bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Mandatory Data Collection on Multiresistant Bacteria for Internal Surveillance in a Hospital
Authors: Mikolajczyk R. T. , Krämer A. , Sagel U.
Published: March 2018

Objectives:
Multiresistant pathogens cause major clinical problems and considerably increase treatment costs. Since 2001 the Protection Against Infection Act (PIA) obligates hospitals in Germany to the documentation of multiresistant bacteria. We analyzed the use of these data for routine internal surveillance.

Methods:
We used standard data collected for the mandatory documentation and studied consecutive diagnoses of Methicillin-resistant Staphylococcus aureus (MRSA) in a 893-bed tertiary level hospital in North Rhine-Westphalia in Germany. Based on the Poisson distribution for the cumulative yearly incidence of MRSA, we defined a threshold level for an outbreak.

Results:
During a 12-month time period 80 patients were diagnosed with MRSA. The time structure and spatial distribution of different MRSA phenotypes (defined through specific antibiotic resistance patterns) were consistent with the within-hospital transmission. In the two preceding time periods of 12 months each, 15 respectively 8 patients with MRSA were found. The defined alert threshold level for cumulative yearly incidence was crossed in the beginnings of the outbreak.

Conclusion:
Monitoring the mandatory data collected on multiresistant bacteria allows the early detection of accumulations suspect for the within-hospital transmission. This knowledge can be used for a fast reaction and breaking off the transmission chains.
Knowledge and Process Management in Health Care Organizations
Authors: Stefanelli M.
Published: March 2018

Objective:
Medical knowledge management and care process management have become to be considered as valuable strategic assets that can lead to sustained increase in Health Care Organization (HCO) performance. Thus, it is essential to investigate which are the enablers for promoting knowledge-based organizations (people, organization, process, and system perspectives). Although they are essential for a HCO to manage knowledge effectively, it is still unclear how to employ them in more principled fashion. This requires innovative management strategies to determine effective ways of utilizing knowledge resources and capabilities available both within and outside the organization.

Method:
This paper reviews knowledge and process management theories, methods, and technologies that are potentially effective in building high performance HCOs. They come from a variety of fields behind computer science and medical informatics, e.g. from business and organization sciences to psychological and cognitive sciences, from epistemology to sociology. However, the success in developing future Health Information Systems (HIS) requires their incorporation into a new conceptual framework after recognizing how peculiar are the characteristics of HCOs with respect to other organizations. Investigating the nature of knowledge, in general, and of medical knowledge, in particular, is essential to define which services the future HIS should provide to foster collaboration between patients and health professionals. The knowledge creation process is then described in order to emphasize its dynamic and social characteristics. The potential of workflow technology for building innovative HISs is analyzed together with several basic research issues which are very challenging for researchers in the field.

Result:
A framework for augmenting the conceptual analysis of theories, methods, tools and effects of knowledge management in building high performance HCOs.
Selected Impressions on the Beginning of the Electronic Medical Record and Patient Information
Authors: Klar R.
Published: March 2018

Objectives:
To present an overview of early European and American work on Electronic Medical Records and patient information.

Method:
The invited lectures of “pioneers of electronic patient information” given at the farewell symposium of Wolfgang Giere in Frankfurt, Germany, are summarized and discussed.

Results:
The origin of medical record writing goes back to Hippocrates and over many centuries this important medical duty was regarded as an annoying, laborious and error-prone task. First steps towards a better medical record started in 1936 with punch cards. In the 1960s the minimum basic data set, a unique patient ID was introduced and even for outpatients first com-puterized medical record systems were developed applying some important standards and well accepted data structures. Nowadays multimedia are included in patient record systems, highly specialized subsystems e.g. for radiology or cardiology are available, and semantic and statistic mining techniques as well as medical classifications and standardized terminologies support evaluation. All these methods should primarily improve the quality of care, reduce errors, improve communication between multiple specialists, reduce wait times for patients and improve efficiency.

Conclusions:
Over decades it became obvious that the structure of a medical record notably for coded data but also for narrative text and pictures must be carefully modelled. Well maintained standardized health terminologies and medical classifications are important issues for a user-friendly electronic medical record, which bring benefits for clinicians and patients.
A Terminological and Ontological Analysis of the NCI Thesaurus
Authors: Smith B. , Goldberg L. , Ceusters W.
Published: March 2018

Objective:
The National Cancer Institute Thesaurus is described by its authors as “a biomedical vocabulary that provides consistent, unambiguous codes and definitions for concepts used in cancer research” and which “exhibits ontology-like properties in its construction and use”. We performed a qualitative analysis of the Thesaurus in order to assess its conformity with principles of good practice in terminology and ontology design.

Materials and Methods:
We used both the on-line browsable version of the Thesaurus and its OWL-representation (version 04.08b, released on August 2, 2004), measuring each in light of the requirements put forward in relevant ISO terminology standards and in light of ontological principles advanced in the recent literature.

Results:
We found many mistakes and inconsistencies with respect to the term-formation principles used, the underlying knowledge representation system, and missing or inappropriately assigned verbal and formal definitions.

Conclusion:
Version 04.08b of the NCI Thesaurus suffers from the same broad range of problems that have been observed in other biomedical terminologies. For its further development, we recommend the use of a more principled approach that allows the Thesaurus to be tested not just for internal consistency but also for its degree of correspondence to that part of reality which it is designed to represent.
A Signal Processing Pipeline for Noninvasive Imaging of Ventricular Preexcitation
Authors: Hanser F. , Pfeifer B. , Seger M. , Hintermüller C. , Modre R. , Tilg B. , Trieb T. , Berger T. , Roithinger F. X. , Hintringer F. , Fischer G.
Published: March 2018

Objectives:
Noninvasive imaging of the cardiac activation sequence in humans could guide interventional curative treatment of cardiac arrhythmias by catheter ablation. Highly automated signal processing tools are desirable for clinical acceptance. The developed signal processing pipeline reduces user interactions to a minimum, which eases the operation by the staff in the catheter laboratory and increases the reproducibility of the results.

Methods:
A previously described R-peak detector was modified for automatic detection of all possible targets (beats) using the information of all leads in the ECG map. A direct method was applied for signal classification. The algorithm was tuned for distinguishing beats with an adenosine induced AV-nodal block from baseline morphology in Wolff-Parkinson-White (WPW) patients. Furthermore, an automatic identification of the QRS-interval borders was implemented.

Results:
The software was tested with data from eight patients having overt ventricular preexcitation. The R-peak detector captured all QRS-complexes with no false positive detection. The automatic classification was verified by demonstrating adenosine-induced prolongation of ventricular activation with statistical significance (p <0.001) in all patients. This also demonstrates the performance of the automatic detection of QRS-interval borders. Furthermore, all ectopic or paced beats were automatically separated from sinus rhythm. Computed activation maps are shown for one patient localizing the accessory pathway with an accuracy of 1 cm.

Conclusions:
The implemented signal processing pipeline is a powerful tool for selecting target beats for noninvasive activation imaging in WPW patients. It robustly identifies and classifies beats. The small beat to beat variations in the automatic QRS-interval detection indicate accurate identification of the time window of interest.
Evaluation of Health Information Applications – Challenges Ahead of Us
Authors: Brender J.
Published: March 2018

Objectives:
The aim of the paper is to review the challenges for evaluation in the light of characteristics of the healthcare sector, present as well as future.

Methods:
The approach is a synthesis based on highlights from the literature.

Results:
The review addresses the following issues: 1) the role of evaluation activities within a systems development or implementation context; 2) suggestions on the nature of success and failure characteristics; and 3) evaluation aspects viewed in the perspective of different types of systems. Constructive evaluation, evaluation being the act of bringing about a decision-making basis, is perceived as the means to minimize failure and maximize success from the very beginning of the development or implementation. Based on these discussions, the challenges that evaluation and evaluators are facing are debated.

Conclusion:
The ultimate challenge ahead is first to fill the gap of presently needed evaluation methods. This need is in particular related to evaluation of cognitive and work process-oriented aspects of IT-based solutions. Finally, the challenge is to provide constructive evaluation methods and methodologies for dealing with the full complexity and dynamics of the target domain, for application within the entire life-cycle of the IT-based systems and solutions.
Lest Formalisms Impede Insight and Success: Evaluation in Health Informatics
Authors: Anglin C. , Schaafsma J. , Pantazi S. , Grimm N. , Moehr J. R.
Published: March 2018

Objectives:
To illustrate the advantages of an open-ended formative evaluation approach using a project-specific selection of methods over the controlled trial approach in the evaluation of health information systems. To illustrate factors leading to success and others impeding it in a telehealth project.

Methods:
The methods and results of an evaluation of the BC Telehealth Program are summarized.

Results:
The evaluation gave a comprehensive picture of the project, including assessment of the effects of an array of telehealth applications, and their economic impact. Factors leading to success and others preventing it are identified from the level of overall program management to the project specifics. The results include unanticipated effects and explanations for their reasons of occurrence. Neither the comprehensiveness of information nor the timeliness was achieved in a related project using a controlled trial approach.

Conclusions:
Not all types of health information system projects can be evaluated using the controlled trial approach. This approach may impede important insights. It is also usually much less efficient. Funding agencies and journal editors have to take this into account when selecting projects for funding and submissions for publication.
Factors Influencing Success and Failure of Health Informatics Systems
Authors: Ammenwerth E. , Nykänen P. , Talmon J. , Brender J.
Published: March 2018

Objectives:
The aim is to gain information on factors influencing success and failure for Health Informatics applications from a group of medical informaticians.

Methods:
Based on the presentations at a special topic conference on success and failure in Health ICT and analysis of the proceedings, we conducted a Delphi study on success and failure aspects.

Results:
A total of 110 success factors and 27 failure criteria were identified, distributed on categories like functional, organizational, behavioral, technical, managerial, political, cultural, legal, strategy, economy, education and user acceptance. These factors and criteria were rated for six different system types. Unanimously it was agreed that “collaboration and co-operation” and “setting goals and courses” are “essential for the success” of clinical systems, and “user acceptance” for educational systems. Similarly, the score “essential in order to avoid a failure” were given unanimously on clinical systems for “response rate and other performance measures” and on administrative systems for “not understanding the organizational context” with “not understanding or foreseeing the extent to which the new IT-system affects the organization, its structure and/or work procedures” as the highest scoring sub-item.

Conclusions:
All success factors and failure criteria were considered relevant by the Delphi expert panel. There is no small set of relevant factors or indicators, but success or failure of a Health ICT depends on a large set of issues. Further, clinical systems and decision support systems depend on more factors than other systems.
A Modified Method of Activity-based Costing for Objectively Reducing Cost Drivers in Hospitals
Authors: Toyabe S. , Kurashima S. , Okada M. , Akazawa K. , Cao P.
Published: March 2018

Objectives:
Activity-based costing (ABC) is widely used to precisely allocate indirect costs to medical services. In the ABC method, the indirect cost is divided among the medical services in proportion to the volume of “cost drivers”, for example, labor hours and the number of hours of surgery. However, the workload of data collection of cost drivers can be time-consuming and a considerable burden if there are many cost drivers. The authors aim to develop a method for objectively reducing the cost drivers used in the ABC method.

Methods:
In the ABC method, the cost driver is assigned for each activity. We assume that these activities and cost drivers are the best combination. Our method, that is cost driver reduction (CDR), can objectively select surrogates of the cost drivers for each activity in ABC from candidate cost drivers. Concretely, the total indirect cost of an activity is temporarily allocated to the medical services using each candidate of cost drivers. The difference between the costs calculated by each candidate and the proper cost driver used in ABC is calculated to evaluate the similarity by the evaluation function.

Results:
We estimated the cost of laboratory tests using our method and revealed that the number of cost drivers could be reduced from seven in the ABC to four. Similarly, the results of cost estimation obtained by our method were as accurate as those calculated using the ABC.

Conclusions:
Our method provides two advantages compared to the ABC method: 1) it provides results that are as accurate as those of the ABC method, and 2) it is simpler to perform complicated estimation of hospital costs.
Computer-Assisted Analysis of 4D Cardiac MR Image Sequences after Myocardial Infarction
Authors: Ehrhardt J. , Stork A. , Bansmann M. P. , Lund G. K. , Handels H. , Säring D.
Published: March 2018

Objectives:
Spatial-temporal MR image sequences of the heart contain information about shape and motion changes and pathological structures after myocardial infarction. In this paper a Heart Analysis Tool (HeAT) for the quantitative analysis of 4D MR image sequences of infarct patients is presented.

Methods:
HeAT supports interactive segmentation of anatomical and pathological structures. Registration of Cine- and DE-MR image data is applied to enable their combined evaluation during the analysis process. Partitioning of the myocardium in segments enables the analysis with high local resolution. Corresponding segments are generated and used for inter/intra-patient comparison. Quantitative parameters were extracted and visualized.

Results:
Parameters like endocard movement in the infarcted area of six infarct patients were computed in HeAT. Parameters in the infarct area show the expected dysfunctional characteristics. Based on theses parameters passive endocardial movement and myocardial areas with decreased contraction could be identified.

Conclusion:
In contrast to other software tools HeAT supports the combination of contour information of Cine-MR and DE-MR, local analysis with high resolution and inter/intra patient comparison. HeAT enables an observer-independent evaluation of the complex cardiac image data. Using HeAT in further studies can increase the understanding of left ventricle(LV) remodeling.
Statistical Methods for the Validation of Questionnaires
Authors: Schmidt M. E. , Steindorf K.
Published: March 2018

Objectives:
Questionnaires used in epidemiological studies should be validated. However, unclarity exists about the appropriate statistical methods and interpretation of validation studies. Thus, we investigated the theory and practice of statistical evaluation approaches.

Methods:
Using three platforms, a literature review, own simulations, and a validation study performed by ourselves, we worked out relevant limitations, advantages, and new important aspects of evaluation methods.

Results:
Our systematic literature review, based on physical activity questionnaires, revealed that correlation coefficients are still the common approach in validation studies, found in 41 of 46 reviewed publications (89.1%). This practice has been criticized in the theoretically oriented literature for more than 20 years. Appropriate evaluation methods as recommended by Bland and Altman were found in only ten publications (21.7 %).

We showed that serious bias in questionnaires can be revealed by Bland-Altman plots but may remain undetected by correlation coefficients. With our simulations we refuted the argument that correlation coefficients properly investigate whether a questionnaire ranks the subjects sufficiently well. Further, with Bland-Altman analyses we could evaluate differential errors with respect to case-control status in our validation study. Yet, this was not possible with correlation coefficients, because they generally do not identify systematic bias. In addition, we show a potential pitfall in the interpretation of Bland-Altman plots that might occur in specific rare instances.

Conclusions:
The commonly used correlation approach can yield misleading conclusions in validation studies. A more frequent and proper use of the Bland-Altman methods would be desirable to improve epidemiological data quality.
A Note on Testing for Intervention Effects on Binary Responses
Authors: Henderson R. , Kao C.-F. , Friede T.
Published: March 2018

Objectives:
In some circumstances controlled trials are not feasible and treatments can only be evaluated using clinical databases. Here we consider the situation where treatment is introduced at a particular calendar time and can only be evaluated by comparison with historical controls. In these circumstances Heuer and Abel recommended using change-point methods to search for change in characteristics over the whole study period rather than simply comparing treated and untreated patients. Their recommendation is to only conclude that the intervention had an effect if a change-point could be demonstrated close in time to the introduction of the new treatment. This reduces the risk of false positives caused by confounding changes in population characteristics or changes in patient management. For binary data we develop a method that follows their philosophy and apply it to an observational study in the treatment of pin sites after orthopaedic surgery.

Methods:
Tests for change in binomial probabilities based on Brownian bridge and Hansen’s approximation for maximally selected X
2 statistics are compared to an exact test by Worsley. The approximate method is generalized to logistic regression models allowing for covariates.

Results:
The agreement of the exact and approximate method is good for sample sizes of 100 or more. The actual test size of the Hansen approximate test allowing for covariates is close to the nominal level, whereas the Brownian bridge approximation is slightly conservative. The change in pin site treatment significantly reduces the risk of infection for both adults and children.

Conclusions:
We consider the Hansen approximation to provide a very good and very simple method for obtaining the p-value when testing for a change in binary data event probabilities, with or without covariates.
Extended Cooperation in Clinical Studies through Exchange of CDISC Metadata between Different Study Software Solutions
Authors: Wiegelmann S. , Verplancke P. , Ohmann C. , Kuchinke W.
Published: March 2018

Objectives:
Our objectives were to analyze the possibility of an exchange of an entire clinical study between two different and independent study software solutions. The question addressed was whether a software-independent transfer of study metadata can be performed without programming efforts and with software routinely used for clinical research.

Methods:
Study metadata was transferred with ODM standard (CDISC). Study software systems employed were MACRO (InferMed) and XTrial (XClinical). For the Proof of Concept, a test study was created with MACRO and exported as ODM. For modification and validation of the ODM export file XML-Spy (Altova) and ODM-Checker (XML4Pharma) were used.

Results:
Through exchange of a complete clinical study between two different study software solutions, a Proof of Concept of the technical feasibility of a system-independent metadata exchange was conducted successfully. The interchange of study metadata between two different systems at different centers was performed with minimal expenditure. A small number of mistakes had to be corrected in order to generate a syntactically correct ODM file and a “vendor extension” had to be inserted. After these modifications, XTrial exhibited the study, including all data fields, correctly. However, the optical appearance of both CRFs (case report forms) was different.

Conclusions:
ODM can be used as an exchange format for clinical studies between different study software. Thus, new forms of cooperation through exchange of metadata seem possible, for example the joint creation of electronic study protocols or CRFs at different research centers. Although the ODM standard represents a clinical study completely, it contains no information about the representation of data fields in CRFs.
Optimizing Diagnostic Test Sequences: The Probability Modifying Plot
Authors: Vries Robbé P. F. de , Verbeek A. L. M. , Severens J. L.
Published: March 2018

The problem of deciding the optimal sequence of diagnostic tests can be structured in decision trees, but unmanageable bushy decision trees result when the sequence of two or more tests is investigated. Most modelling techniques include tests on the basis of gain in certainty. The aim of this study was to explore a model for optimizing the sequence of diagnostic tests based on efficiency criteria. The probability modifying plot shows, when in a specific test sequence further testing is redundant and which costs are involved. In this way different sequences can be compared. The model is illustrated with data on urinary tract infection. The sequence of diagnostic tests was optimized on the basis of efficiency, which was either defined as the test sequence with the least number of tests or the least total cost for testing. Further research on the model is needed to handle current limitations.
Stepwise Evaluation of Information Systems in an University Hospital
Authors: Kuch R. , Prokosch H.-U. , Dudeck J. , Bürkle T.
Published: March 2018

A prospective intervention study with historical control has been performed at Giessen University Hospital, Germany, to investigate the influence of electronic data processing systems on nurses’ working environment. Two wards of the medical department were selected for this study, using the combined approach of work-sampling methods and questionnaires. In the first intervention a central information system with restricted functions was introduced. For the second intervention an additional nursing information system was installed. The distribution of nurses’ worktime into the fields of general nursing care, specific nursing care and administrative activities was not influenced by electronic data processing. No time saving could be measured. Results of the questionnaires did, however, indicate a positive influence of the hospital information system on nurses’ working environment.
Comparison of Genetic Algorithms and Other Classification Methods in the Diagnosis of Female Urinary Incontinence
Authors: Juhola M. , Lammi S. , Viikki K. , Laurikkala J.
Published: March 2018

Galactica, a newly developed machine-learning system that utilizes a genetic algorithm for learning, was compared with discriminant analysis, logistic regression, k-means cluster analysis, a C4.5 decision-tree generator and a random bit climber hill-climbing algorithm. The methods were evaluated in the diagnosis of female urinary incontinence in terms of prediction accuracy of classifiers, on the basis of patient data. The best methods were discriminant analysis, logistic regression, C4.5 and Galactica. Practically no statistically significant differences existed between the prediction accuracy of these classification methods. We consider that machine-learning systems C4.5 and Galactica are preferable for automatic construction of medical decision aids, because they can cope with missing data values directly and can present a classifier in a comprehensible form. Galactica performed nearly as well as C4.5. The results are in agreement with the results of earlier research, indicating that genetic algorithms are a competitive method for constructing classifiers from medical data.
Labeling and Filtering of Medical Information on the Internet
Authors: Diepgen T. L. , Eysenbach G.
Published: March 2018

Internet information undergoes no quality controls and virtually anybody can publish anything. Because of this, it is difficult for searchers to take information retrieved from the Internet at face value. A related problem is the uncontrolled promotion of medical products on the Internet. A further problem of today’s Internet is that authors use no uniform keywords and other descriptive labels, which deteriorates the quality of search results. A solution for all these problems could be widespread use of descriptive and evaluative metainformation associated with medical Internet information. Our concept is based on a recently established infrastructure for assigning metadata to Internet information, the so-called PICS Standard (Platform for Internet Content Selection). We prototyped a PICS-based rating vocabulary for medical information (med-PICS), containing descriptive and evaluative categories, to be used by the webauthor and third-party label services (such as medical associations), respectively. We propose an international effort to assign metadata to medical Internet information.
Managers Reports of Automated Coding System Adoption and Effects on Data Quality
Authors: Jameson R. , Lorence D. P.
Published: March 2018

Objective: Assessment of the adoption of automated classification (encoder) systems in healthcare settings and related effects on perceived data quality.

Methods: Survey of all U.S. accredited medical records managers, summarizing their reports of automated encoding systems and data quality change following adoption of systems.

Results: Significant improvement in data was seen from adoption of automated encoding systems, though variation existed across regions and key demographic variables.

Conclusion: At a national level, there is a need to minimize data quality variation and ensure some degree of nationwide uniformity in the performance of coding systems. If healthcare providers are expected to trust coded data for comparative purposes, there will be a like need for more uniform and standardized system-based performance benchmarks.
Legal Pitfalls in Teleneuropathology
Authors: Walter K. F. J. P. , Walter G. F.
Published: March 2018

Objectives: This study aims to emphasize legal pitfalls, especially the often underestimated liability issues for both clients of telemedicine and “tele-doctors”. The main relevance of telemedicine lies in its capability to link medical practitioners and remote hospitals to larger or specialized facilities in a very fast electronic manner. This may become even more important due to current increases in subspecialization and the demand for more precise diagnosis and consultation in difficult cases. However, every potential user or client of telemedicine should keep in mind that several questions of law are involved.

Methods: In this paper, two case studies representative of practical teleneuropathology scenarios are described. The assessment of the legal implications is focused on the personal liability of the teleneuropathologist.

Results: The far-reaching personal liability of the teleneuropathologist can lead to situations in which neither the insurance of the hospital nor the private professional liability insurance could be called on to refund possible damages for health impairments of a patient.

Conclusions: In Germany, a contractual exclusion of liability in health matters is not admissible. With regard to the European situation, international agreements such as a European telemedicine law could be conducive to the future border-crossing development of telemedicine though, to date, the legal competencies remain with the single member countries of the European Community.
Electronic Signature for Medical Documents – Integration and Evaluation of a Public Key Infrastructure in Hospitals
Authors: van der Haak M. , Hartmann M. , Haux R. , Schmücker P. , Brandner R.
Published: March 2018

Objectives: Our objectives were to determine the user-oriented and legal requirements for a Public Key Infrastructure (PKI) for electronic signatures for medical documents, and to translate these requirements into a general model for a signature system. A prototype of this model was then implemented and evaluated in clinical routine use.

Methods: Analyses of documents, processes, interviews, observations, and of the available literature supplied the foundations for the development of the signature system model. Eight participants of the Department of Dermatology of the Heidelberg University Medical Center evaluated the implemented prototype from December 2000 to January 2001, during the course of an intervention study. By means of questionnaires, interviews, observations and database analyses, the usefulness and user acceptance of the electronic signature and its integration into electronic discharge letters were established.

Results: Since the major part of medical documents generated in a hospital are signature-relevant, they will require electronic signatures in the future. A PKI must meet the multitude of responsibilities and security needs required in a hospital. Also, the signature functionality must be integrated directly into the workflow surrounding document creation. A developed signature model, fulfilling user-oriented and legal requirements, was implemented using hard and software components that conform to the German Signature Law. It was integrated into the existing hospital information system of the Heidelberg University Medical Center. At the end of the intervention study, the average acceptance scores achieved were x = 3,90; sD = 0,42 on a scale of 1 (very negative attitude) to 5 (very positive attitude) for the electronic signature procedure. Acceptance of the integration into computer-supported discharge letter writing reached x = 3,91; sD = 0,47. On average, the discharge letters were completed 7.18 days earlier.

Conclusion: The electronic signature is indispensable for the further development of electronic patient records. Application-independent hard and software components, in accordance with the signature law, must be integrated into electronic patient records, and provided to certification services using standardized interfaces. Signature-oriented workflow and document management components are essential for user acceptance in routine clinical use.
Implications of Nondifferential Misclassification on Estimates of Attributable Risk
Authors: Vogel C. , Gefeller O.
Published: March 2018

Objectives: Only the effects of isolated nondifferential misclassification of exposure or disease on the estimates of attributable risk have been discussed in the literature. The aim of this paper is to broaden the spectrum of scenarios for which implications of misclassification are available.

Methods: For this purpose, a matrix-based approach allowing a comprehensive, unified analysis of various structures of misclassification is introduced. The relative bias or – in the situation of covariate misclassification – the relative adjustment are presented for the different misclassification scenarios.

Results: Under nondifferential misclassification of exposure or disease, the attributable risk is biased towards the null with the only exception of perfect sensitivity of exposure classification or perfect specificity of disease classification both leading to an unbiased attributable risk. From these two marginal effects, the consequences of simultaneous nondifferential independent misclassification of exposure and disease on the attributable risk are derived in the matrix-based approach. Misclassification of a dichotomous covariate leads to partial adjustment.

Conclusions: To a large extent, the results for the attributable risk are in accordance with the well-known results for the relative risk. The algebraic differences between the two risk measures, however, make it necessary to repeat the methodological considerations for the attributable risk.
An Inventory of Publications on Computer-Based Medical Records: An Update
Authors: van der Lei J. , Moorman P. W.
Published: March 2018

Objectives: In 1998, we reported a steady increase in the number of publications indexed in MedLine with the MeSH term ‘Medical Records Systems, Computerized’. No signs indicating an increasing interest of high-impact medical journals to publish on the computer-based patient record could be determined. In this review we provide an update.

Methods: We retrieved and analyzed all English publications indexed before Feb 22 2002 in PubMed with the MeSH term ‘Medical Records Systems, Computerized’.

Results: We retrieved a total of 5856 publications, of which 1824 (31%) appeared in a journal with an impact factor in the year of publication. The total impact-score shows an upward trend.

Conclusions: The results show that the earlier observed increase in number of publications did not persist in the second half of the nineteen-nineties. Since the mid-nineties, there has been a steady yearly production of publications indexed with the MeSH term, reflecting a sustained interest in the domain. However, the volume of publications appearing in journals with higher impact factors is increasing. Furthermore, high-impact journals, such as the “British Medical Journal”, the “Lancet” and “Annals of Internal Medicine” regularly publish on the subject, reflecting an interest well beyond the medical informatics community.
Change Management of Shared and Local Versions of Health-Care Terminologies
Authors: Shahar Y. , Oliver D. E.
Published: March 2018

Local sites that adopt a shared health-care terminology for computer-based systems have local needs that prompt the local-terminology maintainers to make changes to the local version of the shared terminology. If the local site is motivated to conform to the shared terminology, then the burden lies with the local site to manage its own changes and to incorporate the changes of the shared version at periodic intervals. We call this process synchronization. We survey current approaches that address problems of sharing and local modification, and we present the CONCORDIA model, which supports carefully controlled divergence of a local version from a shared terminology. CONCORDIA provides the underlying design and methodology for the implementation of a synchronization-support tool.
Realization of Security Concepts for DICOM-based Distributed Medical Services
Authors: Thiel A. , Tolxdorff T. , Bernarding J.
Published: March 2018

Exploiting distributed hard- and software resources for tele-medicine requires a fast, secure, and platform-independent data exchange. Standards without inherent security mechanisms such as DICOM may ease non-authorized data access. Therefore, exemplary telemedical data streams were analyzed within the Berlin metropolitan area network using specialized magnetic resonance imaging techniques and distributed resources for data postprocessing. For secure DICOM communication both the Secure Socket Layer Protocol and a DICOM-conform partial encryption of patient-relevant data were implemented. Partial encryption exhibited the highest transfer rate and enabled a secure long-term storage. Different data streams between secured and unsecured networks were realized using partial encryption.
Nonparametric Selection Method of Survival Predictors with an Application to Breast Cancer
Authors: Troupé M. , Manuceau J. , Lánska V. , Vaillant J.
Published: March 2018

Mutual information between a survival variable and covariables provides a new tool for selecting covariables with a high predictive value whenever there is no reasonable parametric model with respect to the observed phenomena. The information rate carried out by covariables can be tested by means of a decomposition similar to the analysis of variance. Moreover, a method based on information conservation can be used for aggregating survival curves corresponding to different modalities of the same selected predictor which increases the prediction efficiency. These results are applied to survival data from 1304 patients with breast cancer followed over a period of ten years.
On Prognostic Models, Artificial Intelligence and Censored Observations
Authors: Anand S. S. , Hamilton P. W. , Hughes J. G. , Bell D. A.
Published: March 2018

The development of prognostic models for assisting medical practitioners with decision making is not a trivial task. Models need to possess a number of desirable characteristics and few, if any, current modelling approaches based on statistical or artificial intelligence can produce models that display all these characteristics. The inability of modelling techniques to provide truly useful models has led to interest in these models being purely academic in nature. This in turn has resulted in only a very small percentage of models that have been developed being deployed in practice. On the other hand, new modelling paradigms are being proposed continuously within the machine learning and statistical community and claims, often based on inadequate evaluation, being made on their superiority over traditional modelling methods. We believe that for new modelling approaches to deliver true net benefits over traditional techniques, an evaluation centric approach to their development is essential. In this paper we present such an evaluation centric approach to developing extensions to the basic k-nearest neighbour (k-NN) paradigm. We use standard statistical techniques to enhance the distance metric used and a framework based on evidence theory to obtain a prediction for the target example from the outcome of the retrieved exemplars. We refer to this new k-NN algorithm as Censored k-NN (Ck-NN). This reflects the enhancements made to k-NN that are aimed at providing a means for handling censored observations within k-NN.
Effects of Case Removal in Prognostic Models
Authors: Vinterbo S. , Ohno-Machado L.
Published: March 2018

Constructing and updating prognostic models that learn from training cases is a time-consuming task. The more compact, and yet informative, the training sets are, the faster one can build and properly evaluate such models. We have compared different regression diagnostic methods for selection and removal of training cases in prognostic models. Univariate determinations were performed using classical regression diagnostic statistics. Multivariate determinations were performed using (1) a sequential “backward” selection of cases, and (2) a non-sequential genetic algorithm. The genetic algorithm produced final models that kept few cases and retained predictive capability. A genetic algorithm approach to case selection may be better suited for guiding removal of cases in training sets than a univariate or a sequential multivariate approach, possibly because of its ability to detect sets of cases that are influential en bloc but may not be sufficiently influential when considered in isolation.
Prognosis of Body Fluid Level by Fuzzy Logic Technique
Authors: Chan W. , Naghdy F.
Published: March 2018

Surgical fluid replacement is a critical issue in medicine as the fluid volume excess or deficit can both complicate the patient’s condition. Currently, the administration of fluid volume is carried out primarily based on the experience and expertise of the anaesthetist as there is no analytical method available to estimate the patient’s fluid level. The development of a decision support system (DSS) to assist the anaesthetist in estimating the required fluid infusion rate for a particular patient has been the focus of this research paper. The DSS is developed based on Fuzzy Logic Control (FLC) technique which is ideal for developing input/output models in an unstructured and/or complex environment. The fuzzy rules used in the DSS are derived automatically from the clinical data produced in surgical operations. The DSS employs a Multi Rule Base (MRB) learning scheme to adapt its model according to the significant variation in the physiological parameters of a patient. The performance of the developed algorithms is validated through experimental work using clinical data. The results obtained so far are encouraging.
Standardization of Health Informatics – Results and Challenges
Authors: Klein G. O.
Published: March 2018

Objectives: This review article aims to highlight the importance of standards for effective communication and provides an overview of international standardization activities.

Methods: This article is based on the experience of the author of European standardization in CEN, which he leads, and the global work of ISO, where he is leading the security working group, and an overview of the work of DICOM, IEEE and HL7, partly using their web presentations.

Results: Health communication is highly dependent of the general development of information technology with standards coming from ISO/IEC JTC1, ITU and several other organizations e.g. IETF, the World Wide Web consortium and Open group. A number of standardization initiatives have been in progress for more than ten years with the aim to facilitate different aspects of the exchange of health information. Electronic record architecture, Message structures, Concept representation, Device communication including imaging and Security are the main areas.

Conclusions: Important results have been achieved, and in some fields and parts of the world, standards are widely used today. Unfortunately, we are still facing the fact that most healthcare information systems cannot exchange information with all systems for which this would be desired. Either the existing standards are not sufficiently implemented, or the required standards and necessary national implementation guidelines do not yet exist. This causes unacceptable risks to patients, inefficient use of healthcare resources, and sub-optimal development of medical knowledge. Fortunately, the different bodies are now largely co-operating to achieve global consensus.
Computer Order Entry System Decreased Use of Sliding Scale Insulin Regimens
Authors: Payne T. H. , Anawalt B. D. , Achtmeyer C. E.
Published: March 2018

Introduction

Objectives: Despite evidence documenting their ineffectiveness, sliding scale insulin is a commonly used regimen for glucose management for hospitalized patients with diabetes mellitus. At the Veterans Affairs Puget Sound Medical Center, where computer order entry has been mandated, we tested the hypothesis that an evidence-based minimal intervention order (supplemental insulin only when fasting serum glucoses exceeded 400 mg/dl) would decrease the use of sliding scale insulin orders.

Methods: Using a computerized order entry system, providers were initially offered a traditional sliding scale order or their own ad hoc orders for glycemic control of inpatients. After 34 weeks providers were offered a third option; a “minimal intervention order” with supplemental insulin only for glucose >400 mg/dl. We extracted all regular insulin orders and performed a retrospective review of insulin sliding scale orders written between December 1, 1998 and November 16, 1999. We compared the frequency of traditional insulin sliding scale orders before and after the introduction of the minimal intervention order.

Results: Nearly all orders in the first 34 weeks were traditional insulin sliding scales. We found a significant decrease in the number of traditional insulin sliding scale orders in the 16 weeks after the introduction of a computerized quick-order for minimal intervention, from 978/1007 (97.1%) to 254/398 (63.8%) (P <0.001).

Conclusions: A simple, evidenced-based quick-order in a computer order entry system rapidly and significantly reduced use of sliding scale insulin regimens for glycemic control of inpatients.
Prevalence and Conditions of Urinary Incontinence among the Elderly
Authors: Koyanagi A. , Mihara S. , Kawazu S. , Uemura T. , Nakano H. , Gotou Y. , Nishizawa M. , Noyama A. , Hasegawa C. , Nakano M. , Koyama W.
Published: March 2018

In Japan, elderly disorders and diseases have markedly increased in recent years, because of rapid aging and an increasing number of older persons. The situation is creating serious social and community problems. These disorders, particularly dysuria and urinary incontinence (UI), disturb the quality of life (QOL) in latelife. Few reports on UI have been published, but precise investigation into the community level remains to be made. Our presentation is the development, implementation and evaluation of elderly UI in Kumamoto Prefecture. This study includes 2,304 people (male: 856, female: 1,448), over 65 years of age, living in two different communities; one is an urban (K) and the other is a typical rural area (S). The rate of UI was in homebound elderly persons, male: 4.7%, female: 11.3%, and in nursing home residents, male: 16.2%, female: 23.2%. The condition of UI was: almost Urinary Urgency in male (61.5%), and Stress Incontinence (such as, caused by coughing, sneezing, and exercise) in female (46.3%). The influence of UI on the activity of daily life was investigated. Most of the male cases were giving concerns for family and community. In contrast, females hesited to participate in group excursions and outdoor exercise, and had a tendency to live alone or indoors. However, most persons (81.5%) with UI did not visit a physician. From this investigation, we conclude that a community health care program and public support system are essential for proper understanding and solution of the elderly UI problem.