PREDICTIVE PERFORMANCE OF THE BAYESIAN-ANALYSIS - EFFECTS OF BLOOD-SAMPLING TIME, POPULATION PARAMETERS, AND PHARMACOSTATISTICAL MODEL

The present paper reports theoretical equations for the predictive per formance of the Bayesian forecasting method. The precision of paramete r estimates and predicted concentrations for an individual was describ ed by general equations with the aid of a variance-covariance matrix o f parameter estimates that involved the Bayes theorem. The equations w ere applied to assess the predictive performance of the one-point Baye sian method in association with blood sampling time, the population pa rameters, and the pharmacostatistical model. The simulation study show ed that the prediction error in parameter estimates essentially depend ed upon the sampling time but the magnitude of dependency was affected by the size of inter- and intraindividual variances. With a smaller v alue of interindividual variance, the dependency on sampling time was less apparent. Effects of sampling time were further examined using cl inical data obtained from 20 patients taking theophylline, and the res ults were in good agreement with the theoretical consideration. The pr esent general equations are useful to investigate the sampling strateg y as well as structural and variance modeling on the predictive perfor mance of the Bayesian method.