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PubMed1992

[Quality control in hematology].

Qualified quality control is a necessary part of modern haematology: we cannot deem laboratory results reliable until effective quality checking is included. Quality assessment includes external (national, regional) and internal (intra-laboratory) control. We suggest to found a Czech national external quality control agency for haematology based on principles which were declared by the World Health Organization. Internal control includes correct identification of samples, analytical control (standardization of test, evaluation of accuracy and precision) and biological quality control (history of patient's characteristics, relation to other laboratory results in clinical context). The deviation index, which is expressed either as a number or verbally 'excellent', 'good', 'satisfactory', or 'unsatisfactory', can supply rapid information on the quality of results in the haematological laboratory.

Hematology↗
PubMed1977

Suitability of commercial enzyme control sera for the quality control of activity determinations of L-aspartate aminotransferase and L-alanine aminotransferase in human serum.

Details of a systematic approach to suitability testing of commercial control sera are given for substrate optimized L-aspartate aminotransferase and L-alanine aminotransferase methods at 37 degrees C. Their acceptability for control purposes of standardized methods depends on: (1) the range of control values in relation to borderline values, (2) stability, (3) aspect, clarity, (4) NADH consumption in preincubation time, (5) blank activities, (6) kinetic data as half saturation constants and saturation curves, (7) influence of effectors, (8) isoenzyme pattern. These evaluation criteria are proposed for suitability testing. The term "representativeness" should be introduced as a special criterion for main characteristics of control materials. The authors want to point out the close connection with standardization of methods.

Absorption↗
PubMed2004

Quality control for interviews to obtain dietary recalls from children for research studies.

Quality control is an important aspect of a study because the quality of data collected provides a foundation for the conclusions drawn from the study. For studies that include interviews, establishing quality control for interviews is critical in ascertaining whether interviews are conducted according to protocol. Despite the importance of quality control for interviews, few studies adequately document the quality control procedures used during data collection. This article reviews quality control for interviews and describes methods and results of quality control for interviews from two of our studies regarding the accuracy of children's dietary recalls; the focus is on quality control regarding interviewer performance during the interview, and examples are provided from studies with children. For our two studies, every interview was audio recorded and transcribed. The audio recording and typed transcript from one interview conducted by each research dietitian either weekly or daily were randomly selected and reviewed by another research dietitian, who completed a standardized quality control for interviews checklist.Major strengths of the methods of quality control for interviews in our two studies include: (a) interviews obtained for data collection were randomly selected for quality control for interviews, and (b) quality control for interviews was assessed on a regular basis throughout data collection. The methods of quality control for interviews described may help researchers design appropriate methods of quality control for interviews for future studies.

Child↗
PubMedDate not supplied

Quality control for the clinical chemistry laboratory.

Since the beginning of the twentieth century, different methods to control the quality of analyses have been in use. The advent of modern analytical instruments has prompted the need for such controls. In a modern clinical chemistry laboratory, quality control is an important tool to maintain the high predictive value of the methods in use. In this article the most important aspects of quality control are outlined. For further study, I recommend the references listed at the end of this article.

Clinical Chemistry Tests↗
PubMed1988

Quality control in therapeutic drug monitoring.

Quality control of routine drug assays, like most immunoassays, should mainly be the responsibility of each individual laboratory: intra-laboratory quality control. External quality assessment should direct its efforts in particular to non-routine methods and to new assays. However, it may sometimes also be very useful to have laboratory results of routine assays studied in external programmes, since vague requests or difficult interpretations of drug concentrations need discussion outside the individual laboratory.

Caffeine↗
PubMed1979

Stability of mean values of organic analytes 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 mean values of six organic analytes in 48 commercial pools of lyophilized chemistry quality control serum is evaluated. These pools, provided by five manufacturers, have been used by nine Regional Quality Control Programs participating in the College of American Pathologists Quality Assurance Service. Creatinine yielded stable mean values in 88% of the pools studied. Both albumin and urea nitrogen demonstrated manufacturer and method-related changes in mean values. Bilirubin, cholesterol, and uric acid changes in mean values were independent of control serum manufacturer, predominant in calibrator-standardized automated procedures, and were clustered by years.

Bilirubin↗
PubMed1986

Experience with quality control in clinical chemistry.

The introduction of statistical quality control of clinical chemical analyses has not only provided documentation of the reliability of analytical results and led to improvements in reliability, it has also led to marked improvements in the methods, reagents, calibration materials, control specimens and equipment used. Beyond this, the availability of reliable analytical results has enabled further development of the theoretical concepts underlying thought and action in clinical chemistry. The present paper provides an overview of developments in quality control in the Federal Republic of Germany since 1964. The uniform basic program for quality control with control specimens, as set forth in the Guidelines of the Medical Society of West Germany and required in all states of the country since 1971, is described and our experience with it discussed. Internal quality control consists of separate precision control and accuracy control procedures. External quality control in the form of short-term interlaboratory surveys with control specimens provides an objective check on accuracy. The assigned values for the required accuracy control specimens are determined under routine conditions in particularly well-equipped and well-staffed laboratories headed by particularly highly qualified individuals. The laboratories are independent of the manufacturers of control specimens, calibration materials, reagents and equipment. Over the years, the assigned value determinations have also provided valuable information about the structure of the data and about the reliability criteria for the analytical results. Based on the experience gained with this system, a new concept for quality control was developed in which the method-dependent assigned values are replaced by method-independent reference method values. The requirements for quality control, i.e., the maximum acceptable imprecision and the maximum acceptable deviation of the analytical results from the reference method value or the assigned value, are specified after consideration of the clinical requirements, that is, their effects on medical decision-making.

Chemistry, Clinical↗
PubMed1995

Quality control of imprint and tissue section DNA ploidy analysis in image analysis systems utilizing cell culture-based control materials.

Currently, there are no standard controls available for quality control of DNA ploidy assays in image analysis systems. The authors have developed a system of controls based on cultured human cell lines that can mimic tissue sections and touch preparations. This allows for quality control for the entire process for DNA ploidy analysis from the initial cutting of the paraffin block or production of the touch preparation through fixation, staining, and interactive image analysis. The use of cell line controls rather than normal tissue is advantageous because of cell population homogeneity and the volume of uniform slides that are obtainable. This system, while providing an excellent means of controlling day-to-day performance of DNA ploidy analysis, may also be adapted for use as a means of multi-institutional proficiency testing.

Cytological Techniques↗
PubMed1982

Glucose stability in lyophilized chemistry quality control serum. A study of data from the quality assurance service (QAS) program of the College of American Pathologists.

Data from 2.5 million glucose analyses on pools of lyophilized human quality control serum were used to evaluate analyte stability in the prereconstitution phase. Input information was from laboratories in Regional Quality Control Programs that use CAP Quality Assurance Service (QAS) data processing. Of 31 pools in use between 1977 and 1981, decreasing glucose concentration was detected by, at least, one method in 26 pools, and by two or more methods in 21 pools. Method-associated average decrease in concentration varied from 0.13 mg/dL/month (glucose oxidase-electrode) to 0.19 mg/dL/month (automated glucose oxidase-colorimetric). Bidirectional instability as a function of analytic method, i.e., increase with "mild" methods, decrease with "rigorous" methods that was noticed previously with pools analyzed between 1973 and 1977, was no longer seen. Dominant directional changes in the later pools were downward by all methods, when statistically significant trends were demonstrated.

Blood Glucose↗
PubMed1996

[Quality assurance in radiology: quality control of radiographic cassettes].

A "quality team" in radiology, whose members are the authors of this paper, has implemented a quality control program to test the cassettes with intensifying screen systems used in radiology departments. 149 systems-124 of them for general purpose radiology and 25 for mammography-were submitted to the following tests: visual inspection of radiographic cassettes and intensifying screens, screen-film contact, intensifying screen cleanliness and relative sensitivity of the intensifying screens. The results of each type of test are reported in detail in the paper, on a 3-point scale: good, sufficient and poor. The overall results of the quality control tests show 78% of general purpose radiology cassettes to qualify as good (69%) or sufficient (9%), while 22% were of poor quality. 88% of the mammographic cassettes qualified as good (76%) or sufficient (12%), while 12% were of poor quality. All tests were easy to perform and required limited resources. The necessary procedures to keep quality high over time are also reported. To conclude, the results obtained with our quality control program could be used as an effective tool to address and plan the turnover of the cassettes with intensifying screens which are usually used in diagnostic radiology practice.

Evaluation Studies as Topic↗
PubMed2001

Therapeutic drug monitoring of antiepileptics by capillary electrophoresis. Characterization of assays via analysis of quality control sera containing 14 analytes.

Quality assurance is an important aspect in therapeutic drug monitoring (TDM). Capillary electrophoresis (CE) assays for determination of (i) ethosuximide via direct injection of serum or plasma, (ii) lamotrigine after protein precipitation by acetonitrile and analysis of an aliquot of the acidified supernatant, and (iii) carbamazepine and carbamazepine-10,11-epoxide after solute extraction followed by analysis of the reconstituted extract are characterized via analysis of a large number of commercial quality control sera containing up to 14 analytes (9 of them are anticonvulsants) in sub-therapeutic, therapeutic and toxicologic concentration levels. CE data obtained in single determinations are shown to compare well with the spike values and the mean of data determined in other laboratories using immunoassays and/or high-performance liquid chromatography, values that are reported by the external quality control scheme. Carbamazepine and ethosuximide drug levels are also shown to agree well with those determined in our departmental drug assay laboratory using automated immunoassays. The presented data reveal the effectiveness of assay assessment via analysis of quality control sera and confirm the robustness of the assays for TDM in a routine setting.

Anticonvulsants↗
PubMed1977

Mycological culture media and its quality control.

The need for control of the quality of media used in the isolation and identification of fungi is an important aspect of the overall quality control of laboratory culture media; however, guidelines for such controls have not been available. In this paper, primary isolation media with and without appropriate drugs are suggested for use on a variety of specimens. Positive and negative quality control organisms that indicate clear-cut postiive and negative results on the fungal media to be tested are listed. Several alternative procedures for maintenance of fungi are discussed.

Culture Media↗
PubMed2004

[Studies on quality control of Xueyakang capsule].

OBJECTIVE: To establish the quality control standard for Xueyakang capsule. METHOD: Radix Rehmanniae, Cacumen Platycladi, Folium Artemisiae Argyi, Folium Nelumbinis were identified by TLC, and the content of quercitrin was determined by HPLC. RESULT: The TLC sports developed was fairly clear, the HPLC method showed good repeatability, and the average recovery of quercitrin was 100.7% with RSD 2.0%. CONCLUSION: The method is simple, accurate and can effectively control quality of Xueyakang capsule.

Antihypertensive Agents↗
PubMed2003

Laboratory quality control: using patient data to assess analytical performance.

Quality control plays a vital role helping to ensure the reliability of laboratory test results. The application of statistical quality control has been a component of laboratory medicine for approximately 50 years. Many of the control rules based on the early applications of statistical quality control have remained essentially unchanged since their initial introduction. Optimization of quality control rules can vary depending on the application for which a test is to be used. This review explores the various applications of laboratory quality control procedures and their role in identifying laboratory error. The ubiquitous use of computers in today's laboratories has enabled the development of more sophisticated means of assessing laboratory quality. The use of the Six Sigma technique and its adoption by the laboratory community is one example. Other examples include the use of patient-derived quality control procedures as a means of assessing laboratory performance. Early examples of these types of applications include use of Bull's algorithm, anion gap measurements, and delta checking. More recent applications include the correlation of laboratory test results, the average of normals procedure, and the Bhattacharya method.

Chemistry, Clinical↗
PubMed1987

Formative evaluation: an approach to ongoing quality control.

Improving the quality of long-term care for the elderly is an issue often debated but rarely resolved. Many ideas have been tried to improve the system, but formative evaluation has generally not been used as a resource for quality control. This paper has described the need for formative evaluation, its special characteristics and practices, and some hypothetical applications for long-term care issues. Above all else, formative evaluation is a philosophy that stresses the use of systematically collected information for program improvement. This implies a marriage of theory and practice, of need and response, of innovation and reflection. The elderly who require long-term care deserve the highest quality possible. Formative evaluation is one tool to ensure they receive what is needed.

Evaluation Studies as Topic↗