Published on January 1, 2012 | http://doi.org/10.5867/medwave.2012.01.5293
Fundamentals of critical analysis: the concept of validity and analysis essentials
Fundamentos del análisis crítico: concepto de validez y condiciones básicas para el análisis
Abstract
Critical analysis of literature is an assessment process that allows the reader to get an idea of potential error in the results of a study, errors arising either from bias or confusion. Critical analysis attempts to establish whether the study meets expected criteria or methodological conditions. There are many checklists available that are commonly used to guide this analysis, but filling out a checklist is not tantamount to critical appraisal. Internal validity is defined as the extent to which a research finding actually represents the true relationship between exposure and outcome, considering the unique conditions in which the study was carried out. Attention must be given to the inclusion and exclusion criteria that were used, on the sampling methods, on the baseline characteristics of the patients that were enrolled in the study. External validity refers to the possibility of generalizing conclusions beyond the study sample or the study population. External validity includes population validity and ecological validity. Lastly, the article covers potential threats to external validity that must be considered when analyzing a study.