External Quality Assessment Scheme (IEQAS) in Haematology at National Institute of Health, Islamabad, Pakistan

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1 CURRENT PRACTICES ARTICLE External Quality Assessment Scheme (IEQAS) in Haematology at National Institute of Health, Islamabad, Pakistan Birjees Mazher Kazi, Nazish Gul Ibrahim, Nadira Jadoon, Nadia Nisar and Masood Anwar ABSTRACT Objective: To document overall performance and improvement, if any, gained through participation in an International External Quality Assessment Scheme (IEQAS). Study Design: Descriptive study. Place and Duration of Study: The Haematology Department, Public Health Laboratories Division, National Institute of Health, Islamabad, Pakistan, from January 1996 to December Methodology: Overall performance of blood parameters and parasite identification were analysed. Individual values were assessed against consensus value (mean ± SD) and deviation index (DI) from the mean, whereas coefficients of variation (CV) were calculated for years 1996 to The results are expressed as percentage of accurate versus inaccurate results, deviation index (DI) and coefficient of variation (%CV). Results: The laboratory achieved 87.74% of values within acceptable limits for haemoglobin, 72.03% for white blood count, 69.49% for platelet and 77.03% for reticulocyte estimation. Results were satisfactory, having DI values less than 3 for all four parameters. %CV values was found to be dependent on the type of test performed and varied among different parameters. Difficulty has been observed in identifying Plasmodium malariae and ovale. Conclusion: Participation in External Quality Assessment Schemes is extremely beneficial for the improvement of laboratory performance and quality of care. Evaluation of the survey results on a regular basis serves as a useful guide to assess overall performance of the laboratory. Standardization of analytical procedures, equipments and reagents, continuous monitoring of personnel competency and thorough investigation of discordant results significantly contributes to the delivery of quality diagnostic services. Key words: Quality assurance. Healthcare. Haematology. INTRODUCTION Accurate and timely laboratory information has become the foundation upon which current disease treatment, prevention and control programmes are based. The benefit of quality controlled results leads to proper diagnosis and treatment of the patient besides having an overall impact on the entire health care delivery system. The adverse events associated with compromised diagnostic services would include inaccurate diagnosis, inappropriate case management, a prolonged hospital stay, economic, financial and social stress, distrust by the clients and authorities, increased morbidity and mortality and shrinkage of workforce. Quality assurance is the cornerstone of quality diagnostic services for achieving confidence in standardized services provided by laboratories to the patients and clients. Quality assurance in the laboratory encompasses all planned and systematic actions and Department of Public Health Laboratories Division, National Institute of Health, Islamabad, Pakistan. Correspondence: Dr. Nazish Gul Ibrahim, Flat No. 213, Garden Centre, Manikjee Street, Garden East, Karachi. noshi213@hotmail.com Received November 26, 2008; accepted September 16, programmes which are designed to provide confidence that a product or service will meet customer expectations. It also refers to the activities necessary to ensure that a module, component or system conforms to established technical requirements. 1 The external quality assessment (EQA) refers to a system wherein an outside agency scrutinizes the results of the participating laboratory with an objective to have a general impression about the quality of services that a particular lab provides. The major advantage of participation in EQA schemes (EQAS) is quality improvement as a result of continuous monitoring and gaining confidence within the framework of the health care delivery system. Another advantage is cause analysis of discordant results. This helps in achieving quality improvement by making active interventions which in turn provide guidance to laboratories in identifying the source of error and instituting corrective actions. 2,3 The World Health Organization (WHO)-EQAS for haematology is distributed to 80 laboratories in 58 member states by the WHO Collaborating Centre based in National External Quality Assessment Scheme (UKNEQAS) located at Watford General Hospital, UK. The scheme assesses the participating laboratories to 786 Journal of the College of Physicians and Surgeons Pakistan 2009, Vol. 19 (12):

2 External quality assessment scheme (IEQAS) in haematology correctly quantify the haemoglobin level and number of white blood cells and platelets. In addition, blood film slides are provided to determine the percentage of reticulocytes, comment on cell morphology and identify blood parasites. 4 The Public Health Laboratories Division (PHLD) of the National Institute of Health (NIH), Islamabad has been mandated by the Government of Pakistan for disease prevention and control using laboratory medicine tools and to carry on requisite public health interventions. It not only provides diagnostic services to the community but also shares the responsibility of monitoring specific trends and conducting surveillance activities for various communicable and non-communicable diseases. The Haematology Department of PHLD is participating in WHO-IEQAS regularly since 1986 with the aim of providing quality diagnostic services to its clients all over the country. In the present study, data was analysed to document the overall performance and improvement as a result of participation in IEQAS throughout the study period. METHODOLOGY Results of the IEQAS survey received from January 1996 to December 2006 were included in the study. The Haematology Department receives bi-monthly samples (six times per year) to quantify haemoglobin (Hb) level, number of white blood cells and platelets. Fixed pseudo white cells (chicken cells) and fixed human platelets are suspended in haemolysate for Hb, WBC and platelet estimation. From 1996 to 2005, haemoglobin estimation and other cell counts were performed using Sysmex KX which was replaced by Sysmex KX-21 in Reticulocytes films were stained with azure B while morphology films with May-Grunwald Giemsa. Blood films for parasite identification were stained with 1:10 Giemsa. 5 Slides are examined by lab haematologists. Results are recorded on the proforma provided and returned within 30 days of the distribution date through a preliminary report by the Haematology Department PHLD. Full survey analyses reports are distributed by IEQAS following the week of the final date for return of results. In survey analyses report, the overall performance of all parameters for all participating laboratories is provided. As per IEQAS performance parameters, the performance of the labs participating in the scheme is excellent if none of the results have a deviation index (DI) 3. If 1-3 of the results have a DI more than 3, the performance for that particular survey is termed acceptable. If more than 3 of the results have deviation index 3 the performance is unacceptable. If major discrepancies in any of the components of the survey are observed, refresher training courses are organized by WHO to resolve the same. 4 Data was analyzed using Statistical Package for Social Sciences (SPSS) software version 15. Individual values were assessed against a consensus value (mean ± SD), deviation index (DI) from the mean and coefficient of variation (CV) were calculated. Frequencies and percentages of all the correct and incorrect results were calculated individually for each component of the survey. The results are expressed as a percentage of accurate versus inaccurate results, deviation index (DI) and coefficient of variation (%CV). RESULTS Results of 118 samples for Hb, WBC and platelets each, 76 samples for reticulocytes estimation and 108 samples for parasite identification were included in the initial analyses. Figure 1 shows the percentage of correct and incorrect results for regular components of the survey i.e. Hb, WBCs and platelets. The laboratory performed well throughout the study period in relation with blood counts done on automated analyzers. Results for haemoglobin, white blood cells and platelets were within the reference ranges; therefore, they were found to be in agreement with the survey results. A total of 84.74% (100 out of 118) of the results for haemoglobin estimation were correct followed by WBC (72.03%; 85 out of 118) and platelets (69.49%; 82 out of 118). The lowest rate of incorrect results was observed for haemoglobin (15.25%) followed again by WBC (27.96%) and platelets (30.5%). The percentage of accurate results for reticulocytes was found to be 77.6% (59 out of 76), whereas the accuracy rate was observed to be relatively lower regarding identification of blood parasites (Figure 2). Figure 3 shows the deviation index (DI) values available for blood counts and reticulocytes. Results were variable among individual components of the survey but the overall DI values lie fairly well within the acceptable limits with a majority of the results having a DI value less than 3. Further analysis of results having DI values less than 3 allowed us to classify the results into three categories; excellent (DI > -2.0 to < 1.0), satisfactory (DI 1.0 to < 2.0) and out of acceptable limits (DI < -2.0 or > 2.0). Overall, the laboratory achieved % of values with excellent results, 15.24% of results were within acceptable limits and graded as satisfactory whereas 20.52% of values showed a high deviation from the reference range (Table I). As a final part of analysis, mean DI values ± standard deviation and coefficient of variation (CV%) for Journal of the College of Physicians and Surgeons Pakistan 2009, Vol. 19 (12):

3 Birjees Mazher Kazi, Nazish Gul Ibrahim, Nadira Jadoon, Nadia Nisar and Masood Anwar Percentage Figure 1: Percent values of correct and incorrect results for regular components of the survey i.e. haemoglobin, WBC and platelets. Percentage Figure 2: Percent values of correct and incorrect results for reticulocyte estimation and identification of parasites. Table I: Categorization of deviation index (DI) values. Excellent Satisfactory Unacceptable Year (n)* DI >-2.0 to < 1.0 DI >1.0 to < 2.0 DI (<-2.0 or > 2.0) DI value (%) DI value (%) DI value (%) 1996 (23) 21 (91.30) 01 (4.34) 01 (4.34) 1997 (22) 22 (100) Nil Nil 1998 (42) 28 (66.66) 05 (11.90) 09 (21.42) 1999 (31) 15 (48.38) 04 (12.90) 12 (38.70) 2000 (41) 25 (60.97) 07 (17.07) 09 (21.95) 2001 (28) 12 (42.85) 06 (21.42) 10 (35.71) 2002 (40) 22 (55) 06 (15) 12 (30) 2003 (29) 16 (55.17) 07 (24.13) 06 (20.68) 2004 (21) 14 (66.66) 01 (4.76) 06 (28.57) 2005 (20) 12 (54.54) 04 (20) 04 (20) 2006 (44) 32 (72.72) 11 (25) 01 (2.27) Total (341) 219 (64.22) 52 (15.24) 70 (20.52) (n)*: number of samples each year for which DI values were given. haemoglobin, WBC, platelet and reticulocytes were calculated for each year (Table II). Deviation index (DI) + standard deviation (SD) for haemoglobin ranged between -0.6±0.7 to 2.4±1.3, for WBC between -2.6±2.6 to 0.8±1.6, for platelets between -3.5± 2.7to 0.9±0.4 and for reticulocytes between -1.4± 2.1 to 9.0 ±0. CV values varied among individual components and were found to be lowest for all the four components for the year A similar pattern has been observed in the year In 1998 and 1999 higher CV values were obtained for reticulocytes and haemoglobin estimation respectively. Similar results were obtained for haemoglobin in 2002 and CV values were consistently lower for platelets (range to 1, mean -1.89) followed by WBC (range to 11.68, mean 1.6), reticulocytes (-2.60 to 52.40, mean 7.99) and haemoglobin (-1.58 to 81.86, mean 11.50). Among all the four parameters best consistent values were observed for platelet counts. DI Values Haemoglobin Number of samples per year Number of samples per year Number of samples per year Number of samples per year Figure 3: Deviation index values for haemoglobin, WBCs, platelets and reticulocyte estimation. 788 Journal of the College of Physicians and Surgeons Pakistan 2009, Vol. 19 (12):

4 External quality assessment scheme (IEQAS) in haematology Table II: Comparative analysis of various parameters of quality assurance survey. Year Haemoglobin WBCs Platelets Reticulocytes Mean DI±SD* CV** CV% Mean DI±SD CV CV% Mean DI±SD CV CV% Mean DI±SD CV CV% ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± * DI±SD= Deviation Index ± Standard Deviation; **CV= Coefficient of variation. DISCUSSION Ensuring reliable results of the tests performed in haematology laboratories is essential owing to the problems related to complex automated instruments and an ever increasing workload. 6,7 External quality assessment provides a unique analyses of laboratory output that identifies problems with the performance not always detectable by internal quality control activities. 2 The Haematology Department PHLD is enrolled with WHO IEQAS since The published data regarding participation experience in an international external quality assessment scheme from Pakistan is scarce. This prompted us to evaluate and document the participation experience in an EQA scheme and highlight factors affecting these results. The most promising finding reflected by the study is that the laboratory was successful in achieving and maintaining quality standards. As reflected by the results, the overall performance remained satisfactory through-out the study period in relation with tests done on automated analyzers. As described earlier, from 1996 till 2005 the tests were performed on Sysmex KX which was replaced by Sysmex KX-21 in year It would have been worth comparing the results performed on these different analyzers but the duration is too short to draw a conclusive impression. Another observation made during the study was that the identification of Plasmodium falciparum and vivax was quite precise; whereas, difficulty was observed in identifying Plasmodium malariae and ovale. Infections with these parasites are not frequently encountered in local clinical practice and are, therefore, difficult to diagnose. The World Health Organization in their recent report has also documented poor results on malarial identification and refresher courses are being organized in order to address the issue. 4 Taking into consideration the deviation from reference values provided by IEQAS, overall results were satisfactory having DI values less than 3 for all four parameters (Figure 3). The performance has been graded as acceptable by an IEQAS survey. 5 Further categorization of DI values on the basis of reference ranges provided by the surveyor reflected that from 1998 till 2001 the number of results out of reference range (Table I) was relatively high (20.52%). The unavailability of qualified senior level supervision during the said period might have contributed for the variation in IEQAS results. The presence of skilled supervision, continuous training of laboratory staff and regular monitoring of personnel competency significantly affects the outcome of laboratory services. When senior level trained professionals rejoined, the results improved as reflected by only one result with high DI value for reticulocytes count in year 2006 during subsequent years. Another important observation while conducting data analysis was that the results were variable in terms of %CV values, as quoted by other studies as well. 8,9 CV values were found to be dependent on the type of test performed and varied among different parameters of the survey (Table II). It is difficult to comment on the consistency of data based on CV values alone. Monitoring of the laboratory data based on various statistical parameters and assessing consistency can be extremely beneficial and may improve the results. We have planned to concentrate upon the current variability observed and strictly monitor this issue for further improvement. Conducting a retrospective analysis, we were unable to determine the extent of pre-analytical errors involved in various assays, personnel competency or cause analysis of discordant results. These are significant indicators of work performance and serve as a guide to improve the quality of the laboratory. 6,8,10-12 Investigation of discordant findings not only shares cause of error but also contributes towards the improvement of laboratory services and assists in meeting accreditation requirements Normally, the samples from a quality assessment survey are processed with additional care by the laboratory staff. If the results generated under such circumstances can be erroneous, it could perhaps be anticipated that the magnitude of errors made inadvertently during routine bench work would have been even higher. This exercise would hopefully be Journal of the College of Physicians and Surgeons Pakistan 2009, Vol. 19 (12):

5 Birjees Mazher Kazi, Nazish Gul Ibrahim, Nadira Jadoon, Nadia Nisar and Masood Anwar beneficial in reviewing the system(s) and for capacity building of laboratory staff. Accessibility and affordability of these schemes is still an important issue for developing countries like us and needs to be addressed in this regard. CONCLUSION Participation in External Quality Assessment Schemes is extremely beneficial for the improvement of laboratory performance and quality of care. Standardization of analytical procedures, equipments and reagents, continuous monitoring of personnel competency and thorough investigation of discordant results significantly and positively contributes to the delivery of quality diagnostic services. Evaluation of the survey results on a regular basis serves as a useful guide to assess overall performance of the laboratory. Acknowledgement: The National Institute of Health (NIH), Pakistan is highly indebted to the World Health Organization for their continuous assistance which enabled our participation in the International External Quality Assessment Scheme (IEQAS), UK. NIH also gratefully acknowledges the uninterrupted liaison and quality assurance material provided by the National External Quality Assessment Scheme for General Haematology, United Kingdom (UKNEQAS). REFERENCES 1. Prijavudhi A, Kotivongsa K, Cotivongsa P, Pavaro U. Thailand intensive external quality assessment schemes as dynamic tools for improving laboratory quality and standard. Southeast Asian J Trop Med Public Health 2002; 33(Suppl 2): Richardson H, Gun-Munro J. Quality improvement through investigation of external quality assessment discordant findings. Toronto: Quality Management Programme-Laboratory Services; Raby A, Clark G, Crawford L, McBride E, Marsh V. Blood film morphology external quality assessment surveys: a Canadian quality assurance initiative. Toronto: Quality Management Programme- Laboratory Services (document); World Health Organization. External quality assessment scheme for haematology. [Internet]. [cited 2007]. Availabale from: 5. World Health Organizarion. External quality assessment schemes for blood coagulation. [Internet]. [cited 2009]. Available from: en/index.html 6. Vives-Corrons JL, Jou JM, Pastor C, Reverter C, Jou C. Characteristics of the external quality assessment (EQA) scheme for haematology in Spain. Int J Quality Health Care 1991; 3: Sciacovelli L, Secchiero S, Zardo L, Zaninotto M, Plebani M. External quality assessment: an effective tool for clinical governance in laboratory medicine. Clin Chem Lab Med 2006; 44: Gutierrez G, Jou JM, Carlos Reverter J, Martinez-Brotons F, Domingo A, Antonio Iriarte J, et al. [Standardization Committee for Haematology. External quality assurance program for general haematology. Evaluation of the 1994 results]. Sangre (Barc) 1996; 41: Spanish. 9. Jou JM, Pastor C, Labal F, Jou F, Vives Corrons JL. Evaluation of the first program of external quality control in haematology of the Spanish Haematology and Hemotherapy Association. Experience of 1 year activity. Sangre (Barc) 1989; 34: Spanish. 10. Opartkiattikul N, Bejrachandra S. The external quality assessment schemes in Thailand. Rinsho Byori 2002; 50: Opartkiattikul N, Wongtiraporn W, Tientadakul P, Rungpitarungsi B. Application of indicators for quality improvement in the coagulation laboratory. Southeast Asian J Trop Med Public Health 2002; 33(Suppl 2): Favaloro EJ, Lippi G, Adcock DM. Pre-analytical and postanalytical variables: the leading causes of diagnostic error in hemostasis? Semin Thromb Hemost 2008; 34: Epub 2008 Dec Libeer JC. Role of external quality assurance schemes in assessing and improving quality in medical laboratories. Clin Chim Acta 2001; 309: Sciacovelli L, Secchiero S, Zardo L, Plebani M. External Quality Assessment Schemes: need for recognised requirements. Clin Chim Acta 2001; 309: Gutierrez G, Merino A, Domingo A, Jou JM, Reverter JC. EQAS for peripheral blood morphology in Spain: a 6-year experience. Int J Lab Hematol 2008; 30: Journal of the College of Physicians and Surgeons Pakistan 2009, Vol. 19 (12):