A simple example shows that the parameters seem to correspond as we would expect: take μ = 1/40, Tj = 4 years (i.e. time to reaching ‘low CD4’ treatment threshold), dj = 1 per year (i.e. AIDS-related death rate), then the calculations give pj ≈ 9/40 and aj ≈ 9/50. Here, CD4 is linked to AIDS.