Medical informatics is interdisciplinary avant la lettre.

OBJECTIVE: To discuss the elements of interdisciplinary research and to analyze its contribution to (bio)medical informatics. METHOD: Commenting on 'Informatics and Medicine - From Molecules to Populations' from K. A. Kuhn et al. in this issue of Methods of Information in Medicine. Referring to examples of successfully established interdisciplinary research. RESULTS AND CONCLUSIONS: Medical informatics is an interdisciplinary field avant la lettre. Experience with successful interdisciplinary research already exists for many decades: Interdisciplinary research is not a category of research but a consequence of addressing a complex problem in society, involving the collaboration between and methods drawn from multiple disciplines. Because research is people, personal interactions are critical for interdisciplinary research. Collaboration takes extra time to develop, to build consensus and to understand new methodologies, languages, and each other's culture. Interdisciplinary research requires leaders with vision and expressive skills. Effective scientific and institutional leadership is critical to the success of interdisciplinary groups. Interdisciplinarity begins in the classroom. Interdisciplinary research cannot be effective without interdisciplinary education. Researchers and teachers should immerse themselves in the culture of other disciplines, learning to explain their work in terms understood by people outside their own discipline. Teams that perform interdisciplinary research should promote collaboration, meet regularly, and recognize that it requires a commitment toward good communication and clear goals. Although much progress is achieved by interdisciplinary research, basic monodisciplinary research is still required to advance the frontiers of scientific knowledge, such as in physics or biology.

On Contributing to the Progress of Medical Informatics as Publisher.

May 1st, 2017, will mark Dieter Bergemann's 80th birthday. As Chief Executive Officer and Owner of Schattauer Publishers from 1983 to 2016, the biomedical and health informatics community owes him a great debt of gratitude. The past and present editors of Methods of Information in Medicine, the IMIA Yearbook of Medical Informatics, and Applied Clinical Informatics want to honour and thank Dieter Bergemann by providing a brief biography that emphasizes his contributions, by reviewing his critical role as an exceptionally supportive publisher for Schattauer's three biomedical and health informatics periodicals, and by sharing some personal anecdotes. Over the past 40 years, Dieter Bergemann has been an influential, if behind-the-scenes, driving force in biomedical and health informatics publications, helping to ensure success in the dissemination of our field's research and practice.

The young person's guide to biomedical informatics.

OBJECTIVE: To draw a parallel between the challenges by which a research department in biomedical informatics is confronted and those of a symphony orchestra; in both areas different disciplines and various groups of instruments can be discerned. METHOD: Retrospective, personal review of how to conduct biomedical research. RESULTS: The importance of mastering one's instrument and the harmony between the team members is stressed. The conductor has to motivate all players so that they can have a successful career. Competition between orchestras and performance assessments determine survival and success. A record of refereed publications is crucial for continued existence. CONCLUSIONS: Biomedical informatics is typically multidisciplinary. Hypotheses underlying research should be carefully formulated. The time from research to application may easily take 20 years or more. Mutual trust and knowing each other's competences is essential for success. A good leader gives enough room to all team members to develop their careers. The outcomes of assessment studies are directly related to the quality of publications.

The Renewed Promise of Medical Informatics.

The promise of the field of Medical Informatics has been great and its impact has been significant. In 1999, the Yearbook editors of the International Medical Informatics Association (IMIA) - also the authors of the present paper - sought to assess this impact by selecting a number of seminal papers in the field, and asking experts to comment on these articles. In particular, it was requested whether and how the expectations, represented by these papers, had been fulfilled since their publication several decades earlier. Each expert was also invited to comment on what might be expected in the future. In the present paper, these areas are briefly reviewed again. Where did these early papers have an impact and where were they not as successful as originally expected? It should be noted that the extraordinary developments in computer technology observed in the last two decades could not have been foreseen by these early researchers. In closing, some of the possibilities and limitations of research in medical informatics are outlined in the context of a framework that considers six levels of computer applications in medicine and health care. For each level, some predictions are made for the future, concluded with thoughts on fruitful areas for ongoing research in the field.

A reference data base for multilead electrocardiographic computer measurement programs.

In an effort to standardize and evaluate the performance of electrocardiographic computer measurement programs, a 15 lead reference library has been developed based on simultaneously recorded standard 12 lead and orthogonal XYZ lead data. A set of 250 electrocardiograms (ECGs) with selected abnormalities was analyzed by a group of five referee cardiologists and 11 different 12 lead and 6 XYZ computer programs. Attention was focused on the exact determination of the onsets and offsets of P, QRS and T waves. The referees performed their task on highly amplified, selected complexes from the library in a two round process. Median results of the referees coincided best with the median derived from all programs. An analysis of stability proved that the combined program median was a robust reference. However, some individual program results were widely divergent. Paired t tests demonstrated earlier onset for P and QRS (p less than 0.001), as well as later offset for P and T waves in the median 12 lead than in the XYZ results. Significant differences also existed among results obtained by programs analyzing all standard ECG leads at one time, the so-called multilead programs, and those obtained by the conventional standard three lead analysis programs. As a consequence, the derived P, PR, QRS and QT interval measurements varied quite widely among the various programs. Significant differences were also observed among measurements of Q, R and S duration. Some programs showed Q waves that were on the average 6 ms (p less than 0.001) longer than those of others. This may significantly influence diagnostic performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of automated electrocardiographic diagnosis by combination of computer interpretations of the electrocardiogram and vectorcardiogram.

In the international project "Common Standards for Quantitative Electrocardiography" (CSE), diagnostic results of different computer programs for the interpretation of the electrocardiogram (ECG) and of the vectorcardiogram (VCG) were combined, and it was shown that the "combined program" performs better than each program separately. Because the program MEANS (Modular ECG Analysis System) comprises 2 different classification programs--one for the ECG, the other for the VCG--this allowed investigation of whether the combined interpretations would yield a better diagnostic result than either one separately. This approach requires that a VCG always be recorded in addition to the ECG. To circumvent this complication, the VCG was reconstructed from the simultaneously recorded ECG leads. This reconstructed VCG was then interpreted by the VCG classification program, whereupon the diagnostic interpretations of the ECG and the reconstructed VCG were combined. For the validation, the CSE database of documented ECGs and VCGs (n = 1,220) was used. The combination of the ECG and VCG interpretations yielded a better diagnostic result than each interpretation program separately (total accuracy 74.2% (ECG + VCG) vs 69.8% (ECG) and 70.2% (VCG), p less than 0.001 in both cases). The results for the reconstructed VCG (total accuracy 70.5%) are comparable to those for the ECG and the VCG (p greater than 0.10 in both cases). The performance of the combined interpretations of ECG and reconstructed VCG (total accuracy 73.6%) is approximately the same as that of the combined ECG and VCG (p greater than 0.10). Thus, the performance of an ECG computer program can be improved by incorporating both ECG and VCG classificatory knowledge, using only the ECG itself.

Prolonged QT interval: a tricky diagnosis?

Prolonged heart-rate adjusted QT intervals on the electrocardiogram (ECG) are associated with an increased risk for coronary heart disease and sudden death. However, the diagnosis of the prolonged QT interval is hampered by lack of standards. We studied variations in the prevalence of prolonged QT, based on different common definitions, in a large nonhospitalized population, and compared our results with other studies applying the same definitions. The study population consisted of 2,200 men and 3,366 women participants of the Rotterdam Study, > or =55 years old. The QT interval was computed by our Modular ECG Analysis System (MEANS). Three different formulas to adjust QT for heart rate were used: Bazett's formula (QTc), a linear regression equation (QTlr), and the QT index (QTI). Prolonged QT occurred frequently in both men and women, and its prevalence increased with age. Women had longer heart-rate adjusted QT intervals than men (mean QTc 433 ms vs 422 ms), and mean values for QTlr were lower than for QTc (mean QTlr 422 ms in women and 412 ms in men). Prevalence was highest for prolonged QTlr (31% in men and 26% in women) and lowest for prolonged QTI (6% in men and 9% in women). Comparison with other studies applying the same correction formulas showed large discrepancies in prevalence estimates of prolonged QTc and QTlr, and to a lesser degree of prolonged QTI, possibly due to differences in measurement techniques. Future research is needed to relate QT interval to prognosis, to obtain measurement technique specific reference values of heart-rate adjusted QT measurements, and to obtain age- and sex-specific threshold values for prolonged QT. Such data are needed to use the QT interval with confidence.

Diagnostic interpretation of electrocardiograms in population-based research: computer program research physicians, or cardiologists?

We assessed the performance of diagnostic electrocardiogram (ECG) interpretation by the computer program MEANS and by research physicians, compared to cardiologists, in a physician-based study. To establish a strategy for ECG interpretation in health surveys, we also studied the diagnostic capacity of three scenarios: use of the computer program alone (A), computer program and cardiologist (B), and computer program, research physician, and cardiologist (C). A stratified random sample of 381 ECGs was drawn from ECGs collected in the Rotterdam Study (n = 3057), which were interpreted both by a trained research physician using a form for structured clinical evaluation and by MEANS. All ECGs were interpreted independently by two cardiologists; if they disagreed (n = 175) the ECG was judged by a third cardiologist. Five ECG diagnoses were considered: anterior and inferior myocardial infarction (MI), left and right bundle branch block (LBBB and RBBB), and left ventricular hypertrophy (LVH). Overall, sensitivities and specificities of MEANS and the research physicians were high. The sensitivity of MEANS ranged from 73.8% to 92.9% and of the research physician ranged from 71.8% to 96.9%. The specificity of MEANS ranged from 97.5% to 99.8% and of the research physician from 96.3% to 99.6%. To diagnose LVH, LBBB, and RBBB, use of the computer program alone gives satisfactory results. Preferably, all positive findings of anterior and inferior MI by the program should be verified by a cardiologist. We conclude that diagnostic ECG interpretation by computer can be very helpful in population-based research, being at least as good as ECG interpretation by a trained research physician, but much more efficient and therefore less expensive.

Simulating an integrated critiquing system.

OBJECTIVE: To investigate factors that determine the feasibility and effectiveness of a critiquing system for asthma/COPD that will be integrated with a general practitioner's (GP's) information system. DESIGN: A simulation study. Four reviewers, playing the role of the computer, generated critiquing comments and requests for additional information on six electronic medical records of patients with asthma/COPD. Three GPs who treated the patients, playing users, assessed the comments and provided missing information when requested. The GPs were asked why requested missing information was unavailable. The reviewers reevaluated their comments after receiving requested missing information. MEASUREMENTS: Descriptions of the number and nature of critiquing comments and requests for missing information. Assessment by the GPs of the critiquing comments in terms of agreement with each comment and judgment of its relevance, both on a five-point scale. Analysis of causes for the (un-)availability of requested missing information. Assessment of the impact of missing information on the generation of critiquing comments. RESULTS: Four reviewers provided 74 critiquing comments on 87 visits in six medical records. Most were about prescriptions (n = 28) and the GPs' workplans (n = 27). The GPs valued comments about diagnostics the most. The correlation between the GPs' agreement and relevance scores was 0.65. However, the GPs' agreements with prescription comments (complete disagreement, 31.3%; disagreement, 20.0%; neutral, 13.8%; agreement, 17.5%; complete agreement, 17.5%) differed from their judgments of these comments' relevance (completely irrelevant, 9.0%; irrelevant, 24.4%; neutral, 24.4%; relevant, 32.1%; completely relevant, 10.3%). The GPs were able to provide answers to 64% of the 90 requests for missing information. Reasons available information had not been recorded were: the GPs had not recorded the information explicitly; they had assumed it to be common knowledge; it was available elsewhere in the record. Reasons information was unavailable were: the decision had been made by another; the GP had not recorded the information. The reviewers left 74% of the comments unchanged after receiving requested missing information. CONCLUSION: Human reviewers can generate comments based on information currently available in electronic medical records of patients with asthma/COPD. The GPs valued comments regarding the diagnostic process the most. Although they judged prescription comments relevant, they often strongly disagreed with them, a discrepancy that poses a challenge for the presentation of critiquing comments for the future critiquing system. Requested additional information that was provided by the GPs led to few changes. Therefore, as system developers faced with the decision to build an integrated, non-inquisitive or an inquisitive critiquing system, the authors choose the former.

Evaluation of reporting based on descriptional knowledge.

OBJECTIVE: In an attempt to enhance the completeness and clarity of clinical narratives, the authors developed a general formalism for the entry of structured data. The objective of this study was to gain insight into the expressive power of the formalism through its use for reporting in endoscopy. DESIGN: Each of ten endoscopists reported twice about eight endoscopy videotapes. They produced free-text reports first, and then structured reports using this formalism. Statements in the resulting reports were compared. RESULTS: In total, 6.8% of the endoscopists' statements could not be expressed in structured options. Most of these statements were not due to limitations of the formalism itself. Topics mentioned in the free-text reports were described more frequently in the structured reports and, in addition, the structured reports included a greater variety of topics. Overall, increases of 83% for topics not related to abnormal findings (366 in free-text reports and 671 in structured reports) and 45% for features of abnormal findings (406 in free-text reports and 586 in structured reports) were observed. Although there was an overall information gain, features of abnormal findings were, on average, described by only half of the endoscopists. CONCLUSION: The expressive power of this formalism is promising, but general, multipurpose usage of the acquired data requires that topics be described by a larger percentage of physicians. Since this formalism led to more complete and more uniform data, additional research is justified to study how spontaneous reporting can be augmented further. The few subjects that occurred less often in structured reports suggest a possible negligence effect of structured reporting.

Evaluation of ECG interpretation systems: signal analysis.

Performance analysis of biosignal processing systems which provide diagnostic statements requires particular care. Besides general accuracy requirements, psychological and legal implications for patient and physician have to be considered on both the development and the user sites. Cybernetics and control engineering have provided the basic methodology for performance analysis of systems: in technical systems often mathematically defined functions and signals can be fed into the system to be tested and its response and output provide the necessary performance characteristics after adequate mathematical analysis. For systems which process biosignals, as for example ECG analysis systems, instead of analytically given signals learning and test sets of data derived from patients have to be applied. The performance analysis is done on a statistical basis. In this paper construction and composition of learning and test data sets as well as methods for performance evaluation of the signal processing part of ECG programs are described. Specific reference is made to the European project Common Standards for Quantitative Electrocardiography (CSE) where ten ECG- and nine VCG-programs have been tested. The results of these tests provide reference data and standards for further program development as well as for independent system performance evaluation.

Classification methods for computerized interpretation of the electrocardiogram.

Two methods for diagnostic classification of the electrocardiogram are described: a heuristic one and a statistical one. In the heuristic approach, the cardiologist provides the knowledge to construct a classifier, usually a decision tree. In the statistical approach, probability densities of diagnostic features are estimated from a learning set of ECGs and multivariate techniques are used to attain diagnostic classification. The relative merits of both approaches with respect to criteria selection, comprehensibility, flexibility, combined diseases, and performance are described. Optimization of heuristic classifiers is discussed. It is concluded that heuristic classifiers are more comprehensible than statistical ones; encounter less difficulties in dealing with combined categories; are flexible in the sense that new categories may readily be added or that existing ones may be refined stepwise. Statistical classifiers, on the other hand, are more easily adapted to another operating environment and require less involvement of cardiologists. Further research is needed to establish differences in performance between both methods. In relation to performance testing the issue is raised whether the ECG should be classified using as much prior information as possible, or whether it should be classified on itself, explicitly discarding information other than age and sex, while only afterwards other information will be used to reach a final diagnosis. Consequences of taking one of both positions are discussed.

Signal analysis for ECG interpretation.

In ECG interpretation usually two main areas are discerned: the signal analysis and the diagnostic classification. This article reviews the major developments in the first area. ECG signal analysis itself is subdivided into the stages data acquisition, data transformation, feature selection, and data reduction. These stages are consecutively reviewed, while in the data transformation stage digital filtering, detection, wave typing, beat selection, and boundary recognition are discussed.

Methodology of the modular ECG analysis system MEANS.

The methodology, used in the Modular ECG Analysis System (MEANS) is described. MEANS consists of modules for signal analysis and diagnostic classification. The basic structure of the modular interpretation system remained intact over a period of 20 years, while all modules underwent many changes as a function of experience and insight, and the continuously changing information technology. The article describes the advantages of a modular approach to decision-support systems, the most important ones being easier maintenance of the software package and separate optimization and testing of each module. The overall evaluation of MEANS was done in the CSE study. Evaluation results for modules and for the entire system are presented.

User evaluation of an integrated medical workstation for clinical data analysis.

Results are presented of the user evaluation of an integrated medical workstation for support of clinical research. Twenty-seven users were recruited from medical and scientific staff of the University Hospital Dijkzigt, the Faculty of Medicine of the Erasmus University Rotterdam, and from other Dutch medical institutions; and all were given a written, self-contained tutorial. Subsequently, an experiment was done in which six clinical data analysis problems had to be solved and an evaluation form was filled out. The aim of this user evaluation was to obtain insight in the benefits of integration for support of clinical data analysis for clinicians and biomedical researchers. The problems were divided into two sets, with gradually more complex problems. In the first set users were guided in a stepwise fashion to solve the problems. In the second set each stepwise problem had an open counterpart. During the evaluation, the workstation continuously recorded the user's actions. From these results significant differences became apparent between clinicians and non-clinicians for the correctness (means 54% and 81%, respectively, p = 0.04), completeness (means 64% and 88%, respectively, p = 0.01), and number of problems solved (means 67% and 90%, respectively, p = 0.02). These differences were absent for the stepwise problems. Physicians tend to skip more problems than biomedical researchers. No statistically significant differences were found between users with and without clinical data analysis experience, for correctness (means 74% and 72%, respectively, p = 0.95), and completeness (means 82% and 79%, respectively, p = 0.40).(ABSTRACT TRUNCATED AT 250 WORDS)

Education in medical informatics in The Netherlands: a nationwide policy and the Erasmus curriculum.

The curricula of all Medical Faculties still bear the characteristics of an era in which the physician was not educated in managing medical information systems, using communication networks, and processing knowledge. In attempting to formulate the prerequisites for developing and adjusting future curricula, we discuss the evolution of medical information technology during the past 25 years and give examples to illustrate that, by extrapolating current trends, future developments in information technology, medicine and education can be predicted. A plea is made for a strong interaction between scientific developments in medical informatics and academic education. In addition, a model based on our experience in medical informatics education of over 15 years, is pointed out. Furthermore, a nationwide policy on medical informatics in The Netherlands, is discussed. Our treatise is concluded by presenting the outline of the curriculum in medical informatics at the Erasmus University in Rotterdam. Educational recommendations conclude the paper.

The Delphi method to validate diagnostic knowledge in computerized ECG interpretation.

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 intraobserver 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.

Reconstruction of repetitive signals.

A technique is presented for the reconstruction of signals that suffered sampling-frequency decimation. Two assumptions are made: the original signal has to be repetitive, and no anti-aliasing filter has been used before frequency decimation. The performance of the technique is assessed by using test signals of which the original signal is known.

A new architecture for integration of heterogeneous software components.

An architecture is described that integrates existing applications in a network-wide system. The architecture follows the new open software paradigm, and defines kernel and application services that collaboratively solve the tasks of end-users and provide them with an intuitive user-interface. This paper describes the message language and the kernel mechanism for addressing application services. The architecture has been developed as much as possible to conform with current standards.

Common standards for quantitative electrocardiography: goals and main results. CSE Working Party.

Computer processing of electrocardiograms (ECGs) has over the last 15 years increased rapidly. Still, there are at present no standards for computer ECG interpretation. Different techniques are used not only for measurement and interpretation, but also for transmission and storage of data. In order to fill these gaps, a large international project, sponsored by the European Commission, was launched in 1980 to develop "Common Standards for Quantitative Electrocardiography (CSE)". The main objective of the first CSE study was to reduce the wide variation in wave measurements currently obtained by ECG computer programs. The second study was started in 1985 and aimed at the assessment and improvement of diagnostic classification of ECG interpretation programs. To this end reference libraries of well documented ECGs have been developed and comprehensive reviewing schemes devised for the visual and computer analysis of ECGs. This task was performed by a board of cardiologists in a Delphi review process, and by 9 VCG and 10 standard 12-lead programs developed by university research groups and by industry. A third action was started in June 1989 to harmonize acquisition, encoding, interchange and storing of digital ECG data. The action thus performed have become internationally recognized milestones for the standardization of quantitative electrocardiography.