Research Improvement On Haemoglobin A1c (HbA1c) Testing Quality In Shanghai Clinical Labs Through Interference Of Quality Management

Research Improvement on Haemoglobin Alc (HbAlc) Testing Quality in Shanghai Clinical Labs Through Interference of Quality ManagementResearch backgroundThe chronic hyperglycemia state of diabetes patients will bring about long term damage, function disorder and Multiple Organ Dysfunction Syndrome (MODS). The mortality caused by diabetes ranks the third just after cardiovascular disease and cancer. Currently, there are 92.4 million diabetes patients in China and RMB 173.4 billion (US$25 billion) a year spent on diabetes treatment. The research from Diabetes Control and Complications Trial (DCCT) and United Kingdom Prospective Diabetes Study (UKPDS) which last for more than a decade discovered that treatment with the control of average blood glucose level and HbAlc below 7.0% can effectively mitigate diabetes, and decrease the incidence rate and severity of retinopathy, nephropathy and neuropathy. It is recommended to use HbAlc as the screening and diagnosis marker in 2009. American Diabetes Association(ADA)published a guideline named Standards of Medical Care in Diabetes,2010 which regards HbAlc≥6.5% as the diagnosis criterion of diabetes and measures repeatedly to confirm diagnosis. Thus, the quality of HbAlc measurement plays an important role in the diagnosis and treatment of diabetes.At present, the HbAlc measurement methods include chromatography, electrophoresis, immunology, clinical biochemistry, Point-of-Care Testing(POCT) and so on. These methods are subject to much interference, such as Red Blood Cell(RBC), turnover, jaundice and hyperlipemia. These interfering materials will cause the false increase or decrease of HbAlc value, which influences the accuracy of HbAlc testing results. Besides, the quality control practice, regularized operation and so on will also impact the intra-lab comparability.This study monitors the HbAlc Internal Quality Control (IQC) in Shanghai area by means of choosing appropriate control materials, and establishes the HbAlc External Quality Assessment (EQA) method. It also aims to know about the Coefficient of Variation (CV) of HbAlc test results of clinical labs in Shanghai, to continually improve the HbA1c testing quality by training courses and on spot inspection. Therefore, the accuracy and comparability of clinical lab measurement results can be improved, which provide reliable criteria for diagnosis and treatment of diabetes.Research purposeThrough interference of quality management on HbAlc testing in clinical labs, the CV of HbA1c testing can be lowered and reliability be improved, so that it offers accurate evidence for clinical diagnosis of diabetes.Research content1. Baseline survey:on the HbA1c testing before the intervention of quality management methods.2. Intervention method:training courses, IQC, and on-spot inspection.3. Survey after intervention:compare the intra-lab HbA1c results before and after intervention in Shanghai clinical labs.Research methodThe hospital levels, department, manufacturer, measurement method, traceability, report unit and so on which relates closely to HbAlc test is under investitaion. The surveyed lab will receive our control materials and/or human whole blood sample to test HbAlc. Then the data will be statistically analyzed in order to get an idea of Coefficient of Variation (CV) before any intervention. From 2008 to 2010, I started intervening their quality management process by use of appropriate control materials, theoretical training courses and on spot inspection. In 2009 and 2010, I sent control materials and/or human whole blood sample for surveyed labs to test HbAlc. Then the data will be statistically analyzed in order to know about the improvement of CV after intervention. In the meanwhile, I got the knowledge of test methods among different levels hospitals, the result traceability and so forth, and analyzed the data compared to before intervention ones. Research results1. The number of hospitals that start the HbAlc testing in 2008,2009 and 2010 is 122,176 and 212, respectively.2. In 2008, labs used High-performance Liquid Chromatography (HPLC), Low-pressure Liquid Chromatography (LPLC) and immunoassay methods provided by 10 manufactures,2 POCT methods including microparticle chromatography and immunofluorescence offered by 5 products. In 2009 and 2010,13 manufactures were employed and another affinity chromatography method was added. The distribution of hospital numbers using different testing methods is as follows:2008, each of five methods was adopted by 38,13,20,40 and 11 hospitals; 2009, each of six methods by 59,57,23,22,7 and 8 ones; 2010, each of six methods by 83,79,21,11,7 and 11 ones.3. In 2008, one lab reported International Federation of Clinical Chemistry (IFCC) unit and others reported National Glycohemoglobin Standardization Program (NGSP) unit. In 2009 and 2010, no labs reported IFCC unit.4. The analysis quality results before and after intervention shows that the total coincidence rate is 95.1% in 2008,98.5% in 2009 and 99.3% in 2010, by means of group mean±20% as the evaluation criterion. As for CV analysis, HPLC and LPLC methods testing 2 control materials gave the results of 5.3% and 2.8%,9% and 4.8%; for immunoturbidimetry, microparticale chromatography and immunofluorescence methods the results are 11.6% and 13.1%,5.3% and 5.6%,7.9% and 5.2%. After 1 year intervention, it gave the results of 4.4% and 4.1% and 4.3%,1.4% and 4.6% and 4.2%,1.6% and 6.5% and 6.5%,8.2% and 9.4% and 10.4%,2.8% and 7.7% and 9.8% when using the 5 above mentioned methods to test two control materials and one whole blood sample. The newly added affinity chromatography methods came to the results of 0.0% and 2.3% and 1.1%.5. After two years intervention, according to College of American Pathologists (CAP) issued standard as group mean±10%, the total coincidence in 2009 and 2010 are 93.8% and 94.2%. The 2009 CV results tested by six methods of two controls and one whole blood sample are 3.1% and 3.0% and 3.5%,1.4% and 4.1% and 4.2%,1.6% and 5.7% and 6.6%, 6.2% and 7.9% and 8.1%,2.8% and 3.4% and 8.3%,0.0% and 2.3% and 1.1%; In 2010, the CV results tested both by the same one as in 2009 and two whole blood sample, are 3.1% and 3.0% and 3.3% and 2.8%,4.1% and 3.6% and 4.6% and 3.5%,5.4% and 4.8% and 4.2% and 5.9%,6.0% and 4.5% and 5.9% and 2.2%,3.1% and 2.9% and 2.7% and 3.0%,4.9% and 4.0% and 3.8% and 3.5%. If CV below 5% is adopted as criterion, HPLC, LPLC and affinity chromatography of six methods can meet the criterion. Immuniturbidimetry method has the CV below 7%. The CV of two POCT (microparticle chromatography and immunofluorescence) should be<9%.6. The mean of HbAlc value from two controls used in 2010 (except POCT) are 5.5% and 9.5%, which have the bias of 4.9% and 0.5% in comparison to IFCC reference measurement procedure assigned value.Research conclusionIt is noted that through 3 years intervention, more hospitals start HbAlc tests. The result coincidence rate is increasing, and CV between labs is lowered to different degree. HPLC, LPLC and affinity chromatography are the tendency of selecting measurement methods due to their accuracy. There is 93.8% and 94.2% survey results in 2009 and 2010 that can meet the PT evaluation criterion published by CAP in 2009. The relative bias can be lowered to 0.5% when HbAlc is 9.5%, which meets the accuracy requirement of clinical use.According to this study results,Ⅰsuggest that the HbAlc test lab should select precise test methods, perform internal quality control and participate the external quality assessment scheme to assure measurement quality. In order to promote HbAlc testing result and provide the reliable evidence for diabetes diagnosis, we should perform continual quality management and standardization work.