We have derived estimates of the 6-month risk of progression to AIDS for a given CD4 count, viral load and age. These estimates may be helpful for deciding when to start antiretroviral therapy or when to re-start treatment after an interruption

The estimates should only be used for guidance on when to initiate ART, and not as a hard and fast rule. Such decisions should take account of other information, including clinical status, preparedness to start therapy, adherence, etc. See www.aidsinfo.nih.gov/guidelines and www.bhiva.org for further information.