Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “quality control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1995

Implementing comprehensive quality control in the andrology laboratory.

Comprehensive quality control procedures were integrated into the routine semen analysis workload of a large university-based andrology laboratory. Methods were chosen to match as far as possible those which have been used successfully for many years in disciplines such as clinical chemistry. Levey-Jennings and cusum charts were plotted in order to monitor the immunobead-binding test for antisperm antibodies and a video-taped control sample for computerized semen analysis. A cryopreserved semen control was also charted. Daily manual sperm counts were plotted against the corresponding computer-assisted semen analysis (CASA) value. Multiple readings of 30 slides were used to monitor morphology assessments. Monthly means for morphology were also calculated regularly. Coefficients of variation were calculated for all variables and were found to be more appropriate for some aspects, such as CASA, than for others, such as morphology, when difference from the previous reading of the same slide was found to be more useful. These integrated quality control procedures had a direct influence on the production of results from the laboratory. Together with a high standard of technician training, comprehensive routine quality control based on repeated analyses of control samples is an effective way of assuring the validity of semen analysis results.

Antibodies↗
PubMed2001

[Quality control survey implemented by Japan Medical Association and standardization of external quality assessment in Japan].

International Final Draft on quality management of medical laboratory by International Organization for Standardization (ISO) will be published soon. According to this draft, the accreditation of the laboratories should be given by the third party on the basis of objective matter, and the external quality control survey results is thought to be the most important indices for the accreditation. Although variety of external quality control surveys are now implementing in Japan, most of those surveys are done only once a year. Therefore, we could not evaluate the laboratories performance by any of those survey results. If those quality control surveys are done with the standardized system, summative results from different survey could give us fair evaluation on each participating laboratories. Japan Medical Association (JMA) is now making final draft on standardized method for quality assessment system with the consensus between the JMA, Japanese Society of Laboratory Medicine (JSLM, former Japan Society of Clinical Pathology), Japanese Association of Laboratory Medical Technologists (JALMT) and Japan Registered Clinical Laboratories Association (JRCLA). When this quality assessment system actually starts, Japanese people may receive great benefit from the laboratory tests.

Clinical Laboratory Techniques↗
PubMed1997

Clinical laboratory quality control: a costly process now out of control.

We studied laboratory internal quality control (QC) processes using the College of American Pathologists Q-Probes program. Over 500 institutions participated, providing practices based on approximately 710,000 cholesterol, 880,000 calcium, 400,000 digoxin, and 1,180,000 hemoglobin QC results. The costs of QC included participant median control samples rates comprising 9.1, 9.4, 37.0, and 6.8% for the four analytes respectively, repeat patient test rates of 0.36% for hemoglobin to 0.65% for digoxin, and median delays in reporting results when QC exceptions occurred of 15.8 min for calcium to 24.7 min for hemoglobin. Quality control practices were complex and highly variable among participants and frequently differed from internal laboratory protocols and from long-established quality guidelines. We conclude that QC is costly, and laboratorians frequently do not follow established QC practices, in part because they are complex. To improve compliance, we believe QC practices must be simplified.

Chemistry, Clinical↗
PubMed1979

Quality control by blind sample analysis.

Quality control efforts may be biased consciously or unconsciously. External programs are handicapped by the time lapse before poor performance is disclosed. Bias induced into internal and external quality control efforts by special handling may be eliminated through submission of blind samples originating from wards, clinics, or phlebotomy areas. Evaluation of laboratory performance is obtained under conditions similar to those experienced by the patients' specimens. Calibration performance by operators, which varies considerably, can be monitored. Laboratory clerical activity can be scrutinized and errors quantitated and corrected. Perhaps most important, the sum of the effects of specimen handling and analytic variability can be determined.

Alkaline Phosphatase↗
PubMed2004

Towards an automated quality control of XAS data.

The quality of fluorescence X-ray absorption spectroscopy (XAS) data strongly depends on the identification and elimination of contributions suffering from artificial deviations. To enhance detection of deviations, XAS data are converted here to difference spectra and cumulative difference spectra. A variety of statistical criteria and procedures are examined for their application in the quality control of such data. The criterion best suited in this case is determined and a strategy for the automatic elimination of artefacts is developed: deviation-affected spectra are iteratively removed from the data pool. A threshold is defined to avoid unnecessary reduction of the experimental data pool. Exemplarily the procedure is applied for the quality control of BioXAS data.

Automation↗
PubMed1995

[Quality control in the physician's laboratory].

All measures in quality assurance, including quality control, aim at minimizing and detecting errors in the clinical laboratory. Quality control is performed by using internal quality control material and by participating in external quality assessment schemes. These measures for quality assurance are an essential part of the new index of clinical tests, issued by the federal department for internal affairs on 1 January 1994. An agreement has been signed by the representatives of the associations performing laboratory analyses (hospitals, physicians, private laboratories) and by the health insurances, saying that internal as well as external quality control will be mandatory in Switzerland beginning 1 July 1995. The FMH is now asked to supply the health insurances with a list of physicians performing laboratory analyses until 1 July. For physicians who will not have registered neither with the respective professional organization nor one of the health care insurances by July 1995, the reimbursements will be reduced.

Clinical Laboratory Techniques↗
PubMed1993

[Turning point in quality control: problems at present and themes in future].

Quality control in clinical laboratory has a longer than forty-year history after its introduction. At present, quality control has been considered as one of essential tools to evaluate the quality of clinical laboratory data. However, several problems to be solved have still remained. I clarify the problems at present and declare the themes in future. Problems of internal quality control (IQC): Analytical precision of clinical laboratory test has remarkably improved recent years because of the advancement of technologies including analytical procedures and instruments. However, analytical accuracy has not attained the subjects. Furthermore, QC procedures have been converting into subjects and it has been generally considered that using a lot of QC material and QC method is a good manner. As a result, fundamental control procedures such as material control, reagent control and instrument maintenance have been ignored. Problems of external quality control (EQC): It has been considered that EQC serves as an indicator of analytical accuracy and shows the average analytical performance of all participants. However, some problems have remained as follows: (1) Problem of samples for proficiency testing. (2) Problem of classification of peer group. (3) Problem of target value. (4) Problem of evaluation criteria. In general, various IQC methods have been used without careful consideration. However, I would like to emphasize that we have to select the best QC method which can detect the error to be checked according to the method performance. For this reason, we have to grasp the purpose of QC and be careful to not change the subjects into the QC procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Forecasting↗
PubMed2006

[Studies on quality control methods of nuxvomica].

Two quality control methods of nuxvomica were established for mutual. By selecting the appropriate measuring wavelength or wavelength range, the contents of strychnine and brucine in nuxvomica were determined without any preliminary separation by a new rapid spectrophotometry and a multi-wavelength linear regression spectrophotometry and with a computer program. The linear range of strychnine measured was 8.0-30.0 microg x mL(-1) (r = 0.999 9); The linear range of brucine measured was 7.0-31.2 microg x mL(-1) (r = 0.999 4). The average recoveries and relative standard deviations of strychnine and brucine were 98.18%-99.82%, 0.56%-1.54% and 100.5%-100.6%, 0.57%-0.62%, respectively. The methods are simple, rapid and reproducible, the interference of two components with each other may be eliminated and the methods are appropriate for quality control of nuxvomica.

Drugs, Chinese Herbal↗
PubMed1978

Use of a programmable desk-top calculator for the statistical quality control of radioimmunoassays.

We have developed an interactive statistical quality-control system for the small- to medium-sized radioimmunoassay laboratory, which can be used in a programmable desk-top calculator instead of the medium- or large-scale computer systems usually required. The design of this quality-control system is modeled after the suggestions of Rodbard and has three components. The first component evaluates the relationship between the measured response variable of the radioimmunoassay and the precision (or variance) of these measurements. This derived relationship is then used in the second component of the system as the basis for the weighting function used to calculate an interative, weighted, least squares regression of the logit-log transformation of the dose-response curve. The third component uses the quality-control parameters statistically calculated from the linearized dose-response curve to monitor whether the assay is "in-control". The calculator tabulates the means and confidence limits for the various parameters and can plot the statistical quality-control charts. The major benefit of this statistical quality-control system is that it allows the real-time computation and plotting of quality-control data with a programmable desk-top calculator.

Computers↗
PubMed1995

Quality control in mammography.

This article describes the essential elements of an effective quality control program in mammography. Quality Control tests recently updated in the 1994 ACR Mammography Quality Control Manual, such as the darkroom fog and limiting spatial resolution tests, are described in detail. The article goes on to describe some common problems in mammography quality control, including processor sensitometry and image quality problems.

Artifacts↗
PubMed1995

[A 100-year-old transatlantic contribution to anesthesiologic quality control].

Aspects of quality assurance or control in anaesthesia were already discussed at the end of the last century. The reports "Zur Narkotisirungs-Statistik" given by the Berlin surgeon Gurlt between 1891 and 1895 are published examples. Answers in questionnaires and additional comments--mainly from German surgical hospital departments--were the main sources of these reports. However, every year some answers also came from foreign countries. In his fifth report Gurlt published in 1895 the full text of a contribution given by Prince from Chicago, Illinois, USA. That report--given here once again in the original form--allows an insight into the practice of anaesthesia in North America in those days. Many of these statements and recommendations are still relevant; they are now essentials of the so-called "quality assurance" or "quality control".

Anesthesia, General↗
PubMed1997

Thoughts on quality-control systems: a laboratorian's perspective.

State-of-the-art prospective quality-control systems entail the use of medically relevant, analyte-specific quality control limits. With analyte-specific limits broader than those generally used in the clinical laboratory, there will be fewer false rejections, fewer unnecessary reanalyses, and shorter delays in run reporting. If the analyte-specific limits are narrower than those used in the laboratory, more errors will be detected, but the user is at risk of identifying errors over which s/he and the manufacturer have little control. The use of various patient data quality-control algorithms is described. Conservatism is stressed in adopting manufacturers' guidelines for surrogate, nondestructive quality-control testing. A simple, optimized approach is suggested for the systematic retrospective review of proficiency data. Finally, an approach is presented for converting from older, previously accepted quality control procedures to more efficient analyte-specific quality control.

Chemistry, Clinical↗
PubMedDate not supplied

[Quality control in parasitology].

A quality control in parasitology has been organized since 1977, under the direction of the Exotic Pathology Society. In 1978, more than 1 200 voluntary laboratories were participating. In 1979, according to the law of the eleventh of July 1975, this control is going to be obligatory for the 3 750 public or private laboratories effecting parasitologic tests. That should improve the quality of these tests, outside any repressive aspect.

France↗
PubMed2004

Design of internal quality control for reference value studies.

Internal quality control should assure that the desired quality goals are achieved during reference value studies. Quality goals are often stated in the form of allowable limits of error, such as an allowable total error or an allowable bias. For reference value studies, it may be more appropriate to utilize a goal for allowable bias. In either case, it is possible to calculate a metric in the form of the critical systematic error that can be used to guide selection or design of the internal quality control procedure. A graphical tool, called the critical-error graph, facilitates the selection by superimposing the calculated critical systematic error on the power curves of different control rules and numbers of control measurements. Examples are provided to illustrate the calculation of the critical systematic error from both an allowable total error goal and an allowable bias goal, using figures from an extensive tabulation of available total error and bias goals.

Bias↗
PubMed1998

[Histopathologic consultations for quality control. Ethical aspects].

Histopathology and cytopathology are subjective, descriptive methods and there is a need for second opinion of second pathologist. This should be solved in a systematic way from both, organisational and financial point o view. This could not rely on a friendly consultation of a colleague pathologist only. Consultations are integral part of quality assurance and quality control. Quality control in gynaecological cytopathology is associated with reexamination of 1 in every 100 negative cytological smears. High grade dysplasia of the gastric mucosa requires rapid second endoscopy and second opinion prior to gastrectomy. All this is discussed from the point of view of common sense and ethics which (thanks God) are compatible. Protection against unwanted genetic molecular tests still is not satisfactory.

Ethics, Medical↗
PubMed1979

An evaluation of two methods of laboratory quality control.

Two methods for quality control of automated blood counters have been compared: (1) monitoring results from patients' samples, and (2) analysis of results of a stable whole-blood control. The latter method proved better able to distinguish calibration changes from patient variation.

Erythrocyte Indices↗
PubMed1996

[Quality control in clinical trials].

Quality control (QC) in clinical trials means the procedures which insure protection of human subjects from research risk, reliability of the data, and thereby assures internal consistency. This has been developed since 1970s in the US, by establishing various regulations which are now called GCP. From the viewpoint of total QC, it should be emphasized that rigorous review of protocol by the Institutional Review Board and obtaining Informed Consent are prerequisites for insuring the quality of the given trial at high scientific level. When pursuing a clinical trial, first of all, facilities of the institutions and the ability of investigators must be of high quality. For this reason, at each institution previous data related to trials should be thoroughly reviewed and analyzed prior to developing a protocol. Educational courses in QC in clinical practice are invaluable. QC of diagnosis means, for example, central pathology review and standardization of diagnostic procedures and process. Secondly, at each institution, data managers collect the data and submit them to the central office at the indicated time. In order to evolve clinical trial, continuous education for data managers and expansion of their job are encouraged. Thirdly, at the statistical center independent from the research group office, subject-specific data managers, the biostatistical staff, must check submitted forms for completeness, consistency and accuracy. Finally, at the data analysis, quality evaluation of the research should also be carried out. Throughout the trial, monitoring and audit are particularly important to assure quality. The sponsor has the responsibility of monitoring the trial and make rigorous onsite visits, and the individual study group also have a monitoring program, while the FDA and the NCI audit by themselves. The purpose of audit is not only to assure data reliability but also to check out patient compliance to drug, education as to regulations and rules of clinical trials and the analysis of violations so as to provide suggestions to improve medical care.

Clinical Trials as Topic↗