Table 1.

Descriptive characteristics of the 14,069 individuals from the PLCO Cancer Screening Trial, who had a diagnostic colonoscopy and met the inclusion criteria for this study

	Advanced adenoma		3+ non-advanced adenoma		1–2 non-advanced adenoma		No adenoma		Total
	N	%	N	%	N	%	N	%	N	%
Total	2,446	17	483	3	3,957	28	7,183	51	14,069	100
Sex
Male	1,652	68	360	75	2,514	64	3,927	55	8,453	60
Female	794	32	123	25	1,443	36	3,256	45	5,616	40
Age at colonoscopy (yr)
55–59	518	21	81	17	791	20	1,410	20	2,800	20
60–64	796	33	191	40	1,373	35	2,602	36	4,962	35
65–69	668	27	128	27	1,069	27	1,918	27	3,783	27
70–74	396	16	70	14	591	15	1,016	14	2073	15
≥75	68	3	13	3	133	3	237	3	451	3
Family history
Yes	310	13	59	12	438	11	785	11	1,592	11
No	2,059	84	406	84	3,376	85	6,146	86	11,987	85
Unknown	77	3	18	4	143	4	252	4	490	3
Smoking status
Never	903	37	163	34	1,575	40	2,799	39	5,440	39
Current	366	15	77	16	548	14	1,015	14	2,006	14
Former	1,177	48	243	50	1,834	46	3,369	47	6,623	47
BMI, median (IQR)	27.2 (24.6, 30.3)		27.3 (24.7, 30.3)		27.6 (25.1, 30.7)		27.1 (24.4, 30.1)		27.1 (24.6, 30.2)
Aspirin and/or ibuprofen use in past 12 mo
Yes	1,376	56	283	59	2,376	60	4,354	61	8,389	60
No	1,070	44	200	41	1,581	40	2,829	39	5,680	40
Prior self-reported endoscopya
Yes	746	30	184	38	1,695	43	3,447	48	6,072	43
No	1,700	70	299	62	2,262	57	3,736	52	7,997	57
First positive FSG
Baseline	1,814	74	338	70	2,509	63	4,171	58	8,832	63
Year 3	128	5	25	5	267	7	468	7	888	6
Year 5	504	21	120	25	1,181	30	2,544	35	4,349	31
e-score
Quartile 1 (lowest)	556	23	117	24	967	24	1,877	26	3,517	25
Quartile 2	586	24	106	22	1,034	26	1,791	25	3,517	25
Quartile 3	627	26	121	25	990	25	1,779	25	3,517	25
Quartile 4 (highest)	677	28	139	29	966	24	1,736	24	3,518	25
PRS
Quartile 1 (lowest)	454	19	99	20	969	24	1,972	27	3,494	25
Quartile 2	509	21	124	26	1,060	27	1,932	27	3,625	26
Quartile 3	590	24	149	31	1,110	28	1,959	27	3,808	27
Quartile 4 (highest)	893	37	111	23	818	21	1,320	18	3,142	22
Length of follow-up, median (IQR) (yr)	15.9 (12.1–19.0)		15.5 (12.2–18.7)		15.4 (12.5–18.9)		15.1 (12.2–18.5)		15.3 (12.2–18.7)

BMI, body mass index; e-score, environmental risk score; FSG, flexible sigmoidoscopy; IQR, interquartile range; PLCO, Prostate, Lung, Colorectal, and Ovarian; PRS, polygenic risk score.

^aIndividuals whose first positive flexible sigmoidoscopy was at year 3 or 5 and attended the baseline screen in PLCO were considered to have a prior endoscopy.