Table 7.
Coefficient of variation (between-run), bias, and observed total error results for 2 canine urine cortisol concentrations and the 2 quality control material levels.
| Spiked urine samples | ||||||||
| Cortisol level | Target values, nmol/L (μg/dL) | Precision (%) | Bias (%) | TEo (%) | ||||
| Between-run CV | SR | RB | AB | TEoSR | TEoRB | TEoAB | ||
| L4 | 38.6 (1.4) | 9.55 | 42.3 | 8.7* | –1.09 | 61.4 | 27.8 | 20.2 |
| L8 | 552 (20) | 4.60 | 19.8 | –10.7 | 28.9 | 19.9 | 10.3 | |
| QCM | ||||||||
| Cortisol level | Target values,* nmol/L (μg/dL) | Precision (%) | Bias (%)† | TEoQCM (%) | ||||
| Between-run CV | SR | RB | AB | TEoQCM.SR | TEoQCM.RB | TEoQCM.AB | ||
| QCM1 | 193 (7.0) | 5.42 | 35.8 | 8.7* | –1.09 | 46.6 | 19.5 | 11.9 |
| QCM2 | 389 (14.1) | 4.51 | 19.8 | –10.7 | 28.7 | 19.7 | 10.1 | |
AB = average bias; CV = coefficient of variation; Lx = level x (see dilution Table 1); RB = range-based bias; SR = spiking-recovery bias; TEo = observed total error.
*
Closest available bias.
†
There were no target values provided by the manufacturer of the QCM for canine urine cortisol. Means are provided to give an idea of the tested level. Because of the absence of target values, the QCM bias could not be assessed. Instead, TEoQCM was calculated using the biases from the spiking recovery study (SR) and the comparison study (RB and AB) at similar urine cortisol concentrations.