bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of Physician Order Entry: Results of a Cross-Site Qualitative Study
Authors: Gorman P. N. , Lavelle M. , Stavri P. Z. , Lyman J. , Fournier L. , Carpenter J. , Ash J. S.
Published: March 2018

Objective: To identify perspectives of success factors for implementing computerized physician order entry (POE) in the inpatient setting.

Design: Qualitative study by a multidisciplinary team using data from observation, focus groups, and both formal and informal interviews. Data were analyzed using a grounded approach to develop a taxonomy of patterns and themes from the transcripts and field notes.

Results: A taxonomy of ten high level themes was developed, including 1) separating POE from other processes, 2) terms, concepts, and connotations, 3) context, 4) tradeoffs, 5) conflicts and contradictions, 6) collaboration and trust, 7) leaders and bridgers, 8) the organization of information, 9) the ongoing nature of implementation, and 10) temporal concerns.

Conclusion: The identified success factors indicate that POE implementation is an iterative and difficult process, but informants perceive it is worth the effort.
Cognitive Tools in Medical Teamwork: The Spatial Arrangement of Patient Records
Authors: Timpka T. , Bång M.
Published: March 2018

Objectives: As a preliminary for the design of Computer-Based Patient Records, the aim of this paper is to build an understanding of the roles physical artifacts like paper-based patient records play in supporting cognition and collaboration in the health-care settings.

Method: A small ethnographically-informed study was conducted in the emergency room at a 250-bed hospital in Sweden from the perspective of Distributed Cognition.

Results: To track work-in-progress, clinicians placed patient records on a desk to form a shared public display that represented the current problem state for the health-care team. The results of the study suggest that the patient records and other physical artifacts are used by clinicians in different ways to form cognitive tools that offload memory tasks and support joint attention and collaboration.

Conclusion: To design Computer-Based Patient Records that more appropriately support cognition and teamwork, it is important to investigate how clinicians make use of the paper-based patient records. Practitioners take advantage of existing tools frequently to deal with cognitively demanding tasks and collaboration issues.
An Activity-Theoretical Method for Studying User Participation in IS Design
Authors: Lehenkari J. , Hyysalo S.
Published: March 2018

Objectives: This paper aims to present an activity-theoretical method for studying the effects of user participation in IS development.

Methods: This method is developed through a case study of the process of designing a diabetes database.

Results and Conclusions: The method consists of a historical analysis of the design process, an ethno-graphical study of the use of the database, and researcher-driven interventions into the on-going user-producer interaction. In the historical analysis, we study particularly which user groups of the database have influenced the design work and which perspectives need to be incorporated into the design in the near future. An analytical model consisting of perspectives on local design, particular technology, and societal domain is introduced as a conceptual tool for this analysis. We also introduce the possibility of employing the historical analysis in guiding an ethno-graphical study of the user sites and researcher-driven interventions, which provide the participants with tools for improving their design process.
The ‘Seamless Web’: The Development of the Electronic Patient Record in Aarhus Region, Denmark
Authors: Jensen C. B.
Published: March 2018

Objectives: The article surveys the organization of the current project to develop an electronic patient record in the Aarhus Region, Denmark.

Methods: The article is based on various policy documents and reports as well as a number of semi-structured interviews with project managers from the EPR organization in Aarhus County and with participants in the development process at local hospitals. This material is used to present and discuss the framing of the project in a ‘discourse coalition’. Results: The stabilization of a specific discourse coalition has been an important factor in ensuring the success of the development project up to the present moment. This coalition became relatively stable by integrating a diverse set of actors in a story-line about the relationships between cooperation, management and technology in the medial sector, and has influenced the modular organization of the project.

Conclusions: The successful maintenance of the discourse coalition allows the project to appear ‘seamless’ from the outside. Conversely, the project is likely to be continually reviewed as successful only to the extent that it is able to flexibly keep the fluctuating set of relevant actors in alignment. If the practical work of keeping a coalition in place remains invisible it becomes easy to imagine an ideal way of planning large socio-technical projects, like developing an ECR. But practical success is more likely to be achieved if one takes seriously the thorough intertwining of discursive, organizational and technical aspects of development projects.
Integrating Health Information Systems: A Critical Appraisal
Authors: Monteiro E.
Published: March 2018

Objectives: The aim of this paper is to critically assess some of the underlying assumptions behind these initiatives and analyze the dominant expressions, forms and mechanisms of integration.

Methods: This paper employs a discourse analysis to elicit the notion of integration of information systems and its consequences for electronic patient record systems.

Results and Conclusions: An alternative strategy is outlined, encouraging a more decentralized, multi-vocal approach acknowledging the productive role of related and duplicated information and preserving the existing variety of information systems.
Intraindividual Specificity and Stability of Human EEG: Comparing a Linear vs a Nonlinear Approach
Authors: Schmid G. B. , Stassen H. H. , Dünki R. M.
Published: March 2018

We have applied the so-called “unfolding dimension approach’’ to reanalyze an earlier longitudinal EEG study. Both linear and nonlinear approaches show that the EEG comprises a static, person-specific part upon which nonstatic and state-specific parts are superimposed. The intraindivi-dual specificity and stability of the genetic part are similar between methods. This is assessed by comparing the outcome of a person to his own outcomes at later times (14 days and 5 years later). The nonlinear method revealed a median correlation coefficient = 0.55, whereas advanced linear methods showed a median = 0.84. An apparent effect for the 5-year interval was detected with the nonlinear method and is discussed in terms of the different assumptions of the two approaches concerning EEG signal generation.
Non-stationary Myoelectric Signals and Muscle Fatigue
Authors: Scott R. N. , MacIsaac D. , Parker P. A.
Published: March 2018

A mathematical derivation for the mean frequency of a myoelectric signal (MES) is provided based on an amplitude modulation model for non-stationary MES. With this derivation, it is shown that mean frequency estimates of stationary and non-stationary myoelectric signals theoretically are not significantly different in a physiologically practical context. While this prediction is confirmed via a computer simulation, it is refuted with empirical evidence. Regardless, it is shown in a final study that mean frequency is capable of tracking a downward shift in the power spectrum with fatigue even in non-stationary myoelectric signals.
Neurologial Interpretations and the Information in the Cognitive Pupillary Response
Authors: Zimmerman S. , O’Neill W. D.
Published: March 2018

It has been known for 70 years that the human pupil dilates when a person responds to a cognitive task. Further, it is known that parasympathetic pupillary innervation decreases with raised attention state while sympathetic innervation increases. But the information the pupil transmits during elevated attention states about such neurological dynamics and a quantitative measure of this information have defied statistical modelling. Now we describe experiments using a short-term memory task called an acoustic impulse test in which the pupillary dynamics in response to random acoustic impulses are recorded with a high resolution (0.01mm) pupillometer with the result that parasympathetic and sympathetic pupillary dilation components are quantifiable, as is the information transmitted by these components.
Clinical Data Retrieval: 25 Years of Temporal Query Management at the University of Vienna Medical School
Authors: Gall W. , Duftschmid G. , Dorda W.
Published: March 2018

Objectives:
Today, many clinical information systems include analysis components which allow clinicians to apply a selection of predefined statistical functions that satisfy typical cases. They are mostly to inflexible to handle complex, non-standard problems, however. The focus of this paper, therefore, is to present an approach that enables clinicians to autonomously create ad hoc queries including temporal relations in an interactive environment.

Methods:
We developed the query language AMAS, which was specifically customized for users from the medical domain to flexibly retrieve and interpret temporal, clinical data. AMAS provides for a significant temporal expressiveness in data retrieval using timestamped clinical databases and relies on an operator-operand concept for the specification of a query.

Results:
Within the last 25 years, four different clinical retrieval systems have been implemented at the Department of Medical Computer Sciences, based on the AMAS query language. Currently, these systems allow access to the medical records of more than 2 million patients. Physicians of 46 different departments at the University of Vienna and Graz Medical Schools have made extensive use of these systems in the course of clinical research and patient care, executing more than 10.000 queries per year.

Conclusions:
We discuss a list of 20 issues that represent the most essential lessons we have learned in the development of the four systems mentioned above. Amongst others, our experiences indicate that the operator-operand concept allows an intuitive specification of complex, temporal queries. Further, customization to different user classes, based on their statistical background, is essential.
Estimation of Age-specific Reference Intervals for Skewed Data
Authors: Moussa M. A. A.
Published: March 2018

Objectives:
To compare Cole’s LMS method with Wright and Royston’s Exponential-Normal (EN) method for estimating reference intervals and generating smooth centile curves for the body mass index (weight in kg/height in meters squared) measurements of children aged 6 to 13 years.

Methods:
In the LMS method, the parameters L (the power needed to normalize the data), M (median) and S (coefficient of variation) are modeled as smoothed fits of maximum likelihood estimates. In the Exponential-Normal method, the three parameters mean, standard deviation and skewness are estimated separately using multiple regression techniques.

Results:
The centiles generated by the LMS and EN methods are close in most of the age groups. The 2.5th and 97.5th quantiles of the interval of the differences between the loss function scores of the LMS and EN methods calculated by bootstrap was found to include zero, indicating that the difference in loss function scores of the two methods is random and not systematic.

Conclusions:
The two methods are simple to use and generate comparable centile curves.
A Resource Server for Medical Training
Authors: Darmoni S. , Souf N. , Dufresne E. , Beuscart R. , Brunetaud J. M.
Published: March 2018

Objectives:
We have developed a RESOURCE SERVER to collect and store various elements used by a professor during his lecture.

Methods:
The server manages four types of objects: ELEMENTS, RESOURCES (set of elements referring to a given topic), INDEXES (to organize the resources for further search and use), and USERS (to identify providers, users, and access rights). If an ELEMENT s modified, the RESOURCE is automatically updated.

Results:
An example (preparation of an anatomy lecture) explains how the RESOURCE SERVER works in three steps: organization of the training material, indexing, and retrieval.

Conclusions:
The RESOURCE SERVER will help instructors develop, update and share pedagogic resources for supporting their training courses, lessons and conferences. Moreover, these techniques, based on Internet technologies for easy handling of and access to these resources, allow local and distant access. Within the general framework of the French-speaking Virtual Medical University, the RESOURCE SERVER will represent an important link between data collection and its use in intelligent pedagogic training.
Influenza Immunizations in the Elderly: A Continuous Quality Improvement Project
Authors: Evans M. F. , Bloom J. , Juma A.
Published: March 2018

As part of the continuous quality improvement program at The Toronto Hospital’s Department of Family & Community Medicine (TTH-DFCM), it was considered necessary to examine the structures, processes and outcomes of influenza immunization for the elderly. Objective: The study sought to (a) document the current influenza immunization process; (b) quantify influenza immunization rates for elderly patients during two consecutive immunization seasons (1996 and 1997), and compare these rates across physician teams, attending staff vs. residents, patient gender, and patient age groups; (c) compare influenza immunization rates with other centers; and (d) identify barriers and propose solutions to improve influenza immunization rates in the elderly. Design: Evaluation Formative Research. Setting: A computerized roster of 15,000 patients at The Toronto Hospital, Department of Family and Community Medicine, a University of Toronto academic teaching center. Participants: Active patients age 65 years and over. Dependent variable: Influenza immunization. Independent variables: Physician Teams, Physician status, Patient gender, and Patient age group. Results: Immunization rates of attendees increased from 75.4% to 78.7%; over 3% increase from 1996 to 1997. Major subgroups which benefited from increased immunization rates were patients in the Blue team, patients age 70-74 years, and female patients. Conclusion: This study presents a rigorous examination of the components of the influenza immunization program, and demonstrates improved immunization rates over a two-year period. Suggestions for future action have been identified. The study design can also serve as a model for future clinical quality improvement projects.
Assessing and Improving the Quality of Information for Health Evaluation and Promotion
Authors: Gillies A.
Published: March 2018

Studies by the author based upon a sample of over 1.1 million patients in the North West of England have shown that the introduction of computers cannot be demonstrated to produce significant improvements in health promotion activity. Other studies have revealed error rates in health-care information systems in excess of 50%. This paper considers the reasons for these findings and demonstrate that there is a level of maturity of information management required before information systems can make a significant contribution to health promotion and evaluation. With the advent of locality commissioning and a re-affirmation of the emphasis upon health promotion activity set out in Health of the Nation and Our Healthier Nation [8], the role of information management has become even more significant. The paper presents a maturity model developed by the author, known as General Practice Information Maturity Model (GPIMM) that provides a strategic framework to improve the use of information by practices and to improve practice to enable viable sharing of accurate information. The paper will show the model can be used as a basis for the development of training and information strategies. The model identifies computerised practices as being in one of five stages of maturity: (1) Computerised, (2) Computerised PHC Team, (3) Coded, (4) Bespoke, (5) Paperless. The model specifically leads practices to a point in their development where they are able to carry out health evaluation, promotion and audit activities as a routine activity. Once these activities form part of practice activity they are then extended to encompass a group of practices such as a Primary Care Group. Finally, a case study is presented to show how the model was used to enable two very different but geographically neighbouring practices to work together towards the establishment of a common dataset. This dataset will be used to enable health promotion and evaluation activity to be provided for a total population of over 20,000 patients.
From Phenotype to Genotype: Issues in Navigating the Available Information Resources
Authors: McCray A. T. , Bodenreider O. , Mitchell J. A.
Published: March 2018

Objectives:
As part of an investigation of connecting health professionals and the lay public to both disease and genomic information, we assessed the availability and nature of the data from the Human Genome Project relating to human genetic diseases.

Methods:
We focused on a set of single gene diseases selected from main topics in MEDLINEplus, the NLM’s principal resource focused on consumers. We used publicly available websites to investigate specific questions about the genes and gene products associated with the diseases. We also investigated questions of knowledge and data representation for the information resources and navigational issues.

Results:
Many online resources are available but they are complex and technical. The major challenges encountered when navigating from phenotype to genotype were (1) complexity of the data, (2) dynamic nature of the data, (3) diversity of foci and number of information resources, and (4) lack of use of standard data and knowledge representation methods.

Conclusions:
Three major informatics issues arise from the navigational challenges. First, the official gene names are insufficient for navigation of these web resources. Second, navigational inconsistencies arise from difficulties in determining the number and function of alternate forms of the gene or gene product and maintaining currency with this information. Third, synonymy and polysemy cause much confusion. These are severe obstacles to computational navigation from phenotype to genotype, especially for individuals who are novices in the underlying science. Tools and standards to facilitate this navigation are sorely needed.
Scalable Software Architectures for Decision Support
Authors: Musen M. A.
Published: March 2018

Interest in decision-support programs for clinical medicine soared in the 1970s. Since that time, workers in medical informatics have been particularly attracted to rule-based systems as a means of providing clinical decision support. Although developers have built many successful applications using production rules, they also have discovered that creation and maintenance of large rule bases is quite problematic. In the 1980s, several groups of investigators began to explore alternative programming abstractions that can be used to build decision-support systems. As a result, the notions of “generic tasks” and of reusable problem-solving methods became extremely influential. By the 1990s, academic centers were experimenting with architectures for intelligent systems based on two classes of reusable components: (1) problem-solving methods – domain-independent algorithms for automating stereotypical tasks – and (2) domain ontologies that captured the essential concepts (and relationships among those concepts) in particular application areas. This paper highlights how developers can construct large, maintainable decision-support systems using these kinds of building blocks. The creation of domain ontologies and problem-solving methods is the fundamental end product of basic research in medical informatics. Consequently, these concepts need more attention by our scientific community.
A Realistic Model of Human Structure from the Visible Human Data
Authors: Pflesser B. , Pommert A. , Riemer M. , Schubert R. , Schiemann T. , Tiede U. , Schumacher U. , Höhne K. H.
Published: March 2018

The computer-based 3D models of the human body reported to date suffer from poor spatial resolution. The Visible Human project has delivered high resolution cross-sectional images that are suited for generation of high-quality models. Yet none of the 3D models described to date reflect the quality of the original images. We present a method of segmentation and visualization which provides a new quality of realism and detail. Using the example of a 3D model of the inner organs, we demonstrate that such models, especially when combined with a knowledge base, open new possibilities for scientific, educational, and clinical work.
Analysis of Data Associated with Seemingly Temporal Clustering of a Rare Disease
Authors: Goldbourt U. , Chen R.
Published: March 2018

Three statistical tests aimed at detecting temporal clustering within a given short series of diagnoses are presented. These tests are based on a standardized time interval between consecutive diagnoses. Two of the tests (the Cuscore and the Sets tests) are derived from sequential monitoring techniques which are sensitive to temporal clustering within the data set. The third test (R test) is not sequential and its sensitivity is focused on the average increase in the overall rate of the disease rather than on clustering within the series. Power curves are presented for conditions related to the intensity level of the subtle epidemic, the cluster size and the number of diagnoses. None of the techniques showed highest efficiency over all the specified conditions. The R test is the most efficient when the relative risk is 2 or less, and the Cuscore test is the most efficient method when the relative risk is ≥2.5.
Knowledge-Acquisition Tools for Medical Knowledge-Based Systems
Authors: Lanzola G. , Quaglini S. , Stefanelli M.
Published: March 2018

Knowledge-based systems (KBS) have been proposed to solve a large variety of medical problems. A strategic issue for KBS development and maintenance are the efforts required for both knowledge engineers and domain experts. The proposed solution is building efficient knowledge acquisition (KA) tools. This paper presents a set of KA tools we are developing within a European Project called GAMES II. They have been designed after the formulation of an epistemological model of medical reasoning. The main goal is that of developing a computational framework which allows knowledge engineers and domain experts to interact cooperatively in developing a medical KBS. To this aim, a set of reusable software components is highly recommended. Their design was facilitated by the development of a methodology for KBS construction. It views this process as comprising two activities: the tailoring of the epistemological model to the specific medical task to be executed and the subsequent translation of this model into a computational architecture so that the connections between computational structures and their knowledge level counterparts are maintained. The KA tools we developed are illustrated taking examples from the behavior of a KBS we are building for the management of children with acute myeloid leukemia.
Representing Clinical Narratives Using Conceptual Graphs
Authors: Baud R. H. , Rassinoux A. M. , Wagner J. C. , Lovis C. , Juge C. , Alpay L. L. , Michel P. A. , Degoulet P. , Scherrer J. R.
Published: March 2018

The analysis of medical narratives and the generation of natural language expressions are strongly dependent on the existence of an adequate representation language. Such a language has to be expressive enough in order to handle the complexity of human reasoning in the domain. Sowa’s Conceptual Graphs (CG) are an answer, and this paper presents a multilingual implementation, using French, English and German. Current developments demonstrate the feasibility of an approach to natural Language Understanding where semantic aspects are dominant, in contrast, to syntax driven methods. The basic idea is to aggregate blocks of words according to semantic compatibility rules, following a method called Proximity Processing. The CG representation is gradually built, starting from single words in a semantic lexicon, to finally give a complete representation of the sentence under the form of a single CG. The process is dependent on specific rules of the medical domain, and for this reason is largely controlled by the declarative knowledge of the medical Linguistic Knowlege Base.
The Learning Process in the Epistemology of Medical Information
Authors: Clancey W. J.
Published: March 2018

Progress in the past few decades in representing medical knowledge, along with the availability of low-cost, powerful workstation computers, has increased interest in encoding all medical records in electronic form. But despite the advantages of legibility, access, and automated performance reviews, computerization may also restrict what can be recorded and rigidify health care interactions with patients. Balancing the beneficial and negative effects requires an understanding of medical practice, especially the difference between human knowledge and today’s computer programs. Human perceptual and conceptual capabilities bring an aspect of improvisation and reinterpretation to every human action, which in general computers today cannot replicate. Designers of medical record systems must consider the creative process by which descriptions are generated by people, as well as the collaborative process by which descriptions of past work are reinterpreted for guiding future decisions. This paper provides a framework for understanding these issues, illustrated by design opportunities.
An Ontology-based Multi-agent Architecture for Distributed Health-care Information Systems
Authors: Lanzola G. , Stefanelli M. , Falasconi S.
Published: March 2018

Managing patients in a shared-care context is a knowledge-intensive activity. To support cooperative work in medical care, computer technology should both augment the capabilities of individual specialists and enhance their ability of interacting with each other and with computational resources. Thus, a major shift is needed from centralized first generation health-care information systems to distributed environments composed of several interconnected agents, cooperating in maintaining a full track of the patient clinical history and supporting health-care providers in all the phases of the patient-management process. This paper outlines a general methodology to make architectural choices while designing or integrating new software components into a distributed health-care information system. A particular stress is laid on the specification of shared conceptual models, or ontologies, providing agents committing to them with the common semantic foundation required for effective interoperation.
Evaluation of Techniques for the Presentation of Laboratory Data. II: Accuracy of Interpretation
Authors: Hoeke J. O. O. , Bonke B. , van Strik R. , Gelsema E. S. , Verheij R.
Published: March 2018

Four tabular and two graphical techniques for the presentation of laboratory test results were evaluated in a reaction time experiment with 25 volunteers. Artificial variables and values were used to represent sets of 12 laboratory tests to eliminate the possible effects of clinical experience. Analyses focused on four types of errors in interpretation. Color-coded tables and one of the color-coded graphs greatly (2.8 times or better) reduced the number of incorrectly classified test results, as compared to the reference presentation technique. This was mainly due to a reduction of the number of abnormal test results that were not noticed by the subjects when using these presentation techniques.
Morphosemantic Analysis and Translation of Medical Compound Terms
Authors: Dujols P. , Aubas P. , Baylon C. , Grémy F.
Published: March 2018

This paper describes an automatic procedure for morphosemantic analysis and translation of compound medical terms. This analysis is of interest for the automatic indexation of medical discharge reports and summaries. Since words with the suffix -osis may have many different semantic interpretations, such -osis forms are taken as examples for a general method that avoids the difficulties in interpreting medical terms as reported in other studies.
Controlled Trial on Medical Birth Notification Design
Authors: Mäkelä M. , Teperi J. , Hemminki E.
Published: March 2018

In a controlled trial, two different forms were compared with respect to thoroughness of completing medical data on procedures during pregnancy, labor, and in newborns. The contents of 547 forms filled in by hospital personnel were compared to data abstracted from hospital records by trained research assistants. Forms with open-ended questions lacked information on 29% of the most common procedures and forms with a check-box format 9%. The results support the use of the check-box format in routine collection of data on common medical procedures.
Is a Picture Worth a Thousand Medical Words? A Randomized Trial of Reporting Formats for Medical Research Data
Authors: Elting L. S. , Bodey G. P.
Published: March 2018

Monitoring data that vary over time is an essential component of medical practice. This is doubly true in clinical trials in which the overall safety and efficacy of investigational treatments in populations must be monitored in addition to the status of the individual patients who receive them. We report the results of a randomized trial of four reporting methods for time-dependent information derived from clinical trials; narrative text, table, pie chart and icon. Multivariate analysis of variance with a repeated measures design was used to analyze the efficiency of subjects’ (physicians, research nurses and laboratory personnel) assimilation of information. Icons were found to be superior to the other reporting formats tested in both speed (p <0.0001) and accuracy (p = 0.02). The differences were most pronounced in subjects’ first exposure to the data, suggesting that icons reduce the time needed for training. We conclude that icons are a valuable method for presentation of time-dependent information in medical settings.
Multivariate Procedures to Describe Clinical Staging of Melanoma
Authors: Manton K. G. , Woodbury M. A. , Wrigley J. M. , Cohen H. J.
Published: March 2018

Analyzing multivariate clinical data to identify subclasses of patients being treated for a specific disease may improve patient management and increase understanding of the behavior of disease under clinical conditions. In some cases, patients have been classified on prognostic characteristics using standard risk assessment procedures (e.g.. Cox’ regression). This requires long term follow-up, differentiates patients only on attributes relevant to survival, and assumes that patients are sampled from a common population. Other approaches involve the use of clustering algorithms to classify patients into categories based on multiple clinical attributes. We illustrate the use of a multivariate statistical procedure to directly characterize patients on multiple clinical characteristics. The procedure is designed to analyze discrete response data with parameters representing individual differences within groups. Its use is illustrated for patients with Stage I melanoma in determining how age is related to treatment response in different patient groups.
Balancing Acute and Long-term Care: The Mathematics of Throughput in Departments of Geriatric Medicine
Authors: Harrison G. W. , Millard P. H.
Published: March 2018

The empirical distribution of length of stay of patients in departments of geriatric medicine is fit extremely well by a sum of two exponentials. Most of the patients in a geriatric department are rehabilitated and discharged or they die within a few weeks of admission, but the few who become long-stay patients remain for months or even years. A model is presented for the flow of patients through a geriatric department, which has analogies to models of drug flow in pharmacokinetics. The theoretical model explains why the empirical pattern of length of stay in the occupied beds fits a sum of two exponentials; conversely, the empirical distribution, obtained from the midnight bed state report, can be used to study the effect of various policy decisions on both immediate and future admission rates for the department, and shows the benefits of policies which reduce long-stay patient numbers by improving long-stay rehabilitation.
Comparison of Rheumatological Diagnoses by a Bayesian Program and by Physicians
Authors: Moens H. J. , van der Korst J. K.
Published: March 2018

A Bayesian decision support system was developed for the diagnosis of rheumatic disorders. Knowledge in this system is represented as evidential weights of findings. Simple weights were calculated as the logarithm of likelihood ratios on the basis of 1,000 consecutive patients from a rheumatological clinic. The effect of various methods to improve performance of the system by modification of the weights was studied. Three methods had a mathematical basis; a fourth consisted of weights adapted by a human expert, which allowed inclusion of diagnostic rules such as defined in widely accepted criteria sets. The system’s performance was measured in a test population of 570 different cases from the same clinic and compared with predictions of diagnostic outcome made by rheumatologists. The weights from a human expert gave optimal results (sensitivity 65% and specificity 96%), that were close to the physicians’ predictions (sensitivity 64% and specificity 98%). The methods to measure the performance of the various models used in this study emphasize sensitivity, specificity and the use of receiver operating characteristics.
Medical Reasoning and Patient Requests in Decision-Making for Female Genitourinary Infections
Authors: Timpka T. , Buur T.
Published: March 2018

The aim of this study was to investigate General Practitioners’ (GPs’) collection and analysis of data on women presenting with lower genitourinary (GU) complaints, also taking into account patient preferences. For 135 patients seen after nurse triage, eleven GPs recorded the clinical data they had explored, an evaluation of the patient’s desire (or not) for medical interventions, a preliminary diagnosis with certainty estimate, and management actions.

Whether a clinical data item was explored varied between 97% of the patients for fever to 15% for pelvic examination. Decisions regarding diagnosis followed to a large extent results from screening laboratory tests. For prescription of antibiotics the patient’s desire (or not) for medical interventions was a significant discriminant. The GPs reported the lowest diagnostic certainty for diagnosis of urethritis, the highest for cystitis. Factors contributing to physicians’ uncertainty in their decisionmaking were assumed patient reluctance for medical interventions and negative screening tests.

In conclusion, patient requests and preferences significantly influenced the GPs, even though results from screening laboratory tests were mainly used as the basis for decisions. The high reliance on screening tests may often cause other clinical information to be neglected. Thus, the uncertainty regarding patients with negative laboratory test results may reflect that important information is not included in the clinical analysis.
Poisson Approximation to a Negative Binomial Process in the Surveillance of Rare Health Events
Authors: Gallus G. , Marchi M. , Radaelli G.
Published: March 2018

The Poisson approximation to a negative binomial process is evaluated regarding the surveillance of rare health events in the framework of the “Sets” scheme. This scheme defines an alarm in terms of “distance” between consecutive events of interest. The system’s parameters are determined by minimizing the expected delay for an alarm when a given increase in the event rate has occurred, subject to a restriction on the rate of false alarms. It is shown that the main consequence of the Poisson approximation lies in an increase of the false alarm probability with respect to the assigned one, whilst influence on the expected delay for a true alarm is lower. It is, however, found that over a large range of practical instances, the Poisson assumption provides a reasonable description of the negative binomial process.
Modelling and Simulation of Complex Control Structures in Cell Biology
Authors: Sandblad B. , Meinzer H.P.
Published: March 2018

Biological and biomedical tissues and organs represent very complex and highly dynamic systems. The problem to model such complex systems is twofold. First, it is necessary to identify and describe the biological properties and the connecting control mechanisms of the studied system and its subparts. Here, biological knowledge is often missing. Secondly, we are confronted with the problem to formulate the model of the control structure in a form that allows model analysis. Here, a normal mathematical formalism is often inadequate. To solve these modelling problems and to develop methods for building models of complex control structures that will enable the formulation of dynamic systems in biology, a framework for building such models is presented. The model framework is here mainly used for studies of dynamic cell structures, but the possible application areas are more general. An example is given for modelling cell structures of epithelial tissues in the intestine.
MS2/Cardio: Towards a Multi-Service Medical Software for Cardiology
Authors: Combi C. , Pozzi G. , Rossi R. , Pinciroli F.
Published: March 2018

Many clinics are interested to use software packages in daily practice, but lack of integration of such packages seriously limits their scope. In practice this often entails switching between programs and interrupting the run of an individual program. A multi-task approach would not solve this problem as it would not eliminate the need to input the same data many times, as often occurs when using separate packages. The construction of a Multi-Service Medical Software package (MSx2) is described, which was also developed as an example of practical integration of some clinically relevant functions. The package runs on a personal computer in an MS-DOS environment and integrates a time-oriented medical record management unit (TOMRU) for data of ambulatory patients, and a drug information management unit (DIMU) concerning posology, content, effects, and possible interactions. Of the possible database configurations allowed by MSx2, the cardiology patient database (MSx2/C) and hypertensive patient database (MSx2/H) were developed and described here. Clinical information to be included in the configurations was obtained after discussion and consensus of clinical practitioners. MSx2/C was distributed to several hundred clinical centers during computerized courses to train future users. MSx2 can easily transfer patient data to statistical processing packages.
Application of Adjusted Survival Curves to Renal Transplant Data
Authors: Bender R. , Schultz A. , Pichlmayr R. , Grouven U.
Published: March 2018

An important means in the analysis of survival time data is the estimation and graphical representation of survival probabilities. In this paper unifactorial parametric and non-parametric survival curve estimators and two types of adjusted survival curves based on a parametric multifactorial approach are applied to renal transplant data. It is shown that the resulting survival curves can differ substantially. The unifactorial survival curves yield biased results in case of serious disequilibrium in the data. This drawback of the unifactorial methods has been overcome by the use of adjusted survival curves which take possible distortions in the data set into account. The benefits of adjusted survival curves in assessing potentially prognostic factors are elucidated by the application to data from renal transplantation.
Computerized Electrocardiogram Diagnosis: Fuzzy Approach
Authors: Degani Rosanna
Published: March 2018

This paper investigates the computerized analysis of electrocardiographic signals. The biological variability, the laáck of standards in the definition of measurements and of diagnostic criteria make the classification problem a complex task. Two basic methods of the diagnostic process are described: the statistical model and the deterministic approach. In particular, a model for ECG classification will be illustrated where the imprecise knowledge of the state of cardiac system and the vague definition of the pathological classes are taken care of by means of the fuzzy set formalism.
Health Program Effectiveness Measurement: A Case of Degenerative Disease
Authors: Klementiev A. A.
Published: March 2018

An administrator of a Health Program aiming at the control of a specified disease has a need for a quantitative evaluation of the consequences of the Program’s realization. On the population level, Lifetime Lost (LTL) figures calculated for both target and reference populations might be used for this purpose. The LTL methodology provides a user with a new procedure for medical data processing. It allows to estimate the LTL values from mortality data only, without the laborious procedure of registration of the morbidity episodes in target and reference populations. This approach is valid for a special case of degenerative diseases.
Significant Left Ventricular Hypertrophy in Subjects with Normal Resting Pressures but Exaggerated Pressure Response During Light Exertion
Authors: Bowyer A. F. , Thomas R. A. , Cannon C. E.
Published: March 2018

Concentric left ventricular hypertrophy (LVH) frequently occurs in subjects with normal resting systolic and diastolic pressures (SP and DP, respectively). LVH in this normotensive-hypertrophic group (NH) may be due to an abnormally exaggerated pressure response to exercise. The SP and DP responses to exercise were studied in 130 subjects free from coronary artery disease or cardiomyopathy. The NH subjects (n = 35) had normal resting pressure (SP ≤140 and DP ≤85 mmHg) and increased LV wall thickness (T) by echocardiography (T >1.1 cm). A normal control group (NN) (n = 57) and a hypertensive control group (HH) (n = 23) were simultaneously evaluated. The original groups, subgroups censored for age and weight, and matched-pair subgroups demonstrated greater exercise SP for NH than for NN (p <0.005). Moreover, the rate of SP increase with exercise was greater for NH than for NN or HH (p <0.05). Hence, an exaggerated exercise SP response may have been the stimulus for LVH in these NH subjects.
A Methodology for Determining Patients’ Eligibility for Clinical Trials
Authors: Kemper C. A. , Lane N. M. , Carlson R. W. , Musen M. A. , Tu S. W.
Published: March 2018

The task of determining patients’ eligibility for clinical trials is knowledge and data intensive. In this paper, we present a model for the task of eligibility determination, and describe how a computer system can assist clinical researchers in performing that task. Qualitative and probabilistic approaches to computing and summarizing the eligibility status of potentially eligible patients are described. The two approaches are compared, and a synthesis that draws on the strengths of each approach is proposed. The result of applying these techniques to a database of HIV-positive patient cases suggests that computer programs such as the one described can increase the accrual rate of eligible patients into clinical trials. These methods may also be applied to the task of determining from electronic patient records whether practice guidelines apply in particular clinical situations.
The Explanatory Role of Events in Causal and Temporal Reasoning in Medicine
Authors: Buekens F. , Ceusters W. , De Moor G.
Published: March 2018

The logic of time and the way we reason about time is intrinsically connected with the way we reason about causality. In this paper, we focus our attention on some of the less obvious ways in which reasoning about time and causality interact. It is explained why in temporal reasoning a firm distinction has to be made between the ontology, i. e., what happens, and the way we describe the ontology. Temporal events need to be redescribed in such a way that they causally explain why some of the events are followed by the others. While building a temporal/causal theory, certain events may be omitted, not because they do not play a causal role, but because they do not play an explanatory role. In doing so, it is possible to eliminate the distinction between theories representing time as dense, and theories that represent time as discrete.
On-Line Beat-to-Beat Monitoring of Spectral Parameters of Heart Rate Variability Signal Using a Pole-Tracking Algorithm
Authors: Bianchi A. M. , Cerutti S. , Mainardi L. T.
Published: March 2018

Spectral parameters extracted from the heart rate variability (HRV) signal are obtained on a beat-to-beat basis, following a procedure which uses two recursive algorithms. In the first step of the procedure the set of the AR model coefficients is updated each time a new RR value is available. Then from the estimated AR model parameters, the new position of the poles of the model transfer function in the complex z-plane is evaluated and, finally, through a residual calculation, it is possible to calculate the spectral parameters which quantify the control of the autonomic nervous system in assessing the cardiac frequency (i.e., power and frequency of LF and HF components). The whole procedure has first been tested on a simulated time series, in order to evaluate its performance in tracking the dynamic changes during different conditions; next the algorithms were employed in the study of the HRV signal for continuous monitoring of non-stationary conditions.
Trends in Nonlinear Signal Processing
Authors: Hämäläinen M. , Lipping T. , Neuvo Y.
Published: March 2018

In this paper, we review several nonlinear filtering methods having desirable complementary properties to those of linear filters. Most of these methods are based on the median filter. Basic properties of these filters as well as some of their applications are reviewed.
A Noxious Agents Information System with State-wide Participation of the Public Health Service
Authors: Kobusch A.-B. , Kohn-Schulze E. , Fehr R.
Published: March 2018

With environmental health receiving increased attention by Public Health Services, there is a need to access as efficiently as possible detailed, current, and reliable information of physico-chemical, epidemiological, and toxicological as well as regulatory and legal aspects on this subject. Correspondingly, targets 19 and 35 of WHO’s “Health for all 2000” strategy all for information systems to meet these demands. On this basis, a Noxious Agents Information System (NIS) was designed with three components: PC-based information workstations allowing access to portable and online databases; a dedicated modular database system providing “immediate answers” as well as support for more comprehensive information retrieval; and a cooperative network for training, information exchange, and consultation. During 1992-93, the system was introduced in Germany in the State of North Rhine-Westphalia, and 54 of 59 eligible institutions (92%) of the Public Health Service decided to participate, proving a virtually state-wide introduction to be feasible. Details are presented of the NIS concept and its realization, and limitations and future perspectives are discussed.