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Table 3 Clinical agreement and misclassification rates between CD4 measured on EDTA Day 0 (reference test) and CD4 measured on ST Day 7 and Day 14 (index test) at CD4 thresholds for ART eligibility of 350 cells/μL and 500 cells/μL

From: Opportunities to improve storage and transportation of blood specimens for CD4 testing in a rural district in Zimbabwe using BD vacutainer CD4 stabilization tubes: a stability and diagnostic accuracy study

EDTA Day 0 ST Day 7 Sensitivity: 100 (78.2 – 100); PPV: 100 (78.2 – 100)
≤350 ≤350 Total Specificity: 100 (89.7 – 100); NPV: 100 (89.7 – 100)
≥350 15 0 15 Total misclassification rate: 0
≥350 0 34 34 Upward misclassification rate: 0
Total 15 34 49 Downward misclassification rate: 0
EDTA Day 0 ST Day 14 Sensitivity: 83.3 (35.9 – 99.6); PPV: 100 (47.8 – 100)
≤350 ≥350 Total Specificity: 100 (75.3 – 100); NPV: 92.9 (66.1 – 99.8)
≤350 5 1 6 Total misclassification rate: 5.2
≥350 0 13 13 Upward misclassification rate: 5.2 (1/19)
Total 5 14 19 Downward misclassification rate: 0
EDTA Day 0 ST Day 7 Sensitivity: 100 (85.2 – 100); PPV: 88.5 (69.8 – 97.6)
≤500 ≥500 Total Specificity: 88.5 (69.8 – 97.6); NPV: 100 (85.2 – 100)
≥500 23 0 23 Total misclassification rate: 6.1 (3/49)
≤500 3 23 26 Upward misclassification rate: 0
Total 26 23 49 Downward misclassification rate: 6.1 (3/49)
EDTA Day 0 ST Day 14 Sensitivity: 88.9 (51.8 – 99.7); PPV: 80.0 (44.4 – 97.5)
≤500 ≥500 Total Specificity: 80.0 (44.4 – 97.5): NPV: 88.9 (51.8 – 99.7)
≥500 8 1 9 Total misclassification rate: 15.7 (3/19)
≥500 2 8 10 Upward misclassification rate: 5.2 (1/19)
Total 10 9 19 Downward misclassification rate: 10.5 (2/19)