. Author manuscript; available in PMC: 2021 Apr 1.

Published in final edited form as: Gastrointest Endosc. 2019 Dec 7;91(4):905–916.e4. doi: 10.1016/j.gie.2019.11.043

Table 1.

Demographic characteristics of CRC-free patients at screening by adenoma status

Characteristics		CRC-free patients at screening		Patients without adenoma		Patients with adenoma
Number of CRC-free patients at screening (%)		25,008		17,478	(69.9)	7,530	(30.1)
Age^α (% of total)	40–49 years	3,794	(15.2)	2,930	(77.2)	864	(22.8)
	50–59 years	11,805	(47.2)	8,599	(72.8)	3,206	(27.2)
	60–69 years	6,449	(25.8)	4,196	(65.1)	2,253	(34.9)
	70–89 years	2,960	(118)	1,753	(59.2)	1,207	(40.8)
	Mean age (SD)	58.1	(9.2)	57.3	(9.0)	59.9	(9.4)
Sex^α (% of total)	Male	11,422	(45.7)	7,402	(64.8)	4,020	(35.2)
	Female	13,482	(53.9)	9,988	(74.1)	3,494	(25.9)
	Missing	104	(0.4)	88	(84.6)	16	(15.4)
Race^α (% of total)	White	10,937	(43.7)	7,325	(67.0)	3,612	(33.0)
	Black	12,961	(51.9)	9,343	(72.1)	3,618	(27.9)
	Other	984	(3.9)	708	(72.0)	276	(28.0)
	Missing	126	(0.5)	102	(81.0)	24	(19.0)
Had adenoma^* (% of total, ADR)		7,530	(30.1)	-		7,530
Had advanced adenoma^*		1,436	(5.7)	-		1,436
≥3 nonadvanced adenomas^*		639	(2.6)	-		639
Cecum intubation rate		97.6%		97.6%		97.5%
Procedures (% of patients)
1^st screening only		17,189	(68.7)	13,363	(77.7)	3,826	(22.3)
+1 additional procedure		5,352	(21.4)	3,209	(60.0)	2,143	(40.0)
+2 or more procedures		2,467	(9.9)	906	(36.7)	1,561	(63.3)
Total procedure time, minutes^α Median (25^th, 75^th percentile)		22.0	(16,30)	18.0	(14,25)	24.0	(18,32)
Withdrawal time, minutes^α Median (25^th, 75^th percentile)		10.0	(7,14)	8.0	(6,10)	11.0	(8,16)
Interval CRCs (% of total)		67		31	(46.3)	36	(53.7)
2001–2014 screened cohort - PYO		200,834		138,608		62,226
Mean years of follow-up (median)		8.1	(8.5)	7.9	(8.5)	8.3	(8.5)
2001–2008 cohort:^**	Patients	15,808		10,746	(68.0)	5,062	(32.0)
	PYO	164,804		113,035		51,769
Mean years of follow up (median)		10.5	(10.5)	10.5	(10.5)	10.3	(10.5)

PYO = Person-years of observation; ADR = adenoma detection rate

^α

p<0.001.

Includes 55 persons with missing polyp histopathology reports.

^**

In a previous study the 2001–2008 screened cohort followed through 2009 was documented using the standardized incidence ratio method.²⁵ The current study uses this cohort followed through 2015 to compare the lifetime risk ratio with that of the full cohort to evaluate persistence of CRC risk reduction with cohort aging and time since first screening.

Notes: Advanced adenoma is defined as adenoma with villous/tubulo-villous features, size ≥1 cm, or high-grade dysplasia. IQ range: interquartile range. Follow-up duration: From screening date to the first of 3 events: diagnosed with CRC, died from any cause, or end of follow-up period (December 31, 2015). Student t-test used for continuous variables, chi-square test for count variables.