Comparison of the accuracy of hemoglobin point of care testing using HemoCue and GEM Premier 3000 with automated hematology analyzer in emergency room
Abstract
The laboratory analysis provides accurate, but time consuming hemoglobin level estimation especially in the emergency setting. The reliability of time-sparing point of care devices (POCT) remains uncertain.
We tested two POCT devices accuracy (HemoCue(R)201+ and Gem(R)PremierTM3000) in routine emergency department workflow. Blood samples taken from patients admitted to the emergency department were analyzed for hemoglobin concentration using a laboratory reference Beckman Coulter LH 750 (HBLAB), the HemoCue (HBHC) and the Gem Premier 3000 (HBGEM).
Pairwise comparison for each device and HbLAB was performed using correlation and the Bland-Altman methods. The reliability of transfusion decision was assessed using three-zone error grid.
A total of 292 measurements were performed in 99 patients. Mean hemoglobin level were 115 +- 33, 110 +- 28 and 111 +- 30 g/l for HbHC, HbGEM and HbLAB respectively.
A significant correlation was observed for both devices: HbHC versus HbLAB (r2 = 0.93, p < 0.001) and HBGEM versus HBLAB (r2 = 0.86, p < 0.001). The Bland-Altman method revealed bias of MINUS SIGN 3.7 g/l (limits of agreement MINUS SIGN 20.9 to 13.5) for HBHC and HBLAB and 2.5 g/l (MINUS SIGN 18.6 to 23.5) for HBGEM and HBLAB, which significantly differed between POCT devices (p < 0.001).
Using the error grid methodology: 94 or 91 % of values (HbHC and HbGEM) fell in the zone of acceptable difference (A), whereas 0 and 1 % (HbHC and HbGEM) were unacceptable (zone C). The absolute accuracy of tested POCT devices was low though reaching a high level of correlation with laboratory measurement.
The results of the Morey's error grid were unfavorable for both POCT devices.