## 3 Results
### Recurrence Rates  
For the analysis of the recurrent biliary events, the recurrent biliary events were also divided into three time periods after the index admission: inpatient, within two months, and after two months. The results showed that patients with comorbidities had a significantly increased risk of recurrent biliary events, particularly diabetes (95% CI 0.716-0.951), liver cirrhosis (95% CI 0.594-0.991), and pancreatitis (95% CI 0.725-0.991). There were no significant differences (\(p=0.596\)) in the recurrent biliary event rates between the early cholecystectomy group and intermediate cholecystectomy group (aHR: 0.967, 95% CI: 0.855-1.094); however, there were significant differences (\(p\leq 0.001\)) between the early cholecystectomy group and delayed cholecystectomy group (aHR: 1.704, 95% CI: 1.498-1.939) in the multivariable analysis. The recurrent biliary event-free survival was analyzed with Kaplan-Meier statistics, as shown in Figure 2.  
In our subgroup analysis, as shown in Table 3, from 1998-2013 and by the time of the announcement of the 2013 Tokyo guidelines, 19,686 choledocholithiasis patients who underwent therapeutic ERCP were selected from the nationwide population databases. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Recurrence**} & \multicolumn{4}{c}{**Mortality**} & \multicolumn{4}{c}{**Complications**} \\ \cline{2-13}
**Variable** & **Adjusted** & **95\%** & **95\%** & **9\%** & **Adjusted** & **95\%** & **95\%** & **P** & **Adjusted** & **95\%** & **95\%** & **P** \\  & **HR** & **CI** & **CI** & **PI** & **HIR** & **CI** & **CI** & **CI** & **OR** & **CI** & **CI** & **PI** \\ \hline Diagnosis to & & & & & & & & & & & & & \\ LC (months) & & & & & & & & & & & & & \\  
These patients were also further divided into 4,894 (24.86%) intermediate cholecystectomies, 2,365 (12.01%) delayed cholecystectomies, and 12,427 (62.13%) early cholecyst. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Variable** & **Total** & & **1998–2013** & & **2014–2015** & \multirow{2}{*}{_p_} \\ \cline{2-2} \cline{5-8}  & \(n\) & \% & \(n\) & \% & \(n\) & \% & \\ \hline Total & 22,996 & 53.88 & 19,686 & 85.61 & 3310 & 14.39 & \multirow{4}{*}{_<0.001_} \\ Diagnosis to & & & & & & & \\ LC (months) & & & & & & & \\ Group A: 0 (at & & & & & & \\ the same time) & 13,989 & 60.83 & 12,427 & 63.13 & 1562 & 47.19 & \multirow{4}{*}{_<0.001_} \\ Group B: \textgreater{}0, \textless{}2 & 5970 & 25.96 & 4894 & 24.86 & 1076 & 32.51 & \multirow{4}{*}{_<0.001_} \\ Group C: \textgreater{}2 & 3037 & 13.21 & 2365 & 12.01 & 672 & 20.30 & \multirow{4}{*}{_<0.001_} \\ Gender & & & & & & & \\ Male & 11,006 & 47.86 & 9282 & 47.15 & 1724 & 52.08 & \multirow{4}{*}{_<0.001_} \\ Female & 11,990 & 52.14 & 10,404 & 52.85 & 1586 & 47.92 & \multirow{4}{*}{_<0.001_} \\ Age (years) & \multicolumn{2}{c}{58.85 \(\pm\) 16.29} & \multicolumn{2}{c}{58.29 \(\pm\) 16.18} & \multicolumn{2}{c}{62.19 \(\pm\) 16.55} & \multicolumn{2}{c}{<0.001_} \\ Recurrence & & & & & & & 0.012 \\ Without & 21,310 & 92.67 & 18,208 & 92.49 & 3102 & 93.72 & \multirow{4}{*}{_<0.001_} \\ With & 1686 & 7.33 & 1478 & 7.51 & 208 & 6.28 & \multirow{4}{*}{_<0.001_} \\ Mortality & & & & & & & \\ Without & 21,351 & 92.85 & 18,110 & 91.99 & 3241 & 97.92 & \multirow{4}{*}{_<0.001_} \\ With & 1645 & 7.15 & 1576 & 8.01 & 69 & 2.08 & \multirow{4}{*}{_<0.562_} \\ Complications & & & & & & & \\ Without & 14,219 & 61.83 & 12,157 & 61.75 & 2062 & 62.30 & \multirow{4}{*}{_<0.001_} \\ With & 8777 & 38.17 & 7529 & 38.25 & 1248 & 37.70 & \multirow{4}{*}{_<0.001_} \\ \hline \hline \end{tabular} \(p\): Chi-square/Fisher exact tests were used to evaluate the categorical variables, and a one-way ANOVA with a Scheffe post hoc test was used to evaluate the continuous variables.  
\end{table} 
Table 3: Characteristics of the study. Figure 2: Kaplan–Meier for cumulative incidence of recurrence aged 20 and over stratified by diagnosis to LC months with log-rank test.