A Thirty-Year Follow-Up Surveillance Study for Neoplasia of a Dutch Ulcerative Colitis Cohort

Table 1

Characteristics of the patient population (𝑛=293).

	Mean (sd)	Range
	years	Min.	Max.
Age at diagnosis	33.8 (13.8)	4.1	69.4
Age at first surveillance colonoscopy	44.1 (13.8)	18.2	79.3
Age at end of follow-up	53.1 (14.8)	21.2	84.0
Time from onset of symptoms to first surveillance colonoscopy	12.0 (4.7)	8.0	38.0
Follow-up period of intact colon*	10.8 (6.9)	0.1	27.1
Interval between surveillance colonoscopies*	2.0 (1.2)	0.1	10.1
Age at death (𝑛=39)	68.1 (16.3)	26.3	97.6

∗Only patients with follow-up colonoscopies, 𝑛=245.