XII. From Clinical Judgment to Cross-sectional Survey
Main Article Content
Keywords
Cross-sectional studies, Cohort studies, Case-control studies, Clinical trial
Abstract
A longitudinal study, whether it is a clinical trial or a cohort study, has the virtue of following the logical sequence in which the components of the causality phenomenon occur. However, in a cross-sectional study, this logical sequence does not exist and it is consistent with the measurement of the three components (baseline state, maneuver and result). “Clinical judgment” helps us to artificially reconstruct these components in the time sequence in which they occurred. However, the way in which the population is assembled and how the information is obtained —cross-sectional-wise and retrolectively— entails the risk of producing biases. Although the use of cross-sectional survey in order to associate a maneuver with a probable outcome is difficult and often generates errors (especially when pathological phenomena are studied), it is extraordinary to show the development of a healthy subject simulating a longitudinal study, as is happens when height and weight are estimated according to age; this type of design has been named “longitudinal cross-sectional study”.
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