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[Monitoring management of nosocomial infections in a neurosurgical department].

Fulfilling a nosocomial infection watch program in a neurosurgery department lead to assess the basic situation i.e. the same characteristics related to both surgery and I.C.U. (incidence rate of wound infections 3%, of bronchopulmonary tract infections 20.8% and of urinary tract infections 9.1%). To ensure feasibility of data collection and data accuracy, strategy was based on weekly passive epidemiological data collection, laboratory data and monthly confrontation with neurosurgery's practitioners.

Bacteriological Techniques↗

BrainIT: a trans-national head injury monitoring research network.

BACKGROUND: Studies of therapeutic interventions and management strategies on head injured patients are difficult to undertake. BrainIT provides validated data for analysis available to centers that contribute data to allow post-hoc analysis and hypothesis testing. METHODS: Both physiological and intensive care management data are collected. Patient identification is eliminated prior to transfer of data to a central database in Glasgow. Requests for missing/ ambiguous data are sent back to the local center. Country coordinating centers provide advice, training, and assistance to centers and manage the data validation process. RESULTS: Currently 30 centers participate in the group. Data collection started in January 2004 and 242 patients have been recruited. Data validation tools were developed to ensure data accuracy and all analysis must be undertaken on validated data. CONCLUSION: BrainIT is an open, collaborative network that has been established with primary objectives of i) creating a core data set of information, ii) standardizing the collection methodology, iii) providing data collection tools, iv) creating and populating a data base for future analysis, and v) establishing data validation methodologies. Improved standards for multi-center data collection should permit the more accurate analysis of monitoring and management studies in head injured patients.

Biomedical Research↗

Lower limb amputations during 3 years in Hungary.

We reviewed nationwide hospital data of amputations during 3 years to provide a comparison with similar data gathered about 20 years ago. Data were provided by the National Medical Records Centre and processed by our personally developed programmes. The cause of amputation was most often vascular disease, amputees were usually elderly, and the large majority of amputation surgery was carried out on the lower limb. The rate of transtibial amputation has increased favourably in the last 2 decades, but there are large regional differences within the country. Mortality parameters remarkably exceed those of foreign countries. Although the data accuracy is compromised, there are still ways of exploiting the data in favour of quality improvement of care, e.g. improve transtibial amputation rate, reduce mortality. The publication of data can be of benchmarking importance for hospitals by enabling them to compare their own results with those of other hospitals, as well as to develop and improve performance.

Adult↗

Accuracy of radiographers red dot or triage of accident and emergency radiographs in clinical practice: a systematic review.

AIM: To determine the accuracy of radiographers red dot or triage of accident and emergency (A&E) radiographs in clinical practice. MATERIALS AND METHODS: Eligible studies assessed radiographers red dot or triage of A&E radiographs in clinical practice compared with a reference standard and provided accuracy data to construct 2 x 2 tables. Data were extracted on study eligibility and characteristics, quality, and accuracy. Pooled sensitivities and specificities and chi-square tests of heterogeneity were calculated. RESULT: Three red dot and five triage studies were eligible for inclusion. Radiographers' red dot of A&E radiographs in clinical practice compared with a reference standard is 0.87 [95% confidence interval (CI) 0.85-0.89] and 0.92 (0.91-0.93) sensitivity and specificity, respectively. Radiographers' triage of A&E radiographs of the skeleton is 0.90 (0.89-0.92) and 0.94 (0.93-0.94) sensitivity and specificity, respectively; and for chest and abdomen is 0.78 (0.74-0.82) and 0.91 (0.88-0.93). Radiographers' red dot of skeletal A&E radiographs without training is 0.71 (0.62-0.79) and 0.96 (0.93-0.97) sensitivity and specificity, respectively; and with training is 0.81 (0.72-0.87) and 0.95 (0.93-0.97). Pooled sensitivity and specificity for radiographers without training for the triage of skeletal A&E radiographs is 0.89 (0.88-0.91) and 0.93 (0.92-0.94); and with training is 0.91 (0.88-0.94) and 0.95 (0.93-0.96). CONCLUSION: Radiographers red dot or triage of A&E radiographs in clinical practice is affected by body area, but not by training.

Clinical Competence↗

Electromyographic biofeedback to improve lower extremity function after stroke: a meta-analysis.

OBJECTIVE: To examine the efficacy of electromyographic (EMG) biofeedback compared with conventional physiotherapy for improving lower extremity function in stroke patients. DATA SOURCES: A literature search covering the years 1976 to 1995 in MEDLINE, CINAHL, and EXCERPTA MEDICA. STUDY SELECTION: Studies of adults after stroke, in which the treatment group received biofeedback alone or with conventional physical therapy and the control group received conventional physical therapy. Outcomes included functional measures related to the lower extremity. The study design criterion was that all must be randomized controlled trials. DATA EXTRACTION: Study quality was assessed independently by two observers-using eight criteria. Data for analysis were extracted by two observers to ensure accuracy. DATA SYNTHESIS: For outcomes that were analyzed in more than one study, meta-analyses were done. Seventy-nine studies were identified as potentially relevant and eight studies met the selection criteria. The mean effect sizes were: for ankle dorsiflexion muscle strength, 1.17 (95% CI, .50-1.85; p = .0006); for gait quality, .48 (95% CI, -.06-1.01; p = .08); for ankle range of motion, .07 (95% CI, -.42-0.57; p = .78); for ankle angle during gait, .52 (95% CI, -.18-1.21; p = .14); for stride length, .09 (95% CI, -.56-.73; p = .80); and for gait speed, .31 (95% CI, -.16-.78; p = .20). CONCLUSIONS: The results indicate that EMG biofeedback is superior to conventional therapy alone for improving ankle dorsiflexion muscle strength.

Adult↗

Bridging decision analytic modelling with a cross-sectional study. Application to Parkinson's disease.

The ideal study design for demonstrating the possible health outcomes and costs associated with a new drug would be a naturalistic prospective study. However, it is not often feasible to derive the required information from scientifically sound prospective studies. In these cases, decision analytic models may provide some of the missing information. However, the use of a Delphi panel to gather data for these models is a major concern because of potential bias and data accuracy. Because reimbursement of pharmaceuticals is often based on economic data derived from modelling studies, it is obvious that potential bias due to the use of Delphi panels should be minimised. In this manuscript we present an alternative data source for modelling studies: the cross-sectional study. Data from such studies can be used to yield costs and utilities for Markov health states. The overall combined design may be considered a hybrid between a naturalistic prospective study and a modelling study by maximising the pros and minimising the cons of both types of design, including an increase of external validity. This hybrid design is based on bridging the probabilities derived from the literature and clinical trials with information on costs and utilities from a cross-sectional study. This design also has logistical advantages, namely a shorter required study duration compared with prospective naturalistic studies for chronic diseases. This combined design was illustrated using a Markov model for Parkinson's disease.

Cross-Sectional Studies↗

Accuracy of estimated phylogenetic trees from molecular data. II. Gene frequency data.

The accuracies and efficiencies of three different methods of making phylogenetic trees from gene frequency data were examined by using computer simulation. The methods examined are UPGMA, Farris' (1972) method, and Tateno et al.'s (1982) modified Farris method. In the computer simulation eight species (or populations) were assumed to evolve according to a given model tree, and the evolutionary changes of allele frequencies were followed by using the infinite-allele model. At the end of the simulated evolution five genetic distance measures (Nei's standard and minimum distances, Rogers' distance, Cavalli-Sforza's f theta, and the modified Cavalli-Sforza distance) were computed for all pairs of species, and the distance matrix obtained for each distance measure was used for reconstructing a phylogenetic tree. The phylogenetic tree obtained was then compared with the model tree. The results obtained indicate that in all tree-making methods examined the accuracies of both the topology and branch lengths of a reconstructed tree (rooted tree) are very low when the number of loci used is less than 20 but gradually increase with increasing number of loci. When the expected number of gene substitutions (M) for the shortest branch is 0.1 or more per locus and 30 or more loci are used, the topological error as measured by the distortion index (dT) is not great, but the probability of obtaining the correct topology (P) is less than 0.5 even with 60 loci. When M is as small as 0.004, P is substantially lower. In obtaining a good topology (small dT and high P) UPGMA and the modified Farris method generally show a better performance than the Farris method. The poor performance of the Farris method is observed even when Rogers' distance which obeys the triangle inequality is used. The main reason for this seems to be that the Farris method often gives overestimates of branch lengths. For estimating the expected branch lengths of the true tree UPGMA shows the best performance. For this purpose Nei's standard distance gives a better result than the others because of its linear relationship with the number of gene substitutions. Rogers' or Cavalli-Sforza's distance gives a phylogenetic tree in which the parts near the root are condensed and the other parts are elongated. It is recommended that more than 30 loci, including both polymorphic and monomorphic loci, be used for making phylogenetic trees. The conclusions from this study seem to apply also to data on nucleotide differences obtained by the restriction enzyme techniques.

Algorithms↗

Applications of artificial neural network in AIDS research and therapy.

In recent years considerable effort has been devoted to applying pattern recognition techniques to the complex task of data analysis in drug research. Artificial neural networks (ANN) methodology is a modeling method with great ability to adapt to a new situation, or control an unknown system, using data acquired in previous experiments. In this paper, a brief history of ANN and the basic concepts behind the computing, the mathematical and algorithmic formulation of each of the techniques, and their developmental background is presented. Based on the abilities of ANNs in pattern recognition and estimation of system outputs from the known inputs, the neural network can be considered as a tool for molecular data analysis and interpretation. Analysis by neural networks improves the classification accuracy, data quantification and reduces the number of analogues necessary for correct classification of biologically active compounds. Conformational analysis and quantifying the components in mixtures using NMR spectra, aqueous solubility prediction and structure-activity correlation are among the reported applications of ANN as a new modeling method. Ranging from drug design and discovery to structure and dosage form design, the potential pharmaceutical applications of the ANN methodology are significant. In the areas of clinical monitoring, utilization of molecular simulation and design of bioactive structures, ANN would make the study of the status of the health and disease possible and brings their predicted chemotherapeutic response closer to reality.

Acquired Immunodeficiency Syndrome↗

Registries and administrative data: organization and accuracy.

In this article the organization and accuracy of the population registry and administrative data base in Manitoba, Canada are discussed. The overall data management strategy and a framework for analyzing the accuracy of such data are presented. The generally high quality of the Manitoba registry file (necessary to track individuals over time) and the hospital claims is supported by comparisons with other data sources. Hospital claims' main quality problems concern the reliability of certain secondary diagnoses and the level of aggregation necessary for reasonable agreement with other data collection methods (such as chart reviews). Finally, some of the research possibilities associated with population registries and administrative data are outlined.

Adolescent↗

Quality control in multicentric clinical trials. An experience of the EORTC Gynecological Cancer Cooperative Group.

Data Quality is a central requirement of scientific research and external monitoring is essential in multicentric clinical trials (MCT). A quality control (QC) study was conducted in the main Institutions participating in EORTC-GCCG Protocol number 55863 - randomised phase III trial of vindesine, cisplatin, bleomycin and mitomycin-C (BEMP) versus cisplatin (P) in disseminated squamous cell carcinoma of the uterine cervix - in order to assess the impact of variations in data quality on the conclusions of the trial. The reliability of the different centres in following the protocol was investigated by a questionnaire covering drug prescription, local facilities and the procedure for preparation and administration of chemotherapy. The 'treatment protocol adherence' was evaluated by recalculation of the ideal protocol dose and its comparison with the actual delivered dosage at each cycle of chemotherapy. 'Data quality control' was assessed by comparison of data on case report forms (CRFs) with the corresponding items in the medical records. Eleven centres participating in the trial were visited by the same team of reviewers. Striking differences were noted in the chemotherapy administration procedures and between the type and quality of hospital files. Overall, there was an acceptable level of data quality and protocol compliance. Data accuracy was 81.8% (range: 65. 6-97%) of the 4424 items checked. Incorrect data were found in 7.0% (2.3-14.5%), data were missing on the form in 3.6% of cases (0-12%) and data was on the form but not in the file in 7.6% of cases (0. 7-17.5%). Causes of inaccuracy were analysed. Both problems in data management but also in a lack of clarity of the protocol and/or CRFs were to blame. Training and supervision of data managers, precision in writing protocols, standardisation of some aspects of CRFs and the use of a checklist for chemotherapy data and treatment toxicities would have avoided many of these errors. The need for QC in all collaborative groups performing MCT is emphasised. A literature review on QC in MCT dealing with chemotherapy is included.

Antineoplastic Combined Chemotherapy Protocols↗

Continuous ice core melter system with discrete sampling for major ion, trace element and stable isotope analyses.

We present a novel ice/firn core melter system that uses fraction collectors to collect discrete, high-resolution (<1 cm/sample possible), continuous, coregistered meltwater samples for analysis of eight major ions by ion chromatography (IC), >32 trace elements by inductively coupled plasma sectorfield mass spectrometry (ICP-SMS), and stable oxygen and hydrogen isotopes by isotope ratio mass spectrometry (IRMS). The new continuous melting with discrete sampling (CMDS) system preserves an archive of each sample, reduces the problem of incomplete particle dissolution in ICP-SMS samples, and provides more precise trace element data than previous ice melter models by using longer ICP-SMS scan times and washing the instrument between samples. CMDS detection limits are similar to or lower than those published for ice melter systems coupled directly to analytical instruments and are suitable for analyses of polar and mid-low-latitude ice cores. Analysis of total calcium and sulfur by ICP-SMS and calcium ion, sulfate, and methanesulfonate by IC from the Mt. Logan Prospector-Russell Col ice core confirms data accuracy and coregistration of the split fractions from each sample. The reproducibility of all data acquired by the CMDS system is confirmed by replicate analyses of parallel sections of the GISP2 D ice core.

Chromatography, Ion Exchange↗

TRED: a Transcriptional Regulatory Element Database and a platform for in silico gene regulation studies.

In order to understand gene regulation, accurate and comprehensive knowledge of transcriptional regulatory elements is essential. Here, we report our efforts in building a mammalian Transcriptional Regulatory Element Database (TRED) with associated data analysis functions. It collects cis- and trans-regulatory elements and is dedicated to easy data access and analysis for both single-gene-based and genome-scale studies. Distinguishing features of TRED include: (i) relatively complete genome-wide promoter annotation for human, mouse and rat; (ii) availability of gene transcriptional regulation information including transcription factor binding sites and experimental evidence; (iii) data accuracy is ensured by hand curation; (iv) efficient user interface for easy and flexible data retrieval; and (v) implementation of on-the-fly sequence analysis tools. TRED can provide good training datasets for further genome-wide cis-regulatory element prediction and annotation, assist detailed functional studies and facilitate the decipher of gene regulatory networks (http://rulai.cshl.edu/TRED).

Animals↗

IUPAC gas chromatographic method for determination of fatty acid composition: collaborative study.

An international collaborative study of IUPAC methods II.D.19 and II.D.25 for preparation and GLC analysis of fatty acid methyl esters was begun in 1976. The IUPAC methodology, applicable to animal and vegetable oils and fats and fatty acids from all sources, contains special instructions for preparation and analysis of methyl esters of fatty acids containing 4 or more carbon atoms (analysis of milk fat). Twenty-three collaborators participated in the analysis of 5 known mixtures, 4 vegetable oils, 1 fish oil, and 2 butterfats. Several blind duplicate samples were included. The experimental data were subjected to statistical analysis to examine intra- and interlaboratory variation. Reproducibility and accuracy data for the higher fatty acid (14:0-22:1) mixtures and fish and vegetable oils were satisfactory and were in good agreement with results from an AOCS Smalley Committee check sample program involving analysis of the same samples. Typical coefficients of variation (%) at various concentrations were 15 (2% level), 8.5 (5% level), 7 (10% level), and 3 (50% level). Low recoveries and poor reproducibility were characteristics of results obtained for butyric acid in the butterfat and related known mixtures. A coefficient of variation of about 19% was found for analysis of butyric acid in butterfat, vs coefficients of variation in the range of 4-13% for similar levels of other components in butterfat and other samples. The IUPAC methodology for GLC analysis of fats and oils other than milk fats has been adopted by the AOAC as official first action to replace the current GLC method, 28.063-28.067.

Animals↗

Enantioselective assay of chloroquine and its main metabolite deethyl chloroquine in human plasma by capillary electrophoresis.

A sensitive assay for the determination of chloroquine (Clq) and its pharmacologically active metabolite deethyl chloroquine in plasma by capillary electrophoresis (CE) is developed. Plasma levels of drug and metabolite are measured using HeCd laser-induced fluorescence (LIF) detection over a range of three orders of magnitude from 2 to 1000 ng/mL after liquid-liquid extraction. A limit of detection of 0.5 ng/mL is achieved. Validation of the method yields intra- and interday precision data within the limits of 10% (20% at limit of quantitation) and intra- and interday accuracy data greater than 6% throughout the whole working range. The method is applied for the drug monitoring of patients treated with Clq. Based upon this assay, two enantioselective CE-LIF methods for Clq and its main metabolite are developed. Mixtures of substituted gamma-cyclodextrins are used as chiral selectors. A baseline separation of the enantiomers of both analytes in one run is achieved in less than 11 min (method A) and less than 9 min (method B), respectively. Hydroxychloroquine is used as the internal standard for both methods.

Antimalarials↗

Data quality and quality control of a population-based cancer registry. Experience in Finland.

Cancer registries should pay great attention to the quality of their data, both in terms of completeness (all cancer patients in the population are registered) and accuracy (data on individual cancer patients must be correct). In addition to technical measures in the data processing, different types of checks and comparisons should be routine practice. Active research policy and ambitious, research-oriented staff with competence in medicine, biostatistics and computer science are essential in terms of maintaining good data quality.

Finland↗

Voice reaction times with recognition for Commodore computers.

Hardware and software modifications are presented that allow for collection and recognition by a Commodore computer of spoken responses. Responses are timed with millisecond accuracy and automatically analyzed and scored. Accuracy data for this device from several experiments are presented. Potential applications and suggestions for improving recognition accuracy are also discussed.

Animals↗

Active patellar tracking measurement: a novel device using ultrasound.

BACKGROUND: Many patients suffer patellar instability that may relate to transient patellar tracking abnormalities. OBJECTIVE: To develop and test a technique to measure dynamic patellar tracking. STUDY DESIGN: Controlled laboratory and in vivo study. METHOD: A functional knee brace was modified to allow an ultrasound transducer to be mounted laterally to the femur, following the path of the patella during knee movement. An ultrasound system was used to measure patellar mediolateral position parallel to the femoral transepicondylar axis. Ten subjects with no patellar instability were studied to obtain patellar tracking and accuracy data. RESULTS: The interobserver and intraobserver reproducibility ranged from 0.2 +/- 0.1 mm to 1.0 +/- 0.5 mm. The accuracy of the ultrasound measurement was checked against magnetic resonance imaging and was 0.6 +/- 1.9 mm. The patella moved medially then laterally from extension to flexion when sitting. Squatting and stepping produced a more lateral path, without the initial medial translation. The patella was more lateral during knee extension than during flexion. CONCLUSIONS: This novel method for measurement of dynamic patellar mediolateral tracking was found to have good intraobserver and interobserver reproducibility, and the measurements matched closely with those obtained from magnetic resonance imaging reconstructions of static patellar positions. Some preliminary data for tracking in 3 activities were obtained from 10 normal knees.

Adult↗

Pulse code modulation telemetry in ski injury research. I. Instrumentation.

Measurement problems can be classified into instrumentation, data transmission and recording, and analysis. This paper focuses on the transmission of multichannel, high-volume, high-frequency, high-accuracy data. Boot-ski dynamometer and skier velocity anemometer data provide 13 channels of max. 8-mV signals requiring 8-microvolt resolution or 4.45-Newton dynamometer resolution. The data transmission system features durability, power consumption approx. 10 Watts, weight 4.54 kp, range greater than 3,500 m, frequency response 250 Hz, accuracy 1 per cent, temperature stability, dynamic range plus or minus 2 inches. The transducer signals are ampflified to plus or minus 10 V for the 100-kbps PCM system. Special AC amplifiers, driven by an amplitude-stabilized power oscillator, were designed for elimination of radio frequency interference (RFI), improved stability and high signal/noise. Sixteen words are sequentially sampled at 521/sec-13 data, 2 frame counters, and 1 sync. The ground station consists of the PCM decoder with real-time capability and an analog tape recorder. Data is subsequently buffered and formatted onto digital tape by mini-computer.

Athletic Injuries↗