bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic Planning of Clinical Documentation
Authors: Haux R. , Leiner F.
Published: March 2018

All information obtained from a patient in the course of medical care is a potential part of clinical documentation. The documentation usually serves a number of different purposes. The task of a documentation system is to fulfil these purposes in a methodically correct manner and as economically as possible. This requires that the properties of the documentation system be planned systematically with a view to the goals pursued. To support systematic planning, a “documentation protocol” is proposed analogous to the “study protocol” used for controlled clinical trials. The individual sections of the proposed documentation protocol are described and the design options which exist in the corresponding planning phases are pointed out. Experience gained by the application of the documentation protocol is discussed.
FreeCall, a System for Emergency-Call-Handling Support
Authors: Koster W. , Šrámek M. , Schreiber G. , Zocca V. , de Vries B. , Post W. M.
Published: March 2018

This article describes a system for the optimization of the pre-hospital assessment of emergency, in cases involving thoraco-abdominal complaints and consciousness problems. This assessment is performed by nurses on the basis of a telephone interview at ambulance dispatch centers. The system has a body of biomedical and policy knowledge available to guide the interview and to provide advice.
Medical Informatics: Once More Towards Systematization
Authors: Haux R.
Published: March 2018

Commenting on a paper by Van Bemmel (Medical Informatics, Art or Science? [1]), the following questions are raised: What is the meaning of medical informatics?, How to systematize medical informatics?, Is medical informatics an art, a science or a technology?. It is argued that medical informatics is concerned with the systematic processing of data, information and knowledge in medicine and health care, and that medical informatics is not just the application of computers in these fields. Three classifications for medical informatics research and education are presented. It is concluded that medical informatics is a scientific medical discipline, similar to surgery, internal medicine, epidemiology, or microbiology; and that medical informatics has a strong relationship with the health sciences concerning its field of application, and to informatics concerning its methods and tools. It is a cross-sectional discipline, with relevance for virtually all other specialties of medicine and the health sciences. This is the reason for its impact on research and education in these specialties. It also causes that the quality of the processing of data, information and knowledge has a direct and considerable effect upon the quality of health care in practically all these specialties.
District Level Information Systems: Two Cases from South Africa
Authors: Braa J. , Shung King M. , Heywood A.
Published: March 2018

The health system in South Africa has to date been fragmented and centralised. The priority of the new government is to establish an integrated and decentralised district health system of which a key element is the development of district health and management information systems (H & MIS). This paper presents experiences from two projects in the Western Cape in which a process to establish a district-based H & MIS was initiated and a situation analysis of the information systems was done. The two projects applied different research methods but the results show with remarkable consistency that much time is used on data collection, but information is not used at local level. The projects have applied different approaches towards developing a district H & MIS but in both important pre-requisites for a successful, action-led H & MIS include local ownership and motivation, a process based around existing local management structures and the active involvement of the community
Detecting Hidden Relations between Time Series of Mortality Rates
Authors: Helfenstein U.
Published: March 2018

In the present report a method is described which may help to decide if a disease is influenced by an environmental factor which fluctuates in time: For each of two naturally arising subgroups of a population (such as males and females) an ARI MA model (autoregressive integrated moving average model) is identified. These models are used as filters to remove the autocorrelation in each series. If the resulting crosscorrelation function between the two filtered series shows a marked peak at time lag 0 this may indicate that such an environmental factor is present. The procedure is demonstrated using yearly data of mortality rates among the elderly.
Development of an Instrument for the Management of Computer User Attitudes in Hospitals
Authors: Bailey J. E.
Published: March 2018

Measuring and managing user attitudes toward various aspects of computer systems is an important part of making those systems effective. In this paper, results of an effort to adapt and test a technique for measuring user satisfaction in hospitals are presented. These results include extensive empirical tests of the technique. Comparison norms for hospital computer user satisfaction are also presented and interpreted. Analysis software for using the technique as a management tool is presented. Finally, experiences using the concept are presented.
The Delphi Method to Validate Diagnostic Knowledge in Computerized ECG Interpretation
Authors: Kors J. A. , Sittig A. C. , van Bemmel J. H.
Published: March 2018

We investigated the applicability of the Delphi method for increasing the agreement among multiple cardiologists on, firstly, their classifications of a set of electrocardiograms and, secondly, their reasons for these classifications. Five cardiologists were requested to judge the computer classifications of a set of thirty ECGs. If a cardiologist disagreed with the computer classification, he had to provide a new classification and a reason for this change. The results of this first round were compiled and anonymously fed back to the cardiologists. In a second round the cardiologists were asked once again to judge the ECGs and to rate the reasons provided in the first round. The level of agreement was estimated by means of the kappa statistic. The Delphi procedure substantially increased the agreement on the classifications among the cardiologists. The final agreement was very high and comparable with the intra-observer agreement. There was also a high level of agreement on the reasons provided by the cardiologists. However, their use in improving the program’s performance is hampered by the qualitative nature of many of the reasons. Suggestions are given for a more formalized elicitation of knowledge.
Converting the Representation of Medical Data: Criteria to Code the Underlying Cause of Death
Authors: Pisanelli D. M. , Rossi-Mori A.
Published: March 2018

This study deals with a set of coding directives that were conceived for trained coding clerks and rely upon knowledge of their cultural background. These directives were formalized and adapted for computer use and in this form must rely upon a background of explicit medical knowledge. Medical data on death certificates are an invaluable source of information regarding prevention of major causes of death. These causes are coded and tabulated worldwide by means of the International Classification of Diseases (ICD). The ICD manual issues directives to achieve uniformity of coding throughout the world. The coder is required to trace back the flow of events which caused death and to single out the most significant concept from the statistical point of view. After emphasizing the problems encountered in the formalization, the methodological contribution of this work to the identification of a modular architecture for a system which represents and “reshapes” knowledge from medical documents is presented. Therefore we focus on the features of the two kinds of knowledge that must be supplied to a knowledge-based system, in order to enable it to perform semantic conversions on given medical data, namely: i) generic guidelines; ii) detailed medical knowledge.
Sensitivity and Specificity of Acid Phosphatase to Detect Prostate Cancer Using Data from a Hospital Information System
Authors: Zwetsloot-Schonk Johanna H. M. , Hermans J. , Frolich Marijke , Snitker P. , Zwartendijk J. , Souverijn J. H. M.
Published: March 2018

Indices of diagnostic tests, such as sensitivity and specificity, should be determined using diagnostic test results of patients tested in clinical practice. Hospital information systems that store data on diagnostic tests and diagnoses might be used for sampling the desired study population and in the actual process of collecting the data.

This paper presents, as an example, a study calculating the sensitivity and specificity of the prostate-specific acid phosphatase test. All data needed in the study were obtained from the hospital information system of Leiden University Hospital. The final health status of each patient was assessed by the cancer registry of the system. The reason for ordering the test was deduced from data on histopathological examinations of prostatic tissue. The actual selections made from the central database are described in dataflow diagrams. The sensitivity of the test was found to be 0.34 and the specificity 0.88, using a discrimination value o f 1.00 U/I. The impact of the reason for ordering the test on the specificity is illustrated. Possible biases of these measured values are discussed.
Use of a Hospital Database to Determine the Characteristics of Diagnostic Tests
Authors: Zwetsloot-Schonk Johanna
Published: March 2018

Test indices are often determined by comparing test results of healthy persons with test results of patients known to have the disease. However, the patient population for which the test is ordered in clinical practice often differs from the study population on which the test indices are based. Hence, these indices are not applicable to clinical practice and should be recalculated using data from daily clinical practice. Two major problems of using routinely collected data are discussed: the assessment of the final health status and tracing the reason for ordering the test. Prior considerations are given to the use of hospital information systems (HIS) to sample the patient population that is desired and to collect the necessary data for calculating test indices. We investigated whether the HIS of Leiden University Hospital (which is presented as an example) can be used to calculate the indices of clinical laboratory tests, histopathologic examinations and radiodiagnostic investigations. The results indicate that the registration of diagnoses must be improved and that a way must be found to capture the implicit reasoning for ordering diagnostic tests.
Methodology of ECG Interpretation in the Glasgow Program
Authors: Devine B. , Latif S. , McLaughlin S. , Shoat D. B. , Watts M. P. , Macfarlane P. W.
Published: March 2018

This paper describes the methods currently used in Glasgow Royal Infirmary for computer analysis of electrocardiograms. The software is designed to analyse from 3 to 15 simultaneously recorded leads, with facilities for analysis of rhythm and serial changes. Options for Minnesota Code (with serial comparison) and XYZ lead interpretation are available.
Methodology of ECG Interpretation in the Padova Program
Authors: Degani R. , Bortolan G.
Published: March 2018

The main lines ofthe program designed for the interpretation of ECGs, developed in Padova by LADSEB-CNR with the cooperation of the Medical School of the University of Padova are described. In particular, the strategies used for (i) morphology recognition, (ii) measurement evaluation, and (iii) linguistic decision making are illustrated. The main aspect which discerns this program in comparison with other approaches to computerized electrocardiography is its ability of managing the imprecision in both the measurements and the medical knowledge through the use of fuzzy-set methodologies. So-called possibility distributions are used to represent ill-defined parameters as well as threshold limits for diagnostic criteria. In this way, smooth conclusions are derived when the evidence does not support a crisp decision. The influence of the CSE project on the evolution of the Padova program is illustrated.
Probabilistic Diagnosis Using a Reformulation of the INTERNIST-1/QMR Knowledge Base
Authors: Shwe M. A. , Heckerman D. E. , Henrion M. , Horvitz E. J. , Lehmann H. P. , Cooper G. F. , Middleton B.
Published: March 2018

In Part I of this two-part series, we report the design of a probabilistic reformulation of the Quick Medical Reference (QMR) diagnostic decision-support tool. We describe a two-level multiply connected belief-network representation of the QMR knowledge base of internal medicine. In the belief-network representation of the QMR knowledge base, we use probabilities derived from the QMR disease profiles, from QMR imports of findings, and from National Center for Health Statistics hospital-discharge statistics.

We use a stochastic simulation algorithm for inference on the belief network. This algorithm computes estimates of the posterior marginal probabilities of diseases given a set of findings. In Part II of the series, we compare the performance of QMR to that of our probabilistic system on cases abstracted from continuing medical education materials from Scientific American Medicine. In addition, we analyze empirically several components of the probabilistic model and simulation algorithm.
Probabilistic Diagnosis Using a Reformulation of the INTERNIST-1/QMR Knowledge Base
Authors: Shwe A. M. , Heckerman E. D. , Henrion M. , Horvitz J. E. , Lehmann P. H. , Cooper F. G. , Middleton B.
Published: March 2018

We have developed a probabilistic reformulation of the Quick Medical Reference (QMR) system. In Part I of this two-part series, we described a two-level, multiply connected belief-network representation of the QMR knowledge base and a simulation algorithm to perform probabilistic inference on the reformulated knowledge base. In Part II of this series, we report on an evaluation of the probabilistic QMR, in which we compare the performance of QMR to that of our probabilistic system on cases abstracted from continuing medical education materials from Scientific American Medicine. In addition, we analyze empirically several components of the probabilistic model and simulation algorithm.
Expert System Design in Hematology Diagnosis
Authors: Diamond L. W. , Priolet G. , Sultan C. , Nguyen D. T.
Published: March 2018

A two-part study was designed to test the hypothesis that sufficient information is available from a modern hematology analyzer (the Coulter STKS) to reach a reliable intermediate conclusion which can be used as input to the next decision-making level in the design of a high-performance expert system for hematology diagnosis. In phase one, we analyzed the performance of three probabilistic systems (using Bayes’ rule) which interpret STKS data: a control system which took the traditional approach of classifying cases into specific diagnoses, and two test systems which were designed to reach only an intermediate conclusion but not a final diagnosis. One of the test systems classified cases into “textbook categories” of disease and the other utilized defined diagnostic patterns. The systems were tested with 150 cases. The pattern approach ranked the correct choice first in 141 of 150 cases (94%). In phase two, we abandoned Bayes’ rule, reformulated the pattern approach into a heuristic classification system, and tested its reliability on 820 cases. The algorithm of the reformulated system was able to classify all 820 cases into the same predominant pattern as a panel of three experienced laboratory hematologists.
A Genetic Algorithm to Improve a Neural Network to Predict a Patient’s Response to Warfarin
Authors: Narayanan M. N. , Lucas S. B.
Published: March 2018

The ability of neural networks to predict the international normalised ratio (INR) for patients treated with Warfarin was investigated. Neural networks were obtained by using all the predictor variables in the neural network, or by using a genetic algorithm to select an optimal subset of predictor variables in a neural network. The use of a genetic algorithm gave a marked and significant improvement in the prediction of the INR in two of the three cases investigated. The mean error in these cases, typically, reduced from 1.02 ± 0.29 to 0.28 ± 0.25 (paired t-test, t = −4.71, p <0.001, n = 30). The use of a genetic algorithm with Warfarin data offers a significant enhancement of the predictive ability of a neural network with Warfarin data, identifies significant predictor variables, reduces the size of the neural network and thus the speed at which the reduced network can be trained, and reduces the sensitivity of a network to over-training.
Philosophies for the Design and Development of Clinical Decision-Support Systems
Authors: Heathfield H. A. , Wyatt J.
Published: March 2018

Little significance is attached by medical informatics workers to the many practical issues which affect the development of clinical decision-support systems. We examine the current state of research in clinical decision-support, the characteristics and motivations of developers, and the perceptions of intended end-users. Factors which adversely affect the success of systems are highlighted and pointers to good practice discussed. We then propose a coherent approach to system development, consisting of requirements analysis, software design, implementation, testing, evaluation and maintenance.
Taking Inventory of Medical Decision Support Software Development
Authors: Miller R. A.
Published: March 2018

Response to Heathfield HA, Wyatt J. Philosophies for the design and development of clinical decision-support systems. Meth Inform Med 1993; 32: 1-8.
A Coherent Philosophy for Development or a Straightjacket for Research?
Authors: Szolovits P. , Pauker S. G.
Published: March 2018

Response to Heathfield HA, Wyatt J. Philosophies for the design and development of clinical decision-support systems.
Discrimination and Reproducibility of an Information Maximizing Multivariable Model
Authors: Conant R. C. , Tape Th. G. , Wigton R. S. , Heckerling P. S.
Published: March 2018

Predictor variables for multivariate rules are frequently selected by methods that maximize likelihood rather than information. We compared the discrimination and reproducibility of a prediction rule for pneumonia derived using extended dependency analysis (EDA), an information maximizing variable selection program, with that of a validated rule derived using logistic regression. Discrimination was measured by receiver-operating characteristic (ROC) analysis, and reproducibility by rederivation of the rule on 200 replicate samples of size 250 and 500, generated from a training cohort of 905 patients using Monte Carlo techniques.

Four of the five predictor variables selected by EDA were identical to those selected by logistic regression. With each variable weighted by its conditional contribution to total information transmission, EDA discriminated pneumonia and nonpneumonia in the training cohort with an ROC area of 0.800 (vs 0.816 for logistic regression, p = 0.60), and in the validation cohort with an area of 0.822 (vs 0.821 for logistic regression, p = 0.98). EDA demonstrated reproducibility comparable to that of logistic regression according to most criteria for replicability. Replicate EDA models showed good discrimination in the training and testing cohorts, and met statistical criteria for validation (no significant difference in ROC areas at a one-tailed alpha level of 0.05) in 80.8% to 94.2% of cases.

We conclude that extended dependency analysis selected the most important variables for predicting pneumonia, based on a validated logistic regression model. The information-theoretic model showed good discriminatory power, and demonstrated reproducibility according to clinically reasonable criteria. Information-theoretic variable selection by extended dependency analysis appears to be a reasonable basis for developing clinical prediction rules.
Integrated Clinical Decision Support Using an Object-Oriented Database Management System
Authors: Frost R. D. , Gillenson M. L.
Published: March 2018

Clinical decision support systems assist in diagnosis, alert to abnormal conditions, and manage patient data. Such systems tend to emphasize one of these features at the expense of the others and tend to be developed on an ad hoc basis. In this work, a technique is developed for creating an integrated clinical decision support system wholly within a general-purpose object-oriented database management system. The diagnostic and alerting requirements are accomplished with encapsulated methods and a novel use of the object-oriented database management class-hierarchy structure. The patient data management requirement is satisfied by the normal data management capabilities of the object-oriented DBMS.
Response of General Practitioners to Computer-Generated Critiques of Hypertension Therapy
Authors: van der Does E. , Man in ’t Veld A. J. , Musen M. A. , van Bemmel J. H. , van der Lei J.
Published: March 2018

We recently have shown that a computer system, known as HyperCritic, can successfully audit general practitioners’ treatment of hypertension by analyzing computer-based patient records. HyperCritic reviews the electronic medical records and offers unsolicited advice. To determine which unsolicited advice might be perceived as inappropriate, builders of programs such as HyperCritic need insight into providers’ responses to computer-generated critique of their patient care. Twenty medical charts, describing in total 243 visits of patients with hypertension, were audited by 8 human reviewers and by the critiquing-system HyperCritic. A panel of 14 general practitioners subsequently judged the relevance of those critiques on a five-point scale ranging from relevant critique to erroneous or harmful critique. The panel judged reviewers’ comments to be either relevant or somewhat relevant in 61 to 68% of cases, and either erroneous or possibly erroneous in 15 to 18%; the panel judged HyperCritic’s comments to be either relevant or somewhat relevant in 65% of cases, and either erroneous or possibly erroneous in 16%. Comparison of individual members of the panel showed large differences; for example, the portion of HyperCritic’s comments judged relevant ranged from 0 to 82%. We conclude that, from the perspective of general practitioners, critiques generated by the critiquing system HyperCritic are perceived equally beneficial as critiques generated by human reviewers. Different general practitioners, however, judge the critiques differently. Before auditing systems based on computer-based patient records that are acceptable to practitioners can be introduced, additional studies are needed to evaluate the reasons a physician may have for judging critiques to be irrelevant, and to evaluate the effect of critiques on physician behavior.
Work-Sampling: A Statistical Approach to Evaluation of the Effect of Computers on Work Patterns in Healthcare
Authors: Sittig D. F.
Published: March 2018

An increasing number of health-care institutions are in the process of implementing clinical computing systems. The need for an accurate assessment of the clinical, administrative, social, and financial effects of such systems has been recognized. Techniques have been developed to evaluate these effects on the work patterns of health-care workers including: time-motion analysis, subjective evaluations, review of departmental statistics, personal activity records, and work-sampling. This study reviews these techniques, discusses both positive and negative aspects, and presents a step-by-step description of work-sampling.
Distinguishing Individual Linkages of Personal Records from Family Linkages
Authors: Newcombe H. B.
Published: March 2018

Errors occur in the automated linkage of medical and other records into personal histories, when household and family identifiers get wrongly treated in the same way as the strictly personal identifiers. This is because overwhelming evidence that two records refer to the same household or family, does not mean they necessarily represent the same person. Current practice in probabilistic record linkage fails to make this distinction, and combines indiscriminately the calculated odds from the mix of identifiers pertaining to all three sorts of entity. A tactic is described that avoids the resulting problem of mistaken personal identity. It does so by first converting composite odds from comparisons of household and family particulars, to a magnitude that contributes correctly to the overall evidence in favour of a strictly personal linkage.
Access to Medical Databases; Theory and Practice
Authors: Bakker A. R.
Published: March 2018

Response to: Pangalos GJ: Medical database security policies. Meth Inform Med 1993; 32: 349-56.
Safety and Decision Support in Oncology
Authors: Harris A. L. , Das S. K. , Wyatt J. C. , Hammond P.
Published: March 2018

The management of patients with cancer involves the administration of complex treatment protocols with frequent monitoring of the effects of treatment on the malignant disease as well as on the general health of the patient. The number and wide variety of protocols used in treatment trials, and the amount of clinical data generated suggest the need for computer-based support. The toxicity of many of the treatments used and the severity of the disease itself underline the safety-critical nature of all decisions made by oncologists, the physicians and surgeons who treat cancer patients. This paper presents recent work on the analysis of safety issues arising from the design and implementation of a protoype decision-support system for oncologists. It illustrates the benefits of combining both informal and formal approaches to the analysis and representation of safety, firmly based on a thorough and detailed study of the domain in cooperation with oncologists, pharmacists and medical informaticians.
The Relative Accuracy of a Variety of Medical Diagnostic Programs
Authors: Todd B. S. , Stamper R.
Published: March 2018

Acute abdominal pain is one of the most widely studied applications of computer-aided diagnosis. The usual approach is to apply Bayes’ theorem with the assumption of conditional independence (“independence Bayes”). We compared various approaches to designing diagnostic programs for abdominal pain of suspected gynaecological origin. The methods range from statistical to knowledge-based. All programs were evaluated using a database of 1,270 cases collected retrospectively. Our results suggest that in this application no significant improvement in accuracy can be made by taking interactions into account, either by statistical or by knowledge-based means; independence Bayes is near-optimal. As far as accuracy is concerned, there appears to be little point in pursuing knowledge-based approaches. However, the “nearest neighbours” method using a new metric appears to be at least as accurate as independence Bayes. We argue that the nearest neighbours method is more suitable than independence Bayes for clinical use because of greater accountability.
A Compartmental Model for Simulation of IGF-I Kinetics and Metabolism
Authors: Sonksen P. H. , Jones R. H. , Boroujerdi M. A.
Published: March 2018

A compartmental model for the simulation of in-vivo insulin-like growth factor one (IGF-I) kinetics and metabolism is presented. The model is based on the concept that IGF binding proteins (IGFBPs) act as a reservoir for IGF-I in plasma, thereby restricting its access to the extravascular space. The model is divided into two subsystems; a binding model for IGF-I and IGFBP, and an IGF-I clearance model, which includes the binding of IGF-I to IGF-I receptors. The non-linear differential equations describing the model are based on the law of mass action. Given the steady state condition, the linearized form of the model, describing tracer kinetics of IGF-I and IGFBPs is developed. It is demonstrated that using the available data, it is possible to assign values to the model parameters, thereby allowing simulation of the model to obtain information not accessible by direct observation.
A Unified Approach to the Design of Clinical Reporting Systems
Authors: Salgado N. C. , Azevedo A. P. , Lopes L. , Raposo V. D. , Almeida I. , Galvão de Melo E. , Gouveia-Oliveira A.
Published: March 2018

Computer-based Clinical Reporting Systems (CRS) for diagnostic departments that use structured data entry have a number of functional and structural affinities suggesting that a common software architecture for CRS may be defined. Such an architecture should allow easy expandability and reusability of a CRS. We report the development methodology and the architecture of SISCOPE, a CRS originally designed for gastrointestinal endoscopy that is expandable and reusable. Its main components are a patient database, a knowledge base, a reports base, and screen and reporting engines. The knowledge base contains the description of the controlled vocabulary and all the information necessary to control the menu system, and is easily accessed and modified with a conventional text editor. The structure of the controlled vocabulary is formally presented as an entity-relationship diagram. The screen engine drives a dynamic user interface and the reporting engine automatically creates a medical report; both engines operate by following a set of rules and the information contained in the knowledge base. Clinical experience has shown this architecture to be highly flexible and to allow frequent modifications of both the vocabulary and the menu system. This structure provided increased collaboration among development teams, insulating the domain expert from the details of the database, and enabling him to modify the system as necessary and to test the changes immediately. The system has also been reused in several different domains.
An Information System for Epidemiology based on a Computer-Based Medical Record
Authors: Verdier C. , Flory A.
Published: March 2018

A new way is presented to build an information system addressed to problems in epidemiology. Based on our analysis of current and future requirements, a system is proposed which allows for collection, organization and distribution of data within a computer network. In this application, two broad communities of users – physicians and epidemiologists – can be identified, each with their own perspectives and goals. The different requirements of each community lead us to a client-service centered architecture which provides the functionality requirements of the two groups. The resulting physician workstation provides help for recording and querying medical information about patients and from a pharmacological database. All information is classified and coded in order to be retrieved for pharmaco-economic studies. The service center receives information from physician workstations and permits organizations that are in charge of statistical studies to work with “real” data recorded during patient encounters. This leads to a new approach in epidemiology. Studies can be carried out with a more efficient data acquisition. For modelling the information system, we use an object-oriented approach. We have observed that the object-oriented representation, particularly its concepts of generalization, aggregation and encapsulation, are very usable for our problem.
Patient Registration and Treatment Allocation in Multicenter Clinical Trials Using a FAX-OCR System
Authors: Kamakura T. , Sakamoto M. , Odaka T. , Nose Y. , Akazawa K.
Published: March 2018

This article describes the design and results of implementation of an automated patient registration and freatment allocation system (RETAS) used in multicenter clinical trials. RETAS was developed using a FAX-OCR system by which handwritten Japanese and English characters, as well as numericals and forms with check boxes, are sent from participating institutions by Fax, processed using an optical character reader, and then transmitted to a host computer at a statistical center. Based on the facsimile data, RETAS can automatically review eligibility, collect patient identification data and provide a randomized treatment allocation. RETAS permits uninterrupted, unattended operation at a statistical center, 24 hours a day, 7 days a week. Therefore, it drastically decreases the workload of personnel at the statistical center needed to support central telephone registration coverage. Consequently, staff members are free to focus on patient registration, treatment allocation, and follow-up of patients. The treatment allocation procedure in this system is based on Pocock and Simon’s minimization method combined with Zelen’s method for institution balancing. By this system it was possible to balance treatment numbers for each level of various prognostic factors over an entire trial and, at the same time, balance the allocation of treatments within an institution. The system currently supports the protocol of a clinical trial for Adjuvant Chemo-Endocrine Therapy for Breast Cancer in West Japan.
Myositis Netz
Authors: Zschüntzsch J. , Preusse C. , Ruck T. , Meuth S. G. , Müller-Felber W. , Stenzel W. , Schmidt J. ,   für das Myositis Netz
Published: March 2018

Entzündliche Muskelerkrankungen stellen eine wichtige Gruppe der seltenen neuromuskulären Erkrankungen dar. Die Diagnose der Myositiden hat einen besonderen Stellenwert, da sie im Gegensatz zu vielen anderen hereditären neuromuskulären Erkrankungen kausal behandelt werden können. Daher ist eine rasche, genaue Diagnosestellung wichtig, um Patienten helfen zu können, bevor irreversible Defizite entstehen. Um Patienten mit der Diagnosestellung einer Myositis und deren Angehörigen bessere Informationen über die Erkrankung zu ermöglichen, hat sich vor einigen Jahren innerhalb der Selbsthilfe der Deutschen Gesellschaft für Muskelkranke e. V. die Diagnosegruppe Myositis gebildet (www.dgm.org). Zum interdisziplinären Austausch von Ärzten und Wissenschaftlern wurde 2015 das Myositis Netz gegründet, welches eine Plattform für wissenschaftliche Kooperationen bietet (www.myositis-netz.de). Hauptziele des Myositis Netz sind es, die Therapie bei Myositis zu optimieren und standardisieren und die Wissenschaft in diesem Bereich zu fördern. In dem vorliegenden Beitrag soll das Myositis Netz mit seinen Aufgaben, Zielen und Teilnehmern vorgestellt werden. Darüber hinaus werden die wesentlichen Fakten zur Diagnostik und Therapie der Myositis kompakt und übersichtlich dargestellt.
Determining the Most Valuable Clinical Variables : a Stepwise Multiple Logistic Regression Program
Authors: Brown B. W. , Engelhard C. , Haipern J. , Fries J. F. , Coles L. S.
Published: March 2018

In solving a clinical problem of diagnosis, prognosis, or treatment choice, a physician must select from among a large group of possible tests. In general, an ordering exists specifying which tests are most valuable in providing relevant information concerning the problem on hand. The computer program package to be described (MW) extracts appropriate data from the ARAMIS data banks and then analyzes the data by stepwise logistic regression. A binary outcome (diagnosis, prognostic event, or treatment response) is sequentially associated with possible tests, and the most powerful combination of tests is identified. For example, the most valuable predictor variable of early mortality in SLE is proteinuria, followed sequentially by anemia and absence of arthritis. Experience with these techniques suggests : 1. optimal certainty is usually reached after only three or four tests; 2. several different test sequences may lead to the same level of certainty; 3. diagnosis may usually be ascertained with greater certainty than prognosis; 4. many medical problems contain considerable non-reducible uncertainty; 5. a relatively small group of tests are typically found among the most powerful; 6. results are consistent across several patient populations; 7. results are largely independent of the particular statistic employed. These observations suggest strategies for maximizing information while minimizing risk and expense.
A Graphic Method for the Evaluation of Diagnostic Tests
Authors: Rossing R. G. , Hatcher W. E.
Published: March 2018

The theory of decision-making has been previously applied to the evaluation of laboratory tests in clinical diagnosis taut the emphasis on formulae and equations has discouraged many physicians from attempting to understand the concept. This paper offers a graphic portrayal of the four possible decision outcomes : true negative, false negative, true positive and false positive. The presentation permits a graphic representation of the concepts of specificity, sensitivity, accuracy, predictive value of a laboratory test and information content as well as of the receiver-operating-characteristic (ROC) curve. It demonstrates why disease incidence has no effect upon specificity, sensitivity and the ROC curve but has a strong influence upon accuracy and information content and especially upon the predictive value of a positive laboratory test. The graphic method is applicable to theoretical distributions and to distributions based on actual laboratory data.
Functional Characteristics of a Computerized Medical Record
Authors: Hammond W. E. , Stead W. W. , Straube M. J. , Jelovsek F. R.
Published: March 2018

Research-based clinical information systems are presently being developed. This paper discusses some characteristics which such systems must have to be successful and affordable outside the research world. Problems of data entry, verification, and correction must be dealt with. Programs must be bug-free, and provisions must be made for data protection and integrity, for growth of record files, and for the ultimate purging of those files.

Functional characteristics of a computerized medical record — TMR — developed at Duke University are presented, based on three health care facilities : the University Health Services Clinic with an active file of 33,000 patients; the Renal Dialysis Unit of the Durham Veterans Hospital with an active file of 300 patients; and the Department of Obstetrics and Gynecology with an active file of 7,000 patients. These functional characteristics include the rate of growth of files, the length of various components of the record, the type and length of program modules, and various system function response times.
The Measurement of Performance in Probabilistic Diagnosis V. General Recommendations
Authors: Habbema J. D. F. , Hilden J. , Bjerregaard B.
Published: March 2018

Guidelines are offered concerning the use of evaluation tools, with emphasis on the simplest and most informative ones amongst those proposed in Parts I—IV of this series. Moreover, the main areas of future research and development, as the authors see them, are pointed out.
Adverse Drug Reactions— A Computer-assisted Application of Correspondence Analysis for Automatic Causality Assessment
Authors: Bastin Ch. , Wertheimer P. , Venulet J.
Published: March 2018

An assessment forra comprising 27 questions relating to adverse drug reactions and causal relationship was completed for 204 subjects. Questions providing no information were disregarded and answers to the remaining questions recorded and subjected to a correspondence analysis.

The correspondence analysis returned a set of mappings together with new quantitative variables to which discriminant analysis was applied aiming at a future allocation of individuals to causality groups.

Results of the analysis, based on data from the 204 subjects, demonstrated that in 61.3% of cases assessment of causality obtained with discriminant analysis was identical with the assessment made by a medical evaluator.

The allocation rule was subsequently applied to data from 100 new case reports and, in a similar percentage (60%) of cases, allocation to the causality groups coincided with the evaluator’s assessment.
Evaluation of a Computer-assisted Screening Method for Medical History Records
Authors: Seelos H.-J.
Published: March 2018

An economical, effective and convenient medical-technical method for the overall classification of medical records will be presented, a method which facilitates diagnostical classification and frees the medical practitioner from the time-consuming task of putting numerous questions to the patient. The individual stages of development of this method are described. The first experiences are encouraging and are reported.
Management of Ventricular Fibrillation during Acute Myocardial Infarction
Authors: Northover B. J.
Published: March 2018

Analysis of electrocardiograms tape-recorded from patients admitted to hospital with acute myocardial infarction revealed that the pattern of ventricular extrasystolic activity was not significantly different among those who subsequently developed ventricular fibrillation and those who did not. Episodes of ventricular fibrillation occurred predominantly within 4 hours from the start of infarction. Patients were 3 times less likely to survive an episode of ventricular fibrillation if they also had left ventricular failure than if this feature was absent. Management of episodes of ventricular fibrillation was compared in patients before and after the creation of a specially staffed and equipped coronary care unit. The success of electric shock as a treatment for ventricular fibrillation was similar before and after the creation of the coronary care unit. An attempt was made to determine which features in the management of ventricular fibrillation in this and in previously published series were associated with patient survival.
The Use of Morphosemantic Regularities in the Medical Vocabulary for Automatic Lexical Coding
Authors: Wolff Susanne
Published: March 2018

The Neo-Latin portion of medical vocabulary exhibits morphosemantic regularities that make it possible to determine both English syntactic subclasses and medical semantic subclasses from formal properties of these lexical items alone. This paper describes an experimental program for the automatic creation of dictionary entries that exploits the formal regularities to obtain dictionary entries sufficient for computerized medical text analysis as presently carried out by the New York University Linguistic String Project (LSP) system. Although automatic dictionary preparation does not supersede manual classification, the program takes a considerable burden off the dictionary worker’s shoulders and speeds the costly preprocessing stages of computerized text analysis.
The Similarity Approach to EEG Analysis
Authors: Stassen H. H.
Published: March 2018

A method of approach to EEG analysis has been proposed which is based upon the concept of similarity. It especially aims at the analysis of the between-subject and within-subject similarity of EEG spectral patterns by means of adaptive procedures. Repeated measurements from the same individual were used as design samples, and new registrations after 14 days were referred to as test samples in order to determine the calibration parameters of the approach. The discrimination between the distributions of between-subject and within-subject similarity coefficients served as the criterion for the optimization algorithm. The optimization was terminated when the discriminating power reached 92% for both design samples and test samples. Accordingly, EEG spectral patterns were found to measure the distinct individuality of the EEG with good precision and to be stable over time.

Consequently, a detailed analysis of the between-subject similarities by evaluating the fine graduations of mutual differences was of special interest. The realization of this idea led to a methodological problem because all basic information existed only in the form of non-metric similarity matrices. The problem was solved by means of a non-metric MDS which led to a geometric representation of the relational data. The final configuration of image points suggested a partitioning into 4 natural groupings comprising about ¾ of the samples. The remaining measurements were either isolated elements or formed smaller clusters whose relevance remained undecided. Contrary to traditional EEG classifications, this approach provided not only abstract clusters but also the positions of patterns within clusters and the relative positions of clusters to each other. The latter seems to be important in connection with the analysis of reactive changes in the human EEG, particularly because other investigations have shown that the effects of centrally acting substances are highly dependent upon the specific type of EEG.
Pattern Recognition in Histo-Pathology: Basic Considerations
Authors: Schlegel W. , Kayser K.
Published: March 2018

A basic concept for the automatic diagnosis of histo-pathological specimen is presented. The algorithm is based on tissue structures of the original organ. Low power magnification was used to inspect the specimens. The form of the given tissue structures, e. g. diameter, distance, shape factor and number of neighbours, is measured. Graph theory is applied by using the center of structures as vertices and the shortest connection of neighbours as edges. The algorithm leads to two independent sets of parameters which can be used for diagnostic procedures. First results with colon tissue show significant differences between normal tissue, benign and malignant growth. Polyps form glands that are twice as wide as normal and carcinomatous tissue. Carcinomas can be separated by the minimal distance of the glands formed. First results of pattern recognition using graph theory are discussed.
The Use of Critical Cues and Prior Probability in Decision-Making
Authors: Balla John
Published: March 2018

Six case vignettes were administered to 76 subjects, comprising 62 students and 14 expert physicians. The aim was to show how the different groups used.prior probability and strong individual cues, as opposed to patterns, in coming to a diagnosis. Diagnostic confidence was also assessed to see how this varied with expertise.

It was tentatively concluded that the novice is more likely to perceive in patterns than the expert, the latter being more adept at handling prior probability as a separate cue. Experts are also better at perceiving individual, heavily weighted cues than novices and are more likely to accept incomplete patterns to make a diagnosis.

In spite of less knowledge, students will make a positive diagnosis more often than experts. This may be a reflection on educational methods, where it is threatening not to know and where students do not learn that diagnosis is probabilistic and uncertain.

These are indications to teach better concepts of prior probability, weighting of cues and the uncertain nature of diagnosis, as well as being less threatening if students do not .
A Monitoring System for Chronic Diseases
Authors: Chen Rina , Mantel N. , Connelly R. R. , Isacson P.
Published: March 2018

A statistical technique for detecting an increase in the rate of a chronic disease is proposed. The technique is based on the time interval between consecutive diagnoses. An increase is considered significant when all the intervals are shorter than the appropriate critical duration. The technique was applied to data collected by a state-wide cancer registry and results are illustrated for two types of cancer.
Future Developments of Data Processing in Health Care
Authors: Reichertz Peter
Published: March 2018

An analysis is made concerning the development of data processing in medicine and of medical informatics as a genuine methodological discipline. A classification is given for the major application areas: 1) Data analysis, 2) Information logistics and 3) Signal analysis.

The present development is seen to be characterized by a tendency towards »peripheralization« and decomposition of central systems. Out of this development the necessity is formulated for medical informatics to move away from system realization and maintenance to methodological orientation and genuine research work in the field of information analysis, system analysis, decision support, development of general concepts for networks and application systems and quality assessment. New technological activities are expected in the field of imaging and endoprosthetics. The necessity for educational programs is emphasized.