A mathematical model for scheduling screening tests for progressive diseases

In this paper, a mathematical model describing the stochastic process underlying the etiology of noncontagious, curable, progressive diseases is developed. In our previous study of progressive diseases, the reliabilities of screening tests were assumed to be constants, independent of how long the individual has had the disease. The purpose of this study is to develop more insight into modeling the disease process, and the interaction of screening tests with the natural behavior of the disease. To accomplish this task, more realistic screening parameters are selected, and optimum policies for mass screening programs under different reliabilities of screening tests are developed. These modifications make the model general enough to be applicable to a larger class of progressive diseases that includes breast cancer. Solutions to two simplified versions of the model for childhood neuroblastoma illustrate the use of our proposed procedure.