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At least 199 records · Page 11Linked to original sources
PubMed1983

Quality control for the clinical laboratory.

Quality control is a management discipline by which laboratories assure the validity of their results for bedside management of patients. The thrust of quality control has been the laboratory's efforts at improving analytic variability associated with the measurement process. Through increasing emphasis on automation and participation in laboratory improvement programs, laboratory imprecision and inaccuracy have decreased over the past 15 years. Recent advances in the practice of quality control include use of new types of quality control materials, changing concepts of what is out of control, and the introduction of microcomputer applications.

Clinical Laboratory Techniques↗
PubMed1986

Quality control in cytopathology.

Quality control in cytopathology involves specimen collection, preparation, screening, and final diagnosis. The measures to assure the optimal performance and to detect the malfunctions in these areas are discussed. Careful selection and application of proper procedures, proper training and continuing education of cytotechnologists and pathologists, and reasonable workload for screening cytotechnologists and important factors in quality assurance.

Pathology, Clinical↗
PubMed1979

Accuracy in interlaboratory quality control programs.

Interlaboratory quality control programs provide an important contribution to achieving and maintaining accuracy in clinical laboratories. The various strategies for providing accurate target values in the two principal types of interlaboratory programs are reviewed.

Laboratories↗
PubMed1976

Regional quality control.

Methods of quality control of some major haematological techniques are described. These methods have been applied in haematology laboratories serving a population of 2 million using existing facilities for preparation and transport of the necessary materials.

Blood Cell Count↗
PubMed1987

CT quality control.

A daily quality control (QC) protocol for a GE 9800 computed tomography (CT) scanner is described which quantitatively assesses system noise, an index of high contrast resolution, and the reproducibility of CT numbers for four phantom materials. The mean values and variation for each QC parameter under normal operating conditions have been determined, and their use in assessing CT scanner performance is discussed.

Quality Control↗
PubMed1997

The EWMA control chart: properties and comparison with other quality-control procedures by computer simulation.

A quality-control chart based on exponentially weighted moving averages (EWMA) has, in the past few years, become a popular tool for controlling inaccuracy in industrial quality control. In this paper, I explain the principles of this technique, present some numerical examples, and by computer simulation compare EWMA with other control charts currently used in clinical chemistry. The EWMA chart offers a flexible instrument for visualizing imprecision and inaccuracy and is a good alternative to other charts for detecting inaccuracy, especially where small shifts are of interest. Detection of imprecision with EWMA charts, however, requires special modification.

Algorithms↗
PubMed1978

Serum cholesterol analysis in the C.B. Heart Project. Intra-and inter-laboratory continuous quality control.

Standardization and quality control of measurements are of crucial importance in large medical surveys. In the C.B. Heart Project serum cholesterol analyses in the central laboratory were extensively controlled with regard to precision as well as accuracy. All measurements are carried out in side-by-side duplicate, the maximum difference allowed being 0.3 mmol/l. Bench control, aiming at maintaining linearity and precision with control limits, requires insertion of standard solutions and several serum controls into every run. Control values must fall within 2 S.D. limits from the established mean values, e.g. 4.1 +/1 0.25 mmol/l and 8.2 +/- 0.25 mmol/l. A very reliable check on the precision was obtained by blind introduction of duplicate patient specimens. Repeatability (within-run precision) as calculated each month has S.D. values of approx. 0.10--0.20 mmol/l, whereas reproducibility (long-term precision) S.D. values are 0.15--0.25 mmol/l. Accuracy is checked in the Cooperative Standardization Programme of the WHO Regional Lipid Reference Centre in Prague. This makes the C.B. Heart Progject results comparable with other standardized studies. Our bias approximates +3% and usually remains within WHO "narrow limits".

Cholesterol↗
PubMedDate not supplied

[Documentation and quality control].

Documentation and quality control in hospitals are not only required due to legal obligations, but should be a representation, how physicians see themselves. The fast changes in medical treatment procedures makes adequate techniques of information management indisposable. In the past data analysis in hospitals was characterized by a too strong restriction in variables under study, and a too sharp project orientation with the consequences, that many tasks had to be done repeatedly and an overview on the whole situation wasn't achieved either. So in recording postoperative wound sepsis many separate aspects have to be taken into consideration and microbiological results have to be stored in a way, that differentiation over time is possible. For medical data management a time oriented database structure is therefore advisable and more adequate than a relational one.

Cross Infection↗
PubMed1999

Quality control in urinalysis.

Quality control (QC) has been introduced in laboratories, and QC surveys in urinalysis have been performed by College of American Pathologist, by Japanese Association of Medical Technologists, by Osaka Medical Association and by manufacturers. QC survey in urinalysis for synthetic urine by the reagent strip and instrument made in same manufacturer, and by an automated urine cell analyser provided satisfactory results among laboratories. QC survey in urinalysis for synthetic urine by the reagent strips and instruments made by various manufacturers indicated differences in the determination values among manufacturers, and between manual and automated methods because the reagent strips and instruments have different characteristics, respectively. QC photo survey in urinalysis on the microscopic photos of urine sediment constituents indicated differences in the identification of cells among laboratories. From the results, it is necessary to standardize a reagent strip method, manual and automated methods, and synthetic urine.

Automation↗
PubMed1989

Reliability of skin smear results: experiences with quality control of skin smears in different routine services in leprosy control programmes.

The quality control of skin smears is an important tool in improving the diagnosis of leprosy. We evaluated the skin smears sent to us by 50 laboratory technicians of 29 projects in Asia, Africa and South America. The skin smears were judged according to taking, staining and reading. The correlation was altogether satisfactory. In reading, a low correlation was found in 11% (42 slides) and it was seen that the highest percentage of low correlations was found in the false negative smears. The evaluation of cases with a low correlation leads to the conclusion that using the new WHO classification of 1988 will not reduce the number of incorrectly classified cases. From 42 slides showing a low correlation of their BI results, 7% led to a different classification (paucibacillary instead of multibacillary or vice versa) according to the WHO definition given in 1982, but 8% according to the 1988 WHO definition.

Humans↗
PubMed2006

Towards eliminating the use of animals for regulatory required vaccine quality control.

Traditionally, regulatory required vaccine quality control relies on the use of laboratory animals. Both batch testing for safety and testing for potency are based on animal models. Quite often these models include procedures that induce severe pain and suffering. This has urged the development of 3Rs methods. Some examples of recent achievements in the quality control of toxoid vaccines are the replacement of challenge procedures by serological methods, the reduction of numbers of animals required by changing from multi-dose to single dose testing, and developments in the area of in vitro models and physicochemical techniques. Central in the progress towards the elimination of animal use is the acceptance of the so-called consistency approach. The essence of the consistency approach is that a new batch of vaccine is no longer seen as a unique product but as only one of a series of batches produced from the same starting material (seed lot). Consequently, the new batch shares many of the characteristics of the previous batches produced from the same seed lot. This allows for a new strategy of vaccine quality control consisting of demonstrating consistency in production, placing emphasis on aspects such as in-process testing, and implementing Good Manufacturing Practice and Quality Assurance (QA). The new strategy particularly focuses on non-animal test models such as physicochemical methods and in vitro models. Implementation of the consistency approach might significantly contribute towards the elimination of the use of animals in regulatory required vaccine quality control.

Animal Testing Alternatives↗
PubMed2004

MRI quality control: six imagers studied using eleven unified image quality parameters.

Quality control of the magnetic resonance imagers of different vendors in the clinical environment is non-harmonised, and comparing the performance is difficult. The purpose of this study was to develop and apply a harmonised long-term quality control protocol for the six imagers in our organisation in order to assure that they fulfil the same basic image quality requirements. The same Eurospin phantom set and identical imaging parameters were used with each imager. Values of 11 comparable parameters describing the image quality were measured. Automatic image analysis software was developed to objectively analyse the images. The results proved that the imagers were operating at a performance level adequate for clinical imaging. Some deficiencies were detected in image uniformity and geometry. The automated analysis of the Eurospin phantom images was successful. The measurements were successfully repeated after 2 weeks on one imager and after half a year on all imagers. As an objective way of examining the image quality, this kind of comparable and objective quality control of different imagers is considered as an essential step towards harmonisation of the clinical MRI studies through a large hospital organisation.

Algorithms↗
PubMedDate not supplied

[Quality control in microbiology (author's transl)].

The microbiology quality control importance is emphasized and some particular problems that quality control presents in microbiology are also indicated. There are two types of microbiology quality control as well as for hematology and chemical chemistry: collective quality control, between more laboratories, and individual quality control, in the sphere of each laboratory. A.M.O.I. (Associazione Microbiologi Ospedalieri Italiani) and I.S.V.T. (Istituto Sieroterapico Vaccinogeno Toscano) Sclavo collaborating, have organized a collective quality control between laboratories of different hospitals during the year 1974 and 1975. The results of this control are reported. Although preliminary, they indicate practical importance of microbiology control. During 1975, in fact, the pathogens isolated have been in high percentage than 1976. At last, the future quality control's program aiming at methods's standardization and technical, methodical instructions is indicated.

Bacteriological Techniques↗
PubMed1978

Long-term stability of glucose in lyophilized quality control serum. A study utilizing data from the Quality Assurance Service (QAS) Program of the College of American Pathologists.

The long-term stability of glucose in 45 commercial pools of lyophilized quality control serum is evaluated. The pools have been used in conjunction with the Quality Assurance Service (QAS) of the College of American Pathologists by laboratories participating in Regional Quality Control Programs. Directional instability of glucose was detected by at least one analytic method in 69% of the pools studied. Two distinct and opposite directional trends in glucose concentration were found. Increasing concentration of analyte, averaging 4.7 mg/dl per year, were observed with manual and automated glucose oxidase methods and the automated neocuproine procedure in approximately one fourth of pool--method combinations. Decreasing concentrations of glucose, averaging 3.0 mg/dl per year, were found with automated ferricyanide and hexokinase methods and the manual orthotoluidine procedure in approximately one third of pool--method combinations. The results are best explained by postulating that in affected pools there is a gradual diminution of free and bound glucose and/or a shift of glucose from the protein-bound to the free state.

Autoanalysis↗
PubMed1984

Principles for developing improved quality control procedures.

Achieving quality goals in the clinical chemistry laboratory requires a comprehensive understanding of the many critical components and factors that are involved in a quality assurance program. The present paper has therefore been divided into sections dealing with quality goals as a rational starting point, determinants of quality for an analytical procedure, assessing the quality of a measurement procedure, assessing the quality of an internal control procedure, improving the quality of internal control procedures, designing an internal control procedure to provide a specified level of quality, strategy for implementing high power control procedures, implications of frequency of errors and predictive value theory on design of control procedures, role of external quality assessment in achieving quality goals, tools needed to improve quality control, and further considerations in achieving quality goals. In designing control procedures we have focused mainly on internal statistical control, emphasizing the new aspects of frequency of analytical disturbances. Less detailed consideration has been given to external quality assessment, though this problem area is also essential to a quality assurance program. Many other aspects have not been discussed, e.g., requirements for control materials, and use of patient specimens for control purposes, though both aspects are obviously very important. Even with these limitations, we think that quality control can be improved by development of better control procedures following the principles outlined here.

Chemistry, Clinical↗