Development and validation of a model to determine risk of refractory benign esophageal strictures

Table 3 Characteristics for included patients in development and validation cohorts

Category	Development cohort (n = 345)	Validation cohort (n = 162)	All (n = 507)
Sex
Female	119	59	178
Male	226	103	329
Age (yr)
50 ≤ n < 70	197	83	280
<50	103	55	158
≥70	45	24	69
Etiology
Achalasia	103	45	148
Post-ESD/ESTD	58	20	78
Postoperative	170	76	246
Caustic	6	7	13
Other	8	14	22
Location of strictures
Cervical	26	14	40
Thoracic	208	107	315
Ventral	111	41	152
Length of strictures (cm)
<2 cm	282	135	417
≥2 cm	63	27	90
Number of strictures
One	325	152	477
Two or more	20	10	30

ESD: Endoscopic submucosal dissection; ESTD: Endoscopic submucosal tunnel dissection.