Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Data Accuracy”

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 1,171 records · Page 65Linked to original sources
PubMed2005

Current status of the European Association for Cardio-Thoracic Surgery and the Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: After utilizing separate congenital databases in the early 1990s, the Society of Thoracic Surgeons (STS) and the European Association for Cardio-Thoracic Surgery (EACTS) collaborated on several joint database initiatives. METHODS: In 1998, the joint EACTS-STS International Congenital Heart Surgery Nomenclature and Database Project Committee was created and a common nomenclature and common core minimum database dataset were adopted and published by the STS and the EACTS. In 1999, the joint EACTS-STS Aristotle Committee was created and the Aristotle Score was adopted and published as a method to provide complexity adjustment for congenital heart surgery. Collaborative efforts involving the EACTS and STS are underway to develop mechanisms to verify data completeness and accuracy. RESULTS: Since 1998, this nomenclature, database, and methodology of complexity adjustment have been used by both the STS and EACTS to analyze outcomes of over 40,000 patients. A huge amount of data have been generated which allow comparison of practice patterns and outcomes analysis between Europe and North America. The aggregate data from the first 5 years of data collection not only make for interesting comparison but also allow examination of regional difference in practice patterns. For example, in the EACTS, out of 4,273 neonates, 885 (20.7%) underwent arterial switch procedures and 297 (6.95%) underwent Norwood stage 1 procedures. In the STS, out of 3,988 neonates, 472 (11.8%) underwent arterial switch procedures and 575 (14.4%) underwent Norwood stage 1 procedures. CONCLUSIONS: This analysis of the EACTS-STS multi-institutional outcomes database confirms that in both Europe and North America, case complexity and mortality is highest among neonates, then infants, and then children. Regional differences in practice patterns are demonstrated, with the overall goal being the continued upgrade in the quality of surgery for congenital heart disease worldwide.

Databases, Factual↗
PubMed1988

A model of automatic attention attraction when mapping is partially consistent.

A model is described to account for the data of Durso, Cooke, Breen, and Schvaneveldt (1987). On the basis of the relative frequency of an item's presentation as a target, the item develops an automatic tendency to attract attention. When stimuli are then displayed, each calls the attention system to a degree determined by its present strength. We assume that attention eventually drifts to the strongest stimulus (which is then given as a response), but in a time determined inversely by the difference in strength between the two strongest stimuli. A version of this model in which the strengths were freely estimated parameters predicted the various elements of the data with good accuracy. In other versions of the model, strength values were derived from assumptions concerning the learning of automatism. Two of these models, quite different in character, captured the major qualitative features of the data. Further empirical tests of the models are suggested.

Attention↗
PubMed2001

Sequence variation and disease in the wake of the draft human genome.

The sequencing phase of the human genome project will soon be over. In its wake, repertoires of sequence polymorphisms among the human population are being sampled and a battery of functional genomics projects, from gene and protein expression studies to whole proteome interaction experiments, are generating vast quantities of data. Now that the data, or the means to generate data, are available it is the application of this information in enhancing our understanding of biology that represents the next formidable challenge. Two prominent issues should be considered. First, existing data must be analysed using the best methods available. The prediction of enzymatic activity for bestrophin, whose gene is mutated in Best macular dystrophy, is described in this review. This is an example of the experimentally testable hypotheses that can result from such detailed and exhaustive analyses. Secondly, the torrents of data from high-throughput studies will need to be made more accessible to all using web-based resources that integrate and digest complementary data types. The internet sites that showcase the human genome sequence are blazing a new trail. Ultimately, the success of genome sequencing and functional genomics will be measured not by the quantity and accuracy of raw data generated, but how rapidly they can be harnessed to span the divide between genotype and phenotype.

Alleles↗
PubMed2005

An outdoor 3-D visual tracking system for the study of spatial navigation and memory in rhesus monkeys.

Previous studies of the navigational abilities of nonhuman primates have largely been limited to what could be described by a human observer with a pen and paper. Consequently, we have developed a system that uses a pair of cameras to automatically obtain the three-dimensional trajectory of rhesus monkeys performing an outdoor spatial navigation and memory task. The system provides trajectories, path length, speed, and other variables that would be impossible for an unaided observer to note. From trajectory data, we computed and validated a path-length measurement. We use this measurement to compare the navigation abilities of several animals. In addition, we provide quantitative data on the accuracy of a method for automatic behavior detection. Currently, the system is being used to examine the sex differences in spatial navigation of rhesus monkeys. We expect that measures derived from the trajectory data will reveal strategies used by animals to solve spatial problems.

Animals↗
PubMedDate not supplied

Chronic neonatal organotin exposure alters radial-arm maze performance in adult rats.

Long-Evans rats were intubated with 0.3 or 1.0 mg/kg of triethyltin sulfate (TET) or 0.3 mg/kg of trimethyltin hydroxide (TMT) from postnatal day 3-29. 1.0 mg/kg of TMT was given on alternate days beginning on postnatal day 3. Learning and memory were assessed in an automated radial-arm maze when the rats were 180-200 days old. With this maze accuracy and activity data can be collected simultaneously. TET or TMT treatment resulted in an increase in the number of days required to adequately perform and radial-arm maze task, and a transient deficit in accuracy. However, the most pronounced effect in both TET and TMT-treated animals was hyperactivity which became manifest on the second day of testing and persisted throughout the remainder of testing.

Analysis of Variance↗
PubMed2005

[Computer assisted methods in reconstructive and function-preserving orbital surgery. New capabilities of computer assisted preoperative surgical planning (CAPP) and computer assisted surgery (CAS)].

BACKGROUND: Orbital reconstruction after tumor or trauma makes high demands on the surgeon when restoring the optic axis and cosmetic features. Computer-assisted preoperative planning surgery (CAPP) and computer-assisted surgery (CAS) allow calculation of the form of the orbital cavity to be reconstructed preoperatively as well as the process of its realization intraoperatively. METHODS: We developed new planning software methods for this surgical procedure. For validation the deviation of accuracy was assessed between the virtual and the real model in eight patients with surgical reconstruction of the orbit. RESULTS: The check of accuracy of the reconstructions compared to the planning of the surgery by fusion of preoperative and postoperative data resulted in a mean deviation of 1.74 mm. The volumetric measurements presented a mean deviation of 0.2 cm(3) with an accuracy of >99%. The accuracy of linear measurements with the techniques of image fusion of the "feature-based" method was 0.38 mm and thus close to the technical threshold of effective data accuracy of 0.35 mm. The enophthalmus could be assessed more objectively with this method compared to using the Hertel index. CONCLUSIONS: CAPP and CAS are helpful in reconstructive orbital surgery to verify the position of the optic axis and the cosmetic result intraoperatively.

Adult↗
PubMed2004

Prediction of the bonding states of cysteines using the support vector machines based on multiple feature vectors and cysteine state sequences.

The support vector machine (SVM) method is used to predict the bonding states of cysteines. Besides using local descriptors such as the local sequences, we include global information, such as amino acid compositions and the patterns of the states of cysteines (bonded or nonbonded), or cysteine state sequences, of the proteins. We found that SVM based on local sequences or global amino acid compositions yielded similar prediction accuracies for the data set comprising 4136 cysteine-containing segments extracted from 969 nonhomologous proteins. However, the SVM method based on multiple feature vectors (combining local sequences and global amino acid compositions) significantly improves the prediction accuracy, from 80% to 86%. If coupled with cysteine state sequences, SVM based on multiple feature vectors yields 90% in overall prediction accuracy and a 0.77 Matthews correlation coefficient, around 10% and 22% higher than the corresponding values obtained by SVM based on local sequence information.

Amino Acids↗
PubMed2005

To smooth or not to smooth? ROC analysis of perfusion fMRI data.

Blood oxygenation level dependent (BOLD) contrast has been widely used for visualizing regional neural activation. Temporal filtering and parameter estimation algorithms are generally used to account for the intrinsic temporal autocorrelation present in BOLD data. Arterial spin labeling perfusion imaging is an emerging methodology for visualizing regional brain function both at rest and during activation. Perfusion contrast manifests different noise properties compared with BOLD contrast, represented by the even distribution of noise power and spatial coherence across the frequency spectrum. Consequently, different strategies are expected to be employed in the statistical analysis of functional magnetic resonance imaging (fMRI) data based on perfusion contrast. In this study, the effect of different analysis methods upon signal detection efficacy, as assessed by receiver operator characteristic (ROC) measures, was examined for perfusion fMRI data. Simulated foci of neural activity of varying amplitude and spatial extent were added to resting perfusion data, and the accuracy of each analysis was evaluated by comparing the results with the known distribution of pseudo-activation. In contrast to the BOLD fMRI, temporal smoothing or filtering reduces the power of perfusion fMRI data analyses whereas spatial smoothing is beneficial to the efficacy of analyses.

Adult↗
PubMed2002

Benefit of population-based screening for phenotypic hemochromatosis in young men.

BACKGROUND: Hereditary hemochromatosis (HH) is a common genetic disease leading to accumulation of iron in the body, most notably in the liver. More men than women become clinically ill. The prognosis is excellent if phlebotomy treatment is started before liver cirrhosis develops. Screening has been recommended, but the benefit of population-based screening has never been shown in a randomized clinical trial. In this article, we estimate the benefit of screening young men, using a theoretical model. METHODS: A phenotypic screening scenario was modelled using a decision tree. Gain of quality-adjusted life-years was used as a measure of benefit, and estimated using Markov processes. Data on the accuracy of the screening tests, the prevalence of HH and the risk of liver cirrhosis were mainly derived from a cross-sectional study on the prevalence and morbidity of HH in 30509 men. Data on the excess mortality of cirrhosis were taken from relevant literature. Sensitivity analysis was done for important variables. RESULTS: Assuming basal case values for variables, screening a cohort of 1000 men aged 30 years for phenotypic HH would gain about 8 quality-adjusted life-years, compared to awaiting symptomatic disease. Based on actual costs of our cross-sectional study, the screening cost was US$250 per quality-adjusted life-year gained. The prevalence of phenotypic HH, the excess mortality of liver cirrhosis, the quality of life in non-cirrhotic HH patients, and the fractions of patients compliant with treatment were the most important variables in the sensitivity analysis. CONCLUSION: Incorporating screening for phenotypic HH in health survey programmes for young men may be worthwhile.

Adult↗
PubMed1985

Detection of acute synthetic vascular graft infection with 111In-labeled leukocyte scanning: an animal study.

Synthetic vascular graft infection is characterized by late diagnosis due to indolent and nonspecific symptoms. Indium-111-labeled leukocyte imaging holds promise as a diagnostic tool to identify vascular graft infection, but reported data on its accuracy are somewhat sparse and conflicting. In this study, 13 mongrel dogs received Dacron aortic interposition grafts. Seven grafts were contaminated at the time of surgery by topical ATCC Staphylococcus aureus concentrated at 10(8) organisms/ml. Six control animals received no graft contamination. All infected animals were sacrificed on the second postoperative day after 111In leukocyte scanning. The results showed a sensitivity of 71%, specificity of 100%, and accuracy of 85% for the 111In leukocyte study in detecting early graft infections; false-positive leukocyte scans in the early postoperative period were not a problem as has been reported by others. These data indicate that leukocyte scanning for graft infection detection is likely to be clinically valuable.

Animals↗
PubMed2005

Use of animal species data in environmental impact assessments.

Environmental Impact Assessments (EIAs) should ideally help minimize adverse effects on biological diversity by considering impacts of projects on wide ranges of species. This paper investigates how recent Dutch EIAs included the species comprising animal diversity. We present results of two studies on fauna data used in the EIAs. Objectives were to determine for different taxa (a) the relative representation of species in Environmental Impact Statements (EISs); (b) the extent to which EISs referred to specific species and the accuracy of survey data referred to; and (c) apparent roles of different EIA actors in species inclusion. EIAs were found to use data on various taxa but on limited numbers of species. The frequency with which taxa were included varied significantly. Birds were most frequently included, followed by mammals, amphibians, and other species groups. The quality of data on birds exceeded that regarding other vertebrates. Our results indicate that (a) EIA working groups of independent experts were the most influential in determining the data to be used; (b) on average, proponents included data more often than required by guidelines; and (c) in 30 to 40% of the EIAs, the participation of nongovernmental organizations prompted use of data. Despite the key role of experts in data inclusion, the taxon rankings found in the EIAs showed little deviation from those observed in studies on people's preferences for species. Given the limited ranges of species considered, it is doubtful that the EIAs examined effectively contributed to conserving animal species diversity.

Animals↗
PubMed1984

Judgment of facial expressions of emotion as a function of exposure time.

The purpose of this experiment was to study the accuracy of judgment of facial expressions of emotions that were displayed for very brief exposure times. Twenty university students were shown facial stimuli that were presented for durations ranging from 10 to 50 msec. The data showed that accuracy of judgment reached a fairly high level even at very brief exposure times and that human observers are especially competent to process very rapid changes in facial appearance.

Adult↗
PubMed1982

Archival data in program evaluation and policy analysis.

Evaluators have typically avoided using existing data sets, choosing instead to collect their own information to maintain control over both the content and quality of the data. As demands on action researchers increase without provision for additional resources, primary data collection may become a luxury and the use of archival data may increase. Though archival data has practical and methodological advantages, there are limitations associated with the utilization of such information. The general problems with secondary data sources include the accuracy, acceptability and accessibility of the information. Following a discussion of these general problems, an example from the Civilian Health and Medical Program of the Uniformed Services (CHAMPUS) reimbursement data set is presented to illustrate specific difficulties with using archival data for evaluation research. Strategies are then presented for minimizing these difficulties, including determining the feasibility of utilization of such data sources, methods for assessing their accuracy and factors to consider in the data acquisition process.

Archives↗
PubMed2006

Reconstruction of facial morphology from laser scanned data. Part I: reliability of the technique.

OBJECTIVES: The aim of this study was to evaluate the effects of scanning parameters on the precision of the data acquired using a facial laser scanner and to assess the reliability of automatic model recording in humans. METHODS: Data were acquired using a laser scanner (Cyberware 3030RGB); analysis and measurements were performed with Rapid Form 2004 software. A mannequin and six volunteers were scanned to investigate the effects of environmental conditions, positioning, head orientation, and software procedures. Precision and accuracy of the data were evaluated comparing six linear measures calculated on scanned data with those obtained directly. Two sessions with different head inclination were performed. The reliability of repeated scans was also assessed measuring the distance between the surfaces reconstructed from two separate scans of the same subject, at 12 anatomical points, in 5 subjects, during two sessions using a different head inclination. Differences were analysed using paired t-tests or analysis of variance (ANOVA). RESULTS: The accuracy of scanning was +/-0.65 mm. The development of a specific protocol resulted in a mean scanning error of 1-1.2 mm and a recording error of 0.3-0.4 mm on repeated scans of human subjects. CONCLUSIONS: This study indicates that scanning of the human face may be hampered by errors and artefacts, mainly due to movements. While the effect of trembling and involuntary movements during the exam may be minimized using faster scanning devices, comparative observation over time may be affected by unreal differences due to the uncertainty of facial expression. The overall error is, however, in the range useful for most clinical studies.

Adult↗
PubMed2005

Reliability of Indiana birth certificate data compared to medical records.

PURPOSE: The purpose of this study was to measure the reliability of data reported on Indiana electronic birth certificates. Knowing the accuracy of birth certificate data is crucial when identifying community health needs and evaluating birth outcomes interventions. METHODS: This study compared 1996 electronic birth certificate data on a random sample of 1050 Indiana hospital births to data abstracted from the hospital medical records for the same patients. Kappa scores, Pearson r correlation values, sensitivity, specificity, and positive predictive values of the birth certificate data were used to measure agreement. RESULTS: Parents' demographic variables had the best agreement, followed by birth outcome variables. Delivery type, cesarean indications, pregnancy history, prenatal care and mother's risk variables were found to have moderate agreement. Agreement was poor for variables measuring labor and delivery complications, obstetric procedures, concurrent illnesses, pregnancy complications, congenital anomalies, and abnormal conditions. CONCLUSIONS: The results of this study clearly show that some important descriptive and outcome data are reliable while infrequent events are generally not. The results indicate a need to improve the quality of data reported on birth certificates.

Adult↗
PubMed1990

The health of Latin Americans exposed to polluted rivers: a triple-blind observational study. Interamerican Group for Research in Environmental Epidemiology.

Accelerating development in South America, with consequent contamination of rivers as the final common pathway of waste, raises concern about adverse effects on the health of riverine populations. We conducted a cross-sectional survey simultaneously in six Latin American nations among people living near a river known to be polluted in each country. Trace metals (arsenic, mercury and lead) were selected as indicators of exposure to industrial effluents. Within each country, we contrasted probability samples from three types of communities: one upstream of point sources of pollution and thus little exposed; one downstream from a site of major development; and one with intermediate exposure. The outcome variables were health status measures elicited by questionnaire and biochemical measures of blood and urine. We examined several possible explanatory and confounding variables, including housing conditions, nutrition, and source of drinking water. The field work was done with triple blinding in that data-gatherers and study subjects were unaware of their group membership and of the study hypotheses, those analysing, specimens and questionnaires were blind to country and community of origin of the material and the investigators reviewed the results in code, committing themselves to conclusions in writing before the codes were broken. Methods were carefully standardized across six countries during training, when pretesting data-gathering instruments and with double coding and extensive accuracy checks of computerized data. There were 900 eligible subjects from 18 communities in six countries. The overall response rate was 92%, the lowest 86%. Results showed an acceptable level of health in all communities and no relationship to exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-Sectional Studies↗
PubMed1990

Validating survey responses to questions about gun ownership among owners of registered handguns.

While survey-based data on firearm ownership are essential for epidemiologic studies of the relation between gun ownership and injuries, the validity of respondent answers to questions about gun ownership has not been confirmed. In order to assess the accuracy of interview data about firearms, in June to August 1987, the authors attempted to contact residents of 75 homes in the cities of Memphis, Tennessee and Seattle, Washington listed as the address of the owner of a recently registered handgun. Despite problems with inaccurate registration data, contact was ultimately made with 55 households, 35 of which consented to a general interview that included a series of questions about gun ownership. Respondents in 31 of these 35 households (88.6%) readily acknowledged that one or more guns were kept in their home. Respondents in three of the remaining four households (8.6%) stated that guns were recently kept in their homes but were no longer kept there. Only one respondent (2.9%) denied categorically that guns of any kind were kept in her home. The authors conclude that, at least among registered gun owners, respondent answers to questions about gun ownership are generally valid and that survey data of this type can be utilized with confidence.

Adult↗
PubMed2005

Intratracheal pressure: a more accurate reflection of pulmonary airway pressure in pediatric patients with respiratory failure.

OBJECTIVES: Peak inflation pressure (PIP) on many ventilators (P(vent)), measured distal to the exhalation limb or Y-piece of the breathing circuit, is assumed as the pressure applied to the airways and lungs. However, in vitro studies show P(vent) data are spurious. There are no studies evaluating the accuracy of P(vent) data for pediatric patients with acute respiratory failure. We hypothesized that intratracheal airway pressure (P(T)) is more accurate than P(vent) and that by using P(vent), abnormally increased imposed resistive work of breathing (WOBi) may go undetected. DESIGN: Prospective and descriptive study. SETTING: A pediatric intensive care unit at a university hospital. PATIENTS: Twenty-one pediatric patients with respiratory failure requiring mechanical ventilation. INTERVENTIONS: All patients were intubated with a commercially available endotracheal tube (ETT) with a pressure measuring the lumen opening at the distal end used for measuring P(T). Pressure/flow sensors positioned between the ETT and Y-piece measured tidal volume (V(T)) and flow rate. P(vent) data were recorded as displayed on the ventilator. WOBi was measured by integrating P(T) and V(T) data. RESULTS: PIP at P(vent) and P(T) were 26 +/- 8 cm H(2)O and 19 +/- 7 cm H(2)O, respectively (p < .05). P(T) measurements averaged 27% less than P(vent). The relationship between P(vent)-P(T) (pressure drop across the breathing circuit and ETT) and flow rate during spontaneous inhalation was highly correlated (r = .80, p < .002), indicating the greater the flow rate, the greater the pressure drop and WOBi. WOBi, ranging from 0.04-1.5 J/L, was measured in 52% of the patients. CONCLUSIONS: P(vent) significantly overestimates PIP. Moreover, P(vent) data does not allow for recognition of increased WOBi for many patients. Clinicians need to be aware of the limitations of P(vent) data and consider using ETTs that allow measurement of P(T), a more accurate reflection of pulmonary airway pressure.

Adolescent↗