Results:
A total of 575 patients were enrolled into the study. The demographic
characteristics and results of groups in terms of the OT, infection
status and the UAS usage were summarized in Table 1, 2 and 3,
respectively.
According to the analysis with regard to the OT; age, sex, BMI, stone
density, and stone free rates were similar between the groups whose
operation time was less than 60 minutes and the group longer than 60
minutes. As expected, stone size and stone surface area was larger
statistically, than in the group whose OT was longer than 60 minutes
(p<0.05, Table 1). The rate of the usage UAS was greater
statistically in the group whose OT was longer than 60 minutes
(p<0.05, Table 1). In addition, infection rates in the group
whose OT was longer than 60 min was higher statistically than in the
group whose OT was lesser than 60 min ( p<0.05, Table 1).
According to the analysis with regard to the infection status; age, sex,
stone size, stone surface area, localisation of the stones were not
statistically different between the group with the infection and the
group without the infection, but the OT was longer statistically in the
group with the infection than in the group without the infection (
94.1±14.2 and 68.01±23.1, for the group 1 and 2, respectively,
p<0.05, Table 2).
According to the analysis with regard to the usage of the UAS; age, sex,
stone size, stone surface area, stone free rates, and infection rates
were not statistically significant between the group in which the UAS
was used and the group not used, however, the OT was statistically
longer in the group in which the UAS was used than in the group in which
the sheath was not used ( 79.3±24.4 and 66.7±22.4, for group 1 and 2,
respectively, p<0.05, Table 3).
Logistic regression analysis revealed that OT is an independent risk
factor for infective process (Table 4). The analysis of ROC curve to
estimate the sensitivity and specificity of OT in predicting infectious
events determined the cut-off point as 87.5min. The area under curve
(AUC) for OT time in terms of the infection risk was 0.82 (sensitivity
89.3%, specificity 69.5%, 95% CI 0.77-0.88; p=0.000) (Fig.1) (Table
5).