Role of point of care Hb diagnostic devices in getting the right picture of anemia control: Tangi Rural Anemia Diagnostic Accuracy Study

Abstract

Objectives: To study the accuracy and reliability of two point of care devices (Hemocue 201 [HC₂₀₁]) and Hemoglobin Colour Scale (HCS) with reference to automated laboratory analyser Sysmex XP 100 (Lab_SXP) and determine factors influencing their performances. To discuss certain design issues while ascertaining these parameters for its judicious use in both clinical context and disease burden studies.

Methods: Reliability and accuracy statistics were calculated for four population subgroups that were selected randomly using cluster sampling in a rural community of eastern India. Appropriate measures were taken to reduce biases in the study. Bland Altmann Plot was used to determine Bias and ROC curve analysis was used to suggest new cut-offs for HCS method.

Results: True prevalence varied across subgroups ranging from 12.56% in adolescent boys to 40.71% in adult women. Sensitivity for HC₂₀₁ was lowest among boys (80.39%) and highest among adult females (92.82%), while specificity was highest among adult males (86.94%) and lowest among adult females (75.00%). The variation across subgroups was due to differences in distribution of underlying Hb values. HC₂₀₁ has potential for use in clinical practice as well as disease burden estimation study. HCS was not suitable for use in clinical setting as the bias (−4.1 g/dl) was unacceptable. However, ROC analysis suggested certain cut-offs for different age groups and can be employed in poor resource settings for disease burden estimation study.

Conclusions: HC₂₀₁ is better than HCS as per the study. However, accuracy parameters are likely to vary depending on the distribution of underlying Hb distribution. Thus, same machines can demonstrate different accuracy parameters in different settings. There is need for designing studies that could help estimate these parameters each time on a subsample which would go a long way in efficiently using technology be it for guiding clinical decisions or public health actions.

Keywords:

• Anemia
• diagnostic accuracy study
• point of care diagnostic device
• Hemocue 201
• hemoglobin colour scale

Transparency

Declaration of funding

Intramural Research Grant No: IMF/27/2016 from AIIMS Bhubaneswar.

Declaration of financial/other relationships

The author have no financial or other relationships to declare. JME peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

PBM designed the study, collected data, analyzed and wrote the first draft and approved it. SM collected the data, analyzed it and revised the manuscript and accepted the final version.

Acknowledgments

We would like to thank our Institute (AIIMS hubaneswar, Institute of National Importance under MoH&FW, Govt of India) for providing intramural grant (No: IMF/27/2016) to meet the cost of all reagents and consumables required for the conduct of the study as well other resources, such as printing and travel facilities to study site throughout the study duration. PBM was working as Associate Professor, Department of Community Medicine and Family Medicine at AIIMS Bhubaneswar at the time of submission of this manuscript.