Pediatric Informatics: Computer Applications in Child Health (Health ...

12 Diagnostic Decision Support 169
and via the World Wide Web. The system is comprised of four modules: Diagnosis,
Epidemiology, Therapy, and Microbiology:
Diagnosis module:
This consists of an interface where users may input any
combination of 217 signs, symptoms, laboratory findings, and demographics,
using a checkbox exploding hierarchical tree interface (Fig. 12.3). The system
returns a ranked differential diagnosis calculated using Bayes’ rule. The user
can drill down to further information on a disease by “clicking” on the listed
diagnosis (including an approximation of the P(F|D) for each finding). The user
can also click on “Why Not” to see why specific diagnoses have been omitted
and display findings which exclude the diagnosis. GIDEON has the ability to
differentiate prevalence regionally. For example, in a child with diarrhea and
abdominal pain in Haiti, Shigella is the more likely diagnosis, whereas in the
United States, it is Campylobacter (See Figs. 12.3 and 12.4). 28 GIDEON is limited
to one of the 337 infectious diseases in its KB.
Epidemiology module:
This is a compendium of epidemiologic information
about each of the 337 diseases, including agent names, synonyms, phenotype,
reservoir, vector, incubation period, diagnostic tests, clinical hints, vaccines
(when available), typical adult and pediatric therapy including dosing, geographic
distribution including historical (for some diseases dating back to 1917)
annual incidence, images, and expanded clinical information. This module is
also accessible from the ranked list in the Diagnosis Module.
Fig. 12.3 GIDEON Diagnosis module: Haitian child with diarrhea and abdominal pain