Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Certification”

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 973 records · Page 54Linked to original sources
PubMed2001

Development of isotope dilution cold vapor inductively coupled plasma mass spectrometry and its application to the certification of mercury in NIST standard reference materials.

An isotope dilution cold vapor inductively coupled plasma mass spectrometry (ID-CV-ICPMS) method featuring gaseous introduction of mercury via tin chloride reduction has been developed and applied to the quantification and certification of mercury in various NIST standard reference materials: SRM 966 Toxic Metals in Bovine Blood (30 ng x mL(-1)); SRM 1641d Mercury in Water (1.6 microg x mL(-1)); and SRM 1946 Lake Superior Fish Tissue (436 ng x g(-1)). Complementary mercury data were generated for SRMs and NIST quality control standards using cold vapor atomic absorption spectroscopy (CVAAS). Certification results for the determination of mercury in SRM 1641d using two independent methods (ID-CV-ICPMS and CVAAS) showed a degree of agreement of 0.3% between the methods. Gaseous introduction of mercury into the ICPMS resulted in a single isotope sensitivity of 2 x 10(6) counts x s(-1)/ng x g(-1) for 201Hg and significantly reduced the memory and washout effects traditionally encountered in solution nebulization ICPMS. Figures of merit for isotope ratio accuracy and precision were evaluated at dwell times of 10, 20, 40, 80, and 160 ms using SRM 3133 Mercury Spectrometric Solution. The optimum dwell time of 80 ms yielded a measured 201Hg/202Hg isotope ratio within 0.13% of the theoretical natural value and a measurement precision of 0.34%, on the basis of three replicate injections of SRM 3133.

Animals↗
PubMed1999

Performance assessment in support of the 1996 compliance certification application for the Waste Isolation Pilot Plant.

The conceptual and computational structure of a performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) is described. Important parts of this structure are (1) maintenance of a separation between stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, with stochastic uncertainty arising from the many possible disruptions that could occur over the 10,000-year regulatory period that applies to the WIPP, and subjective uncertainty arising from the imprecision with which many of the quantities required in the analysis are known, (2) use of Latin hypercube sampling to incorporate the effects of subjective uncertainty, (3) use of Monte Carlo (i.e., random) sampling to incorporate the effects of stochastic uncertainty, and (4) efficient use of the necessarily limited number of mechanistic calculations that can be performed to support the analysis. The WIPP is under development by the U.S. Department of Energy (DOE) for the geologic (i.e., deep underground) disposal of transuranic (TRU) waste, with the indicated PA supporting a Compliance Certification Application (CCA) by the DOE to the U.S. Environmental Protection Agency (EPA) in October 1996 for the necessary certifications for the WIPP to begin operation. The EPA certified the WIPP for the disposal of TRU waste in May 1998, with the result that the WIPP will be the first operational facility in the United States for the geologic disposal of radioactive waste.

Geological Phenomena↗
PubMed1999

Designing and Evaluating Standard-Setting Procedures for Licensure and Certification Tests.

Passing scores for licensure and certification tests are justified by showing that decisions based on the passing score achieve the purposes of the credentialing program while avoiding any serious negative consequences. The standard should be high enough to provide adequate protection for the public, and not so high as to unnecessarily restrict the supply of qualified practitioners or to exclude competent candidates from practicing. This paper begins by examining the intended outcomes of licensure and certification programs and by outlining the interpretive argument that is typically used for written credentialing examinations. Criteria are then developed for evaluating standard-setting methods in terms of how well they serve the goals of protecting the public, maintaining an adequate supply of practitioners, and protecting the rights of candidates. Finally, the criteria are used to evaluate the Angoff method. This analysis identifies two potential sources of bias in the Angoff method, and suggests ways to control these weaknesses.

Journal Article↗
PubMed1999

Evaluation of the state-of-the-art of butyl- and phenyltin compound determinations in freshwater sediment prior to certification of a reference material.

In order to control the quality of butyl- and phenyltin compound determinations in sediment, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission has started a project, the final aim of which is to certify a freshwater sediment for its contents of a range of organotin compounds (mono-, di- and tributyltin, and mono-, di- and triphenyltin). The first part of this project involved an interlaboratory study which aimed to test the feasibility of preparation of candidate freshwater sediment reference material and to detect and remove most of the pitfalls observed in organotin determinations. This paper presents the main results of this interlaboratory study carried out prior to the certification campaign. The agreement obtained among laboratories for the six compounds determined was considered to reflect the state-of-the-art and was encouraging enough to decide upon the organisation of a certification campaign, which will be concluded in June 1999.

Environmental Monitoring↗
PubMed2001

High resolution ID-ICP-MS certification of an estuary water reference material (LGC 6016) and analysis of matrix induced polyatomic interferences.

Reliable trace metal analysis of environmental samples is dependent upon the availability of high accuracy, matrix reference standards. Here, we present Cd, Cu, Ni, Pb and Zn isotope dilution determination for an estuary water certified reference material (LGC 6016). This work highlights the need for high-accuracy techniques in the development of trace element CRMs rather than conventional inter-laboratory trials. Certification of the estuary water LGC6016 was initially determined from a consensus mean from 14 laboratories but this was found to be unsatisfactory due to the large discrepancies in the reported concentrations. The material was re-analysed using isotope dilution ICP-MS techniques. Pb and Cd were determined using a conventional quadrupole ICP-MS (Elan 5000). Cu, Zn and Ni were determined using a magnetic sector ICP-MS (Finnigan Element), which allowed significant polyatomic interferences to be overcome. Using the magnetic sector instrument, precise mass calibration to within 0.02 amu permitted identification of the interferences. Most interferences derived from the sample matrix. For example, the high Na content causes interferences on 63Cu, due to the formation of 40Ar23Na and 23Na2 16O1H, which in a conventional quadrupole instrument would relate to an erroneous increase in signal intensity by up to 20%. For each analyte a combined uncertainty calculation was performed following the Eurachem/GTAC and ISO guideline. For each element a combined uncertainty of 2-3% was found, which represents a 10-fold improvement compared to certification by inter-laboratory comparison. Analysis of the combined uncertainty budget indicates that the majority of systematic uncertainty derives from the instrumental isotope ratio measurements.

Calibration↗
PubMed1999

The certification of a reference material for the evaluation of methods for the enumeration of Bacillus cereus.

A reference material containing Bacillus cereus was certified by the Community Bureau of Reference (BCR) for its number of colony-forming particles (cfp) in 0.1 ml reconstituted capsule solution. To this end, a batch of approximately 15,000 capsules was produced and tested for its homogeneity and stability. The variation in the number of cfp between capsules (homogeneity) was not found to be significantly different from a Poisson distribution. Stability was tested for extended periods at storage temperature (-20 degrees C) and at various higher temperatures up to 37 degrees C for 4 weeks to simulate transport conditions. Only at 37 degrees C did a small but significant decrease in the number of cfp occur. At -20 degrees C, no decrease in the number of cfp was observed over a period of about 4 years. For certification, 12 laboratories determined the number of cfp on two agars: Mannitol Egg-Yolk Polymyxin agar (MEYP, incubated at 30 degrees C) and Polymyxin pyruvate Egg-yolk Bromothymol blue Agar (PEMBA, incubated at 37 degrees C). The certified geometric mean value on MEYP after 24 h of incubation was 53.4 cfp 0.1 ml-1 of the reconstituted capsule solution (95% confidence interval 51.7-55.2) and on PEMBA, 55.0 (95% confidence interval 52.8-57.4). Based on these certified values, user tables were constructed specifying the 95% confidence limits when testing a smaller number of capsules, as would be done in individual laboratories. Based on the information on homogeneity, stability and the certification study, the BCR decided to certify the material as CRM 528.

Bacillus cereus↗
PubMed2003

[Official health certificates between the legal obligation to professional secrecy and the patient's privacy].

Public health officers have to write a medical certificate for public authorities requesting them to do so. This certificate is to contain all the results of medical examinations required for the respective purpose, thus enabling the recipient authorities to take the decisions incumbent on them, such as those judging fitness for service or entitlement to claim. In case the persons concerned agree, a transmission of data is admissible independent of statutory provisions. However, this should always be oriented towards minimum data transmission. Nevertheless, lack of consent or even an adverse intention of the person concerned cannot serve as a blockade in so far as the public health officer has complied with current criminal and data privacy regulations.

Computer Security↗
PubMed1975

Certification-of-need: The Massachusetts experience.

Massachusetts, like 22 other states, regulates its health-care industry in part through a certification and changes in service. As a basis for assessing the program's impact, data from the first 19 months are aggregated. A total of 209 determinations were made during the period, 21 involving beds in general hospitals, and 107 beds in long-term-care facilities. They apparently forestalled the addition of 478 beds in the general-hospital sector and of 1885 long term-care beds. Most of the 40 "facility-improvement" and 35 of 37 clinic proposals were approved. Fifteen determinations were appealed. Hindrances to assessment certification-of-need are formidable. As a consumer-oriented regulatory tool, it is valuable though limited since it can only react to proposals and can neither initiate nor provide positive incentives for new programs.

Acute Disease↗
PubMedDate not supplied

The preparation, validation and certification of the aflatoxin content of two peanut butter reference materials.

The preparation of two peanut butter reference materials and the certification of their aflatoxins B1, B2, G1, G2 and total aflatoxin contents is described. The materials were prepared and certified within the BCR Programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture (Wagstaffe and Belliardo 1990). Reference material RM 385 was prepared from naturally contaminated peanuts, roasted and ground into a paste and then blended with uncontaminated peanut butter to achieve the desired aflatoxin concentrations. Details are given of the blending and canning procedure, and the checks to ensure homogeneity and stability of the material. Reference material RM 401 was similarly prepared but from an uncontaminated peanut butter. The certification exercise was carried out by nine laboratories using a variety of extraction and clean-up procedures, but all using high performance liquid chromatography (HPLC) as the determinative stage although operating under a variety of chromatographic conditions. RM 385 was certified as containing aflatoxins B1, B2, G1 and G2 at levels of 7.0 +/- 0.8 micrograms/kg, 1.1 +/- 0.2 micrograms/kg, 1.7 +/- 0.3 micrograms/kg and 0.3 +/- 0.2 micrograms/kg respectively (total aflatoxin content of 10.1 +/- 1.5 micrograms/kg) and RM 401 as containing aflatoxin B1, B2 and G2 at less than 0.2 micrograms/kg and aflatoxin G1 at less than 0.3 micrograms/kg (total aflatoxin content less than 0.9 micrograms/kg). The materials are intended for the verification of methods used to determine aflatoxins in nuts and nut products.

Aflatoxin B1↗
PubMedDate not supplied

Postural instability induced by virtual reality exposure: development of a certification protocol.

Exposure to virtual environments often causes users to experience symptoms of motion sickness. An accessory manifestation of motion sickness symptoms is postural disequilibrium. If the postural disequilibrium that occurs persists beyond the time an individual is within the confines of the laboratory or system site, user safety could be compromised and products liability issues could be forthcoming. In this study, a portable, automated postural assessment system is developed that can be employed before and after exposure to a virtual reality (VR) system in order to certify that a user's balance on exiting the system is at least demonstrably as good as it was on entering. It is argued that if the "coming out" balance performance is sufficiently poorer than the "going in" balance, then the user should be retained until the pretest balance performance is regained. The results from a set of normative and validation experiments on postural equilibrium identified several reliable measures of stance that could serve as a basis for certification. Furthermore, a new automated video-based measure using only head movement showed that performance over sessions is stable and reliable. The head movement changes that occur with stimuli, such as alcohol and simulator exposure, are well behaved, predictable, and significant even with small samples. The implication is that the proposed objective measure of postural stability, in conjunction with procedures for obtaining self-reports of symptoms, can afford some measure of certification that exposure to a given VR system is without harm.

Accident Prevention↗
PubMed1981

Death certificate study of leukemia among farmers from Wisconsin.

The risk of leukemia among farmers and dairy farmers in particular was studied with the use of mortality records from Wisconsin, 1968-76. A comparison of occupation as noted on the death certificate for 1,499 cases and a like number of matched controls revealed a slight [odds ratio (OR) = 1.10], but statistically nonsignificant, excess risk of leukemia among farmers. The risk was highest among those born after 1897 (OR approximately 1.50) or dying before age 71 years (OR approximately 1.35) among dairy farmers (whether noted on death certificates or identified by county agricultural agents of the Cooperative Extension Programs of the University of Wisconsin) and all farmers alike. The under-representation of farmers among controls with smoking-related causes of death, however, may partially account for these findings. Stratification by county of residence showed significantly elevated risks among farmers from counties with heavy dairy production (OR = 1.40) and fertilizer use (OR = 1.42).

Age Factors↗
PubMed1986

Centralization, certification, and monitoring. Readmissions and complications after surgery.

Research on adverse outcomes following common surgical procedures has suggested the importance of hospital and surgeon variables. Policy directions depend on which factors are important in influencing patient outcomes and what sorts of policies are feasible. Focusing on where a given procedure is performed highlights a concern for centralization; emphasizing who should perform a particular operation implies physician certification. Finally, monitoring involves identifying particular hospitals that appear to have relatively poor (or relatively good) results. This paper analyzes patient, surgeon, and hospital characteristics associated with serious postdischarge complications of hysterectomy, cholecystectomy, and prostatectomy in patients age 25 and over in Manitoba, Canada, following surgery during 1974 through 1976. The three procedures differ markedly in the ease of prediction of the probability of complications and in the predictive importance of patient, hospital, and physician variables. The predictors worked fairly well for cholecystectomy, somewhat less well for hysterectomy, and not well at all for prostatectomy. Hospital variables were not generally important in the multiple logistic regressions. After controlling for case mix and type of surgery, physician surgical experience was found to account for relatively large differences (almost two to one) in the probability of patient complications following cholecystectomy. Cholecystectomy might be a candidate for certification because of the epidemiology of the operation. As of the mid-1970s, a substantial proportion of the cholecystectomies were being performed by physicians with comparatively little ongoing experience with this type of procedure. Moreover, a monitoring perspective identified one hospital with a significantly higher postcholecystectomy complication rate, even after physician experience was taken into account. Both identifying which procedures should be attended to and focusing on problems following surgery are important beyond Manitoba and highly relevant to such American requirements as Peer Review Organizations. Methods of increasing the efficiency of using claims data for quality assurance studies are outlined.

Cholecystectomy↗
PubMed1969

Sick absence certification. Analysis of one group practice in 1967.

Certificates of inability or fitness to work were issued on 6,161 occasions in one year in one group practice. Half the episodes of illness lasted for seven days or less, and two thirds of the episodes ended on a Sunday. Clearly in most cases the doctor does no more than countersign the patient's declaration of his fitness or not to work. Abolition of short-term medical certification would probably have little effect on absenteeism or the sums paid out as sick benefit.

Absenteeism↗
PubMed1987

Organic solvents and presenile dementia: a case referent study using death certificates.

Occupational exposure to organic solvents has been implicated in the development of "presenile dementia" in several studies. The death certificates of all men aged under 65 dying in England and Wales bearing presenile dementia as cause of death were collected for the years 1970-9 (n = 557): control death certificates were obtained, matched for age and sex. No significant differences were found between the groups as regards estimated occupational exposure to either organic solvents or lead.

Dementia↗
PubMedDate not supplied

Geographic differences in mortality from stroke in North Caroline. 1. Analysis of death certificates.

Analysis of death certification in North Carolina for a three-year period, 1969 through 1971, showed regional differences in mortality rates from stroke in white men, with the highest rates in the Plains (tobacco growing and farming) area and the lowest rates in the Mountain region. These geographic differences in death rates were observed in all but the youngest age decade and also in the various types of stroke, i.e., hemorrhagic and occlusive cerebrovascular diseases. This regional variation in mortality, however, was not present in white women or blacks. The prevalence at death of heart disease, hypertension and diabetes also was higher in the Plains than in the Mountain region, suggesting that the observed geographic variation of stroke mortality is related to one or more of these major risk factors. It is concluded that the geographic differences in stroke mortality, which had been reported during previous decades, are real and are not due to variations in death certification, errors in diagnosis, or other explanations that might artificially produce inaccuracies in vital statistics.

Adult↗
PubMed1991

The accordance of diagnoses in a computerized sick-leave register with doctor's certificates and medical records.

A register has been built for planned epidemiological studies of sick-leave, containing all cases exceeding 6 days in a population of 184,000, over a period of 3 years. The diagnoses were coded from medical certificates. To assess the quality of this information this study reviews the medical certificates of 2,364 cases. In 299 cases the corresponding medical records are reviewed and independent diagnoses made. The coding and entering of data into the register is correct in 98% of cases. The independently-made diagnoses match exactly the ones registered in 50% of cases. When grouping the diagnoses into 39 groups, the match on group level is 72%. Ten percentage points of the mismatch are caused by specified overlaps between groups. The remaining 18% mismatch is caused mainly by different interpretations or unspecific labelling of the disease states, not so much by them being obscure in themselves or by doctor covering up unpleasant diagnoses.

Absenteeism↗
PubMed1989

Assessment of gerontology certificate program quality: a follow-up study of graduates.

A follow-up survey of gerontology certificate program graduates was undertaken to elicit views about quality and impact of their interdisciplinary studies, professional roles, and usefulness of course offerings. Graduates provided recommendations about essential course content and suggestions to assist the university in certificate program development. The data strongly support program objectives and direction.

Curriculum↗
PubMed2002

IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C. International Federation of Clinical Chemistry and Laboratory Medicine. Part 7. Certification of four reference materials for the determination of enzymatic activity of gamma-glutamyltransferase, lactate dehydrogenase, alanine aminotransferase and creatine kinase accord.

This paper is the seventh in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C and the certification of reference preparations. Other parts deal with: Part 1. The Concept of Reference Procedures for the Measurement of Catalytic Activity Concentrations of Enzymes; Part 2. Reference Procedure for the Measurement of Catalytic Concentration of Creatine Kinase; Part 3. Reference Procedure for the Measurement of Catalytic Concentration of Lactate Dehydrogenase; Part 4. Reference Procedure for the Measurement of Catalytic Concentration of Alanine Aminotransferase; Part 5. Reference Procedure for the Measurement of Catalytic Concentration of Aspartate Aminotransferase; Part 6. Reference Procedure for the Measurement of Catalytic Concentration of Gamma-Glutamyltransferase. A document describing the determination of preliminary reference values is also in preparation. The certification of the catalytic activity concentrations as determined by the recently elaborated IFCC primary reference methods at 37 degrees C of four enzyme preparations, namely IRMM/IFCC 452 (gamma-glutamyltransferase), IRMM/IFCC 453 (lactate dehydrogenase 1), IRMM/IFCC 454 (alanine aminotransferase) and IRMM/IFCC 455 (creatine kinase) is described. Homogeneity data were derived from previous results. Stability was assessed using recently obtained data as well as data from previous stability studies. The collaborative study for value assignment was performed under a strict quality control scheme to ensure traceability to the primary reference method. Uncertainty of the materials was assessed in compliance with the Guide to the Expression of Uncertainty in Measurement. The certified values obtained at 37 degrees C are 1.90 microkat/l +/- 0.04 microkat/l (114.1 U/l +/- 2.4 U/l), for gamma-glutamyltransferase, 8.37 microkat/l +/- 0.12 microkat/l (502 U/l +/- 7 U/l), for lactate dehydrogenase 1, 3.09 microkat/l +/- 0.07 microkat/l (186 U/l +/- 4 U/l), for alanine aminotransferase and 1.68 microkat/l +/- 0.07 microkat/l (101 U/l +/- 4 U/l), for creatine kinase. The materials are intended for internal quality control as well as for the evaluation of test systems as required by recent European Union legislation. Furthermore, the materials can be used to transfer accuracy from a reference method to a routine procedure provided the procedures exhibit the same analytical specificity and the certified materials are commutable.

Alanine Transaminase↗