IX. From Clinical Judgment to Clinical Trial

Abstract

Two strategies are described, intended to understand causality and documenting it with the best evidence: the clinical judgment and clinical trial. In the first one, the baseline state, the maneuver and the outcome are identified, each one with characteristics showing the complexity of the causality phenomenon, whose control allows for systematic errors to be prevented: in the baseline state, inadequate assembly and susceptibility bias; during the application of the maneuver, the performance bias; in the outcome measurement, detection and transfer biases. In the clinical trial, the tactics that try to isolate the effect of the principal maneuver from that of other components of the causality phenomenon —previously described in the clinical judgment section— are mentioned. For that purpose, the opportunity for the maneuver to be manipulated, and the temporary nature of the causal relationship are used. Its characteristics include allocation and blinding of the maneuver, feasibility of its early interruption, the analysis according to the adherence to the maneuver, the groups to be compared, the transient nature of the comparative maneuver and the informed consent. When the physician applies this knowledge in a conscious and structured manner with his/her patient, he/she improves his/her efficiency and brings medical practice closer to clinical research.