Sue J. LeeKasia StepniewskaNicholas AnsteyElizabeth AshleyKaren BarnesTran Quang BinhUmberto D'AlessandroNicholas P.J. DayPeter J. De VriesGrant DorseyJean Paul GuthmannMayfong MayxayPaul NewtonFrancois NostenPiero OlliaroLyda OsarioLoretxu PinogesRic PriceMark RowlandFrank SmithuisRobert TaylorNicholas J. WhiteMahidol UniversityRoyal Darwin HospitalShoklo Malaria Research UnitUniversity of Cape TownChoray HospitalPrins Leopold Instituut voor Tropische GeneeskundeCentre for Clinical Vaccinology and Tropical MedicineAcademic Medical Centre, University of AmsterdamUniversity of California, San FranciscoInstitut de Recherche en Sciences de la SantéUganda Malaria Surveillance ProgramEpicentreNational University of LaosUniversity of OxfordOrganisation Mondiale de la SanteCentro Internatcional de Entrenamiento e Investigaciones MedicasLondon School of Hygiene & Tropical Medicine2018-07-122018-07-122008-08-22Malaria Journal. Vol.7, (2008)147528752-s2.0-49649123369https://repository.li.mahidol.ac.th/handle/20.500.14594/19301Background. Malaria is a very important cause of anaemia in tropical countries. Anaemia is assessed either by measurement of the haematocrit or the haemoglobin concentration. For comparisons across studies, it is often necessary to derive one measure from the other. Methods. Data on patients with slide-confirmed uncomplicated falciparum malaria were pooled from 85 antimalarial drug trials conducted in 25 different countries, to assess the haemoglobin/haematocrit relationship at different time points in malaria. Using a linear random effects model, a conversion equation for haematocrit was derived based on 3,254 measurements from various time points (ranging from day 0 to day 63) from 1,810 patients with simultaneous measurements of both parameters. Haemoglobin was also estimated from haematocrit with the commonly used threefold conversion. Results. A good fit was obtained using Haematocrit = 5.62 + 2.60 * Haemoglobin. On average, haematocrit/3 levels were slightly higher than haemoglobin measurements with a mean difference (± SD) of -0.69 (± 1.3) for children under the age of 5 (n = 1,440 measurements from 449 patients). Conclusion. Based on this large data set, an accurate and robust conversion factor both in acute malaria and in convalescence was obtained. The commonly used threefold conversion is also valid. © 2008 Lee et al; licensee BioMed Central Ltd.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1186/1475-2875-7-149