Evaluation of the diagnostic accuracy of the HemoCue device for detecting anaemia in healthy school- aged children in KwaZulu-Natal, South Africa

Abstract

Background. The prevalence of anaemia in school-aged children is reported to be high (>10%), yet neither the onset of anaemia nor the disease causing it is easily established. Any form of anaemia, even if mild, can compromise children’s health and survival. This study was conducted to generate data to support or reject use of the HemoCue device as a potential point-of-care method for haemoglobin (Hb) assessment in field and primary healthcare settings.

Objective. To assess the validity of the HemoCue in relation to the gold-standard laboratory method.

Methods. A cross-sectional study of children aged 6 - 8 years, analysing the diagnostic accuracy of the HemoCue in determining Hb levels in venous blood. Agreement between the HemoCue and laboratory techniques was evaluated using the Bland-Altman plot. The intra-class correlation coefficient was used to assess within-subject variability of measured Hb.

Results. A trend of underestimation of Hb values was noted. The mean Hb with the HemoCue was 11.70 g/dL and that with the laboratory method 12.19 g/dL. The mean difference between the two methods was 0.49 g/dL, with a standard deviation of 0.77 g/dL (95% confidence interval –0.59 - –0.38). Discrepancies >1 g/dL were identified in 14.1% of cases. Bias increased with increasing Hb values.

Conclusion. The HemoCue was found to be comparable to the standard laboratory method for determining Hb concentrations in school-aged children. Its usefulness for screening healthy children was demonstrated, although a full blood count is recommended if anaemia or iron deficiency is suspected.