The algorithm used for the tool above are the exact same as published by:

Mocroft A, Ledergerber B, Zilmer K, Kirk O, Hirschel B, Viard JP, Reiss P, Francioli P, Lazzarin A, Machala L, Phillips AN, Lundgren JD; for the EuroSIDA study group and the Swiss HIV Cohort Study: Short-term clinical disease progression in HIV-1-positive patients taking combination antiretroviral therapy: the EuroSIDA risk-score. AIDS. 2007 Sep;21(14):1867-1875. Abstract link

Table 4. Chance of new AIDS/death in 3, 6 or 12 months following most recent clinic visit.
EuroSIDA risk-score	Chance of new AIDS/death	95% confidence interval
Within 3 months
<1.5	1 in 801	1 in 598 to 1 in 1213
1.5–2.99	1 in 276	1 in 240 to 1 in 326
3.0–4.49	1 in 63	1 in 55 to 1 in 74
>4.5	1 in 17	1 in 15 to 1 in 19
Within 6 months
<1.5	1 in 401	1 in 299 to 1 in 607
1.5–2.99	1 in138	1 in 120 to 1 in 163
3.0–4.49	1 in 32	1 in 28 to 1 in 37
>4.5	1 in 9	1 in 8 to 1 in 10
Within 12 months
<1.5	1 in 201	1 in 150 to 1 in 304
1.5–2.99	1 in 69	1 in 60 to 1 in 82
3.0–4.49	1 in 16	1 in 14 to 1 in 18
>4.5	1 in 5	1 in 4 to 1 in 6

Updated: 03 Dec 2007