Use of Retained Samples for Quality Control of Hematology Analyzers in Low-Resource Laboratories. A Comparative Study Between Retained Samples and Controls
DOI:
https://doi.org/10.21276/apalm.3768Keywords:
coefficient of variation, hematology analyzers, internal quality control, retained samples, standard deviationAbstract
Background: Quality control is essential for verifying the performance of hematology analyzers (HAs).While internal quality control (IQC) materials are recommended, however their use is often limited in low-resource settings due to high costs, short shelf life and logistical challenges. This study is done to evaluate the utility and effectiveness of using retained patient samples for daily quality control in hematology analyzers and to compare their performance with standard IQC data in terms of accuracy and precision.Methods: Retained patient samples were tested in duplicate-once in the morning and again after overnight refrigerated storage (2–4°C). Results were compared with the corresponding IQC data in terms of calculating the coefficient of variation (CV%), standard deviation (SD) and performing statistical analysis for precision and reproducibility. Result: Minimum and maximum range in our study for retained samples for Hb (gm/dl) was 4.60-17.40, WBC (10x3mm/dl) 3.20-23.70, RBC (10x6mm/dl) 1.54-7.72 , Platelets (10x6mm/dl) 77-656. Correlation coefficient between 2 values of retained samples : Hb (0.997), Platelets (0.994), RBC (0.967), WBC (0.993). SD calculated on daily value difference was: Hb (0.15), Platelets (9.61), RBC (0.17), WBC (0.30). There was significant correlation between the IQC and retained sample data on Paired t-test (P < 0.05).
Conclusion: P PAIR testing show significant correlation between retained samples and IQC and correlation coefficient is within limits. Retained human samples could be further studied and standardized for quality control use in resource-limited and remote settings where synthetic controls are cost-prohibitive.
References
1. National Accreditation Board for Testing and Calibration Laboratories. Specific Criteria for Accreditation of Medical Laboratories. 2019;112(1):101.
2. International ISO Standard 15189. Medical Laboratories - Requirements for Quality and Competence (ISO 15189: 2012). Switzerland: International ISO Standard. 2012: 62.
3. National Accreditation Board for Testing and Calibration Laboratories. Specific Criteria for Accreditation of Medical Laboratories. 2019; (1):100.
4. Westgard JO, Westgard SA. Quality control review: Implementing a scientifically based quality control system. Ann Clin Biochem. 2016;53:32-50.
5. Brittin GM, Brecher G, Johnson CA, Elashoff RM. Stability of blood in commonly used anticoagulants. Use of refrigerated blood for quality control of the Coulter Counter Model S. Am J Clin Pathol. 1969;52:690-4.
6. Boos MS, Stewart RE, Miller ML. Temperature- and storage-dependent changes in hematologic variable and peripheral blood morphology. Am J Clin Pathol. 1998;110:537
7. Wood BL, Andrews J, Miller S, Sabath DE. Refrigerated storage improves the stability of the complete blood cell count and automated differential. Am J Clin Pathol. 1999;112:687-95.
8. Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res. 1999;8:135–60.
9. Grillone R, Grimaldi E, Scopacasa F, Dente B. Evaluation of the fully automated hematological analyzer mindray BC 6800: Comparison with Horiba ABX Pentra DX120. Int J Lab Hematol. 2013;36:e55-8.
10. Xiang D, Yue J, Lan Y, Sha C, Ren S, Li Y, et al. Evaluation of Mindray BC-5000 hematology analyzer: A new miniature 5-part WBC differential instrument. Int J Lab Hematol. 2015;37:597-605.
11. Kahar MA. Use of patient sample for quality control of hematology analyzers: Is it a feasible option in resource-poor setting? J Hematol Allied Sci.2023;3:54-60.
12. Vis JY, Huisman A. Verification and quality control of routine hematology analyzers. Int J Lab Hematol 2016;38:100-9.
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Copyright (c) 2026 Shilp Rani, Gunjot Kaur, Babita Rani, Arun Puri

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