A method for systematic assessment of the relative prognostic significance of symptoms and signs in patients with a chronic disease II. Analysis of validity of model and derivation of major prognostic stages

Abstract A model of the course of a chronic disease previously formulated is further explored. Methods for evaluation of the validity of the model are suggested and applied on data from a series of patients with aortic incompetence. The pattern of prognostic symptoms and signs found in patients is compared to that deduced from the model. Patient classes representing different phases of the disease according to the model are derived and the trend of the corresponding survival curves is studied. A method for the systematic derivation of major prognostic stages is finally presented and applied on the data. The analysis defined three stages which were distinctly separated in terms of prognosis and appeared meaningful from the clinical point of view.