An actuarial model for AIDS

Abstract

THIS paper describes fully the actuarial model used by the Institute of Actuaries AIDS Working Party for the calculations presented in AIDS Bulletins Nos 1, 2, and 3. The model is described in terms of states: Clear, At Risk, Positive, Immune (not in fact used by the Working Party), Sick and Dead. Conditional on a given starting position, the proportions in each state at future times are governed by a series of differential equations, which are mostly of the usual actuarial type. However, the representation of infection follows a more complex epidemi-ological model.