Table 1.
Reasons for not switching when first met immunological/clinical criteria for switch in patients receiving and not receiving CD4 monitoring.
Table 2.
CD4 and VL at switch to second-line for first-line failure in patients not receiving CD4 or VL count monitoring (CDM).
Table 3.
Clinical events triggering switch after 44 weeks on ART in patients monitored without CD4 cell counts (CDM).
Figure 1.
VL and CD4 at switch to second-line for first-line failure in patients receiving and not receiving CD4 count monitoring.
(a) in patients not receiving routine CD4 count monitoring (CDM: 20% >250 cells/mm3). (b) in patients receiving routine CD4 count monitoring (LCM: 2% >250 cells/mm3). Footnote 1 Points at >750000 and <400 have a small amount of ‘jitter’ added so that all observations are visible.
Figure 2.
Ability of a single CD4 at switch to second-line for first-line failure to predict VL.
(a) in patients not receiving routine CD4 count monitoring (CDM: 20% >250 cells/mm3). (b) in patients receiving routine CD4 count monitoring (LCM: 2% >250 cells/mm3). Footnote 2 Receiver operator curves (ROC) show how the sensitivity and specificity of CD4 thresholds for predicting VL<400 copies/ml varies as CD4 increases from 1 to 788 (CDM) or 505 (LCM) cells/mm3. The straight line indicates performance no better than chance. The threshold with the greatest probability of correctly classifying each CD4 count according to whether it has VL<400 copies/ml or not is indicated with sensitivity (proportion with VL<400 c/ml who have CD4≥threshold), specificity (proportion with VL≥400 c/ml who have CD4 <threshold), positive predictive value (proportion of patients with CD4 ≥threshold who have VL<400 c/ml) and negative predictive value (proportion of patients with CD4 <threshold who have VL≥400 c/ml).
Table 4.
CD4 and VL at switch to second-line for first-line failure in patients receiving 12-weekly CD4 count monitoring, but no VL monitoring (LCM).