Potential new tool for anemia screening: An evaluation of the performance and usability of the TrueHb Hemometer

Abstract

In low-and middle-income countries, many women experience anemia during pregnancy due to insufficient dietary intake of key micronutrients, parasitic infections, hemoglobinopathies, and chronic infections. Maternal anemia increases perinatal risks for both mothers and infants, and slow progress to reduce the prevalence may be due in part to the lack of affordable tools to quantify hemoglobin levels in antenatal care (ANC) clinics. A simple, inexpensive, accurate, and robust diagnostic is needed to measure hemoglobin in ANC. This study evaluated the performance and usability of the TrueHb Hemometer. A crosssectional diagnostic accuracy study was conducted to compare the accuracy of the TrueHb and the HemoCue® 201+ using capillary samples. Next, analytical performance (precision, coefficient of variation, R 2) of the TrueHb was evaluated in varying environmental conditions using linearity panels with serial dilutions of venous blood samples. Lastly, the usability of the TrueHb Hemometer was assessed across three domains (effectiveness, efficiency, and satisfaction) by 20 ANC providers in Ghana. Capillary blood test results were not well correlated (R 2 = 0.35) between the TrueHB and HemoCue201+, but 80% of TrueHb measurements were within +/-1.0 g/dl of the HemoCue® 201+ hemoglobin values. Precision tests indicated similar mean values across the three environmental conditions (CV<6%). At 21˚C, the TrueHb follows a linear relationship (R 2 �0.96) but does not generate accurate readings below 4.0 g/dl. At 30˚C and 37˚C, the TrueHb follows a linear relationship (R 2 > 0.90) but begins to underestimate the hemoglobin concentration below 7.0 g/dl. The usability study identified potential failure modes due to inadequate instructions and device feedback. With some modifications, both to the product and to the instructions for use, the TrueHb may be suitable for use in ANC settings to help fill the diagnostic gap for anemia screening during pregnancy. Further testing is required with anemic populations in LMIC settings.

Comparison of indirect cyanmethaemoglobin method and TrueHb haemometer point of care test with direct cyanmethaemoglobin (gold standard) method for strengthening anaemia detection at primary health care level

“…In addition to direct and indirect cyanmethaemoglobin methods, a point-of-care (POCT) for haemoglobin (Hb) estimation, TrueHb haemometer test is also available which is useful to cover the diagnostic gap for the screening of anaemia during pregnancy at PHC and community level. [ 9 ] However, its further validation in comparison to the gold standard method was required. Even according to a review published in 2018, for better performance of digital haemoglobinometers (invasive methods) for Hb evaluation in facility as well as community settings, the training of frontline workers and SOPs adherence is required.…”