Diagnostic and analytic performance of four point-of-care hemoglobin testing devices used in routine HIV and maternity care in Uganda.

BACKGROUND

Hemoglobin estimation (Hb) is the most requested hematology test, especially among pregnant/postnatal women and people living with HIV (PLHIV). In Uganda, several point-of-care (POC) Hb testing devices are currently used and performance may be affected by multiple factors. This study evaluated the diagnostic and analytic performance of four Hb POC devices.

METHODS

During October 2021-April 2022, four POC Hb devices (HemoCue Hb 301, DiaSpect Tm, Hemo Control, and VERI-Q Red) were evaluated against the Beckman Coulter as gold standard at four sites: Rakai Health Sciences Program clinic/Kalisizo General Hospital, Mbarara Municipal Council Health Center IV, Mpigi Health Center IV, and Atutur Hospital. Adult, consented participants aged ≥ 18 years, provided 4 mL of venous blood for concurrent Hb testing across the POC Hb devices. Anemia classification followed World Health Organization guidelines: <11.0 g/dl for pregnant women, < 12.0 g/dl for non-pregnant adult women, and < 13.0 g/dl for adult men. The Bland-Altman method was used to assess the agreement of Hb results (mean difference, standard deviation of differences, and limits of agreement). Diagnostic accuracy parameters (sensitivity, specificity, positive predictive value, negative predictive value, and accuracy) were calculated to evaluate the performance of each device compared to the reference machine.

RESULTS

A total of 768 participants (192 from each site), comprising equal numbers of PLHIV and pregnant/postnatal women were recruited. Participants' mean (SD) Hb values were 12.1 (± 2.2) g/dl. There were strong positive correlations (all r ≥ 0.9) between each POC Hb device and the Beckman Coulter.  The mean difference between POC Hb devices and Coulter readings across sites was 0.06 for the HemoCue Hb 301, 0.16 for VERI-Q Red, 0.35 for Hemo Control, and 0.57 for Diaspect Tm, with the Diaspect Tm showing the broadest limits of agreement (-0.76,1.91). The DiaSpect Tm, Hemo Control, HemoCue Hb 301 and VERI-Q Red were at least 94% (79%), 88% (87%), 77% (91%) and 75% (76%) sensitive (specific), respectively, across the study sites.

CONCLUSION

All devices demonstrated clinically acceptable performance (within ± 1 g/dL of the reference hemoglobin), with the HemoCue Hb 301, DiaSpect Tm and Hemo Control performing most comparable to the standard, suggesting potential for interchangeable use.