Fig 1.
Empirical cumulative distribution function was applied to detect potential bias between centers (LIB-05, LIB-07 and LIB-26). Hb = hemoglobin, CL central lab, BGA = blood gas analysis, LIB-05 = Bonn, LIB-07 = Lrankfurt, LIB-26 = Wuerzburg.
Fig 2.
A and B: Histogram with density for hemoglobin pairs from LIB 07 and LIB-26. The relative frequency of Hb difference is displayed (a, b). Sd (Standard deviation), MAD.
Fig 3.
Bland-Altman Plot and LOWESS curve showing the differences of the Hb differences (LIB-07 and LIB-26).
The difference of the Hb values (Hb-CL and Hb-BGA) calculated for each pair and plotted against the mean value of both measurements are displayed ((Hb-CL + Hb-BGA)/2). The LOWESS curve (red line) shows the tendency of mean bias with lower Hb levels. Hb = hemoglobin, CL = central lab, BGA = blood gas analysis.
Fig 4.
Bland-Altman Plot and LOWESS curve showing differences in percentage of Hb pairs (LIB-07 and LIB-26).
The difference in percentage of Hb values (Hb-CL and Hb- BGA) calculated for each pair and plotted against the mean value of both measurements are displayed ((Hb-CL + Hb-BGA)/2). The LOWESS curve (red line) shows the tendency of mean bias expressed as percentage of CL Hb with lower Hb levels. Hb = hemoglobin, CL = central lab, BGA = blood gas analysis.
Fig 5.
Bias depending on smoker status (LIB-07 and LIB-26).
The relative frequencies of Hb pairs in smoker, non-smoker and ex-smoker are displayed. Hb = hemoglobin, CL = central lab, BGA = blood gas analysis.
Table 1.
Possible confounding factors N = absolute number of patients, SD = standard deviation (LIB-07 and LIB-26).
Table 2.
Biases depending on co-medication (LIB-07 and LIB-26).