Figure 1.

Two-way correlation scatter plots comparing (A) EuroImmun, (B) Abbott and (C) Roche immunoassays. Pearson χ² test was used to assess correlations. The results for each test were log transformed to ensure results follow a normal distribution. Negative agreement shown as blue dots, red dots show positive agreement for the two immunoassays, while black dots show disagreement and grey dots as the EuroImmun borderline results. Vertical lines mark the Abbott test range 0.25–1.4. n=880. The graphs show positive correlations between all immunoassays evaluated, with the fewest disagreement of results between the log of Roche and the log of EuroImmun. Fit lines locally estimated scatterplot smoothing (LOESS), with 95% CI shaded.