The Interchangeability of Plasma and Whole Blood Metal Ion Measurement in the Monitoring of Metal on Metal Hips

Figure 4

Applying the correction factors = 1.881 cobalt and = 1.225 chromium obtained from the adjusted regression analyses reduces the mean difference between serum and whole blood concentrations of cobalt (a) and chromium (b) to 0.615 (95% CI: −1.251 to 2.469) and 0.999 (95% CI: −1.314 to 3.314) and positions the limits of agreement more symmetrically on either side of zero.

(a)

(b)