Fig. 1From: Systematic comparison of four point-of-care methods versus the reference laboratory measurement of hemoglobin in the surgical ICU setting: a cross-sectional method comparison studyCorrelation and agreement between point-of-care testings and the reference central laboratory for hemoglobin measurement. a Scatter plot with Pearson correlation analysis. The red color line showed a linear regression curve, where the light-red band represented the 95% confidence interval. b Bland-Altman analysis. A horizontal solid line corresponds to the estimated bias, while two horizontal dash lines represent the upper and lower prediction limits, corresponding to the 95% limit of agreementBack to article page