Fig. 1.

Comparison of 25(OH)D total levels for the two immunoassays against LC-MS/MS total by Passing–Bablok regression analysis (left panels) and Bland–Altman plots [middle (nmol/L) and right panels (%)], for before treatment (A) and after treatment (B). Left panels: thin black lines denote lines of identity; thick blue lines denote regression lines; red lines denote 95% confidence intervals; blue circles denote individual samples. Middle and right panels: thick blue lines denote mean biases; red lines denote 95% confidence intervals; blue circles denote individual samples.