Compliance to specifications in an external quality assurance program: did new biological variation estimates of the European Federation of Laboratory Medicine (EFLM) affect the quality of laboratory results?

Objectives: The results of external quality assurance schemes are evaluated against specifications generally based on biological variation (BV) data. This study was carried out to determine whether new BV values affected the level of compliance to specifications. Our secondary objective was to identify the conditions that would be compromised as a result of poor analytical performance in disease associated markers. Methods: This study was based on the results of the SEQCML External Quality Assurance scheme for the 2015-2022 period. Deviation of the individual result from the target value was estimated. Additionally, we calculated the percentage of results that met the pre-established specification. Results: In 97 of the 133 analytes, the level of compliance was maintained in 80-90 % of the results obtained in the two study periods. In 23 analytes, the level of compliance ranged from 51 to 79 % in the two study periods. In ALT, AST and sodium, the level of compliance was ≤50 % of the results obtained in the first study period, with sodium being the only analyte that maintained this poor level of compliance in the second study period. Conclusions: The level of compliance to specifications remained independent from the specification used (SEQCML or EFLM) for the majority of the analytes. The results for sodium ion were below the target value, which may lead to misdiagnosis of hyponatremia. Non-compensated alkaline picrate methods overestimate creatinine, which may produce false information suggestive of kidney failure.

Impact of implementing a category 1 external quality assurance scheme for monitoring harmonization of clinical laboratories in Spain.

Background: The objective of the present study was to examine the evolution of the analytical performance specifications (APS) used in External Quality Assurance (EQA) schemes, as well as the efficacy of a category 1 EQA scheme in monitoring the harmonization of clinical laboratory results in Spain. Methods: A review of the literature on the types of quality specifications used in schemes in other countries and their evolution was performed. In addition, a comparative analysis of the potential impact that different APS from eight countries had on clinical decision-making was made based on three measurands: sodium, thyroid-stimulating hormone (TSH), and activated partial thromboplastin time (aPTT). Results: Harmonization of analytical methods was demonstrated by assessing whether average results deviated from the certified reference value of control materials within the APS derived from biological variation (BV). The APS used in EQA have evolved from state-of-the-art models to BV. Poor clinical decision-making would occur if the results accepted by some APS were applied. Conclusions: In Spain, only 2 of the 18 measurands studied are considered to be well harmonized. Closer collaboration between laboratories and analytical system providers would be required to resolve discrepancies.

Spanish society of laboratory medicine external quality assurance programmes: evolution of the analytical performance of clinical laboratories over 30 years and comparison with other programmes.

The purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQCML) external quality assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA-SEQCML programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.

Standardization in laboratory medicine: Two years' experience from category 1 EQA programs in Spain.

INTRODUCTION: Standardization is the ability to obtain interchangeable results leading to same medical interpretation. External quality assessment (EQA) is the main support of the on-going harmonization initiatives. Aim of study was to evaluate results obtained from two years category 1 EQA program experience in Spain and determine the impact of applying this type of EQA program on the analytical standardization. MATERIALS AND METHODS: According to the analytical method, traceability and instrument different groups were established which results were evaluated by calculating mean, coefficient of variation and percent of deviation to the reference value. Analytical performance specifications used to the results' evaluation were derived from biological variation for bias and from the inter-laboratory coefficients of variation found in a previous pilot study. RESULTS: Only creatinine measured by enzymatic methods gave excellent results, although few laboratories used this method. Creatine kinase and GGT gave good precision and bias in all, but one instrument studied. For the remaining analytes (ALT, ALP, AST, bilirubin, calcium, chloride, glucose, magnesium, potassium, sodium, total protein and urate) some improvement is still necessary to achieve satisfactory standardization in our setting. CONCLUSIONS: The two years of category 1 EQA program experience in Spain have manifested a lack of standardization of 17 most frequent biochemistry tests used in our laboratories. The impact of the information obtained on the lack of standardization is to recommend abandoning methods such as ALT, AST without exogenous pyridoxal phosphate, Jaffe method for creatinine, and do not use non-commutable calibrators, such as aqueous solutions for calcium and sodium.

Preanalytical quality control program - an overview of results (2001-2005 summary).

BACKGROUND: Preanalytical variables, such as sample collection, handling, transport, and storage, may affect patient results. The number of errors in the preanalytical phase may decrease by following standardized procedures. METHODS: A retrospective analysis (2001-2005) of results obtained through the Spanish Society of Clinical Chemistry and Molecular Pathology Quality Assessment Program for the Preanalytical Phase has been carried out to summarize data regarding the main factors affecting the preanalytical phase quality. In such a program, participants are asked to register rejections and causes for rejection of routine or stat samples usually and locally collected at their laboratories. RESULTS: Results discussed refer to 105 laboratories. Of the 4,715,132 tubes expected to be received during the data collection period among participating laboratories and according to determinations included by clinicians in the request form, 32,977 (0.699%) offered a cause for rejection. Whole blood-EDTA samples and serum samples accounted for 75.6% of all samples collected among laboratories, although they only corresponded to 55.8% of all registered rejections. In total, 81% of rejections arose as a result of the following reasons: "specimen not received" (37.5%), "hemolysis" (29.3%), and "clotted sample" (14.4%). Moreover, plasma-citrate-erythrocyte sedimentation rate exhibited the highest percentage of rejection (1.473%), whereas the lowest rate corresponded to whole blood-EDTA (0.381%). CONCLUSIONS: Overall percentage of rejection is similar to previously published data. As some of the included variables have turned out to be irrelevant, the program has been simplified from the year 2006 onwards.