Discussion
The technical and economic efficiency of medical diagnostic laboratories
of hospitals affiliated with the UUMS was estimated via SFA under VRS
and input-oriented minimization assumption by estimating production and
cost functions in order to evaluate their performance.
The low technical efficiency of medical diagnostic laboratories of the
hospitals indicated the high capacity of inputs in these units. While
using the same level of inputs, these units can increase their outputs
and thus their technical efficiency by 48.1% without any increase in
costs.
The average economic efficiency of the above-mentioned units was 0.931.
Therefore, the efficiency of these units can be improved by reducing
costs by 6.9% without decreasing the value of outputs by increasing the
profit. In other words, the managers of these laboratories must reduce
their costs by optimally combining and distributing inputs, while taking
into account the prices of the used inputs to approach the profitability
frontier.
The average economic efficiency of laboratory units was higher than the
average technical efficiency, which demonstrates the high allocative
efficiency of these units; that is, the combination of inputs in these
units is appropriate. However, service providers in these units can make
the most of this combination to increase service delivery without
changing the amount of inputs in order to increase technical efficiency.
Therefore, in order to reduce costs and increase their profits, the
above-mentioned laboratory units should avoid wasting resources by
enhancing the motivation of the staff and the awareness of the general
principles of medical diagnostic laboratories.
Furthermore, medical diagnostic laboratories of university hospitals had
an increasing return to scale. In other words, the coefficient of
function or degree of homogeneity was >1; that is, if
inputs are increased by 1%, the output of laboratories will increase by
more than 1%. Therefore, the laboratories under study should increase
their supply of services.
Alinejhad et al. in a study entitled “Evaluating the economic
efficiency of clinical laboratories in Iranian public hospitals via DEA
method” achieved the average economic efficiency of 0.676.1 The results of
examining the economic efficiency of laboratory units in hospitals
affiliated with the UUMS by using DEA and SFA methods showed that the
average economic efficiency of the units differed in the two methods
(0.255). This difference could be due to neglecting random effects,
measurement errors, etc. in the DEA method. In general, however, the
average economic efficiency of the studied units in the province is
medium to high, indicating that in the studied units, it is possible to
increase economic efficiency by reducing costs without affecting output
values.
After examining the efficiency of Australian hospitals by using DEA and
SFA, Mortimer et al. concluded that each method of efficiency
measurement has its own characteristics, and there is no single method
for measuring the efficiency whose results would be more precise and
reliable compared to other methods.13
In a study entitled “Analyzing the efficiency changes of Irish
hospitals”, Gannon concluded that the technical efficiency values
obtained from the DEA method were higher than the SFA method; that is,
the inefficiency in the DEA method was underestimated.19
In a study entitled “Evaluating the economic efficiency of CCU in
hospitals affiliated with Tehran University of Medical Sciences”,
Zahavi et al. used both SFA and DEA methods and concluded that these two
methods do not necessarily have the same results in calculating
efficiency, and greater efficiency in one of these methods is not
sustainable for all sectors.20
Lamovsek et al. determined the optimal size of medical laboratories at
the primary healthcare level by using DEA. The average technical
efficiency of the laboratories with the VRS assumption was obtained as
0.9333. The authors concluded that increasing the automation and
consolidation of laboratory activities can affect the efficiency of
laboratories and, thus, costs.4
In evaluating the technical efficiency of the clinical laboratories of
Shiraz University of Medical Sciences, Taheri et al. reported the
average technical efficiency of laboratory units to be 0.92416, which indicates a
high level of technical efficiency in hospital units of Shiraz compared
to Urmia.
In general, SFA is a useful tool for analyzing the efficiency of medical
diagnostic laboratories, and its information may be useful for
policy-making and performance evaluation of these units. The DEA and SFA
methods are also complementary in efficiency measurement, but for
efficiency measurement, it is recommended that the SFA method be first
performed in order to identify the variables having a negative effect
and to exclude them from the model.
One of the limitations of this study was the lack of participation of
the private sector diagnostic laboratories. Better analysis and
conclusions could be obtained from the efficiency status of provincial
laboratories had these laboratories cooperated, and the health planners
in the province could have used better data for decision making.