Table 2.
Hospital antenatal Pima™ field testing using capillary blood
| Phase II | Laboratory Pima™ vs. Predicate | Clinic Pima™ vs. Predicate | ||||
|---|---|---|---|---|---|---|
| Venous EDTA blood | Capillary blood | |||||
| *Pima #1 | *Pima #4 |
*Mean Pima #1 and #4 |
Pima #3 | Pima #2 | All values | |
| N | 91 | 91 | 91 | 43 | 34 | 77 |
| Range of CD4 counts* | 32 - 1186 | 23 - 1299 | 28 - 1243 | 28 - 1092 | 50 - 1056 | 28 - 1092 |
| Mean CD4 count*(median) | 385.6 (341.0) |
399.8 (357.0) |
392.7 (347.0) |
335.0 (405.0) |
350.2 (290.0) |
380.8 (329.0) |
|
%Similarity to Predicate (%SIM Mean ± SD) |
96.9% ± 7.89 |
98.3% ± 7.05 |
97.6% ± 6.5 |
98.6% ± 28.45 |
96.1% ± 16.8 |
98.7 ± 23.02 |
| %SIM CV# | 8.1% | 7.2% | 6.7% | 28.8% | 17.6% | 23.3 |
|
BA bias* ± 1 STDev (PIMA - PLG) (95% CI of bias mean) |
-26.6 ± 73.3 (-41.9 to -11.4) |
-12.4 ± 68.1 (-26.6 to 1.8) |
-19.6 ± 66.1 (-33.3 to -5.8) |
-31.79 ± 213.1 (-97.4 to 33.8) |
-45.5 ± 127.7 (-90.1 to -1.0) |
-37.9 ± 179.5 (-78.3 to 2.87) |
| BA 95% LOA* | -170.4 to 117.1 | -145.8 to 121.0 | -149.1 to 110.0 | -147.4 to 385.9 | -295.8 to 204.6 | -389.1 to 309.8 |
Statistical analysis of Pima™ analysers field-tested in a hospital-based antenatal HCT clinic (N = 77) and in the laboratory (N = 91) during Phase II testing versus predicate reporting. A direct comparison of Pima performance using matched venous vs. capillary blood samples is shown. All values, with the exception of N, refer to CD4 cell counts in cells/mm3. BA = Bland-Altman statistical analysis. LOA = limits of agreement. #Precision of Pima™ to Predicate method expressed as %SIM CV.
*cells/mm3