Geoscience Reference
In-Depth Information
convenience of the facility, waiting time at the facility, and the cost of service. On
the other hand, providers are influenced by setup and operating costs, travel costs for
the staff, and availability of supporting facilities (Calvo and Marks
1973
). From the
community perspective, equity in access among different districts is an important
issue. Moreover, workload equity can be a concern for healthcare staff. Notice also
that some of these factors are very difficult to quantify and measure. Consequently,
the literature focuses on a few of these criteria. Relevant objectives most commonly
applied in the healthcare facility location literature are the following:
Minimize access cost for health consumers.
This cost type can be defined as
travel costs, distance, or travel time from a population district to a health facility,
weighted by the population size of that district. When this is the only objective,
the standard p-median formulation is commonly used for deciding where to
locate a set of health facilities. The following function may represent access cost:
X
X
d
j
c
ij
x
ij
;
(21.1)
i2I
j2J
where I is the set of potential locations for the facilities, J is the set of
populations or districts to serve, d
j
corresponds to the population size in district
j
2
J, c
ij
represents the distance between location i
2
I and district j
2
J,and
x
ij
is a binary decision variable that is equal to 1 if the population in district j is
served from a facility at location i and 0 otherwise.
Maximize population with access to a health facility, or maximize covered
demand.
A cover type objective assumes that a population in a district is covered
(has access) only if it can be assigned to a facility within a pre-determined
maximum distance, and aims to maximize the covered population. Such a type
of objective is appropriate to locate emergency medical services or primary care
centers for under-served populations. When the objective is to minimize the total
access cost, some districts can have very high access costs. Cover type objectives
overcome such undesirable solutions.
Some health services, such as preventive care, are not perceived as essential
by the consumers. However, providing these services is an important public
health goal. Therefore, maximizing the utilization of health facilities is another
cover related objective that was first defined by Calvo and Marks (
1973
). There
are several socio-economical factors that affect health service utilization, such
as income, age, insurance coverage of the population, and convenience and
proximity of the facilities (Institute of Medicine
1993
). Location models are best
suited to account for the “proximity of the facilities” among these factors. Zhang
et al. (
2009
) introduced the concept of “participation” which they measure using
a decreasing function of travel time plus waiting time. In that paper, the goal was
to maximize participation as opposed to coverage. Güne¸setal.(
2014
)defined
participation as a decreasing function of distance, and solved models aiming
at maximizing coverage and participation for a primary care network design
problem.
