Table 1.
Intra-assay variation measured by duplicated concentrations in two proficiency samples tested within a round. Relative percentage difference = 100% × ([largest value−smallest value]/average of smallest and largest).
| ARV←CPL↓ | ATV | DRV | EFV | FTC | LPV | RGV | TFV | Median CPL RPD | Min/Max |
|---|---|---|---|---|---|---|---|---|---|
| Target concentrations (ng/ml) | 1200 | 3500 | 1500† | 600/1250† | 1200 | 800/900† | 120† | ||
| 1 | 3.15 | 4.54 | 3.57 | 0.90 | 0.86 | - | 7.09 | 3.36 | 0.86/7.09 |
| 2 | 1.22 | 0.70 | 1.65 | 0.64 | 0.56 | 0.28 | 11.50 | 0.70 | 0.28/11.50 |
| 3 | - | 2.51 | - | - | 0.45 | - | 1.48 | 0.45/2.51 | |
| 4 | 12.5 | - | 3.51 | 1.61 | 8.69 | 0.75 | 4.53 | 4.02 | 0.75/12.5 |
| 5 | 1.06 | 0.76 | 3.57 | - | 5.14 | - | - | 2.32 | 0.76/5.14 |
| 6 | 1.40 | 0.39 | 3.49 | 5.76 | 6.87 | - | 0.97 | 2.45 | 0.39/6.87 |
| 7 | 1.17 | 4.92 | 1.32 | - | - | 0.76 | 1.25 | 0.76/4.92 | |
| 8 | 1.29 | - | 0.69 | - | 0.50 | - | - | 0.69 | 0.50/1.29 |
| 9 | 4.44 | 1.48 | 3.62 | - | 0.57 | - | 2.55 | 0.57/4.44 | |
| 10 | 0.76 | 10.10 | 1.26 | 6.97 | 2.32 | 10.80 | 2.23 | 2.32 | 0.76/10.80 |
| Median ARV RPD | 1.29 | 1.17 | 3.00 | 1.61 | 2.32 | 0.57 | 3.38 | Overall Median | 1.61 |
| Min/Max | 0.76/12.5 | 0.39/10.10 | 0.69/4.92 | 0.64/6.97 | 0.50/8.69 | 0.28/10.80 | 0.76/11.50 |
†
These duplicate variability was tested in both rounds for these drugs.
The laboratory provided results for both rounds of duplicate testing and the first RPD is reported.
ARV: Antiretroviral; ATV: Atazanavir; CPL: Clinical pharmacology laboratory; DRV: Darunavir; EFV: Efavirenz; FTC: Emtricitabine; LPV: Lopinavir; RGV: Raltegravir; RPD: Relative percentage difference; TFV: Tenofovir.