A METHOD FOR ESTIMATING THE AGE-SPECIFIC RELATIVE RISK OF HIV-INFECTION FROM AIDS INCIDENCE DATA

Using a multiplicative model, the age-specific relative risk of infect ion with the human immunodeficiency virus, HIV, and the time-dependent HIV infection rate can be estimated simultaneously from acquired immu nodeficiency syndrome, AIDS, incidence data. Non-parametric estimates are arrived at by an EM-algorithm, with smoothing, applied to a back-p rojection model. The method gives estimates which lie on a smooth curv e in accordance with strong prior expectations. The approach is illust rated with an application to Australian AIDS data. It is found that th e HIV infection rate tends to be estimated more precisely when age is included as a covariate.