A major interest in Medical Informatics is identifying information needs of clinicians and developing resources to attempt to meet these. The Internet has been of great importance in making knowledge resources immediately available at the point of care. Widespread use of the Internet has encouraged and facilitated the development and distribution of knowledge resources from governmental, commercial, and academic sites. DXplain is one such Internet resource and can be classified as a “niche” resource in that it focuses on the consideration and explanation of the relationship between many clinical manifestations and a plausible differential disease classification. When a clinician encounters a diagnostic dilemma, DXplain is one of the few knowledge resources available in this domain. The program explains and justifies its interpretations and provides access to a knowledge base concerning both the manifestations and the relevant diseases. DXplain has been available via communication networks since 1987. Since 1996, access has been provided via the Web, and approximately 46,000 users have logged almost 122,000 sessions. In the last year, 7087 physicians and 2941 medical students have used DXplain.
The demonstration will discuss the design goals and user interaction characteristics of DXplain, and will illustrate the use of DXplain with audience participation. Emphasis will be on clinical problem solving issues such as the importance and relevance of different clinical findings in the diagnostic classification of a set of findings. DXplain does not attempt to provide the “correct” diagnosis. The chief goal of DXplain is to interact with the user in the entry of the clinical manifestations and to derive a list of alternative plausible diagnoses.
Facilitate use by new users
A fundamental design goal in the continuing development of DXplain is to encourage use without requiring training or any special terminology. The elements of such “user friendliness” are several: (1) a rapid time response; (2) the use of a vocabulary with almost 5000 terms that uses standard medical terminology; (3) the use of synonyms, hierarchical representation of manifestations, and an elaborate algorithm to interact with the user to facilitate the recognition of misspellings and semantic variations; and (4) accepting a virtually unlimited number of findings.
Interpretation and Explanation
In deriving the list of plausible diagnoses for any given set of clinical manifestations, DXplain has the following characteristics: (1) an emphasis on sensitivity over specificity – the emphasis is on augmenting the clinician’s reasoning by providing alternative explanations; (2) explains what findings led the DXplain selection of a particular diagnosis, what additional findings would increase the likelihood of that diagnosis, and what findings would lower the likelihood of that diagnosis (3) compares two or more diagnoses in terms of the importance of the findings which had been entered, and other findings which would be relevant in the discrimination between the diagnoses; (4) provides extra weight in the selection of diseases where immediate diagnosis and management is particularly important; (4) provides links to relevant articles through automatic PubMed links (5) encourages user feedback to suggest additional content and modifications to the database.
Issues to Encourage Widespread and Repeat Use
In order to encourage continuing use by both institutions and individual practitioners DXplain (1) is readily available over the Internet; (2) supports interaction between users and the DXplain editors; (3) can be accessed on a one month trial license at no cost to any medical institution; and (4) can be accessed on an unlimited use basis license by medical schools/institutions at a modest yearly royalty.
Future Work
The following enhancements are now in initial use or are being developed: (1) integration of DXplain with an institutional EMR through standard Internet protocols; (2) integration of DXplain interpretations with commercial knowledge resources over the Internet; (3) leveraging the DXplain Knowledge Base in other projects e.g. a patient simulation exercise to promote clinical problem solving skills for medical students.