## 3 Results
### Results of Analysis of Variance and Contrast Analyses  
The analysis of variance scrutinized the impact of two independent variables--the power setting (in watts) and the urethral access sheath (UAS) size--and their interaction with temperature during RIRS using gravity irrigation only, with the results reported in Table 2.  
Based on the results in Table 2, it was concluded that the laser's power setting emerged as a substantial determinant of temperature in the time range studied. This was evidenced by a highly significant \(F\)-value of 20.12 and a \(p<0.001\), which is far below the conventional alpha level. The partial eta squared (\(\eta^{2}_{\textit{P}}\)) value of 0.24 denoted a medium effect size, suggesting that approximately 24% of the variance in temperature was attributable to the differences in the power settings. The UAS size also exerted a significant influence on temperature, as indicated by an \(F=7.39\) and a \(p=0.007\). However, the partial eta squared (\(\eta^{2}_{\textit{P}}\)) value of 0.03 indicated a small effect size, signifying that about 3% of the variance in temperature can be explained by differences in the UAS size. This finding, albeit statistically significant, showed that the UAS size, as an independent variable, has a comparatively lesser impact on temperature than the power setting. Table 3 presents the results from a contrast analysis evaluating the differences in temperature across various laser power settings for all UAS sizes. This analysis provides insights into the specific pairwise differences between distinct power settings. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline
**UAS** & **Power** & **Mean** & _SD_ & _Mdn_ & _Q1_ & _Q3_ & _Min_ & _Max_ & _Skew._ & _Kurt._ & \(W\) & \(p\) \\ \hline \multirow{4}{*}{10/12 Fr} & 12 & 32.06 & 5.57 & 32.85 & 27.70 & 36.17 & 22.90 & 40.30 & \(-\)0.26 & \(-\)1.27 & 0.94 & 0.117 \\  & 15 & 32.07 & 5.81 & 32.25 & 27.10 & 36.27 & 23.00 & 40.90 & \(-\)0.06 & \(-\)1.34 & 0.94 & 0.160 \\  & 18 & 36.52 & 6.02 & 39.65 & 33.65 & 40.90 & 23.20 & 41.50 & \(-\)1.01 & \(-\)0.47 & 0.79 & **\textless{0.001}** \\  & 20 & 38.61 & 8.50 & 42.75 & 31.62 & 45.20 & 23.30 & 49.70 & \(-\)0.55 & \(-\)1.28 & 0.87 & **0.004** \\  & 25 & 41.66 & 10.09 & 46.45 & 32.23 & 50.40 & 23.30 & 50.90 & \(-\)0.56 & \(-\)1.40 & 0.81 & **\textless{0.001}** \\ \hline \multirow{4}{*}{12/14 Fr} & 12 & 31.92 & 3.82 & 33.40 & 30.58 & 34.30 & 23.20 & 36.20 & \(-\)1.03 & 0.01 & 0.86 & **0.003** \\  & 15 & 32.37 & 3.99 & 32.60 & 30.55 & 35.03 & 23.20 & 38.10 & \(-\)0.67 & \(-\)0.27 & 0.94 & 0.140 \\ \cline{1-1}  & 18 & 34.32 & 4.60 & 35.95 & 32.12 & 37.62 & 23.10 & 39.20 & \(-\)1.04 & \(-\)0.11 & 0.86 & **0.002** \\ \cline{1-1}  & 20 & 37.77 & 6.45 & 40.70 & 35.67 & 42.48 & 23.40 & 43.40 & \(-\)1.11 & \(-\)0.12 & 0.80 & **\textless{0.001}** \\ \cline{1-1}  & 25 & 38.98 & 5.17 & 40.50 & 38.55 & 41.80 & 23.80 & 44.50 & \(-\)1.61 & 1.90 & 0.80 & **\textless{0.001}** \\ \hline \end{tabular}
\end{table} 
Table 1: Descriptive statistics for temperature distribution over a common time range for UASs and power groups, \(n=30\). UAS—ureteral access sheath, _Skew._—skewness; _Kurt._—kurtosis; _W_—statistics of the Shapiro–Wilk test. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Variable** & _df_ & _df.res_ & \(F\) & \(p\) & \(\eta^{2}_{\textit{P}}\) \\ \hline power, W & 4 & 250 & 20.12 & **\textless{0.001}** & 0.24 \\ UAS, size & 1 & 250 & 7.39 & **0.007** & 0.03 \\ \hline \end{tabular}
\end{table} 
Table 2: Results of analysis of variance of aligned rank transformed data (Type III tests) without repeated methods. _df_—degrees of freedom; _df.res_—residual degree of freedom; _F_—statistics of F-test; \(\eta^{2}_{\textit{P}}\)–partial eta squared effect size. The results of the analysis in Table 3 have elucidated the significant influence of different laser power settings on temperature across all UAS sizes. In the lower power spectrum, between 12 W and 15 W, our data did not show a statistically significant temperature difference.