A population dynamics simulation model with application to health planning.

Despite the increasing emphasis on computers and quantitative methods in health services programs, health services administration students are denied access to many of the most powerful tools of systems analysis, including discrete event simulation, because they lack the necessary background in computer programming, simulation methodology, and stochastic processes. This article presents an approach to the modeling of the growth and decline of population groups and their attributes that can be used by students who do not have the extensive quantitative background required to develop the usual discrete event simulation models. The underlying theory, which is based on the behavior of the expectation process of vector Galton-Watson branching processes, can be explained quite easily. An example is presented that uses an age and sex specific model of population growth to investigate policy questions related to the feasibility of the construction of a long-term care facility for a defined population group. Planning decisions are based on the growth and decline of the numbers of individuals in the various age and sex groups. Extensions of the basic methodology are possible that would include projections of the variance-covariance matrix of the population sizes for each year of the projection process. In addition, the model can be extended to include projections of the impact of infectious and communicable diseases on a defined population group together with the effect of categorical disease screening and control programs. Given the basic data utilized in the model, the implementation of the calculations required by the model can be made on modern microcomputer hardware using any of the standard spreadsheet programs.