Quality control (QC) is the cornerstone of accurate and reliable diagnostic testing in hematology laboratories. By implementing both Internal Quality Control (IQC) and External Quality Control (EQC) measures, laboratories can achieve consistent performance and enhance diagnostic precision. ensuring accurate and precise processes to deliver reliable, reproducible, and relevant results. However, maintaining high standards comes with its own set of challenges.

The Importance of Quality Control in Hematology Laboratories

Since laboratory results influence approximately 80% of clinical management decisions, implementing stringent quality control (QC) practices in haematology are essential.  The primary objective is to minimize errors that could lead to incorrect diagnoses or delayed treatments. 1 

In hematology, QC aims to detect and address errors before results are reported, ensure test accuracy and precision, and build trust and confidence in the results for clinicians and patients. 1,2 

By integrating automation, digital systems, and standardized protocols, laboratories can reduce error rates, enhance workflow efficiency, and prioritize patient safety. 3 

Best Practices in Quality Control

Hematology laboratories must implement both internal (IQC) and external quality control (EQC) processes to achieve high-quality results.

Internal Quality Control (IQC)- Monitoring Accuracy within the Laboratory
IQC focuses on systematic methods to ensure test accuracy and reliability. Key aspects include:

• Standardized protocols help to ensure consistency in staining, fixation, and other preanalytical and analytical steps. 4
• Routine checks which are done to regularly assess hematology analyzers and ensure that they function correctly. 5
• Manual Blood Smear Review (MBSR)  with microscopic analysis of well-prepared blood smears which is done to verify results from hematology analyzers. 6

External Quality Control (EQC): Learning Through Peer Comparison

EQC involves participating in external quality assessment schemes (EQAS) to compare laboratory performance with peers, helping to identify knowledge gaps and improve diagnostic accuracy.  7 Alcaraz-Quiles

External quality control allows for the following benefits:

• Benchmarking: Comparing performance with other laboratories. 
• Skill development: Training laboratory personnel to improve their diagnostic competencies. 
• Error identification: Highlighting discrepancies in results for corrective actions. 

Challenges in Quality Control

Despite progress, laboratories face several hurdles in maintaining QC standards.

1. Variability in Blood Smear Preparation

Preparing high-quality blood smears is complex, influenced by factors such as storage time of blood samples before fixation, consistency in morphology across smears and staining procedures and reagent quality. 8

2. Subjectivity in Morphological Analysis

Manual reviews are inherently subjective and demand a high level of technical expertise. 6  Variability in training and experience can impact the consistent and efficient application of laboratory-initiated peripheral blood smear (PBS ) review criteria. 4 Misclassification, such as identifying reactive lymphocytes as neoplastic cells, occurs in 10-26% of cases, highlighting the need for standardized training protocols. 7

3. Lack of Uniform Screening Criteria

Institutions frequently adapt international guidelines to align with local practices. 4 Key factors influencing which blood smears are sent for manual morphological review include the types of hematology analyzers utilized by the laboratories, staff expertise and training, laboratory workload volume, complexity of the laboratory services and financial constraints. 6 As a result, only a subset of smear reviews may be flagged for pathologist evaluation. 4,6

Solutions for Effective Quality Control

Addressing the challenges of effective quality control in the haematology laboratory involves leveraging technology, training, and robust management systems.

1.Automation and Technology Integration: 

Modern hematology analyzers offer advanced features, such as:

• Self-check mechanisms for internal QC. 6
• Digital microscopy systems to standardize morphological analysis. 4
• Laboratory Information Systems (LIS)for streamlined data management and reporting. 2

Automation reduces human error, improves accuracy, and speeds workflows, allowing laboratory staff to focus on complex analyses. 2,3

2. Comprehensive Training Programs

Laboratory staff must stay current with best practices. 3 Training programs should cover topics such as blood smear preparation and analysis, the identification of abnormal cell morphology, as well as adapting to new technologies and guidelines.

3. Establishing Context-Specific Criteria

Standardized protocols for all stages—preanalytical, analytical, and postanalytical—should be implemented, including staining procedures and quality indicators.

Role of Hematology Analyzers in Quality Control

Hematology analyzers have transformed laboratory workflows by being able to rapidly and efficiently handle large sample volumes, minimizing subjective errors by reducing manual intervention and the ability of enhanced features to do automated flagging of abnormal results for review.

The Future of QC in Hematology Laboratories

Advancements shaping the future of quality control include:

• Digital Transformation: Adoption of digital microscopy and automation improves efficiency and reduces subjectivity.
• AI Integration: Artificial intelligence aids in morphological analysis, enhancing accuracy and consistency.
• Global Standardization: Universally accepted QC guidelines are gaining traction, ensuring uniformity across laboratories worldwide

Embracing these advancements will enhance diagnostic accuracy and contribute to better patient outcomes.

Scopio Labs is Revolutionizing PBS and BMA Evaluation

Scopio Labs’ Full-Field Digital Cell Morphology platform, powered by 100X high-resolution imaging, is setting a new standard. This fully digital, *remote capable solution:

• Provides detailed views of clinically relevant blood smear areas and bone marrow aspirate areas.
• Streamlines workflows and enhances standardization.
• Enables real-time collaboration among hematology teams and remote experts via secure networks.

With Scopio Labs, hematology laboratories can significantly elevate their quality control practices.

Conclusion

Quality control is fundamental to the success of hematology laboratories. Effective QC is critical for ensuring the accuracy, precision, and reliability of test results. Addressing challenges such as standardization, subjectivity, and training gaps are essential for maintaining diagnostic excellence. By adopting innovations such as automation, leveraging cutting-edge technology, as well as implementing robust internal and external quality management systems, laboratories can meet the demands of modern healthcare. These efforts ultimately improve patient outcomes and reinforce trust in laboratory medicine.

References:

1. Sudarshan K, Das S, Hemalatha A, Raju K. Quality audit of haematology laboratory: Challenges and opportunities. Adv Hum Biol 2023;13:S75-9. doi: 10.4103/aihb.aihb_197_22
2. AlTamim AIZ, Alqurashy AAM,Alotaibi EAB, Albahlal AAM, Alsubaie AMA, Almutairi ALN, et al. Quality Assurance in Clinical Laboratories: Best Practices and Continuous Improvement Strategies. J Popl Ther Clin Pharmacol [Internet]. 2022;29(04):1365-74. Available from: https://www.jptcp.com/index.php/jptcp/article/view/5831
3. Mankar PD, Hatgaonkar K, Kohale MG, Wankhade RS, Bandre GR. Enhancing quality in hematology laboratory testing: A comprehensive review of preanalytical phase errors and prevention strategies. J Appl Hematol 2024;15:95-101. Available from: https://doi.org/10.4103/joah.joah_3_24
4. Moore M, Chen X, Sadigh S, Seifert R, Mindiola Romero AE, Pozdnyakova O, Courville EL. Evaluating pathologist practices in peripheral blood smear review: A comprehensive practice survey. Am J Clin Pathol. 2024:aqae091. doi: 10.1093/ajcp/aqae091
5. Goel S, Nisal AR, Raj A, Nimbargi RC. Analysis of hematology quality control using six sigma metrics. Indian J Pathol Microbiol. 2024;67(2):332-335. doi: 10.4103/ijpm.ijpm_352_23
6. Comar SR, Malvezzi M, Pasquini R. Evaluation of criteria of manual blood smear review following automated complete blood counts in a large university hospital. Rev Bras Hematol Hemoter. 2017;39(4):306-317. doi: 10.1016/j.bjhh.2017.06.007.
7. Alcaraz-Quiles J, Molina Á, Laguna J, Rodríguez-García M, Gutiérrez G, Luis Bedini J, Merino A. Peripheral blood morphology review and diagnostic proficiency evaluation by a new Spanish EQAS during the period 2011-2019. Int J Lab Hematol. 2021;43(1):44-51. doi: 10.1111/ijlh.13319.
8. Vu QH, Van HT, Tran VT, Huynh TDP, Nguyen VC, Le DT. Development of a robust blood smear preparation procedure for external quality assessment. Pract Lab Med. 2021;27:e00253. doi: 10.1016/j.plabm.2021.e00253

* Scopio’s Full-Field remote capabilities are available through the secure hospital network.