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PubMed1997

International reference standards: antibody standards for the indirect enzyme-linked immunosorbent assay.

Reference standards are used to calibrate similar assay systems against an international reference protocol and to provide a template for the preparation of secondary and/or working standards. Three reference standards are recommended for the indirect enzyme-linked immunosorbent assay: a strong positive standard, a weak positive standard and a negative serum standard. The negative standard should be derived from a single serum or from a serum pool which exhibits typical background activity in the reference protocol. The strong and weak positive standards should be derived from a single serum or from a serum pool which typifies the humoral response (antibody) to natural infection. Suitable candidates for the positive reference standards should exhibit dose/response curves in the mid-range of antibody activity. The strong and weak positive standards should each be prepared from a one-time dilution in the negative standard, to yield antibody activities which are defined by specific points on the linear portion of the dose/response curve. The strong positive standard should represent an antibody activity (absorbance value) midway between the upper and central points and the weak positive standard should represent an antibody activity midway between the central and lower points of the linear portion of the curve. Owing to inherent differences among assay systems, antibody activities should be expressed in relative rather than in absolute terms. It is recommended that the antibody activity of the strong positive standard should denote 100% positivity. The activities of the weak positive and negative standards should then be expressed as relative percentages. Every set of international reference standards should be accompanied by an information sheet which includes, among other things, a plot of the dose/response curve and an indication of the dilutions used to prepare the standards.

Animals↗
PubMed1990

Standard karyotype of the domestic horse (Equus caballus). Committee for standardized karyotype of Equus caballus. The Second International Conference for Standardization of Domestic Animal Karyotypes, INRA, Jouy-en Josas, France, 22nd-26th May 1989.

The following decisions concerning the banded karyotype of the horse (Equus caballus) were made at the second International conference for Standardization of Domestic Animal Karyotypes, held at Jouy-en Josas, France, 22nd-26th May 1989: (1) numbering of the chromosomes was modified to correspond to an arrangement into only two groups (the non-acrocentrics and the acrocentrics) within which the autosomes are placed according to length alone; (2) a more compact karyotype arrangement was adopted: chromosomes 1 to 5 on the first row, 6 to 10 on the second, 11 to 13, and, at the far right, X and Y on the third row, 14 to 19 on the fourth row, chromosomes 20 to 25 on the fifth, and 26 to 31 on the sixth row; (3) the NOR-bearing horse chromosomes were identified as numbers 1, 28 and 31.

Animals↗
PubMed1988

Reporting standards in venous disease. Prepared by the Subcommittee on Reporting Standards in Venous Disease, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery/North American Chapter, International Society for Cardiovascular Surgery.

This report comprises suggested reporting standards for publications dealing with (1) acute lower extremity venous thrombosis, (2) chronic lower extremity venous insufficiency, (3) upper extremity venous thrombosis, and (4) pulmonary embolism. Attempts have been made to set forth numeric grading schemes for disease severity, risk factors, and outcome criteria. Some of the recommendations had to be arbitrary of necessity, but they were judged the most generally acceptable by members of the committee. They are offered not as binding rules but as guidelines whose observance will serve the clarity and precision of communication.

Adult↗
PubMed1999

[Standardization. Sterilization standards and their impact on hospital services].

The European commission produced series of Directives which were aimed at harmonizing the European market whilst maintaining high standards to protect the citizens. Within each directive drafted Essential Requirements which had to be satisfied in order to market throughout Europe. The Medical Device Directive (93/42/EEC) covers the vast majority of medical devices including active non-implantable and non-active implantable medical devices. Demonstration of compliance to harmonized European Standards (EN) was proof of compliance with Essential Requirements of the Directives. The European Standards Body (CEN) created a series of European Standards which would enable to demonstrate compliance with Essential Requirements. The CEN organisation has a pyramidal structure. Standards are produced in the CEN Technical Committees (TC's) composed of representatives from each country's own standards organization. The Technical Committee in turned created a series of Working Groups (WG), who's job it was to actually generate the text of the standards. Two of standards committees are working to generate standards which relate to sterilizers and sterilization: TC102--the standards emanating from this committee are product related, TC 204--the standards relate to sterilization practice. In Poland, the standarisation activity is provide by Polish Committee of Standardisation. From 5th June 1997 operate Problem Commission number 272 for sterilization affairs. The job of the commission consist on translation of European'offs Standards and transform them to Polish Standards. After accede Poland to European Union, Polish hospitals will have to adjust to European Standards.

Centralized Hospital Services↗
PubMed2002

Direct calibration of a reference standard against the air kerma strength primary standard, at 192Ir HDR energy.

The primary standard of low air kerma rate sources or beams, maintained at the Radiological Standards Laboratory (RSL) of the Bhabha Atomic Research Centre (BARC), is a 60 cm3 spherical graphite ionization chamber. A 192Ir HDR source was standardized at the hospital site in units of air kerma strength (AKS) using this primary standard. A 400 cm3 bakelite chamber, functioning as a reference standard at the RSL for a long period, at low air kerma rates (compared to external beam dose rates), was calibrated against the primary standard. It was seen that the primary standard and the reference standard, both being of low Z, showed roughly the same scatter response and yielded the same calibration factor for the 400 cm3 reference chamber, with or without room scatter. However, any likelihood of change in the reference chamber calibration factor would necessitate the re-transport of the primary standard to the hospital site for re-calibration. Frequent transport of the primary standard can affect the long-term stability of the primary standard, due to its movement or other extraneous causes. The calibration of the reference standard against the primary standard at the RSL, for an industrial type 192Ir source maintained at the laboratory, showed excellent agreement with the hospital calibration, making it possible to check the reference chamber calibration at RSL itself. Further calibration procedures have been developed to offer traceable calibration of the hospital well ionization chambers.

Air↗
PubMed1997

Reduction of interlaboratory variability in flow cytometric immunophenotyping by standardization of instrument set-up and calibration, and standard list mode data analysis.

Two workshops addressed the question to which degree standardization of instrument set-up and calibration, and standard list mode data analysis would reduce interlaboratory variability of flow cytometric results on prestained peripheral blood mononuclear cells (PBMC). Standard instrument set-up included uniform positioning of the "windows of analysis" for the forward and sideward light scatter and fluorescence (FL) 1 (i.e., fluorescein isothiocyanate [FITC]) and 2 (i.e., phycoerythrin [PE]) parameters. Reference standards and PBMC, double-stained with FITC- and PE-conjugated monoclonal antibodies covering a wide range of FL intensities and coexpression patterns, were sent out to 25 laboratories in Workshop 1 and to 35 laboratories in Workshop 2 with the following requests: a) to set up instruments according to local and standard protocols, b) to acquire list mode data on the PBMC with both instrument settings, and c) to analyze both datasets according to local protocols. Standard analysis of the list mode data acquired with uniform instrument settings was performed centrally using so-called "latent class model" software (Van Putten et al., Cytometry 14:86-96, 1993). This software provides an automated, "no-gating" analytical method of lymphocyte immunophenotypes and employs fixed FL marker settings as defined prior to each analytical run. In Workshop 1, these markers were set in identical histogram channels for all instruments based on results obtained with a reference instrument. Standard analysis of list mode data acquired after uniform instrument set-up led only to a 13% reduction of interlaboratory variability of results as compared to data analysis using local protocols. The standard protocol for instrument set-up led to uniform positioning of relatively strong FL signals but variable positioning of unstained cells on the FL histogram scales. Hence, standard FL marker settings were inappropriate for some instruments. Therefore, instrument responses to FITC and PE signals in Workshop 2 were calibrated using microbeads labeled with FITC or PE in a range of predefined FL intensities expressed in MESF units (molecules of equivalent soluble fluorochrome). That approach allowed the positioning of the FL markers for the standard analysis on the basis of identical FL1 and FL2 intensities, expressed in MESF units, for all instruments. Standard analysis of list mode data acquired after uniform instrument set-up and calibrated FL marker settings led to a 43% reduction of interlaboratory variability as compared to data analysis to local protocols. We conclude that standard list mode data analysis using fixed FL marker settings reduces the interlaboratory variability of flow cytometric results on prestained PBMC, provided that the instruments have been set up in a uniform way and that FL markers have been standardized on the basis of calibration of each instrument's response to the corresponding FL signals.

Antigens, CD↗
PubMed1990

National standard setting for quality of care in general practice: attitudes of general practitioners and response to a set of standards.

The Nederlands Huisartsen Genootschap (NHG), the college of general practitioners in the Netherlands, has begun a national programme of standard setting for the quality of care in general practice. When the standards have been drawn up and assessed they are disseminated via the journal Huisarts en Wetenschap. In a survey, carried out among a randomized sample of 10% of all general practitioners, attitudes towards national standard setting in general and to the first set of standards (diabetes care) were studied. The response was 70% (453 doctors). A majority of the respondents said they were well informed about the national standard setting initiatives instigated by the NHG (71%) and about the content of the first standards (77%). The general practitioners had a positive attitude towards the setting of national standards for quality of care, and this was particularly true for doctors who were members of the NHG. Although a large majority of doctors said they agreed with most of the guidelines in the diabetes standards fewer respondents were actually working to the guidelines and some of the standards are certain to meet with a lot of resistance. A better knowledge of the standards and a more positive attitude to the process of national standard setting correlated with a more positive attitude to the guidelines formulated in the diabetes standards. The results could serve as a starting point for an exchange of views about standard setting in general practice in other countries.

Attitude of Health Personnel↗
PubMed2002

Establishment of a standard assay method for human thrombomodulin and determination of the activity of the Japanese reference standard.

This study was undertaken to establish a standard method for determination of the activity of human (h) thrombomodulin (TM). The reactions mainly consisted of formation of a h-TM and h-thrombin complex, activation of h-protein C by the complex and digestion of substrate by activated h-protein C. Linear time-dependent formation of p -nitroaniline from the substrate, S-2366, was observed up to 12 min during measurement of the activity of urinary h-TM (uh-TM) reference material by the standard method. Therefore, 10 minutes was established as the reaction time in the standard method. In the standard method, we defined the activity of h-TM forming 0.1 micromol of p -nitroaniline per min in the reaction as 1 JRS Unit. Recombinant h-TM (rh-TM) and uh-TM reference material gave rectilinear dose-response curves within a certain range of specific activities by their original methods in the standard method. The validity of the standard method was assessed based on the coefficients of variation (CV) obtained in the various measurements of h-TM. Intra-batch precision (CV) of h-thrombin and h-protein C was 2.90% and 6.57%, respectively, in the measurement of uh-TM activity. The intra-sample, inter-day, and inter-laboratory precision (CV) was 1.30%, 1.63% and 5.02%, respectively, in the measurement of the first Japanese reference standard for h-TM coded TJRS1. In these assays, the activity of the first Japanese standard was also determined and found to be 205 JRS units per ampoule. When the stability of the Japanese reference standard was assessed by measuring of the standard stored under various thermal conditions, the predicted loss of activity assuming monomolecular degradation according to the Arrhenius equation was less than 3.0% during 103 years at -20 degrees C. These results indicate that the standard method is appropriate for determination of the activity of h-TM and that the Japanese reference standard for h-TM, whose activity was determined here, can be stored at -20 degrees C for long periods without loss of activity.

Analysis of Variance↗
PubMed2003

A model for setting performance standards for standardized patient examinations.

Setting standards for complex performance assessments is difficult. This report describes and evaluates a model for setting performance standards for standardized patient examinations. A variation of a modified Angoff standard-setting procedure was used to set cutoffs for a standardized patient exercise. Analysis of the procedure was based on evaluation of the impact of the iterative process, the ability of the final standards to accurately classify trainees and the judges' confidence in the procedure and final standards. The practicality of the process also was assessed. The iterative steps in this procedure led to a reduction in the variance between the judges' ratings. All seven judges reported confidence in the final standards. The mean time commitment for each judge was 4.7 work hours. This model for setting performance standards successfully set useful standards for this exam, was practical, and can be utilized to set performance standards for other standardized patient examinations.

Clinical Competence↗
PubMed2004

Linking rights and standards: the process of developing "rights-based" minimum standards on food security, nutrition and food aid.

This article examines the recent revision of the Sphere Minimum Standards in disaster response relating to food security, nutrition and food aid. It describes how the revision attempted to incorporate the principles of the Humanitarian Charter, as well as relevant human rights principles and values into the Sphere Minimum Standards. The initial aim of the revision was to ensure that the Sphere Minimum Standards better reflected the principles embodied in the Humanitarian Charter. This was later broadened to ensure that key legal standards and principles from human rights and humanitarian law were considered and also incorporated, in part to fill the "protection gap" within the existing standards. In relation to the food security, nutrition and food aid standards, it was agreed by participants in the process that the human right to adequate food and freedom from hunger should be incorporated. In relation to more general principles underlying the Humanitarian Charter, itself drawn largely from human rights and humanitarian law, it was agreed that there was a need to strengthen "protection" elements within the standards and a need to incorporate the basic principles of the right to life with dignity, non-discrimination, impartiality and participation, as well as to explore the relevance of the concept of the progressive realisation of the right to food. The questions raised in linking rights to operational standards required thought, on the one hand, about whether the technical standards reflected a deep understanding of the values expressed within the legal instruments, and whether the existing standards were adequate in relation to those legal rights. On the other hand, it also required reflection on how operational standards like Sphere could give concrete content to human rights, such as the right to food and the right to be free from hunger. However, there remain challenges in examining what a rights-based approach will mean in terms of the role of humanitarian agencies as duty-bearers of rights, given that the primary responsibility rests with state governments. It will also require reflection on the modes and mechanisms of accountability that are brought to bear in ensuring the implementation of the Minimum Standards.

Altruism↗
PubMed1996

Standards for polysomnography in Canada. The Standards Committees of the Canadian Sleep Society and the Canadian Thoracic Society.

OBJECTIVE: To develop standards for polysomnography in Canada in order to assist in the uniform provision of diagnostic and therapeutic services related to sleep disorders. OPTIONS: Uniform testing versus no current Canadian standards. OUTCOMES: Uniform delivery of health care; reduction in number of repeat studies and their attendant costs. EVIDENCE: Availability of diagnostic laboratories and services, and survey responses (written and oral) from directors of sleep laboratories; the American Thoracic Society statement on indications and standards for cardiopulmonary sleep studies was used as a template. VALUES: Acceptable standards of practice were based on consensus opinion of the standards committees of the Canadian Sleep Society and the Canadian Thoracic Society. The committees comprised specialists in neurology, psychiatry, psychology, respirology and polysomnographic technology; family practitioners and otolaryngologists were also consulted. BENEFITS, HARMS, COSTS: Improved level of care and reduction in duplicate or unnecessary testing; establishment, with available resources, of diagnostic sleep laboratories by appropriately qualified physicians in areas where polysomnography is unavailable. RECOMMENDATIONS: Health care practitioners involved in the diagnosis and treatment of sleep disorders should possess a minimum amount of training (both clinical and research) in sleep disorders medicine. The variables recorded and findings entered in a patient's report must be relevant to the sleep disorder under investigation. The recording equipment must provide reliable, accurate and reproducible data and lend itself to appropriate calibration and quality-control procedures. Facilities for sleep studies must meet patient care safety standards, with provisions for emergency or resuscitative measures when necessary; all personnel must be trained in basic cardiopulmonary resuscitation. VALIDATION: No previous standards concerning polysomnography in Canada exist. The recommended standards were reviewed by all members of the Canadian Sleep Society and a revised document was approved by the Standards Committee of the Canadian Sleep Society and by the Standards and Executive committees of the Canadian Thoracic Society. SPONSORS: These standards are endorsed by the Canadian Sleep Society and the Canadian Thoracic Society. The cost of preparing this statement was borne by the individual members of the standards committees; no external funding was provided.

Calibration↗
PubMed1990

Standardization and harmonization of the blood count: the role of International Committee for Standardization in Haematology (ICSH).

Scientific principles of standardization were first applied in haematology in 1963 when the International Committee for Standardization in Haematology was established with a primary objective to improve the measurement of haemoglobin. Subsequently, ICSH has established Expert Panels on a wide range of haematological topics, including especially a Panel on Cytometry. The purpose of haematological standardization is to obtain precision, accuracy, specificity and harmonization of results between different laboratories in all countries and also between different instruments or methods in the same laboratory. To achieve these objectives ICSH sponsors collaborative studies by scientists from academic centres and from industry and uses a consensus procedure for establishing standards on the basis of the scientific data, followed by an educational programme to ensure that the standards are adopted worldwide. ICSH defines material standards and standardized methods. Material standards are classified as primary international standards, certified reference materials, secondary standards and calibrators. These must be distinguished from control preparations which are intended exclusively for quality control. Standardization of methods must also be considered at four levels: definitive, reference, selected and routine. Each has a place in practice but their roles must be clearly defined. ICSH has an established protocol for evaluation of automated blood cell counters. This defines the levels of precision and accuracy of instrument performance. It is also necessary to assess "clinical utility". The main requirement of the practising haematologist is clinical reliability and harmonization of results for comparability. One of the major functions of ICSH is to provide an interface for collaboration between the manufacturers who develop the instruments and the users in order to achieve this goal.

Anticoagulants↗
PubMed1998

Age standardization of death rates: implementation of the year 2000 standard.

This report discusses the rationale for and implications of the implementation of a new population standard for the age standardization (age adjustment) of death rates. The new standard is based on the year 2000 population and beginning with data year 1999, will replace the existing standard based on the 1940 population. This report also includes a technical discussion of direct and indirect standardization and statistical variability in age-adjusted death rates. Currently, at least three different standards are used among Department of Health and Human Services agencies. Implementation of the year 2000 standard will reduce confusion among data users and the burden on State and local agencies. Use of the year 2000 standard will also result in age-adjusted death rates that are substantially larger than those based on the 1940 standard. Further, the new standard will affect trends in age-adjusted death rates for certain causes of death and will narrow race differentials in age-adjusted death rates. Although age standardization is an important and useful tool, it has some limitations. As a result the examination of age-adjusted death rates should be the beginning of an analysis strategy.

Adolescent↗
PubMed2004

[The influence of medical standards, medical guidelines and economic restrictions on the standard of legal liability].

First we will have to identify the components determining the standard for medical liability in civil law cases. The civil courts have so far uniformly regarded the medical standard defined by physicians themselves as the standard of legal liability. Medical standards are based on scientific knowledge, practical experience and professional acceptance. Clinical guidelines can but need not necessarily reflect medical standards. Moreover, they cannot establish a standard. Second, on this basis the question will be whether economic restrictions should be allowed to alter the standard of legal liability. The answer depends, namely on what is meant by economic restrictions--rationalising or rationing? Rationalising need not be inconsistent with the standard. There are contradicting opinions in the legal literature about whether rationing is considered permissible. With regard to our social insurance system some authors point out that the highest possible standard is established by the statutory health insurance. With reference to the civil law, though, others demand that the medical standard must be given top priority. In accordance with the latter opinion rationing is only permitted in cases of a natural shortage of resources. Shortage of economic resources must not influence the standard of legal liability.

Costs and Cost Analysis↗
PubMed1996

Setting standards of prescribing performance in primary care: use of a consensus group of general practitioners and application of standards to practices in the north of England.

BACKGROUND: There is considerable variation in prescribing, and existing standards against which primary care prescribing is routinely judged consist largely of local or national averages. There is thus a need for more sophisticated standards, which must be widely applicable and have credibility among the general practice profession. AIM: A study aimed to develop a range of criteria of prescribing quality, to set standards of performance for these criteria, and apply these standards to practices. METHOD: A consensus group consisting of eight general practitioners and a resource team was convened to develop and define criteria and set standards of prescribing performance using prescribing analyses and cost (PACT) data. The standards were applied to 1992-93 prescribing data from all 518 practices in the former Northern Regional Health Authority. RESULTS: The group developed criteria and set numeric standards for 13 aspects of prescribing performance in four areas: generic prescribing, prescribing within specific therapeutic groups, drugs of limited clinical value and standards based on prescribing volume. Except for generic prescribing, standards for individual criteria were achieved by between 9% and 34% of practices. For each criterion, a score was allocated based on whether the standard was achieved or not. Total scores showed considerable variation between practices. The distribution of scores was similar between fundholding and non-fundholding practices, and also between dispensing and non-dispensing practices. CONCLUSION: Using a consensus group of general practitioners it is possible to agree criteria and standards of prescribing performance. This novel approach offers a professionally driven method for assessing the quality of prescribing in primary care.

Drug Prescriptions↗
PubMed2002

ASHRAE Standard 62: tobacco industry's influence over national ventilation standards.

OBJECTIVE: To describe the role of the tobacco industry in the development of ventilation standards for indoor air quality by influencing the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE). METHODS: Review of tobacco industry documents available on the internet between January 2001 and March 2002. Search terms included "ASHRAE", "ventilation", "minutes", "memo", and the names of key players and organisations as identified in the initial searches. Analysis of ASHRAE and other relevant documents publicly available and the personal files of a Standard 62 committee member; interviews of a selected number of ASHRAE players; observation of an ASHRAE meeting. RESULTS: The tobacco industry has been involved in the development of ventilation standards for over 20 years. It has successfully influenced the standard and continues to attempt to change the standard from a smoke-free framework into an "accommodation" framework. The industry acts directly and through consultants and allies. The major health groups have been largely absent and the health interests have been poorly represented in standard development. While concentrated in the USA, ASHRAE standards are adopted worldwide. CONCLUSION: The tobacco industry determined that allowing smoking in ventilation standards for indoor air quality was a high priority and dedicated significant human and financial resources to ensure that its interests were represented. The health groups, until recently, have largely ignored the policy implications for tobacco control of standard development. This situation is changing, but unless health groups maintain high visibility within ASHRAE, the tobacco industry may succeed in creating a standard that ignores the dangers of secondhand smoke.

Air Conditioning↗
PubMed1998

Calculation of standard transformed formation properties of biochemical reactants and standard apparent reduction potentials of half reactions.

The standard Gibbs energies of formation and standard enthalpies of formation of species involved in biochemical reactions are used to calculate standard transformed Gibbs energies of formation and standard transformed enthalpies of formation of 62 biochemical reactants (sums of species) at 298.15 K, pH 7, and ionic strengths of 0, 0.10, and 0.25 M. It has been possible to put the oxidized and reduced forms of some reactants in this table because their standard apparent reduction potentials are known at pH 7. This paper emphasizes redox reactions. Two applications have been made of these 62 new values of standard transformed Gibbs energies of formation at pH 7: (1) They have been used to calculate standard transformed Gibbs energies of formation of 16 more biochemical reactants from measurements of apparent equilibrium constants of redox reactions. (2) They have been used to calculate standard apparent reduction potentials at pH 7 for half reactions involving reactants discussed in this article and the previous one. This table of standard apparent reduction potentials can be extended considerably from known apparent equilibrium constants for enzyme-catalyzed redox reactions. This brings the total number of reactants for which the standard transformed Gibbs energy of formation at 298K, pH 7, and ionic strengths of 0, 0.10, and 0.25 M have been calculated to 142.

Energy Transfer↗
PubMed1993

An imaging standard for dentistry. Extension of the radiology DICOM standard.

No standard exists for electronic communication of dental images. However, maxillofacial radiology, being part of general radiology, does have the advantage of having an applicable standard: The American College of Radiology-National Electrical Manufacturers Association Standard for Digital Imaging and Communications in Medicine (Version 3.0). This standard encourages open systems interconnection of imaging equipment over standard networks while maintaining compatibility with earlier point-to-point connection standards. This standard, to be voted on in 1993, moves the American College of Radiology-National Electrical Manufacturers Association into full conformance with the International Standards Organization reference model for network communications. An object-oriented information model lays the groundwork for harmonization with other medical communications standards. This article outlines the American College of Radiology-National Electrical Manufacturers Association components and discusses the rationale of object-oriented design. The relevance of the standard to dentistry is discussed.

Computer Communication Networks↗