SEARCH · PubMed Health

Results for “data quality”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68Linked to original sources

PubMedDate not supplied

Determination of niacin in infant formula by solid-phase extraction/liquid chromatography: peer-verified method performance-interlaboratory validation.

This paper reports the results of the interlaboratory peer validation study of AOAC Peer-Verified Method (PVM) 1:2,000 for the determination of niacin in infant formula by solid-phase extraction/liquid chromatography. We have used a Data Quality Objectives (DQO) approach to address not only method variability and robustness but also accuracy of data through the use of an appropriate reference material in conjunction with the interlaboratory validation study. Our DQO included the following: (1) statistical agreement of analytical results and quantitative recovery between 2 collaborating laboratories; (2) the repeatability relative standard deviation (RSDr) values and the HORRAT (Horwitz ratio) obtained (1.07), which satisfied the criteria of the Horwitz "limits of acceptability" at the analyte level present; (3) validation of lack of interference; and (4) accuracy agreement within assigned values for a certified reference material. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1846 Infant Formula, with a certified value of 63.3 +/- 7.6 microg/g for niacin content, was used as a test material for collaborative study and accuracy assessment. Niacin values obtained by the originating laboratory were 59.7 +/- 4.0 microg/g (95% confidence interval [CI] = 1.4 microg/g with a relative standard deviation [RSD] of 6.7%) and by the peer laboratory were 56.6 +/- 6.6 microg/g (95% CI = 4.1 microg/g, with an RSD of 11.7%). Statistical evaluation using the means equivalence test showed that nicotinic acid values obtained by the peer laboratory were equivalent to those values obtained by the originating laboratory. Linear calibration curves and quantitative recovery were obtained. Integration of the PVM process with a readily available certified reference material gives the user confidence in the accuracy of the data generated by the method through traceability to the reference material used.

Chromatography, Liquid↗

PubMed1992

Mechanical force, manually assisted short lever chiropractic adjustment.

OBJECTIVES: Chiropractic mechanical force, manually assisted short lever adjusting is a spinoff of the specific toggle recoil adjusting techniques, which were based on the original chiropractic subluxation theory propounded by Daniel David Palmer in 1895. This article reviews: a) the principles of the chiropractic subluxation complex from the standpoint of its historical origin and present-day scientific status; b) the purpose and objectives of specific spinal manipulative techniques; c) the use of mechanical adjusting instruments to effect a velocity/direction controlled adjustive thrust; and d) an assessment of scientific and clinical data relating to the biomechanical and neurological aspects of mechanical force, manually assisted short lever adjusting. DATA SOURCES: Prime sources were from the National Library of Medicine's on-line Index Medicus database, the Chirolars Research Resource Retrieval database, the Chiropractic Research Abstract Collection and the Chiropractic Library Consortium's reference works. Direct search of other nonindexed chiropractic sources was limited to those available in the collection of the National Institute of Chiropractic Research. Early information never documented by publication was obtained by written personal communication. STUDY SELECTION: The principal author selected articles reporting data (as opposed to anecdotal reports) from conference proceedings and peer-reviewed journals. DATA EXTRACTION: Data quality was assessed based on experimental conditions such as sample size, study design and statistical analysis. DATA SYNTHESIS: While mechanical force, manually assisted short lever adjusting seemingly is capable of beneficially altering the cause/effect relationship of spinal subluxations, more research in the nature of controlled clinical trials is needed to ascertain its benefits in the chiropractic treatment of specific conditions. CONCLUSIONS: Basic research is needed in order to establish the scientific basis for the chiropractic subluxation syndrome regardless of the technique employed.

Biomechanical Phenomena↗

PubMed2004

Anticoagulation therapy for venous thromboembolism.

CONTEXT: On the basis of theoretical rationale, heparoids and vitamin K antagonists are prescribed to prevent complications of venous thromboembolism (VTE, including pulmonary emboli [PE] and deep vein thrombosis [DVT]). They have been employed as the standard of care for treatment of VTE for over 40 years. OBJECTIVE: Critique the evidence supporting the efficacy of anticoagulants for the treatment of VTE in reducing morbidity and/or mortality. DATA SOURCES: This includes a search of reference lists and Medline. STUDY SELECTION: This includes studies concerning the diagnosis and incidence of PE and DVT, efficacy of anticoagulants in preventing complications, risks of anticoagulant therapy, and the costs of diagnosis and the treatment of VTE. DATA EXTRACTION: I analyzed references cited in reviews and meta-analyses of VTE, and from Medline searches concerning diagnosis and treatment. The data quality and validity of studies depended on the consistency of findings and statistical significance of the data. DATA SYNTHESIS: No placebo-controlled trials of anticoagulants as treatment of PE with objective criteria for diagnosis have been published. Three randomized trials of anticoagulants vs no anticoagulants in DVT showed no benefit with heparin and vitamin K antagonists (combined all-cause mortality: anticoagulants = 6/66, un-anticoagulated controls = 1/60, P = .07). No placebo-controlled trials of low-molecular-weight heparins or thrombolytic drugs have been done; therefore, their efficacy in VTE depends entirely on randomized comparisons with unfractionated heparin. They have not been proven safer or more efficacious than unfractionated heparin. Thrombolysis causes more major and fatal bleeds than heparin and is no more effective in preventing PE. Diagnosing and treating VTE patients in the United States with anticoagulants costs 3.2 dollars to 15.5 billion dollars per year (1992 dollars). Bleeding and complications of angiography cause 1017-3525 deaths annually. CONCLUSION: Anticoagulants have not been proven efficacious or safe in VTE. The bleeding risks and other complications of anticoagulation are unacceptably high. The use of anticoagulants for patients with VTE should be reconsidered.

Anticoagulants↗

PubMed2005

Measuring college sailing teams ability: an application of the many-facet Rasch model to ordinal data.

For those who look at typical approaches to sports ranking, sailing seems an almost impossible challenge, thereby making the evidence supporting Rasch measurement in this study even more intriguing. This article describes our application of MFRM and the results from our analysis of one year's data from the North American college sailing competitions. We discuss the following issues for inclusion in the development of a Rasch model useful to college sailing team ability: 1. The level of data quality (as described by Stevens, 1946) 2. The connectedness of the contests 3. Empty cells (missing data) 4. Interpreting outliers, trends, or unusual results 5. Judges' or polls' bias Our results indicate the utility and precision of MFRM as a tool generally appropriate for ordinal ranking applications and sailing ability specifically.

Adult↗

PubMed1995

Computer-based information collection and feedback for Norwegian municipal health and social services.

Norway is governed by a three-tier parliamentary system where each tier is governed by a popularly selected body: the national parliament, the county councils, and the municipality councils. This three-tier system is in many ways also reflected in the organization, management, and financing of health and social services. A large amount of information (e.g.,statistics and annual reports) flows between the three levels of management. In order to have a proper and efficient information flow, The Norwegian Ministry of Health and Social Affairs has, since 1992, been conducting a nation-wide project for information collection from and feedback to municipal health and social services (see Figure 1). In this presentation, we will present the basic idea behind The Wheel. We will also discuss some of the major activities in and experiences from the project of using Information Technology to implement an electronic Wheel. The following are basic issues to consider in implementing such a system, related to the following basic issues in implementing such a system [1]: Obtaining a unified information basis to: increase the data quality, and compile "definition catalogs" that contain commonly agreed-upon definitions of central concepts and data sets that are used in the municipal health and social services [2]. Achieving electronic data collection, both in terms of the automatic selection and aggregation of relevant data from operational systems in the municipalities and in terms of using Electronic Forms. Experiments with various ways of electronically feeding back the statistics and other comparative data to the municipalities. Providing the municipal users with appropriate tools for using the statistics that are fed back.

Data Collection↗

PubMed2000

Exploring the IBIS data library contents: tools for data visualisation, (pre-) processing and screening. Improved Monitoring for Brain Dysfunction in Intensive Care and Surgery.

During the IBIS project a high-quality data library of continuous and intermittent physiological signals and variables from patients during intensive care and surgery has been collected. To facilitate exploration of the full content of this data library a data browser was developed, which offers a flexible graphical display of the collection of multivariate data. To supplement the functionality of the display of the 'raw' data, a set of screening and pre-processing tools has been developed. A separate trend analysis tool offers a convenient overview of an entire recording focusing on the slow changes in the general state of the patient and the interaction between different physiological subsystems seen from a long-term perspective. A frequency analysis tool for processing the electroencephalography (EEG) signals has been integrated in the data browser to facilitate a quick screening of the cerebral function. The data library is the foundation of the development and validation of biosignal interpretation methods. This process can potentially be more productive using the described tool for algorithm prototyping based on a graphical network specifying the interaction between data processing primitives.

Aged↗

PubMed2001

Optimisation of the discrete conductivity and dissolved oxygen monitoring using continuous data series obtained with automated measurement stations.

During the last five years, research on the relation between pollution loads and ecological river water quality has been done on the Dender river. In addition to biological sampling of macroinvertebrates and fish, automated measurement stations were used too to investigate the spatio-temporal variability of physical-chemical water pollution. This study on on-line water quality data collection is based on a measurement campaign during March-April 2000 with two automated measurement stations at two different sites: the flow control weirs at Geraardsbergen and Denderleeuw. These measurement stations contain sensors for temperature, turbidity, conductivity, pH, redoxpotential and dissolved oxygen. Short wave radiation as well as rainfall were monitored by means of pyranometers and rain gauges. A refrigerated sampler with 24 bottles allowed to take samples for additional laboratory analyses. In this study, continuous measurements of two physical-chemical parameters, conductivity and dissolved oxygen, were analysed to evaluate the adequacy of the current monitoring frequency in Flanders. Analysis showed that discrete conductivity measurements can be sufficient for trend detection, but the measuring frequency must be highly increased from one measurement per month to at least 8 measurements. Continuous measurements for conductivity are preferred because extreme values are obtained as well. For dissolved oxygen, a single measurement per month in not enough. The percentage of dissolved oxygen showed a strong diurnal variation with maxima in the late afternoon (photosynthesis) and minima at night (respiration). This parameter also differed significantly from day to day. Continuous measurements are therefore necessary for a reliable assessment of the dissolved oxygen budget of surface waters. When using discrete measurements for dissolved oxygen, a set time should be introduced to eliminate diurnal variation.

Automation↗

PubMed2004

Immobilized probe and glass surface chemistry as variables in microarray fabrication.

BACKGROUND: Global gene expression studies with microarrays can offer biological insights never before possible. However, the technology possesses many sources of technical variability that are an obstacle to obtaining high quality data sets. Since spotted microarrays offer design/content flexibility and potential cost savings over commercial systems, we have developed prehybridization quality control strategies for spotted cDNA and oligonucleotide arrays. These approaches utilize a third fluorescent dye (fluorescein) to monitor key fabrication variables, such as print/spot morphology, DNA retention, and background arising from probe redistributed during blocking. Here, our labeled cDNA array platform is used to study, 1) compression of array data using known input ratios of Arabidopsis in vitro transcripts and arrayed serial dilutions of homologous probes; 2) how curing time of in-house poly-L-lysine coated slides impacts probe retention capacity; and 3) the retention characteristics of 13 commercially available surfaces. RESULTS: When array element fluorescein intensity drops below 5,000 RFU/pixel, gene expression measurements become increasingly compressed, thereby validating this value as a prehybridization quality control threshold. We observe that the DNA retention capacity of in-house poly-L-lysine slides decreases rapidly over time (~50% reduction between 3 and 12 weeks post-coating; p < 0.0002) and that there are considerable differences in retention characteristics among commercially available poly-L-lysine and amino silane-coated slides. CONCLUSIONS: High DNA retention rates are necessary for accurate gene expression measurements. Therefore, an understanding of the characteristics and optimization of protocols to an array surface are prerequisites to fabrication of high quality arrays.

Animals↗

PubMed2001

How to calculate lead concentration and concentration uncertainty in XRF in vivo bone lead analysis.

The authors provide a substantial correction for calculating estimates of lead concentration and uncertainty for in vivo X-ray fluorescent bone analysis with Cd-109 source. Based on general principles, they provide mathematical techniques for propagation of uncertainties in XRF analysis. They give additional considerations for lowering the detection limit and improving spectral data quality.

Biometry↗

PubMedDate not supplied

The effects of ts-11 strain Mycoplasma gallisepticum vaccination in commercial layers on egg production and selected egg quality parameters.

Live Mycoplasma gallisepticum (MG) vaccines have been USDA approved and licensed for use in commercial layer chickens since 1988; however, egg production and egg quality data exist only for the F strain of MG. Information pertinent to the effects of ts-11 MG on egg and eggshell quality parameters, as well as egg size distribution, is lacking. In this study, pullets were inoculated at 10 wk of age with ts-11 strain MG and placed in biological isolation units at 10 birds/unit. Hen-day egg production, eggshell strength, Haugh unit score, pimpling incidence, and blood/meat spot incidence were monitored and recorded in each trial through a 45-wk production cycle. Further, eggs from all treatments were collected daily, Monday-Thursday, and individually weighed. Results of this study indicate that no significant difference was observed between the treatments for the parameters measured or for egg size distribution. Therefore, these data should lessen producers' concerns pertaining to the impact of ts-11 strain MG on egg production, egg and eggshell quality parameters, and egg size distribution.

Animals↗

PubMedDate not supplied

Collecting quality of life data in EORTC clinical trials--what happens in practice?

Problems with poor compliance when collecting quality of life data (QoL) in randomised clinical trials have prompted investigators to suggest measures to improve data collection. This study sought to look at the practical problems encountered by data managers and nurses in the cross-cultural setting of EORTC trials. A literature search was followed by a poster workshop session at a meeting of the EORTC study Group on Data Management and finally a postal questionnaire. The key problems identified centred around the lack of interest from some clinicians, lack of resources, inadequate protocols and a desire for training in the rationale for collecting QoL data to aid discussions with patients. Despite these problems many data managers and nurses found it rewarding to be on the 'frontline'. Since this study, the EORTC Data Center and in particular the Quality of Life Study Group and the Quality of Life Unit have implemented a number of measures to improve compliance. These include written guidelines for EORTC trials and a training course planned for Autumn 1999.

Data Collection↗

PubMedDate not supplied

Compliance in quality of life data: a Norwegian experience.

Compliance is of extreme importance in assessing quality of life since lost data never can be retrieved. In order to assess this issue in various studies, a cross-sectional study in cured cancer patients, three prospective trials and a normative study were explored. In the cross-sectional study 82 per cent of the patients completed the questionnaires after one reminder. More females than males answered the questionnaires. The compliance rate varied from 99 per cent to 62 per cent in the prospective studies depending upon time after inclusion. It seems that compliance decreases during follow up, primarily because of disease progression. In one of the prospective studies low compliance rate (approximately 30 per cent) was found in the questionnaire assessing religious issues. In the normative study 68 per cent of the population completed the questionnaire. No gender differences were found, but younger males and elderly women were poor compliers. In conclusion, our data support that most patients complete quality of life questionnaires. It seems that patients with inferior education, reduced physical function and with progressive/terminal disease are low compliers. Introduction of the first quality of life questionnaires to the patients is of great importance. Detailed information about the study should be given and the importance of completing the questionnaires should be underlined.

Adult↗

PubMed2001

Dissociating sensory and cognitive contributions to visual persistence I. Photoreceptor response duration as a function of flash intensity, adaptation state, and candidate code.

Numerous careful behavioral studies of visual persistence have reported a variety of apparently contradictory effects. Variation of flash intensity has particularly been found to have both direct and inverse effects on subjective duration. This conflict has been addressed by theories which contain both sensory and cognitive components. Depending on the weight given to these components, one obtains theories which emphasize intensity dependence or task dependence. Few comparably detailed physiological studies of persistence exist. To clarify the issues raised by these theories, we examined the responses evoked in the model photoreceptor of the Limulus lateral eye. To explore the role of sensory variables, we manipulated adaptation state and flash intensity. To explore cognitive variables, the durations of the photoreceptor potentials (RPs) evoked in this model system were assessed by a mutually complementary and complete set of candidate sensory codes. Accordingly, sharp microelectrodes were used to record RPs intracellularly from single photoreceptor cells in response to 40-ms flashes whose intensity was varied over at least 3.6 log units. Two light adaptation states were used which differed in sensitivity by 3.5 log units. This model system made it possible to employ stringent objective assessments of data quality which ensured that only cells which had remained stable for several hours contributed to the present data. A variety of code-dependent trends were found: direct, inverse, invariant, and U-shaped trends related flash intensity to RP duration, while adaptation state interacted with some of these trends. Only some of the expectations which had generated this research were qualitatively corroborated and numerous quantitative discrepancies were found between data and theory. While caution is necessary when generalizing from neural responses to perception, these data indicate that two major gaps now exist in this field. First, both task and stimulus variables need to be exhaustively explored in more complete behavioral experiments. The present data make it more likely that sensory models and cognitive models simply address different aspects of the same phenomenon. Second, similarly detailed questions need to be posed to more central neural loci, particularly to those in the various visual cortices.

Adaptation, Ocular↗

PubMed2004

Can hospital discharge diagnoses be used for surveillance of surgical-site infections?

The aim of this study was to assess the data quality of postoperative infections in a hospital discharge registry in the Emilia-Romagna region of Italy. Data from a prospective regional study of postoperative infections in 6158 patients from 31 of the 36 public hospitals of the region were compared with data from the regional hospital discharge registry, using different classes of ICD-9-CM codes. The sensitivity of the hospital discharge database for postoperative surgical infections was 10% when ICD-9-CM codes directly indicative of postoperative infectious complications were used. When non-specific codes of postoperative complications, not necessarily of infectious origin, were added, the sensitivity reached 21%. At present, the hospital discharge registry is not suited for surveillance of hospital-acquired infection.

Databases as Topic↗

PubMed1998

Validation of computerized Swedish dog and cat insurance data against veterinary practice records.

Large computerized medical databases offer great potential for epidemiological research. However, data-quality issues must be addressed. This study evaluated the agreement between veterinary practice records and computerized insurance data in a large Swedish claims database. For the year 1995, the company insured over 320,000 dogs and cats. A total of 470 hard-copy records were sampled from claims for health care (n = 236) and life insurance (n = 234). Computerized insurance data for these claims were accessed and records from the attending veterinary practices were collected. For health and life claims, respectively, 79.2 and 72.8% of practice records were retrieved. Variables compared between the computer and practice records were breed, sex, date of birth and diagnosis for the claim. The degree of agreement was categorized as agreement, minor disagreement, major disagreement or data missing. Multivariable logistic regression was used to examine factors associated with errors. The observed agreement for breed and sex was excellent. There was 28.9 and 33.8% minor disagreement for the date of birth for health and life claims, respectively. This was mainly because, prior to 1993, the date of birth was coded as the first of January when more complete information was unavailable. Major disagreement (different year of birth) was low for both health and life claims. For health and life claims, the observed agreement for diagnosis was 84.0 and 84.9%, minor disagreement was 6.4 and 4.3%, and major disagreement 5.9 and 9.4%, respectively. Although there was no difference based on size of the veterinary clinic involved, there was a tendency for better agreement between the practice record and the computerized insurance data for claims from clinics with computerized practice records (n = 40) than for clinics with manual practice records (n = 286). Rates of discrepancy were affected by the clerk who processed the claims. Records processed by two of the 21 clerks had significantly more disagreements. Given the nature of the data, it was only possible to calculate a measure of observed agreement. In general, the agreement between data in the insurance-company database and from the practice records was excellent for demographic data such as breed and sex and fair for diagnostic information and date of birth. In general, the data are adequate to support ongoing research with due considerations of certain limitations.

Animals↗

PubMedDate not supplied

Pyriform head: a frequent but little-studied morphological abnormality of sperm.

This study was conducted to investigate the frequency of sperm with a pyriform head in semen samples, to determine the percentage of the occurrence of this abnormal sperm form, and to assess its possible correlation with other semen parameters. The study was designed as a retrospective data analysis in the setting of an andrology laboratory at a tertiary-care academic hospital. Semen quality data were analyzed from 114 subfertile men and 60 fertile men. The Student's t test, the Mann-Whitney nonparametric test, and the Pearson correlation coefficient were used for statistical analysis. Sperm with a pyriform head were present in the semen samples of 98% of the subfertile men and 100% of the fertile men; the percentage of this abnormal sperm form was 22 +/- 14.9% in subfertile and 13% +/- 7.8 in fertile men (p <.001); 16% of the subfertile men presented a higher percentage of these abnormal sperm than the normal upper limit. In some subfertile men with a high percentage of sperm with a pyriform head, their subfertility could be attributed to the cause that produces this morphological abnormality. Moreover, morphological abnormalities in the neck and the tail, as also a cytoplasmic droplet, are significantly more frequent in sperm with a pyriform head than in sperm with a normal head.

Adult↗

PubMed2002

Pediatric functional magnetic resonance imaging: progress and challenges.

Functional magnetic resonance imaging (fMRI) in the pediatric population promises to provide novel insights into the nature of both normal and abnormal functional brain development as well as changes in brain function due to various interventions. Although acquisition of fMRI data from children is associated with a number of methodological challenges, primarily compliance and head motion, good quality data can be obtained. For example, conditioning and personal interactions can improve compliance, and motion reduction techniques can successfully reduce artifacts due to head motion. Analysis of pediatric fMRI data also involves challenges regarding spatial normalization and characterization of the hemodynamic response across development. Substantial progress has been made in understanding cognitive function and developmental disorders in children, but attention to the methodological issues raised in this review and continued investigations in this area are expected to result in further progress.

Brain↗

PubMed2026

The SARS-CoV-2 Integrated Genomic Epidemiology Database (IGED): Linking viral genomes with patient-level metadata to advance statewide genomic surveillance in California.

In July 2021, the California Code of Regulations Title 17 required all laboratories performing SARS‑CoV‑2 whole genome sequencing (WGS) to report their sequencing results to the California Department of Public Health (CDPH). These viral genomic data and patient metadata were compiled into the Integrated Genomic Epidemiology Database (IGED). Linking anonymized viral sequences with patient‑level information enabled monitoring of infectiousness, pathogenicity, transmission dynamics, evolution, and vaccine evasion among emerging SARS‑CoV‑2 lineages. Laboratories performing SARS-CoV-2 WGS transmitted sequencing results to CDPH through Electronic Laboratory Reporting (ELR) and non-ELR pathways. CDPH applied uniform reporting requirements but allowed flexibility in specific data formats to accommodate diverse data systems. To preserve data quality and interoperability across heterogeneous sources, CDPH implemented standardization, validation, and deduplication protocols. Snowflake, a cloud‑based data storage and analytics platform, and Posit Connect, a cloud deployment and automation platform, supported the management, processing, and integration of data within the IGED. The IGED established links between SARS‑CoV‑2 WGS data and epidemiologic metadata for 801,418 sequences, representing 81.7% of all sequences reported in California. Lineages reported to the IGED showed strong concordance with lineage proportions in GISAID. Sequences reported to the IGED had average turnaround times longer than one month, and the majority of sequencing was performed in Southern California and Los Angeles. The IGED enhanced genomic surveillance through predictive modeling and monitoring concerning evolutionary trends such as recombination and saltations in persistent infections. Development of the IGED highlighted the need for standardized data requirements, sustained funding for sequencing, incentives for data submission, and interdisciplinary collaboration to build an effective genomic surveillance system. This framework for linking genomic and epidemiologic data has not only generated critical insights for SARS‑CoV‑2 but also provided the foundation for CDPH and other public health organizations to develop similar IGED‑like systems for other priority pathogens as genomic surveillance expands.

Journal Article↗