Evaluating hemoglobin versus hematocrit measurements in the diagnosis of anemia among pregnant women in Woliso town, Ethiopia: a mixed-methods study.

Anemia during pregnancy remains a public health concern in Ethiopia. While hemoglobin (Hb) concentration is the WHO-recommended standard for diagnosing anemia, hematocrit (Hct) continues to be used in many resource-limited areas. However, evidence comparing Hb- and Hct-based diagnostic classifications among pregnant women in Ethiopia remains limited. This study aimed to evaluate the agreement between hemoglobin- and hematocrit-based diagnostic methods and to determine whether these methods yield comparable estimates of anemia among pregnant women attending antenatal care in Woliso town. A facility-based convergent mixed-methods cross-sectional study was conducted among 280 systematically selected pregnant women from February 1-28, 2023. Venous blood samples were analysed using the Mindray BC-5150 automated haematology analyser (reference standard) and the Mission Hb Hemoglobin Meter. Anemia was defined as Hb < 11 g/dL or Hct < 33%. Agreement between methods was assessed using intra-class correlation coefficients (ICC), Bland-Altman analysis, kappa statistics, and McNemar's test. Logistic regression analysis was performed using hemoglobin-based anemia as the primary outcome. Thirteen purposively selected anemic pregnant women participated in in-depth interviews. Qualitative data were analysed using inductive thematic analysis and integrated with quantitative findings at the interpretation stage. Hemoglobin-based assessment identified anemia in 11.4% (95% CI 8-15%) of participants, whereas hematocrit-based assessment identified 18.6% (95% CI 14-23). The 7.2 percentage-point difference was statistically significant (McNemar's p = 0.018). Agreement between Hb and Hct measurements was substantial (κ = 0.72) with excellent correlation (ICC = 0.89). However, Bland-Altman analysis demonstrated limits of agreement that may influence clinical classification near diagnostic thresholds. Factors associated with haemoglobin-based anemia included unplanned pregnancy, malaria infection, lack of nutritional counselling, and non-use of iron-folate supplementation, although some estimates were imprecise. Qualitative findings converged with quantitative results, highlighting prior illness, limited dietary diversity, and challenges with iron supplementation. Hematocrit-based assessment yielded significantly higher anemia prevalence than hemoglobin measurement, suggesting potential overestimation when Hct is used alone. While agreement between methods was substantial, they are not fully interchangeable in clinical practice. Routine use of standardized hemoglobin-based measurements is recommended to ensure accurate anemia classification among pregnant women.