A computational algorithm associated with patient progress modelling

Patient progress modelling, which was first introduced to provide an alternative to traditional randomised control trials, has now been used in numerous contexts including evaluation of screening programmes and assessment of the public health impact of large scale developments such as waste disposal incinerators. The method uses stochastic compartmental models whose solutions may depend on solving large sets of matrix differential equations. Although specialist software packages are available for this purpose, we propose an alternative method for deriving the solution to such equations that is simple to implement.