Comparison of the CD4 counts obtained from finger prick sample and from paired venous blood . Figure 2A and C: Linear regression analysis: The correlation between the CD4 counts obtained from finger prick sample using PIMA CD4 analyzer (Y axis) and from venous blood using FACSCalibur (2A) and PIMA (2C) (X axis) is assessed. Figure 2B and D: The agreement analysis using the Bland Altman plots. The percent relative bias for CD4 counts from finger prick sample and the paired venous blood using FACSCalibur (Figure 2B) and PIMA (Figure 2D) is plotted on the Y axis and the average of the CD4 count by both the samples is plotted on X axis. The black line represents the mean% relative bias of where as the blue lines represent the range of Mean ± SD.