Læknablaðið - 15.03.1983, Qupperneq 41

LÆKNABLADID
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individual branches, if the final analysis does not link
the information obtained from its’ various sectors
into a fina! operational model. It must be pointed
out, however, that this again necessitates the linkage
of that model to other functions of society.
The risk of overrating and bias in decision-
processes based on the prognoses within a larger
field of events, is mentioned, and exemplified.
Finally, the usefulness of systems analysis for logical
decision-marking within the health services is dis-
cussed: the decision based on systems analysis may
involve each and all of the system’s components.
The collection of information and its linking into
information systems available to systems analysis
with multiple possibilities in arrangement and choi-
ces is obviously necessary in the organization of
health services, and their components; without such
systems, the decision processes, in planning, organi-
zation and management, would be impossible.
Literature references in this chapter: 1-3, 9-14, 16-
18,21-24, 29-33).
Chapter 4: Roentgen Diagnostic Information
Systems
This is a discourse on the application of general
principles of information systems analysis and the
theories of Shannon’s »statistical information theo-
ry« to the roentgen diagnostic process: extensive
reference is made to the works of Yerushalmy,
Tuddenham, Rossman, Garland, Lusted and others
regarding the basic principles of roentgen diagnos-
tic perception, information components in the
roentgen diagnostic system, and errors in interpre-
tation. A model of the roentgen diagnostic informa-
tion system is presented in illustration 4.5.1., mainly
based on the interpretations of Rossman. The
application of the »statistical information theory«
on the evaluation of the transfer functions of the
various system’s components is attempted. As other
authors (Holm, Brolin, i. al), have pointed out, it may
be clearly perceived, that the roentgen diagnostic
process contains components with widely varied
transfer characteristics (capacities) as regards infor-
mation. The transfer of information will always be
fraught with a certain amount of additional signals
(noise), as well as some distortion of the information
in its passage through the components (transdu-
cers). In the roentgen diagnostic information system
as defined and illustrated here, it is obvious that
there are significant sources of additional signals
and »noise« to be coped with in the passage
through the recognition-diagnostic component
(»Radiologist’s Brain«). This fact has not been duly
appreciated by many observers, and Brolin, in her
thesis on radiological reporting, pays especial atten-
tion to such problems as the communication func-
tion of the radiologist in starting the final output
(diagnosis or description).
These factors were especially considered in this
work, with reference to the composition of a
diagnostic code for roentgen diagnostic examina-
tion. It is underlined, that the »final output« necessa-
rily always will be a rather heterogenous group of
data, comprising clear-cut diagnoses as well as more
descriptive terms relating to the final evaluation. As
Thomas has pointed out, the description of the
roentgenologic examination and the diagnostic in-
formation it contains, must be seen as an integrated
part of the total diagnostic evaluation of the patient.
The interaction between the roentgen diagnostic
information and other data, such as anamnesis,
clinical examination etc., is stressed.
This analysis of the roentgen diagnostic informa-
tion system resulted in the following two observa-
tions, serving as main guidelines for the design of
codes, described in chapters 5 and 6:
1) It must be realized, that the sum of information
gathered through a technically highly sophisti-
cated transfer system may be of such magnitude
that relevant information is lost in the final
diagnostic/descriptive process.
2) In designing diagnostic coding systems one must
not overlook the limitation put upon this final
process. Definitions must therefore be logical,
objective, unambiguous and clear.
(Literature references in this chapter: 1, 2, 4, 10, 11,
21,23, 24, 29-31,34-56).
Chapter 5: Registration systems: Personal
identification and other basic statistical data
A description is given of the elementary statistical
data considered necessary in the design of the
registration systems. When the Roentgen Depart-
ment of the Reykjavik City Hospital started as a
new unit in a new hospita! in 1966, that was
considered as an exceptional opportunity to make
prospective trials of dataprocessing statistical and
other information concerning that sector of the
health system, using approaches and methods which
then had not been taken into use in this country, and
where at that time limited experience had been
accumulated abroad. The objectives of this trial are
enumerated:
a) work rationalization
b) increased effectiveness in management
c) aids to realistic quality control, which is a
prequisite for exactness and reliability in per-
formance and evaluation of examinations
d) collection of data for organizational and progno-
stic purposes
e) collection of data for defined medical research
projects
f) collection of data, linked to personal identifica-
tion, for future integration into medical data-
bank.
The following basic information was considered
necessary to attain these orginally formulated ob-
jectives: