Ayuen, S. DholOlupot‑Olupot, PeterMuhindo, RitaOnyamboko, A. MarieAjayi, SeunChimjinda, NatenapaTaya, ChirapornUyoga, SophieWilliams, N. ThomasMaitland, KathrynFanello, CaterinaDay, P. J. NicholasTaylor, R. WalterMukaka, Mavuto2026-07-012026-07-012025Ayuen, D. S., Olupot-Olupot, P., Muhindo, R., Onyamboko, M. A., Ajayi, S., Chimjinda, N., Taya, C., Uyoga, S., Williams, T. N., Maitland, K., Fanello, C., Day, N. P. J., Taylor, W. R., & Mukaka, M. (2025). Comparing HemoCue® and Quantitative Buffy Coat® and Coulter Counter-measured haemoglobin concentrations in African children with acute uncomplicated malaria: a Bland–Altman analysis. Malaria Journal, 24(1), 77. https://doi.org/10.1186/s12936-025-05318-5https://bdears.busitema.ac.ug/handle/123456789/7080ArticleBackground: Anaemia is a deleterious consequence of malaria, and its accurate diagnosis is crucial for effective management. However, laboratory methods for measuring haemoglobin (Hb) concentration, like the Coulter Counter and the Quantitative Buffy Coat® (QBC®), are costly and not widely accessible in resource-limited settings. The pointof-care HemoCue® test is a cheaper alternative and suitable in rural areas. The study aimed to determine the level of agreement between Coulter Counter/QBC® vs. HemoCue®-measured Hb concentrations by Bland–Altman analysis. Methods: As part of a randomized, placebo-controlled trial of single low-dose primaquine in Ugandan and Congolese children with acute uncomplicated Plasmodium falciparum malaria, Hb concentrations were measured on days 0, 3, 7, and 28 using Coulter Counter (Uganda, n=1880 paired values), QBC® (DR Congo, n=1984 paired values) and HemoCue® Hb-301™. The predefined clinically acceptable limits were set at±0.5 g/dL. Results: The Bland–Altman analysis showed that the HemoCue® minus Coulter Counter mean Hb difference was − 0.15 g/dL with lower and upper limits of agreement of − 3.68 g/dL and 3.39 g/dL, respectively. Corresponding HemoCue® minus QBC® values were − 0.23 g/dL, − 1.66 g/dL and 1.22 g/dL. Linear regression of Hb concentration differences vs. mean Hb concentrations showed negative correlations: r=− 0.43 and r=− 0.34 for HemoCue® vs. Coulter Counter and HemoCue® vs. QBC®, respectively. Conclusions: Compared to Coulter and QBC®, mean HemoCue® measured Hb concentrations were lower and, compared to the Coulter or QBC® methods, had an overall tendency to measure lower Hb concentrations with increasing Hb concentrations. Upper and lower limits of agreement were wider than the predefined clinically acceptable limits of±0.5 g/dL. HemoCue® should be used with caution in settings where decisions about blood transfusions are made. Keywords Bland–Altman analysis, Haemoglobin, Anaemia, Malaria, HemoCue, Coulter Counter, QBC®enArticle