Sun, Jun 15, 2025
1- Department of Biochemistry, Smt. Kashibai Navale Medical College and General Hospital, Narhe, Pune- 411041, Maharashtra, India
2- Department of Biochemistry, RKDF Medical College, Hospital and Research Centre, Bhopal- 462026, Madhya Pradesh, India ,charushila.yuvraj@gmail.com
2- Department of Biochemistry, RKDF Medical College, Hospital and Research Centre, Bhopal- 462026, Madhya Pradesh, India ,
Full-Text [PDF 362 kb]
(227 Downloads)
| Abstract (HTML) (740 Views)
Discussion
Quality control is an integral part of quality assurance in clinical laboratories. It involves planned and systematic activities to ensure that the reported results are reliable, accurate, and precise (8). Effective management of quality in health laboratories is essential for generating trustworthy test results that healthcare professionals can rely on for emergency situations and disease management. Laboratory quality, characterized by the accuracy, reliability, and timeliness of reported test results, is crucial in avoiding unnecessary treatments, investigations, complications, and diagnostic delays. Failure to achieve accurate results can lead to increased costs, longer turnaround times, and poor patient outcomes (16).
Assessments play a critical role in evaluating the effectiveness of a laboratory’s quality management system. They involve systematic examination through internal and external audits of the laboratory’s quality management system to ensure compliance with regulatory, accreditation, and customer requirements. EQAS is an important component of assessments, providing valuable data and information for monitoring and documenting analytical quality, detecting errors, and initiating corrective actions. By participating in EQAS programs, laboratories can provide objective evidence of testing quality, instilling confidence in customers, such as physicians, patients, and health authorities (1,16). EQAS is the quality control performed periodically by laboratory personnel with the contribution of an external source, such as a referral laboratory or diagnostic industry (17). Niraula et al. demonstrated that efficient and high-quality laboratory operations critically require EQAS (1).
Our laboratory has been actively participating in the EQAS program since 2014. We strictly adhere to standard operating procedures (SOP) and the manufacturer’s instructions for all investigations as part of our participation. The impact of EQAS extends beyond the analytical process and can also influence the post-analytical phase, including the use of proper units of measurement, rounding off, and accurate reporting (6). Bhatt et al. interpreted that good laboratory practices can be ensured by participation and periodic evaluation of EQAS indicators along with IQC (5).
The EQAS program assesses performance using indicators, such as the SDI and VIS. The SDI measures relative inaccuracy or bias by calculating the difference between the laboratory mean and the target mean, divided by the standard deviation. The VIS, on the other hand, quantifies the deviations from the target value as a percentage. Deviations from expected results prompt laboratories to take corrective actions, such as changing reagents, kits, or instrument calibrations and providing skill training to personnel for proper sample reconstitution and storage (6).
We observed that the majority of parameters achieved excellent SDI scores, with some improvement noted after implementing a structured approach to root cause analysis. Our findings align with previous research that highlights the potential for improving hospital service quality through global participation in EQAS programs (6,18).
We developed a systematic approach for handling deviated EQAS results, including troubleshooting and documentation of analysis. The analysis of EQAS results for deviated parameters was done considering the following points in mind: 1. Identification of deviated parameters. 2. Comparison of the expected and reported results for each deviated parameter. 3. Assessment of the expected SDI range and mean SDI value for each parameter. 4. Examination of equipment operation during the EQAS run to identify any issues. 5. Evaluation of reagent/test performance related to the deviated parameters. 6. Verification that the IQC sample was within acceptable limits on the day of the EQAS run. 7. Confirmation that the appropriate EQAS sample was used/run for the deviated parameters. 8. Investigation of any errors in the reconstitution or storage of the EQAS samples. 9. Analysis of the potential causes of EQAS deviation, including clerical errors in reporting test results to the EQAS organization, mixing up test results, reporting results with the wrong units, using the wrong method or equipment, or other relevant factors.10. Recording the results of repeat analyses using the stored EQAS material for further analysis.
This structured approach was utilized to gain insights into the reasons behind deviated EQAS results and helped us identify potential sources of systematic errors and take appropriate corrective actions, preventive actions, and perform root cause analysis as part of our laboratory’s quality control system. According to Hastings et al. (19), EQAS schemes serve as a surveillance mechanism that effectively detects laboratory errors. By doing so, they play a crucial role in improving the overall quality of diagnostic services provided to patients (19,20). This structured approach was utilized to gain insights into the reasons behind the deviated EQAS results, helping us identify potential sources of systematic errors and take appropriate corrective and preventive actions, as well as perform root cause analysis as part of our laboratory’s quality control system. According to Hastings et al. (19), EQAS schemes serve as a surveillance mechanism that effectively detects laboratory errors. By doing so, they play a crucial role in improving the overall quality of diagnostic services provided to patients (19,20).
In the first cycle of our laboratory, two parameters fell within the mean SDI range of ± 1.01 to ± 2.0. In the subsequent cycle, one parameter also fell within this range. Notably, there was an improvement in the performance of various parameters, including glucose, amylase, total bilirubin, total protein, calcium, uric acid, cholesterol, triglycerides, sodium, potassium, and ALT, compared to the previous cycle. This approach aligns with the ISO 15189 guidelines, which emphasize the importance of laboratory participation in EQAS, monitoring and documenting EQAS results, and implementing corrective actions when predetermined criteria are not met (21,22). While many laboratories run EQAS samples as part of their routine, the critical aspect lies in the analysis of EQAS results and the subsequent implementation of corrective actions. Our laboratory followed a structured approach to refine the outcomes and ensure the quality of testing, in line with the insights provided by Kristensen et al. on handling unacceptable EQAS results and the necessary corrective actions to be taken (18).
Accreditation is another crucial aspect, as it provides formal recognition of an organization’s competency in specific tasks. The ISO 15189: 2012 and ISO 15189: 2022 standards define the criteria for maintaining quality management in medical laboratories (21,22). Participation in EQAS is a prerequisite for ISO15189: 2012 (Now ISO 15189:2012) accreditation, emphasizing the importance of laboratory personnel’s awareness, competence, and continuous improvement through structured root cause analysis and corrective actions (23).
The limitations of our study include monitoring only two EQAS cycles and the exclusion of endocrine parameters. Future longitudinal studies should consider monitoring EQAS in conjunction with internal quality control on a large scale over several cycles, involving routine and endocrine parameters, to comprehensively assess laboratory performance. This approach could reveal trends and patterns in laboratory performance, aiding in the identification of systematic issues that might otherwise go unnoticed.
Conclusion
EQAS not only helps to monitor the analytical performance but also assesses the method performance through inter-laboratory comparison using standardized methods and equipment. This provides the advantage of evaluating the laboratory’s accuracy using blind samples, similar to patient samples, followed by generating a report that compares the individual laboratory’s performance against that of other participants in the program. Our study concluded that formulating and implementing a structured approach to handle deviating EQAS results was beneficial for evaluating the performance of procedures, equipment, materials, and personnel, thereby providing opportunities for improvement in these areas. This ultimately leads to the delivery of high-quality laboratory services. EQAS analysis serves as a valuable tool in quality assurance and improvement, ensuring the comparability of results among different laboratories. Consequently, EQAS plays a significant role as a cornerstone in the accreditation process. The conclusion of the study provides avenues for future research to develop automated systems that utilize EQAS data to trigger corrective actions and notifications when deviations are identified. This could involve integrating EQAS data into laboratory information management systems for efficient monitoring. Moreover, conducting longitudinal studies that track the impact of corrective actions resulting from EQAS feedback over time would provide valuable insights into the sustainability and effectiveness of the quality improvement measures.
Acknowledgement
Not applicable.
Funding sources
No funding was received.
Ethical statement
The study was approved by the Institutional Ethical Committee (Reference number: SKNMC/Ethics/App/2022/879).
Conflicts of interest
The authors declared no conflict of interest.
Author contributions
All authors contributed to designing the study, analyzing and interpreting data, writing the manuscript, and approving the final submission.
Data availability statement
Not applicable
Full-Text: (3 Views)
Introduction
In the realm of evidence-based medicine, laboratory healthcare services are widely recognized as the cornerstone. Clinical lab services link physicians and lab staff, enabling the analysis of patient samples. They are pivotal in diagnosing conditions and aiding medical decisions. Standardization in lab medicine aims for consistent and accurate results across tests, methods, and locations (1). Precise lab measurements ensure proper care and disease management. Standardized practices offer dependable data, aiding healthcare decisions for patient well-being (2-4). Quality control (QC) is a highly scientific and essential tool utilized in clinical laboratories to identify and rectify errors during the analytical phase (5). Despite the clinical biochemist’s profound understanding of QC processes in clinical chemistry laboratories, the significance of adhering to QC measures remains a topic that is often overlooked and overshadowed. This particularly pertains to the application of both internal and external QC in the clinical laboratory (1).
Therefore, incorporating daily internal quality control (IQC) procedures and actively participating in external quality assurance scheme (EQAS) programs serves as strong indicators of adherence to good clinical laboratory practice (GCLP) and ensures the delivery of high-quality laboratory services (5). Internal quality control involves the monitoring of results within a single laboratory, ensuring the accuracy and precision of testing processes. On the other hand, EQAS comprises a set of procedures designed to compare the performance of different laboratories, promoting inter-laboratory proficiency assessment and enhancing overall quality assurance (6). IQC self-assesses lab processes in real time using materials with known values (5,7).
Alongside IQC, laboratories should engage in EQAS to enhance quality standards, foster improvement, and ensure the provision of reliable results (5). EQAS serves a dual role as both an external verification tool for laboratory results and a self-monitoring mechanism. Its benefits extend directly to the laboratory itself, as well as indirectly to its customers, regulatory bodies, and accreditation organizations. EQAS plays a crucial role in ensuring the accuracy and reliability of laboratory testing, which ultimately enhances customer satisfaction, regulatory compliance, and accreditation standards (8,9). Even with identical methods, different laboratories often yield varying results from the same samples. This underscores the importance of objective assessment, which is where EQAS comes in. EQAS offers a systematic review of laboratories, identifying hidden errors that cause result differences.
By reducing such inconsistencies, EQAS ensures accurate and consistent patient reports (6,10). EQAS is a vital laboratory tool. It identifies equipment issues, reagent problems, and gaps in staff training (11). It also triggers timely corrective actions across the analytical, pre-analytical, and post-analytical stages (12). Achieving complete self-sufficiency in healthcare facilities is a challenging task, as there is always room for improvement and development within any system. Therefore, participating in a global EQAS program has the potential to significantly enhance the quality of hospital services (6,13). By engaging in EQAS on a global scale, healthcare facilities can benefit from external evaluations, benchmarking, and the exchange of best practices, ultimately leading to improved quality and better patient outcomes (6,14,15).
Hence, the primary objective of this study was to assess our performance as a participating laboratory in the EQAS program services and investigate the impact of corrective actions implemented, where necessary, to enhance EQAS performance. By conducting this evaluation, we aimed to gain insights into our laboratory’s proficiency in EQAS and identify areas for improvement to further enhance the quality of our services.
Methods
This retrospective observational study was conducted in a tertiary care hospital from October 2019 to September 2021. The study received approval from the institutional ethical committee [SKNMC/Ethics/App/2022/879]. The Biochemistry Department of the laboratory participated in the monthly clinical chemistry EQAS program administered by CMC Vellore EQAS. This program served as the platform for assessing and monitoring the laboratory’s performance in clinical chemistry. In the Department of Clinical Biochemistry, a total of 24 blind samples provided by the EQAS body were received in three separate batches. These samples were stored following the guidelines provided by CMC Vellore EQAS. Each month, the corresponding samples were reconstituted and analyzed for the parameters in which our laboratory participated, using standard protocols and following the schedule provided by the EQAS organizing body. The results were then uploaded onto the EQAS website (CMC Vellore EQAS) on the designated dates, and our performance report was downloaded upon completion of each month’s analysis. For the purpose of this study, a total of 19 parameters from the EQAS program were selected for assessment in our laboratory.
The biochemical parameters included for analysis were glucose, urea, creatinine, total protein, albumin, total bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total cholesterol, HDL cholesterol, triglycerides, uric acid, amylase, calcium, phosphorus, sodium, potassium, and chloride. These parameters were analyzed using the Dry Chemistry automated analyzer Vitros 5600. Performance evaluation was conducted monthly, employing the Standard Deviation Index (SDI) and Variance Index Score (VIS) as the key metrics for the period spanning from October 2019 to September 2021.
The SDI was calculated as the difference between the laboratory value and the target value (Or designated value, DV) divided by the standard deviation (SD) of the mean for the comparison group. The interpretation of the SDI was as follows: an SDI between -1.00 and +1.00 indicated ‘excellent’ performance, an SDI between ± 1.01 and ± 2.00 indicated ‘good’ performance, an SDI between ± 2.01 and ± 2.99 indicated ‘accept with caution (Warning signal)’ performance, and an SDI beyond ± 3.0 indicated ‘unacceptable’ performance and triggered an ‘action signal.’ The EQAS provider assigned the SDI as the statistical tool for the laboratory. The SDI served as a measure of relative inaccuracy or relative bias, providing insights into the performance of the laboratory compared to the comparison group (1,5,6).
The VIS was calculated as the difference between the participant’s results and the group mean, multiplied by 100, and divided by the groupmean. The VIS was interpreted as follows: a VIS below 100 indicated ‘very good’ performance, a VIS between 100 and 150 indicated ‘good’ performance, a VIS between 150 and 200 indicated ‘satisfactory’ performance, and a VIS above 200 indicated performance that was not acceptable. The VIS provided a measure of the percentage variation of the participant’s result compared to the desired coefficient of variation (CV). It allowed for the assessment of the laboratory’s performance in terms of the level of variation observed, helping to determine the quality of the results (1,5,6).
Our performance was evaluated for two consecutive years, from October 2019 to September 2020 and from October 2020 to September 2021. After the first cycle in September 2020, we introduced a root cause analysis for parameters that fell outside the acceptable range, if any, as well as for improving the performance. This analysis aimed to identify the underlying reasons for these deviations and implement corrective measures. The root cause analysis was carried forward into the subsequent cycle, allowing for ongoing evaluation and improvement of our performance.
Results
During the study period from October 2019 to September 2021, we analyzed the mean SDI of each parameter in the EQAS program for biochemistry on a monthly basis. In the first cycle (October 2019 to September 2020), out of the 19 parameters, 17 parameters had a mean SDI within the range of -1 to +1, indicating ‘excellent’ performance. Two parameters, total protein (-1.71) and amylase (-1.33), fell within the range of mean SDI ± 1.01 and ± 2.00, indicating ‘good’ performance. In the subsequent cycle (October 2020 to September 2021), out of the 19 parameters, 18 parameters had a mean SDI within the range of -1 to +1, indicating ‘excellent’ performance. Only one parameter, amylase (-1.14), fell within the range of mean SDI ± 1.01 and ± 2.00, indicating ‘good’ performance. Overall, the SDI showed improvement compared to the previous cycle (Figure 1).
These findings suggest that the majority of parameters consistently performed within the ‘excellent’ category, indicating accurate and precise results. The slight improvement observed in the SDI values between the two cycles indicates an enhanced level of performance in the EQAS program.
Table 1 displays the parameters included in the study, along with their respective mean SDI values and SDI ranges. Notably, none of the 19 parameters exhibited a ‘warning signal’ or ‘unacceptable’ performance. This indicates that all parameters fell within the acceptable range, demonstrating consistent and satisfactory performance in the EQAS program.
In the realm of evidence-based medicine, laboratory healthcare services are widely recognized as the cornerstone. Clinical lab services link physicians and lab staff, enabling the analysis of patient samples. They are pivotal in diagnosing conditions and aiding medical decisions. Standardization in lab medicine aims for consistent and accurate results across tests, methods, and locations (1). Precise lab measurements ensure proper care and disease management. Standardized practices offer dependable data, aiding healthcare decisions for patient well-being (2-4). Quality control (QC) is a highly scientific and essential tool utilized in clinical laboratories to identify and rectify errors during the analytical phase (5). Despite the clinical biochemist’s profound understanding of QC processes in clinical chemistry laboratories, the significance of adhering to QC measures remains a topic that is often overlooked and overshadowed. This particularly pertains to the application of both internal and external QC in the clinical laboratory (1).
Therefore, incorporating daily internal quality control (IQC) procedures and actively participating in external quality assurance scheme (EQAS) programs serves as strong indicators of adherence to good clinical laboratory practice (GCLP) and ensures the delivery of high-quality laboratory services (5). Internal quality control involves the monitoring of results within a single laboratory, ensuring the accuracy and precision of testing processes. On the other hand, EQAS comprises a set of procedures designed to compare the performance of different laboratories, promoting inter-laboratory proficiency assessment and enhancing overall quality assurance (6). IQC self-assesses lab processes in real time using materials with known values (5,7).
Alongside IQC, laboratories should engage in EQAS to enhance quality standards, foster improvement, and ensure the provision of reliable results (5). EQAS serves a dual role as both an external verification tool for laboratory results and a self-monitoring mechanism. Its benefits extend directly to the laboratory itself, as well as indirectly to its customers, regulatory bodies, and accreditation organizations. EQAS plays a crucial role in ensuring the accuracy and reliability of laboratory testing, which ultimately enhances customer satisfaction, regulatory compliance, and accreditation standards (8,9). Even with identical methods, different laboratories often yield varying results from the same samples. This underscores the importance of objective assessment, which is where EQAS comes in. EQAS offers a systematic review of laboratories, identifying hidden errors that cause result differences.
By reducing such inconsistencies, EQAS ensures accurate and consistent patient reports (6,10). EQAS is a vital laboratory tool. It identifies equipment issues, reagent problems, and gaps in staff training (11). It also triggers timely corrective actions across the analytical, pre-analytical, and post-analytical stages (12). Achieving complete self-sufficiency in healthcare facilities is a challenging task, as there is always room for improvement and development within any system. Therefore, participating in a global EQAS program has the potential to significantly enhance the quality of hospital services (6,13). By engaging in EQAS on a global scale, healthcare facilities can benefit from external evaluations, benchmarking, and the exchange of best practices, ultimately leading to improved quality and better patient outcomes (6,14,15).
Hence, the primary objective of this study was to assess our performance as a participating laboratory in the EQAS program services and investigate the impact of corrective actions implemented, where necessary, to enhance EQAS performance. By conducting this evaluation, we aimed to gain insights into our laboratory’s proficiency in EQAS and identify areas for improvement to further enhance the quality of our services.
Methods
This retrospective observational study was conducted in a tertiary care hospital from October 2019 to September 2021. The study received approval from the institutional ethical committee [SKNMC/Ethics/App/2022/879]. The Biochemistry Department of the laboratory participated in the monthly clinical chemistry EQAS program administered by CMC Vellore EQAS. This program served as the platform for assessing and monitoring the laboratory’s performance in clinical chemistry. In the Department of Clinical Biochemistry, a total of 24 blind samples provided by the EQAS body were received in three separate batches. These samples were stored following the guidelines provided by CMC Vellore EQAS. Each month, the corresponding samples were reconstituted and analyzed for the parameters in which our laboratory participated, using standard protocols and following the schedule provided by the EQAS organizing body. The results were then uploaded onto the EQAS website (CMC Vellore EQAS) on the designated dates, and our performance report was downloaded upon completion of each month’s analysis. For the purpose of this study, a total of 19 parameters from the EQAS program were selected for assessment in our laboratory.
The biochemical parameters included for analysis were glucose, urea, creatinine, total protein, albumin, total bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total cholesterol, HDL cholesterol, triglycerides, uric acid, amylase, calcium, phosphorus, sodium, potassium, and chloride. These parameters were analyzed using the Dry Chemistry automated analyzer Vitros 5600. Performance evaluation was conducted monthly, employing the Standard Deviation Index (SDI) and Variance Index Score (VIS) as the key metrics for the period spanning from October 2019 to September 2021.
The SDI was calculated as the difference between the laboratory value and the target value (Or designated value, DV) divided by the standard deviation (SD) of the mean for the comparison group. The interpretation of the SDI was as follows: an SDI between -1.00 and +1.00 indicated ‘excellent’ performance, an SDI between ± 1.01 and ± 2.00 indicated ‘good’ performance, an SDI between ± 2.01 and ± 2.99 indicated ‘accept with caution (Warning signal)’ performance, and an SDI beyond ± 3.0 indicated ‘unacceptable’ performance and triggered an ‘action signal.’ The EQAS provider assigned the SDI as the statistical tool for the laboratory. The SDI served as a measure of relative inaccuracy or relative bias, providing insights into the performance of the laboratory compared to the comparison group (1,5,6).
The VIS was calculated as the difference between the participant’s results and the group mean, multiplied by 100, and divided by the groupmean. The VIS was interpreted as follows: a VIS below 100 indicated ‘very good’ performance, a VIS between 100 and 150 indicated ‘good’ performance, a VIS between 150 and 200 indicated ‘satisfactory’ performance, and a VIS above 200 indicated performance that was not acceptable. The VIS provided a measure of the percentage variation of the participant’s result compared to the desired coefficient of variation (CV). It allowed for the assessment of the laboratory’s performance in terms of the level of variation observed, helping to determine the quality of the results (1,5,6).
Our performance was evaluated for two consecutive years, from October 2019 to September 2020 and from October 2020 to September 2021. After the first cycle in September 2020, we introduced a root cause analysis for parameters that fell outside the acceptable range, if any, as well as for improving the performance. This analysis aimed to identify the underlying reasons for these deviations and implement corrective measures. The root cause analysis was carried forward into the subsequent cycle, allowing for ongoing evaluation and improvement of our performance.
Results
During the study period from October 2019 to September 2021, we analyzed the mean SDI of each parameter in the EQAS program for biochemistry on a monthly basis. In the first cycle (October 2019 to September 2020), out of the 19 parameters, 17 parameters had a mean SDI within the range of -1 to +1, indicating ‘excellent’ performance. Two parameters, total protein (-1.71) and amylase (-1.33), fell within the range of mean SDI ± 1.01 and ± 2.00, indicating ‘good’ performance. In the subsequent cycle (October 2020 to September 2021), out of the 19 parameters, 18 parameters had a mean SDI within the range of -1 to +1, indicating ‘excellent’ performance. Only one parameter, amylase (-1.14), fell within the range of mean SDI ± 1.01 and ± 2.00, indicating ‘good’ performance. Overall, the SDI showed improvement compared to the previous cycle (Figure 1).
These findings suggest that the majority of parameters consistently performed within the ‘excellent’ category, indicating accurate and precise results. The slight improvement observed in the SDI values between the two cycles indicates an enhanced level of performance in the EQAS program.
Table 1 displays the parameters included in the study, along with their respective mean SDI values and SDI ranges. Notably, none of the 19 parameters exhibited a ‘warning signal’ or ‘unacceptable’ performance. This indicates that all parameters fell within the acceptable range, demonstrating consistent and satisfactory performance in the EQAS program.
 Figure 1: Performance of individual parameters according to the mean SDI for the EQAS cycles from October 2019 to September 2020 and from October 2020 to September 2021 |
|
Table 1. The range and mean of Standard Deviation Index (SDI) from October 2019 to September 2021
 |
The monthly analysis of the VIS for each parameter in our study yielded interesting results. In the cycle from October 2019 to September 2020, out of the 19 parameters, 17 parameters (89.47%) achieved scores classified as ‘very good’ performance (VIS<100). Similarly, in the cycle from October 2020 to September 2021, 18 parameters (94.73%) attained scores classified as ‘very good’ performance.
In the October 2019 to September 2020 cycle, two parameters, total protein and amylase, received scores classified as ‘good’ performance (VIS within 100-150). In the subsequent cycle (October 2020 to September 2021), one parameter, amylase, also received a score classified as ‘good’ performance. Notably, none of the parameters fell into the ‘satisfactory’ or ‘not acceptable’ performance limits, indicating a consistently high level of performance across the assessed parameters (Table 2).
These findings demonstrate that the majority of parameters achieved ‘excellent’ scores, indicating high precision and accuracy in the EQAS program. The presence of only a few parameters with ‘good’ scores suggests room for further improvement, which can be addressed through a targeted approach; overall, the performance was commendable.
In the October 2019 to September 2020 cycle, two parameters, total protein and amylase, received scores classified as ‘good’ performance (VIS within 100-150). In the subsequent cycle (October 2020 to September 2021), one parameter, amylase, also received a score classified as ‘good’ performance. Notably, none of the parameters fell into the ‘satisfactory’ or ‘not acceptable’ performance limits, indicating a consistently high level of performance across the assessed parameters (Table 2).
These findings demonstrate that the majority of parameters achieved ‘excellent’ scores, indicating high precision and accuracy in the EQAS program. The presence of only a few parameters with ‘good’ scores suggests room for further improvement, which can be addressed through a targeted approach; overall, the performance was commendable.
Discussion
Quality control is an integral part of quality assurance in clinical laboratories. It involves planned and systematic activities to ensure that the reported results are reliable, accurate, and precise (8). Effective management of quality in health laboratories is essential for generating trustworthy test results that healthcare professionals can rely on for emergency situations and disease management. Laboratory quality, characterized by the accuracy, reliability, and timeliness of reported test results, is crucial in avoiding unnecessary treatments, investigations, complications, and diagnostic delays. Failure to achieve accurate results can lead to increased costs, longer turnaround times, and poor patient outcomes (16).
Assessments play a critical role in evaluating the effectiveness of a laboratory’s quality management system. They involve systematic examination through internal and external audits of the laboratory’s quality management system to ensure compliance with regulatory, accreditation, and customer requirements. EQAS is an important component of assessments, providing valuable data and information for monitoring and documenting analytical quality, detecting errors, and initiating corrective actions. By participating in EQAS programs, laboratories can provide objective evidence of testing quality, instilling confidence in customers, such as physicians, patients, and health authorities (1,16). EQAS is the quality control performed periodically by laboratory personnel with the contribution of an external source, such as a referral laboratory or diagnostic industry (17). Niraula et al. demonstrated that efficient and high-quality laboratory operations critically require EQAS (1).
Our laboratory has been actively participating in the EQAS program since 2014. We strictly adhere to standard operating procedures (SOP) and the manufacturer’s instructions for all investigations as part of our participation. The impact of EQAS extends beyond the analytical process and can also influence the post-analytical phase, including the use of proper units of measurement, rounding off, and accurate reporting (6). Bhatt et al. interpreted that good laboratory practices can be ensured by participation and periodic evaluation of EQAS indicators along with IQC (5).
The EQAS program assesses performance using indicators, such as the SDI and VIS. The SDI measures relative inaccuracy or bias by calculating the difference between the laboratory mean and the target mean, divided by the standard deviation. The VIS, on the other hand, quantifies the deviations from the target value as a percentage. Deviations from expected results prompt laboratories to take corrective actions, such as changing reagents, kits, or instrument calibrations and providing skill training to personnel for proper sample reconstitution and storage (6).
We observed that the majority of parameters achieved excellent SDI scores, with some improvement noted after implementing a structured approach to root cause analysis. Our findings align with previous research that highlights the potential for improving hospital service quality through global participation in EQAS programs (6,18).
We developed a systematic approach for handling deviated EQAS results, including troubleshooting and documentation of analysis. The analysis of EQAS results for deviated parameters was done considering the following points in mind: 1. Identification of deviated parameters. 2. Comparison of the expected and reported results for each deviated parameter. 3. Assessment of the expected SDI range and mean SDI value for each parameter. 4. Examination of equipment operation during the EQAS run to identify any issues. 5. Evaluation of reagent/test performance related to the deviated parameters. 6. Verification that the IQC sample was within acceptable limits on the day of the EQAS run. 7. Confirmation that the appropriate EQAS sample was used/run for the deviated parameters. 8. Investigation of any errors in the reconstitution or storage of the EQAS samples. 9. Analysis of the potential causes of EQAS deviation, including clerical errors in reporting test results to the EQAS organization, mixing up test results, reporting results with the wrong units, using the wrong method or equipment, or other relevant factors.10. Recording the results of repeat analyses using the stored EQAS material for further analysis.
This structured approach was utilized to gain insights into the reasons behind deviated EQAS results and helped us identify potential sources of systematic errors and take appropriate corrective actions, preventive actions, and perform root cause analysis as part of our laboratory’s quality control system. According to Hastings et al. (19), EQAS schemes serve as a surveillance mechanism that effectively detects laboratory errors. By doing so, they play a crucial role in improving the overall quality of diagnostic services provided to patients (19,20). This structured approach was utilized to gain insights into the reasons behind the deviated EQAS results, helping us identify potential sources of systematic errors and take appropriate corrective and preventive actions, as well as perform root cause analysis as part of our laboratory’s quality control system. According to Hastings et al. (19), EQAS schemes serve as a surveillance mechanism that effectively detects laboratory errors. By doing so, they play a crucial role in improving the overall quality of diagnostic services provided to patients (19,20).
In the first cycle of our laboratory, two parameters fell within the mean SDI range of ± 1.01 to ± 2.0. In the subsequent cycle, one parameter also fell within this range. Notably, there was an improvement in the performance of various parameters, including glucose, amylase, total bilirubin, total protein, calcium, uric acid, cholesterol, triglycerides, sodium, potassium, and ALT, compared to the previous cycle. This approach aligns with the ISO 15189 guidelines, which emphasize the importance of laboratory participation in EQAS, monitoring and documenting EQAS results, and implementing corrective actions when predetermined criteria are not met (21,22). While many laboratories run EQAS samples as part of their routine, the critical aspect lies in the analysis of EQAS results and the subsequent implementation of corrective actions. Our laboratory followed a structured approach to refine the outcomes and ensure the quality of testing, in line with the insights provided by Kristensen et al. on handling unacceptable EQAS results and the necessary corrective actions to be taken (18).
Accreditation is another crucial aspect, as it provides formal recognition of an organization’s competency in specific tasks. The ISO 15189: 2012 and ISO 15189: 2022 standards define the criteria for maintaining quality management in medical laboratories (21,22). Participation in EQAS is a prerequisite for ISO15189: 2012 (Now ISO 15189:2012) accreditation, emphasizing the importance of laboratory personnel’s awareness, competence, and continuous improvement through structured root cause analysis and corrective actions (23).
The limitations of our study include monitoring only two EQAS cycles and the exclusion of endocrine parameters. Future longitudinal studies should consider monitoring EQAS in conjunction with internal quality control on a large scale over several cycles, involving routine and endocrine parameters, to comprehensively assess laboratory performance. This approach could reveal trends and patterns in laboratory performance, aiding in the identification of systematic issues that might otherwise go unnoticed.
Conclusion
EQAS not only helps to monitor the analytical performance but also assesses the method performance through inter-laboratory comparison using standardized methods and equipment. This provides the advantage of evaluating the laboratory’s accuracy using blind samples, similar to patient samples, followed by generating a report that compares the individual laboratory’s performance against that of other participants in the program. Our study concluded that formulating and implementing a structured approach to handle deviating EQAS results was beneficial for evaluating the performance of procedures, equipment, materials, and personnel, thereby providing opportunities for improvement in these areas. This ultimately leads to the delivery of high-quality laboratory services. EQAS analysis serves as a valuable tool in quality assurance and improvement, ensuring the comparability of results among different laboratories. Consequently, EQAS plays a significant role as a cornerstone in the accreditation process. The conclusion of the study provides avenues for future research to develop automated systems that utilize EQAS data to trigger corrective actions and notifications when deviations are identified. This could involve integrating EQAS data into laboratory information management systems for efficient monitoring. Moreover, conducting longitudinal studies that track the impact of corrective actions resulting from EQAS feedback over time would provide valuable insights into the sustainability and effectiveness of the quality improvement measures.
Acknowledgement
Not applicable.
Funding sources
No funding was received.
Ethical statement
The study was approved by the Institutional Ethical Committee (Reference number: SKNMC/Ethics/App/2022/879).
Conflicts of interest
The authors declared no conflict of interest.
Author contributions
All authors contributed to designing the study, analyzing and interpreting data, writing the manuscript, and approving the final submission.
Data availability statement
Not applicable
Research Article: Research Article |
Subject:
Biochemistry
Received: 2023/06/8 | Accepted: 2023/10/9
Received: 2023/06/8 | Accepted: 2023/10/9
References
1. Niraula A, BatajuM. External quality assessment practices in clinical biochemistry laboratory: What is the need? Kathmandu Univ. Med. J. 2020; 18(69): 86-92. [View at Publisher] [DOI] [PMID] [Google Scholar]
2. Vesper HW, Miller WG, Myers GL. Reference materials and commutability. Clin Biochem Rev. 2007;28(4):139-147. [View at Publisher] [PMID] [Google Scholar]
3. Jones GR. The role of EQA in harmonization in laboratory medicine - a global effort. Biochem. Med (Zagreb). 2017; 27(1): 23-29. [View at Publisher] [DOI] [PMID] [Google Scholar]
4. Ricos C, Fernández-Calle P, Perich C, Sandberg S. External quality control in laboratory medicine. Progresses and future. Adv Lab Med. 2022; 3(3): 221-231. [View at Publisher] [DOI] [PMID] [Google Scholar]
5. Bhatt RD, Tamrakar D, Maharjan B, Dual R, Shrestha RK, Koju S, et al. Boost up quality assurance through regular evaluation of proficiency testing performance. Ann Clin Chem Lab Med. 2018; 3(1):3-7. [DOI] [Google Scholar]
6. Yerram S. External quality assurance scheme (EQAS): Criteria for evaluating performance of a laboratory. IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB). 2018; 4.4: 16-20. [View at Publisher] [Google Scholar]
7. Westgard JO. Internal quality control: planning and implementation strategies. Ann. Clin. Biochem. 2003; 40 (Pt 6): 593-611. [View at Publisher] [DOI] [PMID] [Google Scholar]
8. World Health Organization. Laboratory quality management system : handbook, Version 1.1. (2011). [View at Publisher]
9. Sciacovelli L, Secchiero S, Padoan A, Plebani M. External quality assessment programs in the context of ISO 15189 accreditation. Clin. Chem. Lab. Med. 2018; 56(10):1644-1654. [View at Publisher] [DOI] [PMID] [Google Scholar]
10. Miller WG, Jones GR, Horowitz GL, Weykamp C. Proficiency testing/external quality assessment: current challenges and future directions. Clin. Chem. 2011; 57(12) :1670-1680. [View at Publisher] [DOI] [PMID] [Google Scholar]
11. CLSI. Using proficiency testing and assessment to improve medical laboratory quality. 3rded. CLSI Guidelines QMS24. Wayne PA. Clinical And Laboratory Standards Institute; 2016. [View at Publisher]
12. Sciacovelli L, Secchiero S, Zardo L, Plebani M. The role of the External Quality Assessment. Biochemia Medica. 2010; 20(2): 160-164. [View at Publisher] [DOI] [Google Scholar]
13. Tiwari E, Mishra S, Singh S, Mishra M. External Quality Assessment Scheme in Biochemistry: Four Years Experience as a Participating Laboratory. Int. J Sci Stud. 2016; 4(4):106-110. [View at Publisher]
14. Badrick T, Gay S, McCaughey EJ, Georgiou A. External Quality Assessment beyond the analytical phase: an Australian perspective. Biochem. Med (Zagreb). 2017; 27(1): 73-80. [View at Publisher] [DOI] [PMID] [Google Scholar]
15. Dufraing K, Lierman, E, Vankeerberghen A, Franke S, Dequeker E. External quality assessment for molecular diagnostic laboratories in Belgium: Can we improve it? Accred. Qual. Assur. 2020; 25: 39-49. [View at Publisher] [DOI] [Google Scholar]
16. World Health Organization. Laboratory quality management system : handbook, Version 1.1. 2011. [View at Publisher]
17. Karkalousos P, Evangelopoulos A. Quality control in clinical laboratories, applications and experiences of quality control. BoD – Books on Demand;2011. [View at Publisher] [DOI] [Google Scholar]
18. Kristensen GB, Meijer P. Interpretation of EQA results and EQA-based trouble shooting. Biochem. Med (Zagreb). 2017; 27(1):49-62. [View at Publisher] [DOI] [PMID] [Google Scholar]
19. Hastings RJ, Howell RT. The importance and value of EQA for diagnostic genetic laboratories. J. Community Genet. 2010; 1(1):11-7. [DOI] [PMID] [Google Scholar]
20. Blasutig IM, Wheeler SE, Bais R, Dabla PK, Lin, J, Perret-Liaudet A, et al. External quality assessment practices in medical laboratories: an IFCC global survey of member societies. Clin. Chem. Lab. Med. 2023;61(8):1404-1410. [View at Publisher] [DOI] [PMID] [Google Scholar]
21. Medical laboratories - Requirements for quality and competence (ISO 15189:2012)BS EN ISO 15189:2012,BSI Standards Publication, IP:The University of Leeds, Version correct as of 11/04/2013 22:47, (c) The British Standards Institution 2013. [View at Publisher]
22. Medical laboratories - Requirements for quality and competence. INTERNATIONAL STANDARD ISO 15189 Fourth edition 2022-12. [View at Publisher]
23. Payne DA, Russomando G, Linder MW, Baluchova K, Ashavaid T, Steimer W, et al. IFCC Committee for Molecular Diagnostics (C-MD). External quality assessment (EQA) and alternative assessment procedures (AAPs) in molecular diagnostics: findings of an international survey. Clin. Chem. Lab. Med. 2020; 59(2):301-306. [View at Publisher] [DOI] [PMID] [Google Scholar]
Send email to the article author
| Rights and permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
Enamad
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.