Proportion of avoidable stent placement in total cohort and in subgroup of those with CBD stones
| Group I | Group II | P value | |
| Patients, n | 598 | 661 | |
| Total ERCPs | 842 | 885 | |
| a) 1 ERCP | 598 | 661 | |
| b) >1 ERCP | 244 | 224 | |
| Patients with CBD stones, n | 375 | 384 | |
| Total biliary stents, n | |||
| a) Initial ERCP | 223 | 192 | |
| b) Follow-up (F/U) ERCP | 73 | 78 | |
| Avoidable stents, n (%) | |||
| a) In total cohort | 63/598 (11) | 13/661 (2) | <0.0001 |
| b) In CBD subgroup | 61/375 (16) | 8/384 (2) | <0.0001 |
| c) Proportion of total stents | 63/223 (28) | 13/192 (7) | <0.0001 |
CBD, common bile duct; ERCP, endoscopic retrograde cholangiopancreatography.