ABSTRACT
The following general structure is typical of many of the studies undertaken in the pharmaceutical sciences. For each of a collection of individual subjects (e.g., clinical patients or experimental animals), measurements of a response of interest have been made at several selected, or observed, values of a related variable (a so-called covariate). For example, in toxicity growth-curve studies the response would be size or weight and the covariate would be time from birth; in pharmacokinetic studies the response would be plasma concentration of a drug and the covariate would be time from administration; in pharmacodynamic studies the response would be therapeutic effect and the covariate would be plasma concentration.
