Table 2.
Multicentre ISI calibration of rTF/95 against RBT/90 performed by the ECAA in 2001
| Centre | N | ISI | CV(b) | Slope of patients only line | INR (RBT/90) | INR (rTF/95) |
| A | 75 | 0.97 | 3.1 | 0.95 | 2.41 | 2.33 |
| B | 73 | 0.99 | 2.2 | 1.08 | 3.09 | 2.95 |
| C | 70 | 1.02 | 2.7 | 1.17 | 2.90 | 2.73 |
| D | 76 | 0.99 | 3.2 | 0.97 | 2.44 | 2.35 |
| E | 73 | 0.95 | 1.9 | 1.00 | 2.96 | 2.96 |
| F | 78 | 0.80* | 4.5 | 0.81 | 2.20 | 2.51 |
| G | 75 | 0.97 | 2.3 | 1.06 | 2.24 | 2.21 |
| H | 73 | 1.05 | 2.7 | 1.14 | 2.58 | 2.37 |
| I | 71 | 1.03 | 2.8 | 0.92 | 2.87 | 2.56 |
| J | 74 | 0.96 | 4.5 | 0.96 | 2.16 | 2.14 |
| Overall | 0.97 | 3.0 | 1.00 | 2.58 | 2.51 | |
| Between laboratory CV | 7.0 | 10.9 | ||||
| Overall, excluding F | 0.99 | 2.8 | 1.03 | 2.63 | 2.51 | |
| Between laboratory CV | 3.5 | 8.6 |
N is the total number of samples used in each calibration. CV(b) is the coefficient of variation of the calibration slope for healthy subjects plus patients. The mean INR for the patients, samples included in the calibration was calculated from RBT/90 and rTF/95 measurements.
*Detected as an outlying result.
CV, coefficient of variation; ECAA, European Concerted Action on Anticoagulation; INR, international normalised ratio; ISI, international sensitivity index.