Time is an inherent feature of many medical applications. These applications can also benefit from the support of object database management systems which better capture the semantics of the complex objects that arise in the medical domain. In this paper, we present a uniform behavioral temporal object model which includes a rich and extensible set of types and behaviors to support the various features of a medical application. We concentrate here on the application of pharmacoeconomic medical trials. Pharmacoeconomics is a field of medical economics in which the costs and outcomes of alternative treatments are assessed and compared, in order to establish which is the most appropriate treatment for a particular illness in a particular setting. We describe in detail the histories and timelines features of our temporal model and show how they can effectively be used to model a pharmacoeconomic trial. We then give an instance of a pharmacoeconomic trial as it would appear in the temporal object model and show, using queries, how a series of different behaviors could be used to retrieve various components of the instance. These components could then be used to assess the alternative treatments involved in the trial and determine their cost-effectiveness.