Jerome-D'Emilia, Bonnie Michele; PhD
VIRGINIA COMMONWEALTH UNIVERSITY, 1998
HEALTH SCIENCES, PUBLIC HEALTH (0573); HEALTH SCIENCES, MEDICINE AND SURGERY
(0564); HEALTH SCIENCES, ONCOLOGY (0992)
In the past two to three decades, major changes have taken place in the surgical
treatment of breast
cancer. In 1972, with the publication of early, randomized clinical trials,
the modified radical mastectomy
became the gold standard treatment for early stage breast cancer. In the early
1980's the results of
several large-scale randomized clinical trials confirmed the efficacy of breast
conserving procedures.
Many studies since that time have compared the relative rates of mastectomy
to rates of breast
conservation surgery for stage I and II breast cancer. Although breast conservation
is almost consistently
reported as underutilized, there have been no theoretical analyses reported
that adequately address this
observation. This study has addressed two research questions. Can classical
diffusion theory
appropriately characterize three distinct medical communities, defined as the
academic medical center,
the non-academic teaching hospital, and the community hospital? And if so, can
the varying rates of
diffusion of breast conservation found in the three categories of medical social
system be explained by
diffusion theory? To address these questions, a number of diverse, theoretically
derived variables were
used to characterize the three medical community types into groups defined by
diffusion theory as
differing in their relative adoption potential. The relative rates of breast
conservation to mastectomy were
then compared across a group of hospitals including each of the three types
of medical communities.
Analysis of variance was used to test for differences between the three groups
of hospitals. MuLtiple
regression analyses were then utilized to assess the factors most significant
in determining the relative
rate of breast conservation surgery to mastectomy at each individual hospital.
Results confirm that the
three groups of hospitals are separate and unique in terms of diffusion theory
characteristics. Thus the
three groups of hospitals are consistent with the categories described in diffusion
theory. Further, a
hospital's adopter group status was found to be a significant factor in explaining
the relative rate of
diffusion of breast conservation in that hospital. A number of control variables
were found to be
significant in previous research comparing the rates of mastectomy and lumpectomy.
Some of these
variables, such as age, stage, income, and availability of radiation treatment,
were found to be significant
in this study as well. Previous studies have attempted to explain the variation
in the utilization of breast
conservation based on the appearance of one or more of this group of control
variables. The addition of
the theoretically defined variable, adopter group status, which was significant
for each of the two years,
1988 and 1994, tested separately, and for the two years over time, provides
a theoretical explanation for
a consistently observed phenomenon. This explanation allows predictions to be
made regarding the
diffusion of breast conservation surgery in the three types of medical communities,
and solidifies
previous research on this topic into a coherent theoretical framework. Further
research is necessary to
validate the applicability of diffusion theory in explaining the variation in
breast conservation utilization.
Social
Systems Simulation Group
P.O. Box 6904 San Diego, CA 92166-0904 Roland Werner, Principal Phone/FAX (619) 660-1603 |