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PubMed1990

Computerized automation of clinical trials.

Over the past decade computers have revolutionized medical record systems. Data is now legible, organized and easily retrievable. The next decade will see a revolution in the way large multi-centre clinical trials are carried out. Computerized automation of trials improves compliance with the protocol, identifies deviations from the randomization system and reduces missing and erroneous data. Computerization also improves recruitment and eliminates mistakes during data transfer. All of these proven advantages are bought for a fraction of the cost of the investigators' time.

Clinical Trials as Topic↗
PubMed2000

Analysis of large-scale gene expression data.

The advent of cDNA and oligonucleotide microarray technologies has led to a paradigm shift in biological investigation, such that the bottleneck in research is shifting from data generation to data analysis. Hierarchical clustering, divisive clustering, self-organizing maps and k-means clustering have all been recently used to make sense of this mass of data.

Algorithms↗
PubMed1997

Automating and improving the data quality of a nursing department quality management program at a university hospital.

BACKGROUND: The development and implementation of a relational database program for nursing quality management at a university hospital was stimulated by a lack of consistent data management and analysis tools in the existing noncomputerized program. PROGRAM DEVELOPMENT AND IMPLEMENTATION: An initial software prototype implemented in the critical care service included data collection instruments for five areas: medication errors, patient falls, returns to an intensive care unit within 48 hours, hospital-acquired skin breakdown, and unplanned extubations. Access to the database was limited and paper reports only were disseminated on a scheduled basis. In a second phase, the database is being deployed throughout the nursing department using a local area network. Nurse managers will enter and interact with the quality database online and have access to graphics, reports, and action plan development. POSSIBLE ERRORS: A wide range of potential errors influences decisions on how to collect, store, retrieve, and process quality management data. Each type of error affects the nurse manager's ability to identify significant patterns or trends that are amenable to intervention. There is no right way of constructing and implementing a quality improvement database; only an optimum balance between cost, complexity, and efficacy. SUMMARY AND CONCLUSIONS: Initial feedback from end uses has been positive. A three-year experience with a personal computer database suggests that the personal computer-based information technology is appropriate for small to medium applications and can support departmentwide CQI efforts. A case scenario using simulated data is included to illustrate the use of computerized reports in assessing and taking action on an increase in falls.

Accidental Falls↗
PubMed2003

Cardiotonic bipyridine amrinone slows myosin-induced actin filament sliding at saturating [MgATP].

Previously reported effects of amrinone on skeletal muscle function suggest that the drug reduces the rate constant of myosin cross-bridge dissociation. We have used the in vitro motility assay to further elucidate the mechanism underlying this effect and to aid these studies a new, improved, filament tracking software was developed in the Matlab environment. The experiments were carried out at 30 degrees C using heavy meromyosin from fast rabbit muscle and rhodamine-phalloidin labeled actin filaments. A slowing effect of amrinone on filament sliding velocity at 1 mM MgATP was observed at drug concentrations >0.3 mM. This effect showed signs of saturation at the highest drug concentrations (1-2 mM) that could be readily tested. The sliding velocity exhibited hyperbolic dependence on [MgATP] with a Vmax of 7.2 +/- 0.9 microm/s and a KM of 0.18 +/- 0.02 mM. Amrinone (1 mM) reduced Vmax by 32 +/- 5% (P < 0.01) and KM by 42 +/- 8% (P < 0.05; n=4). These results are accounted for in the most straightforward way by a model where amrinone acts directly on the actomyosin system and reduces the rate constant of MgADP release. Such a well-defined effect on the myosin cross-bridge cycle makes the drug a potentially useful pharmacological tool for further studies of myosin function both in vitro and in the ordered filament array of a living muscle fiber.

Actin Cytoskeleton↗
PubMed2003

The Australian Centre for Evidence-based Clinical Practice generic audit tool: Auditmaker for health professionals.

Audit is an important step in the process of health care evaluation and quality improvement. Some of the barriers to audit include the lack of support in initiating an audit, difficulty with data collection and lack of time. Auditmaker is a computer package that guides the clinician through the initial process of designing an audit, choosing factors and outcomes to analyse, then provides customizable data entry forms, and finally simple reports summarizing the data. It has user-friendly features, such as help buttons, drop-down lists and built in comorbidities and outcomes of common interest. It provides a generic tool for performing an audit as well as providing an opportunity for different clinicians in different institutions or practice settings to perform similar audits using the same data collection tool, which can provide the basis of benchmarking. Auditmaker is available for downloading from the ACEPBCP website: http://www.acebcp.org.au.

Australia↗
PubMedDate not supplied

A checklist for retrospective database studies--report of the ISPOR Task Force on Retrospective Databases.

INTRODUCTION: Health-related retrospective databases, in particular claims databases, continue to be an important data source for outcomes research. However, retrospective databases pose a series of methodological challenges, some of which are unique to this data source. METHODS: In an effort to assist decision makers in evaluating the quality of published studies that use health-related retrospective databases, a checklist was developed that focuses on issues that are unique to database studies or are particularly problematic in database research. This checklist was developed primarily for the commonly used medical claims or encounter-based databases but could potentially be used to assess retrospective studies that employ other types of databases, such as disease registries and national survey data. RESULTS: Written in the form of 27 questions, the checklist can be used to guide decision makers as they consider the database, the study methodology, and the study conclusions. Checklist questions cover a wide range of issues, including relevance, reliability and validity, data linkages, eligibility determination, research design, treatment effects, sample selection, censoring, variable definitions, resource valuation, statistical analysis, generalizability, and data interpretation. CONCLUSIONS: For many of the questions, key references are provided as a resource for those who want to further examine a particular issue.

Data Interpretation, Statistical↗
PubMed2004

A simple method for the preparation of pseudopure states in nuclear magnetic resonance quantum information processing.

The use of nuclear magnetic resonance (NMR) to carry out quantum information processing (QIP) often requires the preparation, transformation, and detection of pseudopure states. In our previous work, it was shown that the use of pairs of pseudopure states (POPS) as a basis for QIP is very convenient because of the simplicity in experimental execution. It is now further demonstrated that the product of the NMR spectra corresponding to two sets of POPS that share a common pseudopure state has the same peak frequencies as those of the common (single) pseudopure state. Examples of applying two different quantum logic gates to a 5-qubit system are given.

Algorithms↗
PubMed1997

Clinical quality measurement. Comparing chart review and automated methodologies.

OBJECTIVES: This study investigates the use of data from automated systems within a large managed care plan to create indicators of clinical quality. METHODS: Measures from the first year of Health Plan Employer Data and Information Set, HEDIS 2.0, are used to compare chart review and automated analysis methodologies. The contributions of various data systems in creating clinical quality measures are evaluated. RESULTS: Chart review data usually are better for creating clinical quality indicators, although the level of agreement between the two methodologies often is quite high. Computerized patient record systems are found to be the most reliable automated data source, and automated claims are found to be the least reliable. This study's findings suggest that automated encounter systems may provide relatively reliable data. CONCLUSIONS: Managed care plans may not want to rely on automated data alone for clinical quality measurement. The results reported here support the use of combined methodologies such as the "hybrid" method, which utilizes both automated and chart-review data.

Bias↗
PubMed1997

Microsatellite data support an early population expansion in Africa.

We have developed a method for the analysis of microsatellite data that is useful in the elucidation of the demographic history of populations. This method, the PK distribution method of pairwise comparisons, is analogous to the mismatch distribution of sequence comparisons developed for the analysis of mitochondrial sequence data by Rodgers and Harpending and is defined as the distribution of the number of repeat unit differences between alleles when each allele in a sample is compared with every other allele in the sample. Using computer simulations of microsatellite loci, we show that the shape of the distribution of PK changes in a distinctive manner as a function either of time since population expansion or effective population size. Increases in both of these affect the PK distribution in a similar fashion leading to a change from a steep distribution with a Po peak to one with a nonzero peak. Analysis of three data sets from surveys of microsatellite loci in ethnographically defined populations reveals that most (9/12) of the African populations analyzed, but none of the 30 non-African populations showed PK distributions with nonzero peaks. These PK distributions indicate either an earlier expansion or a larger effective population size for African populations. This observation is consistent with the hypothesized African origin of modern human.

Africa↗
PubMed1991

Nonlinear receiver compression effects on the amplitude distribution of backscattered ultrasonic signals.

Nonlinear receiver compression effects on the amplitude distribution of backscattered ultrasonic signals are investigated by using digitized RF signals that have been compressed in a commercially made ultrasonic B-scan imaging instrument. Amplitude distributions of compressed RF and video signals were obtained from regions of B-scan images that correspond to approximately the same physical region in a random medium model with known backscatter amplitude characteristics. The amplitude distribution of the signal before compression was obtained by using a table constructed from measurements of the imaging instrument compression characteristics as a function of time gain compensation. While the results indicate the general form of the decompressed data agrees with single parameter model curves that are predicted by a widely employed Gaussian random process model, the signal-to-noise ratios of the decompressed envelope vary up to 20% from the 1.91 value predicted that model. This implies that effects such as nonlinearities, envelope smoothing, and noise which all may be present in varying degrees in practical ultrasonic imaging instrumentation can cause appreciable departures from theoretical data even under highly controlled conditions.

Data Collection↗
PubMed1997

Daytime and night time motor activity of the small bowel after solid meals of different caloric value in humans.

BACKGROUND: Meals disrupt the interdigestive pattern of small bowel motor activity and convert it into the postprandial pattern. Previous studies have shown that duration of postprandial motor activity depends on the caloric value of a meal, but results from two recent human studies suggested that there is a caloric ceiling, above which an additional increase in the caloric load fails to prolong the postprandial period further. AIM: To investigate the hypothesis of a caloric ceiling by studying daytime motor activity of the human small bowel in response to five solid meals, covering a wide range of calories. METHODS: Eight healthy male volunteers underwent five separate, ambulatory small bowel manometry studies and had a total of 80 meals. For lunch, volunteers ate between one and five portions of a solid meal (220, 440, 660, 880, or 1100 kcal). Ten hours later and 30 minutes before they went to bed, they ate either two or four portions of the same meal (440 kcal or 880 kcal). Recordings were analysed visually for phase III of the migrating motor complex and a validated computer program calculated incidence and amplitude of contractions. RESULTS: Apart from two versus three portions (440 kcal v 660 kcal), postprandial motor activity was significantly prolonged by each 220 kcal increase in the caloric load of the lunch (168 (SEM 14), 305 (22), 298 (23), 368 (36), and 398 (38) min). Mean incidence of contractions was significantly different only between the two extremes tested: 220 kcal and 1100 kcal (2.9 (0.3) v 4.5 (0.6) min-1). Amplitude of contractions did not depend on meal size. Daytime and night time postprandial activity were not significantly different. This was true for duration of fed activity, as well as mean incidence and amplitude of contractions during the postprandial period. CONCLUSION: Caloric value of a meal regulates duration of the fed activity in the human small bowel over a wide range of calories, and-for caloric loads up to 1100 kcal-there is no maximum duration of postprandial motor activity. Furthermore the postprandial small bowel motor activity is very similar between daytime and night time.

Adult↗
PubMed2001

Constructing a fuzzy rule-based system using the ILFN network and Genetic Algorithm.

In this paper, a method for automatic construction of a fuzzy rule-based system from numerical data using the Incremental Learning Fuzzy Neural (ILFN) network and the Genetic Algorithm is presented. The ILFN network was developed for pattern classification applications. The ILFN network, which employed fuzzy sets and neural network theory, equips with a fast, one-pass, on-line, and incremental learning algorithm. After trained, the ILFN network stored numerical knowledge in hidden units, which can then be directly interpreted into if then rule bases. However, the rules extracted from the ILFN network are not in an optimized fuzzy linguistic form. In this paper, a knowledge base for fuzzy expert system is extracted from the hidden units of the ILFN classifier. A genetic algorithm is then invoked, in an iterative manner, to reduce number of rules and select only discriminate features from input patterns needed to provide a fuzzy rule-based system. Three computer simulations using a simulated 2-D 3-class data, the well-known Fisher's Iris data set, and the Wisconsin breast cancer data set were performed. The fuzzy rule-based system derived from the proposed method achieved 100% and 97.33% correct classification on the 75 patterns for training set and 75 patterns for test set, respectively. For the Wisconsin breast cancer data set, using 400 patterns for training and 299 patterns for testing, the derived fuzzy rule-based system achieved 99.5% and 98.33% correct classification on the training set and the test set, respectively.

Algorithms↗
PubMed1991

Use of computerized test batteries for quantifying neurobehavioral outcomes.

Neurobehavioral testing provides for noninvasive assessment of the functional integrity of the nervous system. Neurobehavioral tests have been used as quantitative outcome measures in a number of epidemiologic investigations of the potential effects on the nervous system from exposure to organic solvents, heavy metals, and pesticides. Because of the functional complexity of the nervous system, sets of tests assessing a range of functions have been used, with inconsistency from one study to another. Although there has been recent progress in standardizing a core set of tests for use in occupational epidemiology, major consensus on testing methods has not emerged. Standardization of test methods is essential to provide a consistent database for risk analysis. Automation of data collection provides not only standardization, but also improved time efficiency, of data collection and analysis. The computerized Neurobehavioral Evaluation System (NES) has been developed to address the need for standardized, efficient data acquisition of a range of neurobehavioral variables. Examples of application of NES in epidemiologic studies of workers exposed to solvents are summarized. The need for use of NES as a tool for surveillance and in prospective epidemiologic investigations is emphasized.

Behavior↗
PubMed2004

Comparative evaluation of microarray analysis software.

A wide variety of software tools are available to analyze microarray data. To identify the optimum software for any project, it is essential to define specific and essential criteria on which to evaluate the advantages of the key features. In this review we describe the results of our comparison of several software tools. We then conclude with a discussion of the subset of tools that are most commonly used and describe the features that would constitute the "ideal microarray analysis software suite."

Data Interpretation, Statistical↗
PubMed1994

Computerized analysis of ambulatory long-term small-bowel manometry.

BACKGROUND: Ambulatory long-term manometry is increasingly being used to study small-bowel motility. This study aimed to develop computer-aided data analysis including the elimination of artefacts, identification of individual phasic contractions, and analysis of aboral propagation. METHODS: Data processing included low-pass filtering, base-line adaptation, cross-comparison of channels, and application of threshold values for contraction parameters. Automated analysis was validated by a visual reference standard. RESULTS: Artefacts were related to cardiovascular and respiratory activity, changes in body posture, and contractions of the abdominal wall. Automated recognition of contractions reached a sensitivity of 92% and a positive predictive value of 88% compared with the visual standard. Mean contraction amplitude and duration of computer analysis were 96% and 93%, respectively, of the visually obtained values. Propagation analysis under ambulatory conditions showed good agreement with previous results by stationary recordings. CONCLUSIONS: Computerized analysis provided valid and reproducible data on small-bowel phasic contractile events and propagative activity by digital long-term manometry.

Adult↗