Methods and analyzers for hemoglobin measurement in clinical laboratories and field settings

Abstract

This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. We conducted a literature review for methods used to measure Hb in clinical laboratories and field settings. We described methods to measure Hb and factors influencing results. Automated hematology analyzer (AHA) was reference for all Hb comparisons using evaluation criteria of ±7% set by College of American Pathologists (CAP) and Clinical Laboratory Improvement Amendments (CLIA). Capillary fingerprick blood usually produces higher Hb concentrations compared with venous blood. Individual drops produced lower concentrations than pooled capillary blood. Compared with the AHA: (1) overall cyanmethemoglobin (1.0−8.0 g/L), WHO Colour Scale (0.5−10.0 g/L), paper-based devices (5.0−7.0 g/L), HemoCue® Hb-201 (1.0−16.0 g/L) and Hb-301 (0.5−6.0 g/L), and Masimo Pronto® (0.3−14.0 g/L) overestimated concentrations; (2) Masimo Radical®-7 both under- and overestimated concentrations (0.3−104.0 g/L); and (3) other methods underestimated concentrations (2.0−16.0 g/L). Most mean concentration comparisons varied less than ±7% of the reference. Hb measurements are influenced by several analytical factors. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.This paper describes and compares methods and analyzers used to measure hemoglobin (Hb) in clinical laboratories and field settings. With few exceptions, mean concentration bias was within ±7%, suggesting acceptable performance. Appropriate, high-quality methods in all settings are necessary to ensure the accuracy of Hb measurements.