Table 5. Factors affecting the adequate tissue acquisition of peroral cholangioscopy-guided forceps biopsy for non-stenotic bile duct.

Subgroup	Odds ratio	95% CI	P value
Univariate analyses
Age, <65 or ≥65 years	3.431	0.990–11.892	0.052
Sex, male or female	1.483	0.784–2.805	0.226
Malignancy or benign	0.473	0.205–1.092	0.079
Location of biliary lesion, distal or not-distal	0.461	0.238–0.890	0.021
Length of stricture of biliary lesion, <15 or ≥15 mm	2.442	1.160–5.142	0.019
Macroscopic type, flat type or not-flat type	0.889	0.400–1.975	0.772
Cholangitis, presence or absence	1.242	0.578–2.670	0.578
T-Bil, <1.5 or ≥1.5 mg/dL	0.783	0.415–1.479	0.451
CEA, <5.0 or ≥5.0 ng/mL	0.429	0.121–1.520	0.190
CA19-9, <37 or ≥37 U/mL	1.128	0.596–2.134	0.711
Biopsy site
The bifurcation of the bile duct or not	1.235	0.652–2.338	0.517
Intrahepatic bile duct or extrahepatic bile duct	0.540	0.270–1.080	0.081
Right side or left side	0.503	0.208–1.215	0.127
Procedure time, ≤75 or >75 min	2.837	1.239–6.496	0.014
EST or non-EST	5.476	1.879–15.956	0.002
Multivariate analyses
Age, <65 or ≥65 years	2.917	0.563–15.122	0.202
Malignancy or benign	2.198	0.627–7.701	0.218
Location of biliary lesion, distal or not-distal	0.322	0.139–0.744	0.008
Length of stricture of biliary lesion, <15 or ≥15 mm	1.368	0.541–3.460	0.508
Biopsy site, intrahepatic bile duct or extrahepatic bile duct	0.467	0.216–1.008	0.052
Procedure time, ≤75 or >75 min	3.012	1.092–8.312	0.033
EST or non-EST	7.041	2.117–23.421	0.002

P value: logistic regression model. CI, confidence interval; T-Bil, total bilirubin; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen; EST, endoscopic sphincterotomy.