Comparison of three-fold converted hematocrit and micro-hematocrit in pregnant women

Anemia is one of the common complications of pregnancy. Hemoglobin concentration, Hematocrit, and Red cell count are laboratory tests used to diagnose anemia. In are source poor setting, there is a practice of using three-fold converted Hematocrit. This study is designed to assess the association and acceptability of three-fold converted Hematocrit as compared to the standard Micro-hematocrit method, in pregnant women.

The cross-sectional study conducted from May 18 to June 12, 2018 involved 200 pregnant women who visited the Laboratory for a Hematocrit test. Three milliliter of venous blood was collected with EDTA tube to determine Hematocrit by the Micro-hematocrit method and Hemoglobin concentration measured by a HemoCue Hemoglobin B analyzer. A scatter plot, correlation coefficient, Bland and Altman plot, and Area under curve were employed to assess the agreement and acceptability of the calculated Hematocrit as compared to the standard Micro-hematocrit.

The correlation coefficient, Intraclass correlation coefficient and concordance correlation coefficient were 0.91, 0.94, and 0.89, respectively. The Bland and Altman plot showed a mean difference of 0.94 with the limit of agreement ranges from 0.6 to 1.3. The area under the receiver operating characteristics with cut-off point of Hematocrit <33% was 0.86. The sensitivity and specificity of the calculated method was 95.5% and 71.4%, respectively.

Generally there is excellent association between the two methods. The two methods were identical within inherent imprecision of both methods. Hence, the Hematocrit value, threefold calculated from the Hemoglobin was found to be acceptable to diagnose anemia in pregnant women.