TABLE 2.
Accuracy of universal, heparin-calibrated anti-Xa assay with regard to drug concentration in 845 patients taking rivaroxaban, apixaban, or edoxaban in clinical practice.
| Overall | Rivaroxaban | Apixaban | Edoxaban | |
| Spearman’s correlation coefficient (95% CI) | 0.97(0.97,0.98) | 0.97(0.97,0.98) | 0.96(0.96,0.97) | 0.96(0.94,0.99) |
| Deming regression Slope (95% CI) | 0.008(0.006,0.009) | 0.008(0.007,0.009) | 0.008(0.007,0.009) | 0.006(0.005,0.007) |
| Y-intercept (95% CI) | 0.29(0.15,0.42) | 0.29(0.16,0.40) | 0.14(0.05,0.23) | 0.10(0.015,0.18) |
Ultra-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine drug levels. The Spearman’s correlation coefficient is given (rs), and the coefficients of the Deming regression.