Evaluation of Different Methods of Haemoglobin Estimation Among Malaria‐Infected Patients

BACKGROUND: Haemoglobin (Hb) estimation is essential for assessing anaemia, particularly in malaria-endemic settings. Automated Full Blood Count (FBC) analysers, cyanmethemoglobin spectrophotometry, and portable Hb meters are commonly used, but differences in analytical performance may affect measurements. METHODS: This cross-sectional study compared Hb measurements obtained using an automated FBC analyser, the cyanmethemoglobin method, and a portable Hb meter among 100 malaria-infected patients aged 16-65 years at Kumasi South Hospital, Ghana. Measurements were compared using Pearson's correlation coefficient, intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC), Bland-Altman analysis, percentage error, and Passing-Bablok regression. RESULTS: The three methods showed very strong correlations (r = 0.955-0.992, p < 0.001), excellent ICC (single measures = 0.969; average measures = 0.990), and high concordance (CCC = 0.95-0.99). Mean biases were -0.06 g/dL for FBC analyser versus portable Hb meter, -0.25 g/dL for FBC analyser versus cyanmethemoglobin, and -0.20 g/dL for portable Hb meter versus cyanmethemoglobin. The corresponding 95% limits of agreement were -0.59 to 0.47, -1.48 to 0.98, and -1.35 to 0.95 g/dL, respectively. Passing-Bablok slopes were 1.00 for all comparisons. The FBC analyser and portable Hb meter showed the closest agreement. CONCLUSION: The three methods demonstrated good agreement and broadly comparable Hb measurements. The findings support the practical use of portable Hb meters where point-of-care testing is required, while recognising that agreement does not establish diagnostic accuracy or analytical validation.