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PubMed1985

Computer evaluation of statistical procedures, and a new quality-control statistical procedure.

I describe a program for definitive comparison of different quality-control statistical procedures. A microcomputer simulates quality-control results generated by repetitive analytical runs. It applies various statistical rules to each result, tabulating rule breaks to evaluate rules as routinely applied by the analyst. The process repeats with increasing amounts of random and systematic error. Rate of false rejection and true error detection for currently popular statistical procedures were comparatively evaluated together with a new multirule procedure described here. The nature of the analyst's response to out-of-control signals was also evaluated. A single-rule protocol that is as effective as the multirule protocol of Westgard et al. (Clin Chem 27:493, 1981) is reported.

Chemistry, Clinical↗
PubMed2004

Establishing quality control in the new IVF laboratory.

The ability to create an optimal environment for the culture of oocytes and embryos is important to ensure that embryo viability, and therefore pregnancy outcome, is not compromised. Laboratory performance can be monitored using a quality control system. In setting up a new IVF unit, a comprehensive quality control programme was established to monitor laboratory performance and to detect any problems that potentially may have resulted in a sub-optimal service. The measures employed were designed to optimize the environment for human embryo culture by providing aseptic conditions and security for the gametes and embryos, whilst providing a safe working environment for laboratory staff. Equipment function, consumables and environmental parameters were assessed prior to the commencement of treatment in the new unit. A mouse embryo bioassay was used to assess the ability of the new laboratory and equipment to support mammalian embryo development. Prior to the start of clinical treatments a quality control program highlighted equipment that was functioning sub-optimally, which had the potential to cause problems had it been left undetected. Once clinical treatment commenced, quality control monitoring was continued to ensure that the laboratory functioned to a consistently high standard.

Embryo, Mammalian↗
PubMed2002

Professional telephone advice to parents with sick children: time for quality control!

OBJECTIVE: To assess the quality of professional telephone advice given to parents with sick children. METHODS: All hospitals with an emergency department and a paediatric ward and a designated child health telephone advice line in the greater Brisbane region were invited to participate in the study. Case scenarios involving a febrile baby, a 14-month-old with gastroenteritis and an 18-month-old with a head injury were used three times with each institution. Each of the cases should have elicited a response indicating the need for urgent medical attention. A research assistant presented the symptoms in accordance with the questions of the telephone advice-giver. Aspects of the call were recorded, including time between call made and access to advice-giver, profession of advice-giver, identifying details sought by advice-giver, questions asked about the case presented, length of call, and advice-given. RESULTS: Of the 10 hospitals asked, six agreed to participate. Included in the study were two paediatric hospitals, two general public hospitals, one private hospital, and a Statewide-designated child health telephone advice line. Calls were generally attended to promptly. Only 37 (68.5%) of the advisers recognized the urgency of the case scenarios, with the febrile infant having the least likelihood of eliciting the correct advice (39%). Doctors gave more reliable advice than nurses in the fever scenario, but not in the other cases. CONCLUSIONS: Telephone advice to parents with sick children is easily accessible, but is often dangerously inappropriate. There is a need for tighter quality control and/or for a centralised telephone advice line to prevent inappropriate advice being given to parents.

Child↗
PubMed2002

[Studies on quality control standard of zhishidaozhi tabloid pills].

OBJECTIVE: To develop the quality control standard of Zhishidaozhi Tabloid Pills. METHOD: Applying TLC to identify Radix et Rhizoma Rhei, Fructus Aurantii Immaturus, Rhizoma Coptidis, Radix Scutellariae, and HPLC to determine the content of emodin of Radix et Rhizoma Rhei. RESULT: Radix et Rhizoma Rhei, Fructus Aurantii Immaturus, Rhizoma Coptidis and Radix Scutellariae could be indentified by TLC. Emodin showed a good linear relationship at a rang of 0.0612-0.612 microgram, r = 0.9999. The average recovery was 97.9%, and RSD was 2.1%. CONCLUSION: The methods are accurate and quick, and can be used for the quality control of Zhishidaozhi Tabloid Pills.

Chromatography, High Pressure Liquid↗
PubMed1992

Internal quality control of semen analysis.

OBJECTIVE: To test a scheme for quality control of semen analysis. DESIGN: The reproducibility of assessment of sperm concentration, motility, and morphology was obtained for the same sample measured by different technicians (between or intertechnician variation) and for different samples assessed by each technician with time (within or intratechnician variation). SETTING: Andrology Laboratory. PATIENTS: Semen samples were analyzed from all patients attending the clinic. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Within technician and between technician coefficients of variation for concentration, motility, and morphology. RESULTS: When 100 sperm were routinely assessed, both intratechnician variation, as assessed from the precision of duplicate measurements, and intertechnician variation revealed hyperbolic curves with increasing variation at low percentages (less than 20) of motile or morphological forms. When these low values were excluded, mean intratechnician variations were 5.0%, 8.4%, and 2.8% for concentration, motility, and morphology, respectively, and mean intertechnician variations were, respectively, 6.1%, 5.6%, and 5.6%. Similar mean intertechnician variation for morphology was obtained for repeated assessment of prestained (7.3%) or presmeared (5.9%) slides. The use of cryopreserved semen to monitor longitudinal changes in the technicians' assessments revealed variations of 8.1% to 12% in concentration and 9.7% to 14% in motility. Computing the monthly means for sperm concentration, motility, and morphology over a 4.5-year period revealed a marked reduction in percentage of normal morphological forms, unrelated to the sperm count or mean age of the men attending the clinic. This was shown to be a result of a shift in the assessment by technicians. CONCLUSIONS: Quality control is necessary and possible in an andrology clinic.

Cryopreservation↗
PubMed1995

[Quality control of enzyme immunoassay--assurance and control of analytical sensitivity, accuracy and precision].

Although the basic concept for quality control of enzyme immunoassay (EIA) is the same as that of quality control of the usual chemical analysis, immunological analytic methods including enzyme immunoassay have some specific features depending on the method as compared with the chemical method. In addition to the usual QC method, therefore, it is necessary to add some QC techniques to control the variables derived from the method. In accuracy control of EIA, standard materials, reagents and analytical equipment will be the major sources of error. Points to be considered in accuracy control are described. In precision control of EIA, between-run precision is generally larger than within-run precision. In consideration of the characteristics, mean-Rs-R control chart method and Z-V control chart method appropriate for immunological method are described. Analytical sensitivity expressed as detectability and detection limits is very important in EIA. A procedure to determine the detection limits is described in detail. Between reagent lot difference in immunological reagent is considerably larger than that of chemistry reagent and a shift of the point on the control chart is not adequate to assess the reliability of the patient data. Therefore, an evaluation method of the between reagent lot difference is described. General procedures of precision control are not described here because the procedures are well known.

Immunoenzyme Techniques↗
PubMed2002

Formation, isomerisation and reduction of disulphide bonds during protein quality control in the endoplasmic reticulum.

Efficient protein folding and quality control in the endoplasmic reticulum (ER) require that disulphide bonds are formed in nascent proteins, isomerised during assisted folding and reduced in terminally misfolded molecules. Recent findings in yeast and mammalian cells indicate that specific protein-protein interactions underlie redox control in the ER, allowing these competing reactions to occur simultaneously during protein quality control.

Animals↗
PubMed2003

Monitoring technologist reading skills in a sperm morphology quality control program.

OBJECTIVE: The value of sperm morphology as a predictor of a man's fertilizing potential has often been challenged because of different classification systems used to distinguish between normal and abnormal spermatozoa. The study aimed to monitor the reading skills of 53 laboratory technologists who are enrolled in a continuous quality control program for sperm morphology assessment. DESIGN: Prospective analytical study. SETTINGS: Academic hospital and academic institution setting. PATIENT(S): Sperm samples from the sperm donor program and andrology technicians from sub-Saharan Africa. INTERVENTION(S): Papanicolaou-stained sperm slides were prepared and shipped on a quarterly basis to participating laboratories. Papanicolaou-prestained sperm morphology slides were used as test material for 21 months. MAIN OUTCOME MEASURE(S): Percentage normal spermatozoa.A new statistical model was developed to record reading skills of the participating technicians. Reading skills were classified as marginal (5.7% of cases), good (11.3% of cases), and excellent (83% of cases). RESULT(S): Participants maintained their morphological reading skills and agreed with the reference laboratory by not exceeding a SD limit of 0.2 to set stringent standards for the program. CONCLUSION(S): Technician proficiency can be monitored using the results of a quality control program. A continuous quality control program can be initiated only after intensive training, because baseline values at the onset of the quality control program serves as an internal reference value.

Clinical Competence↗
PubMed2006

Tentative fingerprint-efficacy study of Houttuynia cordata injection in quality control of traditional Chinese medicine.

To establish potent fingerprint for quality control of traditional Chinese medicine, Houttuynia cordata (Saururaceae) injection (HCI), the attempt on fingerprint-efficacy was developed in this study. HCI from ten different factories were determined by gas chromatography-mass spectrum (GC-MS) and classified by hierarchical clustering. The anti-inflammatory effect of HCI was characterized with the rat pleurisy model induced by carrageenin and the mice ear edema model by xylene. The results showed that anti-inflammatory effect of the injections from most of factories on the two models was significant. There was corresponding relationship between the fingerprint of HCI and efficacy to certain extent. The main common constitutes in injection from the factories that possess anti-inflammatory activity were analysed with GC-MS and identified using the NIST Mass Spectral Database. This common pattern of HCI based on the efficacy was helpful for the purpose of quality control.

Animals↗
PubMed1999

Research and quality control in natural family planning with relational database systems.

Research and quality control in natural family planning (NFP) is based on continuous data collection in prospective studies. The quality of the data is determined by the reliability of collection, input, management, and retrieval. During a period of ten years, different relational databases were programmed to manage the large number of very different data in NFP studies. Recently, all experience with different database systems has been summarized by writing and testing a completely new data management system based on MS Access 97: NFPDAT 1.0. This new software is used for data collection, evaluation and administration in NFP Study Groups. Over 200 internal formulae guarantee maximum data consistency while 30,000 cycles from 1477 patients were stored. Easy data evaluation for research and administration is possible with the help of a new report generator even without prior knowledge of SQL (System Query Language) or Visual Basic for MS Access 97. Using this method, interim results for research and quality control can be obtained at any time. NFPDAT can be used by all Natural Family Planning Study Groups using the symptothermal method for research and administration. With the help of NFPDAT, various prospective studies of Natural Family Planning were conducted.

Austria↗
PubMed2004

Colposcopy quality control by remote review of digitized colposcopic images.

OBJECTIVE: This study was undertaken to estimate the accuracy of colposcopy quality control review of subjects' digitized colposcopic images during the atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion triage study (ALTS). STUDY DESIGN: After colposcopic examination and the acquisition of 2 digitized cervical images, colposcopists recorded colposcopic diagnoses in a standardized computer database. The images were transferred by modem to colposcopy quality control reviewers for a blinded interpretation, including assessment of image quality. Reviewers' and colposcopists' diagnoses were compared with histologic diagnoses using standard contingency table methods. RESULTS: Colposcopists and reviewers underdiagnosed 16.1% and 25.3% of subjects, and overdiagnosed 44.7% and 19.8% of subjects compared with histology, respectively. The sensitivity and specificity for detecting cervical intraepithelial neoplasia 2 or greater were 35.4% versus 23.2%, P < .0001, and 89.9% versus 95.0%, P < .0001, respectively, for colposcopists and reviewers. CONCLUSION: Colposcopy quality control by review of digitized colposcopic images in clinical trials warrants further evaluation if the accuracy can be improved.

Biopsy, Needle↗
PubMed2005

Quality control in human in vitro fertilization.

The implementation of suitable quality control (QC) is not only required for the accreditation of a human in vitro fertilization (IVF) laboratory, but is also fundamental to its success. Several assays have been employed to screen culture media and contact supplies. The suitability of one assay in particular, the mouse embryo assay (MEA), has been questioned over the years. Here we discuss how the conditions of such an assay, together with the stage of embryonic development used, have a profound effect on the outcome of the assay. Furthermore, by assessing embryos at multiple time points during the preimplantation period (rather than simply determining blastocyst formation), together with quantitating key parameters such as blastocyst cell number, it is possible to identify suboptimal components of a culture system. As well as identifying those components that result in outright embryonic demise, under the appropriate conditions the MEA can detect components that lead to impaired development. It is proposed that under the appropriate conditions, the MEA is a useful adjunct to quality control in human IVF, but several assays used in concert are better than a single test.

Animals↗
PubMed1988

Quality control of receptor analyses of breast cancer tissue in Denmark.

Quality control investigations of estrogen and progesterone receptor (ER and PgR respectively) analyses can be undertaken using two principally different methods. The first, and the most frequently employed, is by comparing the results of analyses of a lyophilized, standard cytosol. The second method is by comparing the frequency of receptor positivity as well as the distribution of the receptor concentrations determined on a large number of representative biopsies in different laboratories. This latter method can, however, only be used provided that the composition of the population of biopsies studied is similar in the laboratories undertaking such an investigation. Both approaches have been used by the three Danish laboratories participating in the Danish Breast Cancer Cooperative Group (DBCG) project. The international and national quality control programs that these three laboratories have participated in are reviewed in the present paper. From having a poor degree of inter-laboratory reproducibility in 1981, the inter-laboratory reproducibility has improved due to a collaborative standardization effort. Using the clinical data available through the DBCG program, we have been able to demonstrate that suboptimally performed receptor analyses can influence the conclusions of clinical studies regarding patient prognosis in relation to receptor status.

Aged↗
PubMed1976

Quality control of serum alkaline phosphatase assays: project report and discussion of some factors affecting the assay.

The factors which affect the standardisation and quality control of serum alkaline phosphatase assays are discussed. A quality control project was designed to test the performance of seven Birmingham laboratories in the assay of sera with alkaline phosphatase activities outside the range normally tested by the National Quality Control and Wellcome schemes. The results showed that the precision of individual laboratories was satisfactory. Differences between the results of the laboratories were considerable and could be accounted for by differences in methodology. Auto-Analyzer methods employing phenyl phosphate as substrate would best be standardised by adopting the optimised reaction conditions of Buch and Buch (1939); but the borate buffer of these authors should be replaced by the carbonate-bicarbonate buffer of Moss et al. (1971). To avoid the confusion which may arise in future if alkaline phosphatases are reported in U/l irrespective of the substrate, it is suggested that some substrate--indicative nomenclature may be advisable.

Alkaline Phosphatase↗
PubMed1985

Quality control: what are our goals? How much is necessary?

Can laboratories modify their quality control procedures to reduce costs without affecting the quality of patient care? In discussing some approaches to modification, the author focuses on the quality control of batch analyses and methods comparison studies.

Hospital Departments↗
PubMed2006

Formulation, quality control and shelf life of the experimental cytostatic drug cyclopentenyl cytosine.

This paper describes the formulation and quality control of an aqueous sterilized formulation of the experimental cytostatic drug cyclopentenyl cytosine (CPEC) to be used in Phase I/II clinical trials. The raw drug substance was extensively tested. A High Pressure Liquid Chromotography (HPLC) method was validated for the quality control of the formulated product. The aqueous formulation was found to be stable for at least 2 years at 2-8 degrees C. Sterilization (15 min at 121 degrees C) showed no influence on drug stability. The results show that CPEC can be formulated in an aqueous solution. The described HPLC method is a useful tool in the pharmaceutical quality control.

Antineoplastic Agents↗
PubMed2001

[A quality control test of the image obtained with electronic portal imaging devices].

INTRODUCTION: A quality control of the digital image obtained from two electronic portal imaging devices is discussed. The devices are used to verify the radiotherapic treatment setup by comparing online images of the irradiated volume with those of the simulation devices. MATERIAL AND METHODS: Both iView and Target View devices, respectively installed on a dual energy SLi Precise Elekta and Saturne 42 Ge linear accelerators, consist of highly efficient phosphor screen and high quality videocamera, controlled by a workstation, able to generate digital portal images from few cGy doses. A phantom and software package are used to assess the spatial resolution and signal to noise ratio, and to compare tha data obtained. Spatial resolution and signal to noise ratio of both systems were studied as a function of energy, gantry angle and image acquisition parameters. RESULTS: The mean spatial resolutions obtained from the first 30 measurements were 0,265+/-0,012 and 0,220+/-0,010 lp/mm respectively for 6 and 18 MV of Saturne 42 (Target View) and 0,241+/-0,006 and 0,239+/-0,005 lp/mm for 4 and 6 MV of SLi (iView). Spatial resolution decreases as a function of energy, meanwhile there are no significant statistical differences as regards of the acquisition parameters; signal to noise ratio, instead, increases with integration time. Different values of the spatial resolution as a function of gantry angle are due to changes in the screen-camera distance and flexing of the detector housing. The quality control test is performed every 15 days by the technicians of our Radiotherapy Department. We set the reject level of spatial resolution and signal to noise ratio to be three standard deviations below the mean value obtained during the initial EPID characterization: if the measures fall below these values preventative maintenance is scheduled. CONCLUSIONS: The efficacy of the use electronic portal imaging devices for visualizing and quantifying the relative positions of anatomical structures within the radiation field depends on the image quality. It is therefore essential to devise quality control tests for the devices themselves, to guarantee an optimal level of system performance in a fast and efficient manner.

Equipment Design↗
PubMed1984

[A study of quality control for radioimmunoassay kit using moving average method].

New method of quality control based on mean-R control chart for radioimmunoassay (RIA) kit was investigated. Conventional mean-R control chart was hard to found variations in each RIA kits. But the new method, trend variation analysis of mean-R control chart by moving average method, could detect variation among th different lot of RIA kits. This method should be very useful to do a quality control in RIA kits.

Quality Control↗