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At least 685 records · Page 38Linked to original sources
PubMed1995

Role of re-screening of cervical smears in internal quality control.

AIMS: To investigate the use of rapid re-screening as a quality control method for previously screened cervical slides; to compare this method with 10% random re-screening and clinically indicated double screening. METHODS: Between June 1990 and December 1994, 117,890 negative smears were subjected to rapid re-screening. RESULTS: This study shows that rapid re-screening detects far greater numbers of false negative cases when compared with both 10% random re-screening and clinically indicated double screening, with no additional demand on human resources. The technique also identifies variation in the performance of screening personnel as an additional benefit. CONCLUSION: Rapid re-screening is an effective method of quality control. Although less sensitive, rapid re-screening should replace 10% random re-screening and selected re-screening as greater numbers of false negative results are detected while consuming less resources.

Cytological Techniques↗
PubMed2000

An assessment of quality control testing in an emergency department (ED) maintained arterial blood gas analyzer

Emergency medicine by its nature requires the immediacy of laboratory testing. Point of care testing (POCT) affords the ED the fastest access to important laboratory data. To the best of the authors' knowledge, maintenance of an arterial blood gas (ABG) analyzer as a POCT device by ED personnel has not been studied. OBJECTIVE: To determine the accuracy of POCT quality control testing of an ED maintained ABG Analyzer (Gem Premier)-Instrumentation Laboratory). METHODS: We compared comprehensive quality control data obtained when the ABG analyzer was maintained by the Department of Clinical Laboratories with data obtained from the same analyzer when it was maintained by ED attending physicians. Each parameter measured by the ABG analyzer was tested using unknown control samples supplied by the College of American Pathologists. These two groups of data were then compared to the total number of obtained values submitted to the College of American Pathologists. RESULTS: Each parameter measured (n = 7) showed no difference between the two groups in regard to overall pass rate. All values for the two groups fell within the limits of acceptability when compared to all other samples analyzed by the College of American Pathologists (range 159-208 other labs). CONCLUSIONS: ED attendings are capable of quality control maintenance of an ABG analyzer as a POCT device under the quality control testing parameters set forth by the College of American Pathologists.

Journal Article↗
PubMed1981

Long-term stability of a stabilized liquid quality-control serum.

To evaluate the long-term stability of a new liquid quality-control serum ("Decision", Beckman Instruments, Inc.) stabilized with ethylene glycol (330 mL/L), we analyzed it for 22 commonly measured analytes during storage at 2--8 degrees C for 24 days or -15 to -20 degrees C for 55 weeks. Three separate laboratories replicated the analyses, using various analytical methodologies. The data were subjected to linear regression analysis, regressing concentration on time. Analytes were considered unstable when the linear regression coefficient was unequal to zero with 95% or greater probability in all three laboratories. By this criterion all of the analytes were stable for at least 24 days when the control serum was stored at refrigerator temperature and for at least 55 weeks at freezer temperature. We conclude this material is a satisfactory substitute for existing lyophilized quality-control materials and offers certain advantages: stability, vial-to-vial uniformity, decreased waste, and eliminated reconstitution.

Blood Chemical Analysis↗
PubMed1988

1987 Gallie lecture. Quality control in surgical research: importance to the patient.

One of the deficiencies in surgical scholarship is the rarity of timely, well-controlled research to evaluate new operative procedures. The invasive aspect of surgery makes randomized studies more difficult to initiate, and in studies with large numbers of participating surgeons, the impact of unsatisfactory surgical expertise (craftsmanship) is a major variable. In an effort to improve surgical research, the use of quality control data for early assessment of the effectiveness of the operative procedure is strongly recommended. Early postoperative studies of stimulated gastric acid secretion have led to improved surgical performance during trials of operations using vagotomy for control of peptic ulcer disease. Similar, early, quality control studies have been effective when investigating selective shunts for control of variceal bleeding; necessary data include shunt patency, portal perfusion of the liver and obliteration of major portoazygous collaterals. Failure to incorporate objective tests for surgical quality control can lead to erroneous assessment of operations. Carefully planned prospective studies of well-performed operations are urgently needed.

Clinical Trials as Topic↗
PubMed1988

Quality control in the in vitro fertilization laboratory: comparison of bioassay systems for water quality.

Three mouse embryo bioassays [mouse one-cell and two-cell embryos and in vitro fertilization (IVF)] were tested for their ability to discriminate between three sources of water for medium preparation: tap water, high-performance liquid chromatography (HPLC)-grade water, and Milli-Q purified water. No differences could be detected using these assays. The lack of sensitivity of the mouse bioassays could not be attributed to the protein source or medium type. The hamster sperm motility assay (HSMA) permitted quantitative discrimination between water sources (Milli-Q greater than HPLC greater than tap). Media prepared for use in human IVF using water that exceeded minimal HSMA quality standards resulted in pregnancy rates that were greater than those attained with a lot of HPLC water that did not meet these standards. The HSMA can serve as a basis for a quality-control program in the human IVF laboratory.

Animals↗
PubMed2002

Technical quality control practices in mammography screening programs in 22 countries.

OBJECTIVE: To assess current technical quality control (QC) practices within breast cancer screening or surveillance programs internationally. MATERIALS AND METHODS: The International Breast Cancer Screening Network (IBSN) conducted an extensive survey of quality assurance (QA) activities in developed countries known to have population-based breast cancer screening or surveillance programs in place. Twenty-three countries were sent questionnaires that included items about QA and QC requirements at screening sites, the minimum frequencies of QC test performance, and the personnel responsible for performing QC tests. RESULTS: All 23 countries in the IBSN completed general information on their QA practices. Twenty-two countries responded with complete details on their technical QC practices. The responses indicated a pattern of consistently high-quality control practices among population-based breast cancer screening and surveillance programs. Most programs performed the great majority of QC tests. Variations were observed in the performance frequencies of QC tests and in the personnel responsible for performing QC tests. CONCLUSION: QC practices among population-based breast cancer screening and surveillance programs are highly evolved, with the great majority of responding countries following prescribed QC protocols. Further research is needed on appropriate performance frequencies for mammography QC tests.

Accreditation↗
PubMed2000

Internal quality control in virology: validation of immunoassays using a personal computer spreadsheet.

Design of a spreadsheet to evaluate the performance of internal quality control sera used for the validation of immunoassays in virology is described. Developed using Microsoft Excel 97, it can set target limits and analyse control data by application of Westgard quality control rules. It also provides a permanent record of all relevant information concerning each assay run, including action taken to rectify unacceptable performance.

Humans↗
PubMed1996

Development of interpretive criteria and quality control limits for macrolide and clindamycin susceptibility testing of Streptococcus pneumoniae.

A six-laboratory collaborative study was conducted to develop MIC and zone diameter quality control limits and interpretive criteria for antimicrobial susceptibility testing of Streptococcus pneumoniae with azithromycin, clarithromycin, dirithromycin, and clindamycin. The MICs of all of the agents plus erythromycin for 302 clinical isolates of pneumococci that had been selected with an emphasis on resistant strains were determined by use of the National Committee for Clinical Laboratory Standards (NCCLS)-recommended broth microdilution procedure. The zone diameters of the isolates were also determined for the same agents except erythromycin by the NCCLS disk diffusion test procedure. Repeated testing of S. pneumoniae ATCC 49619 with different sources and lots of media and disks allowed development of MIC and zone diameter quality control ranges for these agents. Interpretive criteria for the MIC of azithromycin were established and were as follows: susceptible, < or = 0.5 microgram/ml; intermediate, 1 microgram/ml; and resistant, > or = 2 micrograms/ml. The interpretive criteria advocated for the MICs of clarithromycin and clindamycin were as follows: susceptible, < or = 0.25 microgram/ml; intermediate, 0.5 microgram/ml; and resistant, > or = 1 microgram/ml. Comparison of MICs and disk diffusion zone diameters led to the development of interpretive criteria for the zone diameters for azithromycin, clarithromycin, and clindamycin that correlated well with these MIC breakpoints. Testing of this organism collection also led to the reestablishment of the erythromycin MIC breakpoints as being identical to those of clarithromycin, which resulted in equivalent cross-susceptibility and cross-resistance for the three macrolides that are currently marketed in the United States. Thus, the susceptibility of pneumococci to azithromycin and clarithromycin can be predicted accurately by testing only erythromycin in clinical laboratories. This recommendation, as well as the interpretive and quality control criteria that are described, have been accepted by NCCLS and are included in the latest NCCLS susceptibility testing guidelines.

Anti-Bacterial Agents↗
PubMed2005

A multi-center quality control study of different CA15-3 immunoassays.

A long-term multi-center quality control study of CA15-3 determinations based on measurements of liquid BIOREF CA15-3 control sera was conducted in 17 participating laboratories. Seven different CA15-3 assays were applied using the appropriate automatic immunoanalyzers. CA15-3 means were determined for BIOREF low, medium and high level control sera. Values were 19.3 +/- 2.7 kU/l, 75.2 +/- 11.4 kU/l and 162.9 +/- 37.1 kU/l, respectively. Inter-assay imprecisions were calculated for each of the controls for each laboratory and for each of the methods, with coefficients of variation (CV) ranging from 2.9-15.5%. As a means of evaluation of assay linearity concentration ratios (high/medium, medium/low, high/low) were calculated and found to be in good agreement with reference values throughout the study. Individual long-term time courses of CA15-3 control measurements provided evidence for variability of test results due to changes in assay calibration. Comparisons with CV data obtained with BIOREF controls 17 years ago demonstrate significant improvements of CA15-3 assay precision in recent years. In conclusion, test-independent reference material can be used for CA15-3 quality control and in particular enables applicants to check for long-term stability of CA15-3 assay performance.

Humans↗
PubMed1984

Progress report on a national quality-control survey of triiodothyronine and thyroxin assay.

In January 1980, a national external quality-control survey was organized to evaluate assays for triiodothyronine (T3) and thyroxin (T4). Currently, about 150 laboratories are involved. Each participant has received and assayed 100 quality-control samples during four periods of about six months each. The average analytical performance achieved by the participants in each six-month period was estimated by computing the average between-laboratory agreement (CVT), the overall average bias, and the average laboratory imprecision. During the 2.5 years of the survey, analytical performance has improved for both assays (CVT decreased from 17.0 to 15.7% for T3 and from 13.1 to 12.7% for T4). Analysis of survey results according to the method/kit used (mean kit bias and kit imprecision for the nine kits most used by participants) showed that the analytical reliability of the T4 assay is generally better than that observed for T3, mainly because of the larger systematic differences among T3 kits.

Chemistry, Clinical↗
PubMedDate not supplied

[Introduction of quality control at a health center: evaluation of health consumers' medical records and the problems found].

OBJECTIVE: To present quality control as an effective and dynamising tool, to analyse the quality of the health consumer's medical records and to detect and set in motion the correction of problems. DESIGN: Retrospective crossover study. SETTING: San Martín Health Centre, Vitoria. PARTICIPANTS: General patients who attended clinics in January, February, March and October. Consumers and the human and material resources of the Centre during 1992. INTERVENTIONS: Measures to correct faults found. MEASUREMENTS AND MAIN RESULTS: We analysed a systematic sample of 10% of the records used by the General Practitioners during January and of 5% during February, March and October. We saw an overall improvement in all the sections of consumers' records. The index showing variability of recording between different health providers descended in successive assessments. Twenty-six problems were detected. Through the Coordinator, a solution was set in motion in 100% of them. Of those problems external to the team. CONCLUSIONS: The early introduction of quality control means that problems can be detected and measures put in place to improve and homogenise quality and to dynamise the Team. The quality of the consumer's medical records, the detection and setting in motion of the correction of problems and the use of simple, practical and possible methodology are key.

Health Facilities↗
PubMed1990

Quality control criteria for testing the susceptibility of anaerobic bacteria to meropenem.

Reference values for quality control of in vitro susceptibility tests with meropenem against anaerobic bacteria were determined in a multilaboratory study by the approved National Committee for Clinical Laboratory Standards agar dilution method for the four quality control strains. The study protocol also included the evaluation of microdilution testing, medium additives, and multiple lots of media. The recommended MIC control ranges for three of the control organisms are as follows: Bacteroides fragilis ATCC 25285, 0.06 to 0.125 micrograms/ml; Bacteroides thetaiotaomicron ATCC 29741, 0.125 to 0.5 micrograms/ml; and Eubacterium lentum ATCC 43055, 0.125 to 0.5 micrograms/ml. The modal MIC for Clostridium perfringens ATCC 13124 was at or below the lowest concentration of meropenem tested, and no values are recommended.

Bacteria, Anaerobic↗
PubMed2000

Quality control of cancer screening examination procedures in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.

Investigators for the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial describe quality control procedures for the digital rectal examination, ovarian palpation examination, transvaginal ultrasound, chest X-ray, and flexible sigmoidoscopy. These cancer screening tests are subjective and difficult to standardize. PLCO quality control procedures aim to measure and, where possible, reduce variation, across examiner and screening center, with respect to cancer screening test performance. Initial protocols stressed examiner qualifications, experience, and training; equipment specifications; examination procedures; and definitions for positive tests. The PLCO quality assurance subcommittee developed a final quality assurance plan, which included central approval and registration of PLCO examiners, direct observation of screening test performance during periodic site visits by the National Cancer Institute and coordinating center auditors, periodic analysis of screening test data, and procedures for independently duplicating or reviewing selected examinations. For each modality, the periodic data analyses examine the test-positive and the test-inadequate proportions and aim to identify divergent centers or examiners. Procedures for duplicating examinations specify feasible sample sizes for precise estimates of agreement between examiners, at each center, for each screening test modality, and over a 1-year period. These quality control procedures will help characterize the consistency and reliability of the PLCO cancer screening tests.

Aged↗
PubMed1999

[Quality control in anesthesia. A new frontier].

For several years now, the need for improving healthcare quality has determined the adoption of a businesslike philosophy in American hospitals, through quality control and improvement systems. In Italy, the introduction of this business concept in public healthcare is recent, while quality assurance is still widely ignored. The anesthesiology wards have a central role in making the DRG mechanism work and therefore need computerised systems that can guarantee correct evaluation of results, analysis of efficacy and quality assurance. The development of a quality control and assurance system in anesthesiology, can be achieved by following a few simple guidelines: to identify the indicators, sensitise the personnel towards an attitude of improvement, adopt a computerised database, verify and elaborate data, correct the defects, verify the changes made to the system.

Anesthesia↗
PubMed2006

Rapid cervicovaginal smear screening: method of quality control and assessing individual cytotechnologist performance.

AIM: To validate the method of rapid screening (RS) in the detection of cervical lesions and false-negative results as well as in quality control of cytotechnologist performance. MATERIAL AND METHODS: The RS method was validated on Papanicolaou-stained and initially conventionally analysed vaginal, cervical and endocervical (VCE) smears collected in an opportunistic programme for the detection of cervical carcinoma. The study included 3680 VCE smears from the Department of Gynaecologic Cytology, University Department of Gynaecology and Obstetrics, Zagreb University Hospital Center, Zagreb and from the Department of Clinical Cytology, Osijek University Hospital, Osijek. Histologically verified abnormal findings accounted for 10% of the study samples. Thirteen cytotechnologists, with no previous experience in RS, performed the test. Each slide was examined using the 'step' technique for 1.5 minutes, the findings were classified as negative or abnormal, and the abnormal ones were also classified according to differential cytological diagnosis. The results were compared with those obtained on initial screening. Abnormal findings from a group of initially negative findings were reanalysed using conventional methods to make definitive cytological diagnosis. RESULTS: RS yielded a sensitivity of 83.7%, specificity of 93.7%, positive predictive value of 62.4%, negative predictive value of 97.9% and diagnostic accuracy of 92.6%. Relative to the initial abnormal differential cytological diagnosis, the diagnostic value of RS increased with lesion severity [54.8%, 68.0% and 91.3% for cervical intraepithelial neoplasia (CIN) I, CIN II and CIN III respectively]. RS detected 38 additional positive findings; 94.2% of these were atypical squamous cells of undetermined significance (ASCUS)/abnormal glandular cells undetermined significance (AGUS) and CIN I. The rate of additional positive findings was 1.14% (38/3135). The false-negative rate of initial screening was 9.4% (38/406), and individual cytotechnologist sensitivity was 60.0-100.0%. CONCLUSION: RS could be introduced as an efficient method of quality control to improve the sensitivity of cytological screening as well as for quality control of cytotechnologist performance.

Croatia↗
PubMed2004

[Pressurized solvent extraction in quality control of Chinese herb].

Pressurized solvent extraction (PSE) is a new extraction technology which has been developed in recent years and widely used as sample analysis in environmental, food and pharmaceutical fields. Extraction technique is a key technology in quality control of Chinese herb. Conventional extraction techniques have been a bottleneck of blocking the development of quality control of Chinese herb. This article attempts to review the basic principle, methods, apparatus and main characteristics of PSE and its applications to quality control of Chinese herb.

Chemistry Techniques, Analytical↗
PubMedDate not supplied

MacCueSee: a quality control program for the Macintosh computer.

MacCueSee was written to perform routine calculations on quality control concentration values from radioimmunoassay. It is written in Microsoft QuickBASIC for the Apple Macintosh computer. The program calculates within and between assay standard deviation (S.D.) and coefficient of variation from a spreadsheet file containing concentration values of controls analyzed. It also calculates the average concentration +/- 1 S.D. and contraction +/- 2 S.D. to establish between assay ranges. Its flexibility permits varying replicates between assays and automatic exclusion of missed assays. Within assay variability calculations are made for single, duplicate, and triplicate tubes. Results are displayed and can optionally be printed. In addition to radioimmunoassay, MacCueSee can be applied to a number of analytical methods in which quality control is monitored. An example of program use is included.

Microcomputers↗