The platelet blood smear is an important tool in the evaluation of platelet disorders because it adds useful information to data provided by hematology analyzers. Furthermore, it serves as a tool for the internal quality control of automated counts. The aim of this work was to compare four manual methods of estimating platelets and to correlate the results with automated platelet counts. This study may also assist in the validation of these methods. The methodologies evaluated in this work were the modified Fonio method, the Barbara H. O'Connor method, the Nosanchuk Chang & Bennett method and an alternative method based on the patient's hemoglobin. All methodologies had good correlation coefficients both when compared with the other methods tested and with automated platelet counts suggesting that their use can be recommended for the evaluation of the platelet status of any patient.
Platelet blood smear evaluation; platelet count; quality control; thrombocytopenia; thrombocytosis
