We conducted several conditional logistic regression analyses adjusted for the same pool of variables (geographic origin, AIDS stage, hepatitis B and hepatitis C infection, VL at index date and cumulative duration of PI, of NNRTI and of other treatment use per five years of exposure) and with or without additional adjustment for CD4 cell count nadir at treatment initiation or index date if not treated and for cumulative duration of NRTI use. Here, CD4 is linked to AIDS.