RÉSUMÉ
Evidence based medicine assists in clinical decision-making by integrating critically appraised information with patient's values and preferences within an existing clinical context. A fundamental concept in this paradigm is the hierarchy of information. The randomized clinical trial is recognized as one of the designs that is less prone to bias and therefore of higher methodological quality. Clinical guidelines are one of the principal tools that evidence based medicine uses to transfer scientific information to clinical practice and many of their recommendations are based on these type of studies. In this review we present some of the limitations that the results can have, in even well designed and executed randomized clinical trials. We also discuss why valid results in these types of studies could not necessarily be extrapolated to the general population. Although the randomized clinical trial continues to be one of the best methodological designs, we suggest that the reader be careful when interpreting its results.
La Medicina Basada en Evidencia es una propuesta que asiste en la toma de decisiones clínicas integrando la información críticamente analizada con los valores y preferencias del paciente en el contexto clínico existente. Un concepto fundamental en este paradigma es la jerarquización de la información. El estudio clínico aleatorizado es reconocido como uno de los diseños metodológicos con menor probabilidad de sesgo y por ende de la más alta calidad metodológica. En este tipo de estudios se basan muchas de las recomendaciones de las guías clínicas, que son uno de los principales instrumentos que utiliza la medicina basada en evidencia para transferir la información a la práctica clínica. En esta revisión se exponen algunas de las limitaciones que pueden tener los resultados de estudios clínicos aleatorizados incluso cuando han sido bien diseñados y ejecutados. Se discute también el porqué resultados validos pueden no necesariamente ser extrapolables a la población general en este tipo de estudios. Si bien el estudio clínico aleatorizado sigue siendo uno de los mejores diseños metodológicos, se sugiere que el usuario de la información sea cuidadoso al interpretar sus resultados.
Sujet(s)
Humains , Médecine factuelle/méthodes , Guides de bonnes pratiques cliniques comme sujet , Essais contrôlés randomisés comme sujet/méthodes , Biais (épidémiologie) , Prise de décision , Essais contrôlés randomisés comme sujet/normes , Plan de rechercheRÉSUMÉ
Background: Portfolio is an innovative instrument that promotes reflection, creativity and professionalism among students. Aitn: To describe the development and validation process of a questionnaire to evalúate the use of portfolio in undergraduate medical students. Material andMethods: Focus groups with students and teachers were employed to identify aspects related with portfolio in undergraduate teaching. The Delphi technique was used to prioritize relevant aspects and construct the questionnaire. The validated questionnaire, consistingin 43 Ítems and 6factors, was appliedto 97students (response rote of99.9 percent) in2007and 100students (99.2 percent) in 2008. Each question had to be answered using a Likert scale,from 0 (completely disagree) to 4 (completely agree) The validity and reliability of the questionnaire was evaluated. Results: The questionnaire showed a high reliability (Cronbach alpha = 0.9). The mean total scores obtained in 2007 and 2008 were 106.2 ± 21.2 (61.7 percent ofthe maximal obtainable score) and 104.6 ± 34.0 (60.8 percent ofthe maximal obtainable score), respectively No significant differences were seen in the analysis by factors. Changes in portfolio during 2008 showed differences in Ítems related with organization, evaluation and regulation. Conclusions: The questionnaire is a valid and highly reliable instrument, measuringperceptions about the portfolio by undergraduate medical students. The students perceived an improvement in their creativity and professionalism as one ofthe strengths of portfolio. The weaknesses identified during the implementation process helped us to focus changes in organization and evaluation to improve the portfolio as a dynamic process.