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Objectives: To develop a model as a starting-point for developing a problem-oriented clinical notes application as a generic component of an Electronic Health Record (EHR).Methods: We used the generic conceptualization of Weed's problem-oriented medical record (POMR) to link progress notes to problems, and the Subjective, Objective, Assessment, Plan (SOAP) headings to classify elements of these notes. Health Level 7 (HL7) Version 3 and Unified Modeling Language (UML) were used for modeling. We looked especially at the role of Conditions and Concerns, and how to model these to document clinical reasoning.Results: We developed a generic HL7-based model for progress notes. In this model the specific clinical note has a condition as its reason. An assertion can be made about a condition. Any condition, observation or procedure can be a concern that has to be tracked. Utmost important is the relationship between constituting parts of a progress note and specially between progress notes by linking a progress note to conditions that are part of an earlier progress note. From this model a comprehensive hierarchical condition tree can be built. Several views, such as chronological, SOAP and condition-oriented, are possible. The clinical notes application is used in daily clinical practice. The model meets explicit design criteria and clinical needs.Conclusions: With the comprehensive HL7 standard it is possible to model and map progress notes using SOAP headings and POMR methodology. We have developed a generic, flexible and applicable paradigm by using acts for each assessment that refer to a condition (1), by separating conditions from concerns (2), and by an extensive use of the working list act (3). [ABSTRACT FROM AUTHOR]

Background: The incidence of hypertrophy and recurrent infections of the tonsils/adenoids appears to be decreasing in the Netherlands. It is uncertain whether this is a 'real' decrease in the incidence of disease or an 'artefact'.Aim: To investigate possible causes of the decreasing incidence of adenotonsillar problems among Dutch children.Design Of Study: Observational.Setting: A nationally representative general practice database.Method: Incidence rates were calculated over 2002-2005 among children aged 0-14 years. Multilevel Poisson regression analyses were used to examine the following possible causes of changing incidence rates: change in recording (more substitution codes), change in the demand for care (fewer visits to the GP), and change in the supply of care (fewer antibiotic prescriptions and referrals). Indications for a 'real' change in the incidence of disease were examined by calculating incidence rates of other clinical manifestations of microbial pathogens that may cause adenotonsillar problems.Results: The incidence rate decreased significantly (P = 0.017) from 3.0 to 1.3 per 1000 children per year. Correcting for demand for and supply of care led to a smaller decline in yearly incidence, from 2.9 to 1.7 per 1000 children per year (P = 0.105). No clearly similar trend was found in other clinical manifestations of viruses and bacteria that may cause adenotonsillar problems.Conclusion: Part of the declining trend can be explained by a change in the demand for and supply of care, but no apparent causal clue emerged for the residual declining trend in the incidence of disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to detect striking trends based on a new strategy for monitoring public health. METHODS: We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general practitioners (GPs) or were constructed using a new record linkage method (EPICON). The episodes were used to estimate raw morbidity rates for all codes of the International Classification of Primary Care (ICPC). Multilevel Poisson regression models were used to analyse the trend over time for 15 health problems that showed an obvious change over time. Based on these models, we calculated adjusted incidence rates corrected for clustering, sex and age. RESULTS: During 2002-05, both men and women increasingly consulted the GP because of concern about a drug reaction, a change in faeces/bowel movements and urination problems. Men showed an increase in consultations for prostate problems and venereal diseases. The incidence of chronic internal knee derangement decreased for both sexes. Women consulted their GP less frequently about sterilization and fear of being pregnant. CONCLUSION: The strategy developed proved to be useful to detect trends across a short period of time. Changes in the health care market, such as the increasing availability of over-the-counter drugs and various large advertising campaigns for medications may explain some of the findings. The increasing incidence of health problems in the urogenital area deserves attention as it could reflect increases in the incidence of sexually transmitted diseases (STDs) and urinary tract infections. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we evaluated the internal validity of EPICON, an application for grouping ICPC-coded diagnoses from electronic medical records into episodes of care. These episodes are used to estimate morbidity rates in general practice.Methods: Morbidity rates based on EPICON were compared to a gold standard; i.e. the rates from the second Dutch National Survey of General Practice. We calculated the deviation from the gold standard for 677 prevalence and 681 incidence rates, based on the full dataset. Additionally, we examined the effect of case-based reasoning within EPICON using a comparison to a simple, not case-based method (EPI-0). Finally, we used a split sample procedure to evaluate the performance of EPICON.Results: Morbidity rates that are based on EPICON deviate only slightly from the gold standard and show no systematic bias. The effect of case-based reasoning within EPICON is evident. The addition of case-based reasoning to the grouping system reduced both systematic and random error. Although the morbidity rates that are based on the split sample procedure show no systematic bias, they do deviate more from the gold standard than morbidity rates for the full dataset.Conclusions: Results from this study indicate that the internal validity of EPICON is adequate. Assuming that the standard is gold, EPICON provides valid outcomes for this study population. EPICON seems useful for registries in general practice for the purpose of estimating morbidity rates. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the use, usability, and physician satisfaction of a locally developed problem-oriented clinical notes application that replaced paper-based records in a large Dutch university medical center., Methods: Using a clinical notes database and an application event log file and a cross-sectional survey of usability, authors retrospectively analyzed system usage for medical specialties, users, and patients over 4 years. A standardized questionnaire measured usability. Authors analyzed the effects of sex, age, professional experience, training hours, and medical specialty on user satisfaction via univariate analysis of variance. Authors also examined the correlation between user satisfaction in relation to users' intensity of use of the application., Results: In total 1,793 physicians used the application to record progress notes for 219,755 patients. The overall satisfaction score was 3.2 on a scale from 1 (highly dissatisfied) to 5 (highly satisfied). A statistically significant difference occurred in satisfaction by medical specialty, but no statistically significant differences in satisfaction took place by sex, age, professional experience, or training hours. Intensity of system use did not correlate with physician satisfaction., Conclusions: By two years after the start of the implementation, all medical specialties utilized the clinical notes application. User satisfaction was neutral (3.2 on a 1-5 scale). Authors believe that the significant factors facilitating this transition mirrored success factors reported by other groups: a generic, consistent, and transparent design of the application; intensive collaboration; continuous monitoring; and an incremental rollout.

Aims and Objectives: To research the use of ambiguous language in written information concerning patients' functioning and to identify problems resulting from the use of ambiguous language in clinical practice., Background: Many projects that aimed to introduce standard terminology concerning patients' functioning in clinical practice are unsuccessful because standard terminology is rarely used in clinical practice. These projects mainly aim to improve communication by reducing ambiguous language. Considering their lack of success, the validity of the argument that language ambiguity is used in clinical practice is questioned., Design: An integrative literature review., Methods: A systematic search of the MEDLINE (1950-2012) and CINAHL (1982-2012) databases was undertaken, including empirical and theoretical literature. The selected studies were critically appraised using a data assessment and extraction form., Results: Seventeen of 767 papers were included in the review and synthesis. The use of ambiguous language in written information concerning patients' functioning was demonstrated. Problems resulting from the use of ambiguous language in clinical practice were not identified. However, several potential problems were suggested, including hindered clinical decision-making and limited research opportunities., Conclusion: The results of this review demonstrated the use of ambiguous language concerning patients' functioning, but health professionals in clinical practice did not experience this issue as a problem. This finding might explain why many projects aimed at introducing standard terminology concerning functioning in clinical practice to solve problems caused by ambiguous language are often unsuccessful. Language ambiguity alone is not a valid argument to justify the introduction of standard terminology., Relevance to Clinical Practice: The introduction of standard terminology concerning patients' functioning will only be successful when clinical practice requires the aggregation and reuse of data from electronic patient records for different purposes, including multidisciplinary decision-making and research., (© 2014 John Wiley & Sons Ltd.)

Background: Translating a question into a query using patient characteristics, type of intervention, control, and outcome (PICO) should help answer therapeutic questions in PubMed searches. The authors performed a randomized crossover trial to determine whether the PICO format was useful for quick searches of PubMed., Methods: Twenty-two residents and specialists working at the Radboud University Nijmegen Medical Centre were trained in formulating PICO queries and then presented with a randomized set of questions derived from Cochrane reviews. They were asked to use the best query possible in a five-minute search, using standard and PICO queries. Recall and precision were calculated for both standard and PICO queries., Results: Twenty-two physicians created 434 queries using both techniques. Average precision was 4.02% for standard queries and 3.44% for PICO queries (difference nonsignificant, t(21) = -0.56, P = 0.58). Average recall was 12.27% for standard queries and 13.62% for PICO queries (difference nonsignificant, t(21) = -0.76, P = 0.46)., Conclusions: PICO queries do not result in better recall or precision in time-limited searches. Standard queries containing enough detail are sufficient for quick searches.

Organ allocation systems have become complex and difficult to comprehend. We introduced decision tables to specify the rules of allocation systems for different organs. A rule engine with decision tables as input was tested for the Kidney Allocation System (ETKAS). We compared this rule engine with the currently used ETKAS by running 11,000 historical match runs and by running the rule engine in parallel with the ETKAS on our allocation system. Decision tables were easy to implement and successful in verifying correctness, completeness, and consistency. The outcomes of the 11,000 historical matches in the rule engine and the ETKAS were exactly the same. Running the rule engine simultaneously in parallel and in real time with the ETKAS also produced no differences. Specifying organ allocation rules in decision tables is already a great step forward in enhancing the clarity of the systems. Yet, using these tables as rule engine input for matches optimizes the flexibility, simplicity and clarity of the whole process, from specification to the performed matches, and in addition this new method allows well controlled simulations., (© 2011 The Authors. Transplant International © 2011 European Society for Organ Transplantation.)

Aim: To assess the impact of two modes of spirometry expert support on Family physicians' (FPs') diagnoses and planned management in patients with apparent respiratory disease., Method: A cluster-randomised trial was performed with family practices as the unit of randomisation. FPs from 44 family practices recorded their diagnosis and planned management before and after spirometry for 868 patients. Intervention consisted of spirometry interpretation support by either a chest physician or expert software. Both interventions were compared with usual care (i.e. no additional interpretation support). Change in FPs' diagnoses after spirometry served as the primary outcome. Secondary outcomes were referral rate, additional diagnostic tests, and disease management changes. Effects were expressed as percentages and Odds Ratios (OR) with 95% confidence intervals., Results: Diagnoses changed after intervention in all groups: 47.8% (95% CI 41.8 to 53.9) for chest physician support; 45.0% (95% CI 39.5 to 50.6) for software support; and 53.3% (95% CI 47.2 to 59.4) for usual care. Differences in the proportions of changed diagnosis were not statistically significant: chest physician support versus usual care OR 0.79 (95%CI 0.49 to 1.30); software support versus usual care OR 0.72 (95% CI 0.45 - 1.15). There were no differences in secondary outcomes., Conclusion: Neither chest physician spirometry support nor expert software spirometry support had a significant impact on FPs' diagnosis of respiratory conditions or management decisions., Trial Number: http://www.clinicaltrials.gov/ct/show/NCT00131157?order=1.

Objectives: The research sought to determine the value of PubMed filters and combinations of filters in literature selected for systematic reviews on therapy-related clinical questions., Methods: References to 35,281 included and 48,514 excluded articles were extracted from 2,629 reviews published prior to January 2008 in the Cochrane Database of Systematic Reviews and sent to PubMed with and without filters. Sensitivity, specificity, and precision were calculated from the percentages of unfiltered and filtered references retrieved for each review and averaged over all reviews., Results: Sensitivity of the Sensitive Clinical Queries filter was reasonable (92.7%, 92.1-93.3); specificity (16.1%, 15.1-17.1) and precision were low (49.5%, 48.5-50.5). The Specific Clinical Queries and the Single Term Medline Specific filters performed comparably (sensitivity, 78.2%, 77.2-79.2 vs. 78.0%; 77.0-79.0; specificity, 52.0%, 50.8-53.2 vs. 52.3%, 51.1-53.5; precision, 60.4%, 59.4-61.4 vs. 60.6%, 59.6-61.6). Combining the Abridged Index Medicus (AIM) and Single Term Medline Specific (65.2%, 63.8-66.6), Two Terms Medline Optimized (64.2%, 62.8-65.6), or Specific Clinical Queries filters (65.0%, 63.6-66.4) yielded the highest precision., Conclusions: Sensitive and Specific Clinical Queries filters used to answer questions about therapy will result in a list of clinical trials but cannot be expected to identify only methodologically sound trials. The Specific Clinical Queries filters are not suitable for questions regarding therapy that cannot be answered with randomized controlled trials. Combining AIM with specific PubMed filters yields the highest precision in the Cochrane dataset.

Hospitals and clinics develop Internet strategies to emancipate and empower their patient population. At Radboud University Nijmegen Medical Centre, we developed an Internet-based personal health record that provides patients with general and personal information about their treatment and that provides facilities for communication with fellow patients and with physicians. Because not much is known about information and communication needs of IVF and ICSI patients in relation to their treatment, we observed the intensity of use of this personal health record during the various stages of IVF treatment. We measured the numbers of page views and the number of contributions to the chat room. Data regarding Website use and treatment schedules were available for 51 couples. These couples generated 25,420 page views and posted 11,403 utterances. Two-way analysis of variance showed that significant individual changes occurred in the intensity of use during the different stages of the treatment. During the stages in which there is no contact between the patient and the clinic, patients make use of the Website's communication functions. This reflects the patients' need for continued communication and support during the last stages of treatment, a service that IVF clinics traditionally cannot or do not provide.

Background: The internet introduces new ways to deal with stress. However, it is unclear how its resources are used in everyday life. Using a web-based personal health record (PHR), we observed the patient's online behaviour and linked this to distress, theories on dealing with stress and demographics., Methods: Between 2004 and 2007, all viewed web-pages were logged and categorized into 14 content types. Behavioural styles were elicited using factor analysis. These behavioural styles were subsequently correlated to data on demographics, coping mechanisms and distress from the female partner of the first 53 patient couples that used the PHR., Results: One thousand and fifty patient couples viewed 588 887 web pages during their first treatment cycle. Factor analysis elicited three online behavioural styles explaining 66.9% of all variance in usage of the website: an 'individual information style', a 'generic information style' and a 'communication style'. The 'individual information style' correlated negatively to having paid employment (Spearman = -0.364, P = 0.007) and emotional coping mechanisms (Spearman = -0.305, P = 0.028). The 'communication style' correlated positively to having paid employment (Spearman = 0.318, P = 0.021) and anxiety (Spearman = 0.381, P = 0.005)., Conclusions: IVF patients show three types of online behaviour. Only limited correlations exist between these styles and demographics, coping mechanisms or distress. When planning a website or portal for IVF patients, content should be adopted accordingly.

The present study assessed the impact of computerised spirometry interpretation expert support on the diagnostic achievements of general practitioners (GPs), and on GPs' decision making in diagnosing chronic respiratory disease. A cluster-randomised controlled trial was performed in 78 GPs who each completed 10 standardised paper case descriptions. Intervention consisted of support for GPs' spirometry interpretation either by an expert system (expert support group) or by sham information (control group). Agreement of GPs' diagnoses was compared with an expert panel judgement, which served as the primary outcome. Secondary outcomes were: additional diagnostic test rates; width of differential diagnosis; certainty of diagnosis; estimated severity of disease; referral rate; and medication or nonmedication changes. Effects were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). There were no differences between the expert support and control groups in the agreement between GPs and expert panel diagnosis of chronic obstructive pulmonary disease (OR (95% CI) 1.08 (0.70-1.66)), asthma (1.13 (0.70-1.80)), and absence of respiratory disease (1.32 (0.61-2.86)). A higher rate of additional diagnostic tests was observed in the expert support group (2.5 (1.17-5.35)). Computerised spirometry expert support had no detectable benefit on general practitioners' diagnostic achievements and the decision-making process when diagnosing chronic respiratory disease.

Objective: To study the effect of an Internet-based personal health record on the empowerment of patients undergoing IVF., Design: Randomized clinical trial., Setting: Patients undergoing IVF and intracytoplasmic sperm injection (ICSI) in an academic research environment., Patient(s): We selected patients who were undergoing an IVF or ICSI treatment, have an Internet connection, and speak fluent Dutch., Intervention(s): An Internet-based personal health record that provides patients with general and personal information concerning their given treatment and that also provides facilities for communication with fellow patients and physicians., Main Outcome Measure(s): Patient empowerment (measured as a multidimensional concept consisting of self-efficacy, actual and perceived knowledge, and involvement in the decision process), patient satisfaction, meaning of infertility problems, social support, anxiety, and depression., Result(s): A total of 91 female and 89 male participants were suitable for analysis. No significant differences were observed in per person change in patient empowerment. We did not find any significant differences regarding per person change in patient satisfaction, the meaning of infertility problems, social support, anxiety, and depression., Conclusion(s): Usage of the personal health record did not have any effects on patient empowerment, but, at the same time, the study did not find that the personal health record had any significant adverse effects either.

Methodological training is necessary in order to cope with the ever-growing volume of knowledge by clinical experience. This training involves ways of reasoning and collecting relevant evidence. This type of instruction should be given in concurrence with the first exercises in clinical reasoning. Such instruction should focus on acquisition of the ability to clearly substantiate decisions made during medical practice.

Background: Generic patient-accessible medical records have shown promise in enhancing patient-centred care for patients with chronic diseases. We sought to design, implement and evaluate a patient-accessible medical record specifically for patients undergoing a course of assisted reproduction (IVF or ICSI)., Methods: The personal medical record (PMR) database was developed using three formative evaluation steps, and its user-experience was evaluated through a cross-sectional study. Fifty-four patient-couples receiving an IVF or ICSI treatment in our hospital were granted access to the PMR. Main outcomes concern the usage of the PMR, the perceived usefulness of its functions and user attitudes towards privacy and financial issues., Results: The PMR consists of 15 major functions that can be classified into personal information, general information and communication functions. Fifty-three patient-couples accessed the website and 51 couples filled out the evaluation questionnaire. They rated most functions as useful and preferred personalized to general functions. The results also show that some functions require further development. Patients using the PMR have little concerns regarding privacy, and 76% are willing to pay for such a service in the future., Conclusions: The patients in this study frequently and intensively used the Internet-accessible PMR. This suggests that the PMR offers very useful functions from an IVF/ICSI patient's perspective.

Objective: To determine whether educators consider electronic patient record (EPR)-related education necessary and if so, what subjects have to be taught more extensively in the future., Methods: A list of possibly relevant subjects was determined from the literature. A questionnaire was designed which contained those subjects and the respondents were asked to indicate, for each subject, its competency level and required competency level in current teaching. Since the response rate was low a second questionnaire was developed to have the results of the analysis of the first questionnaire validated by a larger group of educators., Results: In total 45 learning goals were identified from the literature. The questionnaire was sent to representatives of several disciplines: basic medical education, medical specializations, pharmacy, dentistry and nursing. The analysis of the first questionnaire resulted in nine subjects that needed more attention in the future. Because of the low response the needs could not be specified for the individual disciplines. This insight was obtained from a second questionnaire. The response to this questionnaire was high. From the analysis of the second questionnaire differences between views of educators involved in the training of GPs and educators involved in the training of other specializations were observed., Conclusion: Educators find EPR-related education important. There are different opinions about the phase in which EPR-related education should be given.

Objective: A pilot study aimed to determine the extent to which each of three data sources could provide complete and reliable data for valid assessment of clinical performance., Design: Clinical decisions taken in 168 consultations by seven family physicians were reviewed against guidelines for 15 clinical conditions. In total, 206 criteria were reviewed using three sources: medical records, observation in surgery, and structured self-recording by the physicians., Setting and Participants: Seven family practices in the Netherlands., Main Measure: Scores (%) of data recorded/total were obtained for each method. Kappa scores for the agreement between the three data sources were also obtained., Results: Medical record examination provided 40%, observation 72%, and physician self-recording 95% of the data required for the review against guidelines. Nine per cent of the clinical decisions could be reviewed when using medical records, 46% when using observation data, and 69% when using data from prospective self-recording. In particular, decisions in the area of patient education and diagnostic examinations could not be reviewed validly using medical records only. Kappa agreements between the data available from the three sources as well as between the review results appeared to be 0.79., Conclusions: Medical records alone only supply sufficient information for the review of a very limited set of clinical decisions. Physician self-recording has significantly more potential for valid review of a broad range of clinical decisions. Furthermore, self-recording seems a reliable data collection method that deserves further research.

Medical textbooks are an important aid in the process of diagnosing and treating patients. Medical students use these books to acquire the skills necessary for this process, while medical teachers and experienced doctors use them for teaching these competences. We posed the question whether medical textbooks are structured in such a way that medical students are taught to structure knowledge and to make a differential diagnosis in a logical way. Five major textbooks were compared with regard to four clinical problems (gastrointestinal bleeding, anaemia, oedema and heart failure). The presentation appeared to be very variable in respect of logic and systematic arrangement. In fact, it was disappointing that even in well-reputed textbooks, a systematic approach is lacking. We feel there is a need for improvement, in order to facilitate the learning of medical students and to enhance their abilities in clinical problem solving.

Objectives: Many shared-care projects feel the need for electronic patient-record (EPR) systems. In absence of practical experiences from paper record keeping, a theoretical model is the only reference for the design of these systems. In this article, we review existing models of individual clinical practice and integrate their useful elements. We then present a generic model of clinical practice that is applicable to both individual and collaborative clinical practice., Methods: We followed the principles of the conversation-for-action theory and the DEMO method. According to these principles, information can only be generated by a conversation between two actors. An actor is a role that can be played by one or more human subjects, so the model does not distinguish between inter-individual and intra-individual conversations., Results: Clinical practice has been divided into four actors: service provider, problem solver, coordinator, and worker. Each actor represents a level of clinical responsibility. Any information in the patient record is the result of a conversation between two of these actors. Connecting different conversations to one another can create a process view with meta-information about the rationale of clinical practice. Such process view can be implemented as an extension to the EPR., Conclusions: The model has the potential to cover all professional activities, but needs to be further validated. The model can serve as a theoretical basis for the design of EPR-systems for shared care, but a successful EPR-system needs more than just a theoretical model.

Excessive diagnostic testing rarely leads to complete certainty of the disease status of a patient. Because of constraints of health care budgets, physicians should be aware of the diminishing marginal gain of each subsequent test in a testing strategy related to costs. We developed the probability-modifying plot to determine economically efficient sequence of testing without losing clinical effectiveness. Two applications of the model are presented: diagnosis of Helicobacter pylori and diagnosis of benign prostatic hyperplasia. The probability-modifying plots are drawn to visualize and calculate the economic efficiency of all possible test sequences, meaning that although the different test sequences are equally accurate, some have even lower costs than others.

Interactive technology assessment (iTA) provides an answer to the ethical problem of normative bias in evaluation research. This normative bias develops when relevant perspectives on the evaluand (the thing being evaluated) are neglected. In iTA this bias is overcome by incorporating different perspectives into the assessment. As a consequence, justification of decisions based on the assessment is provided by stakeholders having achieved agreement. In this article, agreement is identified with wide reflective equilibrium to show that it indeed has the potential of justifying decisions. We work out several conditions for this agreement to be achievable and just.

Complex knowledge and data intensive nature of the psychoactive drug selection and prescription process often makes for irrational and inconsistent use of psychoactive drugs in clinical practice. After describing the state of the art with respect to psychoactive drug prescription practices and selection processes, our aim is to analyze the advantages of computer support systems in assisting the clinician in his clinical decisions. Finally, we will review the neuropsychiatric expert systems developed for the neuropsychiatric domain. Suboptimal psychoactive drug therapy is common practice, which leads to hospital admissions, extended length of hospital stay, ineffective therapy and increased costs. Furthermore, the psychoactive drug selection process is a complex decision process, using up-to-date integrative knowledge of drugs from basic sciences to the clinical level. Due to the information load, the lack of appropriate up-to-date information at the point of clinical care and the problem of integrating and weighing all information relatively equally, it is questionable whether any clinician can manage such a complex situation with optimal effectiveness. As has been shown in a number of experiments, clinicians can benefit from computer-based systems that provide access to accurate, up-to-date information. We maintain that more rational use of psychoactive drugs in clinical practice is needed, and conclude that rational psychoactive drug prescription is a knowledge and data-intensive task requiring true expertise derived from clinical, pathophysiological and pharmacotherapeutic knowledge. We will be developing a Multidisciplinary Psychoactive Drug Selection advisor system, M-PADS, to support the integration of various types of biomedical information and deliver that integrated information supportive to evidence-based rational drug prescription in the practice of medicine for the drug treatment of individual patients.

The authors describe and discuss clinical problem analysis (CPA), an approach to solving complex clinical problems. They outline the five steps of the CPA model and the essential elements of each step. Next, they discuss the value of CPA's content-independent (methodical) approach and argue that teaching students to use CPA will enable them to avoid some common diagnostic reasoning errors and pitfalls. Finally, they compare CPA with two existing approaches to clinical problem solving.

The problem of disease definition is related to the problem of proving that a certain agent is the necessary cause of a certain disease. Natural kind terms like 'rheumatoid arthritis' and 'AIDS' refer to essences which are discoverable rather than predeterminate. No statement about such diseases is a priori necessarily true. Because theories on necessary causes involve natural kind semantics, Koch's postulates cannot be used to falsify or verify such theories. Instead of proving that agent A is the necessary cause of disease D, we include A in a theoretical definition of D, take this to represent the real meaning of 'D', and discard the pretheoretical definition. This is illustrated by Koch's own attempt to prove he had discovered the necessary cause of tuberculosis. Methodological arguments about disease causation require a clear view of our use of diagnostic terms. Medical lexicographers should do more to provide such a view.

Patient case analysis is an elementary and crucial process which clinicians are daily confronted with. The importance and complexity is reflected in the need to discuss cases in clinicopathological conferences and the documentation of more than 70,000 patient cases in MEDLINE. This paper introduces a generic patient case report language (PCRL) based on general medical temporal concepts to formalise temporal knowledge as present in case descriptions. The lack of such a generic technique is reflected by the fact that computers are very restrictive in accepting patient specific temporal information. Acceptance is almost always controlled and guided by specific predefined disease or treatment models. We strive for a case library consisting of unambiguous patient case descriptions formulated independent from future use.

This paper deals with optimising the use of magnetic resonance imaging (MRI) scanners through the development of a new kind of clinical guidelines called 'substrate-specific protocols'. These protocols would link the descriptive elements of lesions to the most appropriate imaging techniques on the basis of the biophysics of MRI. As many lesions have elements in common, substrate-specific protocols could have a more general character and be more firmly based on evidence than conventional guidelines. We developed an inference model to enter, structure and retrieve knowledge acquired through a literature search. This proved a practicable and attractive approach. Its exactness, however, reveals the imperfections of medical knowledge and clinical practice. We conclude that it could be hard to establish an 'evidence basis' for clinical guidelines, if 'evidence based' means rooted in natural science.

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.

Health technology assessment (HTA) is often biased in the sense that it neglects relevant perspectives on the technology in question. To incorporate different perspectives in HTA, we should pursue agreement about what are relevant, plausible, and feasible research questions; interactive technology assessment (iTA) might be suitable for this goal. In this way a kind of procedural ethics is established. Currently, ethics too often is focussed on the application of general principles, which leaves a lot of confusion as to what really is the matter in specific cases; in an iTA clashes of values should not be approached by use of such ethics. Instead, casuistry, as a tool used within the framework of iTA, should help to articulate and clarify what is the matter, as to make room for explication and consensus building.

Update mechanisms for diagnostic classifications should capture changes in medical knowledge but also allow for comparability across versions. This paper provides a basis for such a mechanism by describing types of IS-A statement and types of knowledge used in the construction of diagnostic classifications. Three types of IS-A statement are used: 'A is by definition a B', 'A is probably a B' and 'A is in theory necessarily a B'. Each relates to a different type of knowledge: knowledge of linguistic conventions, of probabilities, and of empirical theories and their status, respectively. Consequently, the development and maintenance of diagnostic classifications requires a collaboration of medical terminologists and medical scientists. The role of the latter is especially important during updating. Updating is necessitated by changing probabilities and by the introduction or changing status of empirical theories. The linguistic notion of hyponymy oversimplifies the issue.

Objective: In this study an attempt was made to explain some of the interobserver variation in re-restoration decision making using., Method: A simplified re-restoration case was shown to 22 dentists who were asked what treatment decision they would make, and what factors would play a role in their decision. The treatment decisions were compared to the outcomes of a knowledge-system on re-restoration decision making., Results: The dentists unanimously selected re-restoration as the treatment alternative. Half of the dentists preferred amalgam, and the other half chose composite as restorative material. This variation could be explained almost fully by the dentists' weighs on the factors 'tissue loss during preparation', 'restoration and preservation of the chewing function' and 'prognosis and durability of the restoration'. The knowledge system indicated that more than 80% of the dentists actually should have selected composite resin for a restorative material., Conclusions: It was concluded that the availability of knowledge and its application can explain variation in re-restoration decisions. Knowledge systems can be used in designing practice guidelines.

We devised a diagnostic approach based on screening plasma for an Aspergillus antigen with use of a sandwich enzyme-linked immunosorbent assay (ELISA), thoracic computed tomographic scanning, and radionuclide imaging for managing patients at risk for invasive aspergillosis. We used a decision analytic model to compare this alternative strategy with the conventional strategy, which relies only on the presence of clinical symptoms, persistent fever, and chest roentgenographic findings. Use of the alternative strategy reduced the number of patients who would receive antifungal treatment empirically, but this strategy was more expensive. The specificity of the sandwich ELISA had a significant impact on cost, but the sensitivity did not. A 13% prevalence of infection resulted in equal costs for both strategies. As much as 43.3% of the patients treated empirically could be given liposomal amphotericin B (L-AmB) before the conventional strategy became the most expensive. The costs of the alternative strategy were less than those of the conventional strategy when >5.3% of all patients, irrespective of strategy, were treated with L-AmB.

In this article, we describe the state of the art and directions of current development and research with respect to the inclusion of medical narratives in electronic medical-record systems. We used information about 20 electronic medical-record systems as presented in the literature. We divided these systems into 'classical' systems that matured before 1990 and are now used in a broad range of medical domains, and 'experimental' systems, more recently developed and, in general, more innovative. In the literature, three major challenges were addressed: facilitation of direct data entry, achieving unambiguous understandability of data, and improvement of data presentation. Promising approaches to tackle the first and second challenge are the use of dynamic data-entry forms that anticipate sensible input, and free-text data entry followed by natural-language interpretation. Both these approaches require a highly expressive medical terminology. How to facilitate the access to medical narratives has not been studied much. We found facilitating examples of presenting this information as fluent prose, of optimising the screen design with fixed position cues, and of imposing medical narratives with a structure of indexable paragraphs that can be used in flowsheets. We conclude that further study is needed to develop an optimal searching structure for medical narratives.

Guidelines in primary health care have been developed to reduce assumed and undesired variation in certain aspects of care delivery by professionals. If systematically applied guidelines no doubt effect the quality of care. It is argued however that taking an organizational point of view on quality management yields new requirements with respect to development and application of guidelines. It is considered to be essential for managerial control purposes that guidelines have simple and valid indicators to monitor the actual application and to measure the preferred outcome. It is essential that the choice of guidelines to be implemented in an organization is determined in the context of an explicit plan for quality management.