Biomedical subjects

H Ahlfeldt

Publications and source records attributed to H Ahlfeldt.

At least 19 recordsLinked to original sources

PubMed2003

Priority setting in cardiac surgery: a survey of decision making and ethical issues.

OBJECTIVES: The aim of this study was to examine priority setting for coronary artery bypass surgery, and to provide an overview of decisions and rationales used in clinical practice. METHOD: Questionnaires were sent to all permanently employed cardiologists, cardiothoracic surgeons, and anaesthesiologists at nine Swedish hospitals performing adult cardiothoracic surgery. RESULTS: A total of 208 physicians responded (a 44% return rate). There was considerable agreement concerning the criteria that should be used to set priorities for coronary artery bypass interventions (clusters of factors in synthesis). However, there was a lack of accord regarding the use of national guidelines for priority setting and risk indexes. CONCLUSIONS: Basic training and the strong support of ethical principles in priority setting are lacking. The respondents indicated a need for clearer guidelines and an open dialogue or discussion. The lack of generally acknowledged plans and guidelines for priority setting may result in unequal, conditional, and unfair treatment.

Adult↗

PubMed2001

Superficial and deep sternal wound complications: incidence, risk factors and mortality.

OBJECTIVES: Sternal wound complications often have a late onset and are detected after patients are discharged from the hospital. In an effort to catch all sternal wound complications, different postdischarge surveillance methods have to be used. Together with this long-term follow-up an analysis of risk factors may help to identify patients at risk and can lead to more effective preventive and control measures. METHODS: This retrospective study of 3008 adult patients who underwent consecutive cardiac surgery from January 1996 through September 1999 at Linköping University Hospital, Sweden, evaluated 42 potential risk factors by univariate analysis followed by backward stepwise multivariate logistic regression analysis. RESULTS: Two-thirds of the 291 (9.7%) sternal wound complications that occurred were identified after discharge. Of the 291 patients, 47 (1.6%) had deep sternal infections, 50 (1.7%) had postoperative mediastinitis, and 194 (6.4%) had superficial sternal wound complications. Twenty-three variables were selected by univariate analysis (P<0.15) and included in a multivariate analysis where eight variables emerged as significant (P<0.05). Preoperative risk factors for deep sternal infections/mediastinitis were obesity, insulin-dependent diabetes, smoking, peripheral vascular disease, and high New York Heart Association score. An intraoperative risk factor was bilateral use of internal mammary arteries, and a postoperative risk factor was prolonged ventilator support. Risk factors for superficial sternal wound complications were obesity, and an age of <75 years. The 30 day mortality was 2.7% for patients without sternal wound complications and 2/291 (0.7%) for all patients with sternal wound complications, 0.5% for superficial sternal wound complications, and 1.0% for deep sternal infections/mediastinitis. The 1 year mortality rate was 4.8% for patients without sternal wound complications and 11/291 (3.8%) for patients with sternal wound complications, 2.1% for superficial sternal wound complications, and 7.2% for deep sternal infections/mediastinitis. CONCLUSIONS: The risk factors found in this study have been detected and reported in previous studies. The predictive ability was stronger though for deep sternal infections/mediastinitis (those needing surgical revisions) than for superficial sternal wound complications. Earlier recognition of sternal wound complications and aggressive treatment have probably contributed to the relatively low mortality rate seen in this study.

Age Factors↗

PubMed2001

Classification of procedures in the domain of thoracic surgery--a study of reliability in coding.

This paper relates a study of reliability of coding of surgical procedures in the domain of thoracic surgery. The reliability measured is inter-coder variability in form of agreement. Four classifications were used by four physicians on 100 patient cases. The classifications, having differing granularity and structure, were analyzed using a statistical method (kappa). These results are discussed and related to the differences between the classifications. One of the topics for discussion is how the granularity affects the degree of agreement, coupled to the usefulness of the classification. Also the concept of using formal methods for representing classifications is discussed, how this will affect how classifications are designed and used.

Humans↗

PubMed2001

Experiences from development of home health care applications based on emerging Java technology.

Home health care is an expanding area within the health care system. The idea of moving parts of the health care process from expensive specialised hospital care to primary health care and home health care might be attractive in a cost perspective. The introduction of home health care applications must be based on a rigorous analysis of necessary requirements to secure a safe and reliable health care. This article reports early experiences from the development of a home health care application based on emerging Java technologies such as the OSGi platform. A pilot application for follow-up of diabetes patients is presented and discussed in relation to a list of general requirements on home health care applications.

Blood Glucose Self-Monitoring↗

PubMed2000

Evaluation of three Swedish ICD-10 primary care versions: reliability and ease of use in diagnostic coding.

If computer-stored information is to be useful for purposes other than patient care, reliability of the data is of utmost importance. In primary healthcare settings, however, it has been found to be poor. This paper presents a study on the influence of coding tools on reliability and user acceptance. Six general practitioners coded 152 medical problems each by means of three versions of ICD-10, one with a compositional structure. At code level the reliability was poor and was almost identical when the three versions were compared. At aggregated level the reliability was good and somewhat better in the compositional structure. Ideas for improved user acceptance arose, and the study explored the need for several different tools to retrieve diagnostic codes.

Analysis of Variance↗

PubMed1999

Towards a multi-professional patient record--a study of the headings used in clinical practice.

This paper reports on the differences and similarities of headings used in patient records by Swedish health care professionals; nurses, occupational therapists, physiotherapists, dietitians, speech therapists, medical social workers and general practitioners. The background to the study is a national project where representatives from the different health care professions have worked together for two years in an effort to develop a multi-professional database of terms for the health care sector. The study reports on an analysis of the existing multi-professional lists of headings with respect to structure, degree of specialization, synonyms and homonyms. The study is descriptive in nature, gives a status report on the variety of headings used in clinical practice, provides necessary material for a normative approach focusing on a truly multiprofessional patient record in the future.

Humans↗

PubMed1999

Aggregation and reclassification--assessment of GALEN methods in the domain of thoracic surgery.

This paper reports on the experiences from evaluation of GALEN methods for mapping of follow-up categories in the domain of thoracic surgery to an existing classification of surgical procedures. The mapping of the aggregated levels or groups of thoracic procedures presents a genuine problem in relation to strict hierarchical classifications, since the follow-up categories not necessarily fit in the pre-set structure of the classification. The paper reports on the experiences from modelling of the traditional classification as well as modelling of the follow-up categories, together with an analysis of results with a discussion of opportunities and potential problems and pitfalls when applying GALEN models and tools.

Humans↗

PubMed1999

Towards a multi-professional patient record--a study of the use of headings.

This paper reports on the differences and similarities of used headings among Swedish health care professionals; nurses, occupational therapists, physiotherapists, dietetics, logopedics, welfare officers and general practitioners. The background of the study is a national project where representatives of the different health care professionals compiled used headings from clinical practice. Based on that survey, a hierarchical system of headings was constructed in accordance with the notion of record items and record item complexes described in the European Health Care Record Architecture (EHCRA). The work was done separately by the different health care professionals, leading to separate lists of headings. The current study reports on an analysis of these multi-professional lists of headings with respect to structure, degree of specialization, synonyms and homonyms. The study is descriptive in nature, giving a status report of the variety of used headings in clinical practice, providing necessary material for a normative approach with focus on a truly multi-professional patient record in the future.

Humans↗

PubMed1998

Design and application of a terminology management system.

A Swedish data model for handling terminology, Spriterm, is presented in this paper. A prototype terminology management system, using the Spriterm data model in also described. This prototype is implemented is Microsoft ACCESS. Furthermore, two other applications using this prototype as a base are introduced. One World Wide Web based application, and a data dictionary.

Databases as Topic↗

PubMed1998

Semantic modeling of a traditional classification: results and implications.

A primary health care version of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10), together with a three-dimensional model for classification of diseases according to location, origin, and type has been semantically represented. The resulting computer-based version is made available via the World Wide Web.

Disease↗

PubMed1996

Database and knowledge base integration in decision support systems.

Since decision support systems (DSS) in medicine often are linked to clinical databases it is important to find methods that facilitate the work for DSS developers to implement database queries in the knowledge base (KB). This paper presents a method for linking clinical databases to a KB with Arden Syntax modules. The method is based on a query meta database including templates for SQL queries. During knowledge module authoring the medical expert only refers to a code in the query meta database. Our method uses standard tools so it can be implemented on different platforms and linked to different clinical databases.

Artificial Intelligence↗

PubMed1996

Database and knowledge base integration--a data mapping method for Arden Syntax knowledge modules.

One of the most important categories of decision-support systems in medicine are data driven systems where the inference engine is linked to a database. It is, therefore, important to find methods that facilitate the implementation of database queries referred to in the knowledge modules. A method is described for linking clinical databases to a knowledge base with Arden Syntax modules. The method is based on a query meta-database including templates for SQL queries which is maintained by a database administrator. During knowledge module authoring the medical expert refers only to a code in the query meta-database; no knowledge is needed about the database model or the naming of attributes and relations. The method uses standard tools, such as C+2 and ODBC, which makes it possible to implement the method at many platforms and to link to different clinical databases in a standardized way.

Databases, Factual↗

PubMed1995

Machine learning to support diagnostics in the domain of asymptomatic liver disease.

Machine learning procedures, in unsupervised and supervised manner, can enable their users to achieve knowledge hardly comprehensible by even the best experts. This is true also if the clinical knowledge has been carefully assembled in a prospective way. A data set including 165 patients with elevated routine laboratory tests was extensively studied according to clinical history, laboratory profile and liver biopsy. Unsupervised learning by Kohonen feature map disclosed 4 groups of patients: the largest one with no or slight histopathological changes (116) and three smaller, more homogenous, with more diseased patients. Standardized histopathological scorings of the liver specimens defined patients into two groups. Fifty-eight of them were, according to the analysis, recommended for a liver biopsy, due to more severe degrees of inflammation and fibrosis. One-hundred and seven of the patients, in whom liver biopsy was retrospectively considered unnecessary, had only minor degrees of inflammation, fibrosis and/or steatosis. Supervised learning, using the inductive systems based on Quinlan's ID3 and CART algorithms, extracted knowledge in the form of decision trees. This approach could define a need for biopsy either with a very few significant findings or by pathways containing quotients and multiplications of the different basic items. These procedures were analyzed and compared for their theoretical and applicative performances. The cluster and Fischerian discriminant analyses were performed in order to compare the classification performance. The medical appropriateness of the obtained results is satisfying, therefore decision support systems, outlined in this study, should be evaluated in wider clinical practice. To achieve this goal, an example of a Medical Logical Module (MLM), based on the Arden Syntax, is given.

Adult↗

PubMed1994

Experiences from the use of data-driven decision support in different environments.

The paper reports experiences from the implementation and use of data-driven decision support based on the Arden Syntax in three different environments: in a health-care centre, in a clinical laboratory, and in a research department. Methods and tools used for realization of decision support systems (DSSs) are shortly presented, and integration aspects of the DSS with running clinical applications and existing patient databases are discussed. The application areas are also described, together with validation procedures for the developed knowledge modules.

Artificial Intelligence↗

PubMed1994

Integration of data driven decision support into the HELIOS environment.

The development of large-scale, clinically accepted decision support systems (DSS) calls for powerful and commonly available methods and tools for knowledge acquisition, system realisation, and knowledge base maintenance. The paper addresses problems associated with the integration of knowledge-based systems within the clinical setting with special reference to (i) data driven decision support, (ii) the Arden Syntax as a knowledge representation format and, (iii) the HELIOS software engineering environment. Architecture of a DSS based on Arden Syntax and its integration in the HELIOS environment are presented. Realisation of the DSS is discussed in relation to client-server architecture and object-oriented databases, which are essential concepts of the HELIOS environment. Sharability and reusability of the knowledge, together with commonality of used software tools are also discussed.

Database Management Systems↗

PubMed1994

Data driven medical decision support based on Arden Syntax within the HELIOS environment.

Methods and tools for development of data driven decision support systems (DSSs) is an integral part of the HELIOS software engineering environment. The DSS development environment includes tools for knowledge acquisition and knowledge base construction, provides trigger mechanisms for evocation of the knowledge base and an inference engine for execution control of appropriate parts of the knowledge base during run-time. The tools are part of the HELIOS service components and are integrated within the HELIOS communication framework. The work is based on the Arden Syntax, a standard for knowledge representation, allowing medical logic modules (MLMs) to be shared and transferred between institutions.

Artificial Intelligence↗

PubMed1993

Pre-compiling medical logic modules into C++ in building medical decision support systems.

Development of medical knowledge bases is a time-consuming process, and no single medical institution can develop medical knowledge bases covering all areas of medicine. The use of medical knowledge representation standards such as the Arden Syntax is an attempt to enhance the writability and readability of computer-stored knowledge and facilitate transfer and sharing among institutions. A method for the realisation of decision support systems based on knowledge formulated according to the Arden Syntax is presented. An essential tool in this process is a medical logic module (MLM) pre-compiler, translating MLMs into an object-oriented programming language, C++. Advantages of the C++ approach compared with other alternatives are discussed.

Artificial Intelligence↗

PubMed1993

MultiLink--an intermediary system for multi-database access.

The design and implementation is described of MultiLink, a desktop system for direct enduser access to remote bibliographic information. The system is an application of a client-server technique based on a campuswide network, with the objective to assist end-users to accomplish the information--retrieval process by capturing knowledge and expertise for searches in query formulations. MultiLink, via intelligent interfaces, allows users to access several dozens of bibliographic databases. The application integrates regional, national and international resources, and brings library services to the user's desktop level.

Databases, Bibliographic↗