Point-of-care Hemoglobin Measurement in Comparison with Hematology Analyzer: A Cross-sectional Study in Emergency Department

Introduction: Point-of-care hemoglobin testing devices can help emergency physicians to make their clinical decisions in a timelier manner. They can also improve the patient care process by decreasing the length of stay and costs. Although different devices are available now, their diagnostic accuracy remains still uncertain. Objective: This study compares the results of hemoglobin levels measured by a point-of-care hemoglobin testing device and central lab auto-analyzer. Methods: Hemoglobin level was measured both by a point-of-care device (Mission® Plus Hb) and the central laboratory auto-analyzer (Sysmex KX-21N™) in medical cases presenting to emergency department (ED) and requiring hemoglobin (Hb)/hematocrit (Hct) level measurement. The agreement of Hb and Hct between the two methods was assessed based on intraclass correlation coefficient (ICC), Bland-Altman analysis and the Mountain plots. Also, time gap between point-of-care testing and preparation of central lab results was measured. Results: Hb and Hct were measured in 86 cases mostly presented because of gastrointestinal bleeding. We found a good agreement between the two methods for hemoglobin (ICC=0.985) and hematocrit levels (ICC=0.991). The bias was 0.09 and 95% limits of agreement (LoA) were -0.89 to 1.07 for Hb level. Mean of time delay between point-of-care testing and preparation of central lab results was 207.31 minutes (SD=93.66) and this delay was clinically significant (p=0.001). Conclusion: Point-of-care measurement of Hb level provides proper quantitative results in ED patients. It significantly decreases laboratory turnaround time and may be used to improve the patient throughput by decreasing the length of stay in most clinical settings.