Hemoglobin assessment: precision and practicability evaluated in the Netherlands-the HAPPEN study

Most donors do not like the invasive hemoglobin (Hb) measurement in fingerstick capillary samples. Alternative noninvasive devices have recently become available. In this study we assessed the precision and practicability of noninvasive devices and compared them with measurements in capillary and venous samples.

A total of 2589 blood donors were included in the study. Hb levels were measured with the noninvasive devices NBM 200 or Haemospect and compared with values obtained with the invasive devices HemoCue 201 and HemoCue 301 and with venous values. Precision was evaluated in terms of sensitivity and specificity for detection of Hb levels below the cutoff level for donation, taking venous values as "reference values."

Hb levels measured with both invasive and noninvasive devices differed significantly from venous measurements. Measurements with invasive devices correlated stronger with venous values and were more precise. Sensitivity ranged from 30.1% (HemoCue 201) to 3.5% (Haemospect) in men and from 36.6% (HemoCue 201) to 10.8% (Haemospect) in women. Specificity ranged from 99.8% (HemoCue 201) to 95.5% (Haemospect) in men and from 98.9% (HemoCue 201) to 94.6% (NBM 200) in women. Most donors preferred the noninvasive measurement.

Measurements with invasive devices showed stronger correlation and better agreement with venous values than noninvasive devices. Sensitivity was low for all measurement devices, particularly the noninvasive ones. In terms of precision invasive measurement would be preferred for donor screening, although a majority of donors preferred the noninvasive measurement.