Multicentre evaluation of the Boehringer Mannheim/Hitachi 917 analysis system.

The new selective access analysis system BM/Hitachi 917 was evaluated in an international multicentre study, mainly according to the ECCLS protocol for the evaluation of analysers in clinical chemistry. Forty-three different analytes, covering 56 different methods--enzymes, substrates, electrolytes, specific proteins, drugs and urine applications--were tested in seven European clinical chemistry laboratories. Additionally, the practicability of the BM/ Hitachi 917 was tested according to a standardized questionnaire. Within-run CVs (median of 3 days) for enzymes, substrates and electrolytes were <2% except for creatine-kinase MB isoform and lipase at low concentration. For proteins, drugs and urine analytes the within-run CVs were < 4% except for digoxin and albumin in urine. Between-day median CVs were generally < 3% for enzymes, substrates and electrolytes, and < 6% for proteins, drugs and urine analytes, except for lipase, creatine kinase and MB isoform, D-dimer, glycosylated haemoglobin, rheumatoid factors, digoxin, digitoxin, theophylline and albumin in urine in some materials. Linearity was found according to the test specifications or better and there were no relevant effects seen in drift and carry-over testing. The interference results clearly show that also for the BM/Hitachi 917 interference exists sometimes, as could be expected because of the chemistries applied. It is a situation that can be found in equivalent analysers as well. The accuracy is acceptable regarding a 95-105% recovery in standard reference material, with the exception of the creatinine Jaffé method. Most of the 160 method comparisons showed acceptable agreement according to our criteria: enzymes, substrates, urine analytes deviation of slope +/- 5%, electrolytes +/- 3%, and proteins and drugs +/- 10%. The assessment of practicability for 14 groups of attributes resulted in a grading of one-three scores better for the BM/Hitachi 917 than the present laboratory situation. In conclusion, the results of the study showed good analytical performance and confirmed the usefulness of the system as a consolidated workstation in medium-sized to large clinical chemistry laboratories.

Analytical performance of Elecsys 2010--a multicentre evaluation.

The analytical performance of Elecsys 2010 has been assessed in a multicentre evaluation, which involved twelve laboratories from eight countries worldwide. Eleven alanytes (TSH, T4, FT4, T3, FT3, T-up, TNT, CK-MB, HCG, CEA and PSA) were tested using a protocol related to the ECCLS guidelines and the Standard Operating Procedures of the manufacturer. The evaluation was supported by a "Computer Aided Evaluation" (CAEv) program system and telecommunications. Within-run and between-day imprecision for the various analytes with 3% CV and 3 to 8% CV, resp. was comparable to homogeneous immunoassays e.g. for specific proteins on clinical chemistry analysers. The functional sensitivity for TSH, TNT and PSA was met by low concentrations: < 0.02 microIU/ml TSH, < 0.05 ng/ml TNT and < 0.07 ng/ml PSA. TSH is an assay of the third generation according to the recommendation of Spencer. The measured lower detection limit was less or equal to the manufacturer's specifications with the exception of the PSA assay. Drift effects (over eight hours) and signal carry-over effects were not observed. A high-dose hook effect became relevant for concentrations higher than 430,000 IU/HCG--an assay with a dynamic range of 10,000 IU/I. The Elecsys assays showed a high dynamic range and rarely necessary predilutions could be performed by the Elecsys instrument using the Elecsys multidiluent. Endogenous interferences were not observed. Calibration stability was confirmed for one week and data indicated that it could be extended at least for three weeks. The quality assurance experiment showed a good transferability of the results between the participating laboratories. The assigned values of two interlaboratory survey materials were found for most of the analytes within a deviation of +/- 10%. Higher deviations could be explained by differences in standardization and methods. The Elecsys 2010 system offers a high analytical sensitivity in combination with relatively low sample volumes and short measuring times (< or = 18 minutes); a high dynamic measuring range reduces the number of reruns and makes the work-flow more convenient. The electrochemiluninescence technology of Elecsys 2010 shows advantages in system performance without having any drawbacks compared to existing technologies.

Multicentre evaluation of the Boehringer Mannheim/Hitachi 911 Analysis System.

The analytical performance and practicability of the Boehringer Mannheim (BM)/Hitachi 911 analysis system have been assessed in a multicentre evaluation, which involved six laboratories from European countries. Analytes commonly used in classical clinical chemistry were tested in a core programme, which mainly followed the ECCLS guidelines. In addition, a satellite programme covered other analytes, such as proteins, drugs and urine analytes. In total, the study comprised more than 100 000 data items collected over a three-month period. The evaluation was supported with 'Computer Aided Evaluation' (CAEv) and telecommunications.Acceptance criteria for the results were established at the beginning of the study. Nearly all of the analytes met the imprecision limits: within-run imprecision (as CVs) was 2% for enzyme and substrate assays, 1% for ISE methods and 5% for immunoassays; between-day imprecision was 3l% for enzyme and substrate assays, 2% for ISE methods and 10% for immunoassays.No relevant drift effects (systematic deviation >/= 3%) were observed over eight hours. The methods were linear over a wide range. Sample-related and reagent-dependent carry-over can be reduced to a negligible amount by integration of a softwarecontrolled wash-step.Endogenous interferences were found for creatinine (Jaffé method) and uric acid assays (caused by bilirubin), for creatine kinase, creatine kinase MB isoform and gamma-glutamyltransferase (caused by haemoglobin), and for immunoglobulin A (caused by lipaemia)Accuracy was checked by an interlaboratory survey, recovery studies in control materials and method comparison studies. The survey showed that, with the exception of cholesterol and iron in two laboratories, the recovery of analytes did not deviate by more than 5%. Sixty-six of the 77 method comparisons performed met the acceptance criteria. The deviations of the remaining 11 results could be explained by differences in either calibration, application or by the use of different methods.Practicability was assessed using a questionnaire which covered all of the important aspects of an analysis system in the clinical laboratory. Twelve groups of attributes out of 14 were rater higher for the BM/Hitachi 911 than for the present situation in the laboratories concerned. Especially high scores were given for the versatility group.The acceptance criteria for the analytical performance of the BM/Hitachi 911 analysis system were fulfilled in all laboratory segments with few exceptions. The practicability exceeded the requirements in most of the attributes. The results of the study confirmed the usefulness of the system as a consolidated workstation in small- to medium-sized clinical laboratories and in STAT laboratories, or as an instrument for special analytes like proteins and drugs, or for urinalysis in large laboratories.

CAEv-A program for computer aided evaluation.

The evaluation of new reagents and instruments in clinical chemistry leads to complex studies with large volumes of data, which are difficult to handle. This paper presents the design and development of a program that supports an evaluator in the definition of a study, the generation of data structures, communication with the instrument (analyser), online and offline data capture and in the processing of the results. The program is called CAEv, and it runs on a standard PC under MS-DOS. Version 1 of the program was tested in a multicentre instrument evaluation. The concept and the necessary hardware and software are discussed. In addition, requirements for instrument/host communication are given. The application of the laboratory part of CAEv is described from the user's point of view. The design of the program allows users a high degree of flexibility in defining their own standards with regard to study protocol, and/or experiments, without loss of performance. CAEv's main advantages are a pre-programmed study protocol, easy handling of large volumes of data, an immediate validation of the experimental results and the statistical evaluation of the data.