Table 2.
PIMA CD4 Count Results Versus FACSCount
| Variable | Total | <200 | <350 | <500 | ≥500 |
|---|---|---|---|---|---|
| n = 151 | n = 10 (6.6%) | n = 33 (21.9%) | n = 67 (44.4%) | n = 84 (55.6%) | |
| CD4 T cell count (PIMA) | |||||
| Mean (SD) | 537 (273) | 133 (40) | 226 (73) | 307 (104) | 720 (222) |
| Median (IQR) | 141 (103 to 164) | 317 (234 to 384) | 660 (553 to 841) | ||
| CD4 T cell count (FACSCount) | |||||
| Mean (SD) | 570 (308) | 137 (52) | 220 (78) | 308 (117) | 778 (247) |
| Median (IQR) | 163 (76 to 183) | 299 (211 to 413) | 748 (596 to 887) | ||
| Absolute bias, cells/μL (SD) | −32.5 (99.9) | −4.2 (25.3) | 5.9 (48.2) | −1 (66.7) | −57.6 (114.3) |
| LOA, mean (±1.96 SD) | −228.3 to 163.4 | −53.7 to 45.3 | −88.5 to 100.3 | −131.7 to 129.7 | −281.7 to 166.5 |
| Paired t-test for difference in means (95% CI; p) | −32.5 (−48.5 to −16.4; p = .0001) | −4.2 (−22.3 to 13.9; p = .6119) | 5.9 (−11.2 to 23.0; p = .4861) | −1 (−17.3 to 15.3; p = .9026) | −57.6 (−82.4 to −32.8; p < .0001) |
LOA, limit of agreement; CI, confidence interval; IQR, interquartile range.