The observed time periods The sample-based prediction
Sensitivity Specificity PPR PNR
1 month 625/1096 888/1024 625/761 888/1359
  57% 87% 82% 65%
3 month 772/1585 1976/2261 772/1057 1976/2789
  49% 87% 73% 71%
6 month 525/1142 1489/1697 525/733 1489/2106
  46% 88% 72% 71%
12 month 335/851 1102/1254 335/487 1102/1618
  39% 88% 69% 68%
The observed time periods The individual-based prediction
Sensitivity Specificity PPR PNR
1 month 977/1096 887/1024 977/1114 887/1006
  89% 87% 88% 88%
3 month 1295/1585 2031/2261 1295/1525 2031/2321
  82% 90% 85% 88%
6 month 864/1142 1530/1697 864/1031 1530/1808
  76% 90% 84% 85%
12 month 556/851 1130/1254 556/680 1130/1425
  65% 90% 82% 79%
PPR: Predictive positive rate; PNR: Predictive negative rate
Table 2: The sensitivities, specificities, PPR and PNR for cutoff value 350 cells/ mm3 of CD4 for initiation of ART.