Validation of a Modified Sahli's Hemoglobin Method Using Automated CBC: A Feasibility Study for Point-of-Care Testing

Background: For rapid screening of anemia in the field on a mass scale, Hemoglobin is estimated by the Hemoglobin Colour Strip (HCS) method as per the WHO recommendation. However, this method does not provide precise measurements as several factors appear to contribute to incorrect readings. In this context, the modified method can be used in the field as a point-of-care assessment tool without any laboratory involvement, with more precise values close to those obtained in the laboratory-based automated CBC method(CBCA). Methods: 158 Students of both sexes in the age range of 18 to 25 years from the Department of Allied Health Sciences were randomly selected after obtaining their consent for this study. Venous blood was collected and hemoglobin was estimated by the HCS method, Conventional Sahli’s Method, and Sahli’s method with some modifications, and the result was compared with the gold standard for hemoglobin measurement tool, i.e. CBCA method. Results: It was found that modifications to the Sahlis method can improve its accuracy, as evidenced by the significant difference in Hb content between this method and the conventional Sahli’s method. It is also found that the reading obtained through this modified method is as close to the CBCA method. Discussion: Though the conventional Sahli’s method has so many advantages, it also has a good number of limitations. Moreover, in the conventional methodology, the reading of the acid hematin solution is noted till the color of the acid hematin solution matches the standard brown color glass of the comparator. But in reality, there is no single reading in which color just matches, which is purely based on color perception, which can vary and thereby is prone to a false low value than the real one. In such a condition, the recording of the reading under methodology is modified in such a way that the obtained value will be close to the real value compared with the autoanalyzer. Conclusion: From the present set of studies, it can be concluded that the modified Sahli’s method can be used as a more reliable tool for point-of-care largescale screening of anemia.