In the mid-1970s, the medical and administrative staff of the Oncology
Center at Johns Hopkins Hospital recognized a need for a computer-bas
ed clinical decision-support system that organized patients' informati
on according to the care continuum, rather than as a series of event-s
pecific data. This is especially important in cancer patients, because
of the long periods in which they receive complex medical treatment a
nd the enormous amounts of data generated by extremely ill patients wi
th multiple interrelated diseases. During development of the Oncology
Clinical Information System (OCIS), it became apparent that administra
tive services, research systems, ancillary functions (such as drug and
blood product ordering), and financial processes should be integrated
with the basic patient-oriented database. With the structured approac
h used in applications development, new modules were added as the need
for additional functions arose. The system has since been moved to a
modern network environment th the capacity for client-server processin
g.