carry them out. However, they are not ideal if what you want to investigate are frequent outcomes or with long latency periods. In this article, the primary methodological considerations of the design of case-control studies have been reviewed, h...

Introducción: La revisión sistemática es la evaluación comprehensiva, reproducible, crítica y explícita de la mejor evidencia disponible en respuesta a una pregunta de investigación específica. Para conseguir ello las revisiones sistemáticas deben cubrir como mínimo los siguientes siete pasos: i) una pregunta de investigación específica y estructurada usando la técnica PICO; ii) criterios de elegibilidad de las evidencias; iii) una estrategia de búsqueda clara y reproducible; iv) selección de las evidencias y extracción de datos; v) análisis de sesgos; vi) síntesis de resultados; y, vii) publicación. Si los datos son suficientes y homogéneos es factible incluir en las síntesis de resultados el metanálisis de los mismos. De esta manera las revisiones sistemáticas y metanálisis pueden generar conocimiento nuevo y fundamental para la toma de decisiones en el área cl...

Objetive. The cohort study is an observational design. This only includes participants who have the same risk of being exposed, then compares who is exposed and unexposed presents the outcome of interest during the same period. The temporality between the exposure and the outcome of interest in a cohort study is well defined because it is certain that the exposure antecedent to the outcome of interest. Cohort studies can be prospective, retrospective, or a combination of both. One of the main advantages is its longitudinal nature, making it possible to estimate the incidence and relative risk as an association of interest. Some variables may vary over time, so it is essential to use advanced data modeling techniques such as fixed and random effects models.

Introduction: The systematic review is the comprehensive, reproducible, critical, and detailed evaluation of the best available evidence in response to a specific research question. To achieve this, systematic reviews should cover at least the following seven steps: i) a detailed and structured research question using the PICO technique; ii) evidence eligibility criteria; iii) a precise and reproducible search strategy; iv) selection of evidence and data extraction; v) analysis of biases; vi) synthesis of results; and vii) publication. If the data are sufficient and homogeneous, it is feasible to include their meta-analysis to synthesize results. In this way, systematic reviews and meta-analyzes can generate new and fundamental knowledge for decision-making in the clinical and other areas.

Background: Case reports and case series are essential sources of knowledge; however, they only provide low-quality scientific evidence. These studies are common in the medical field because they allow to formulate new hypotheses and to report new and rare pathologies in a structured way and complications or adverse drug events. Hence, the primary objective of a case report or case series is contributing to the scientific knowledge. To publishing these studies, it is recommended to follow the CARE statement's recommendations to guarantee a structured report with a minimum of pertinent and relevant information to make a clear and precise interpretation of the findings. This review aims to provide a scientific writing guide for case reports and case series and maximize their publicity in indexed peer-reviewed journals.