Table 3.

Risk factors for inadequate repeat flexible sigmoidoscopy ^a

Characteristics	All subjects N	Adequate examination n	Inadequate examination n	Proportion with inadequate examination (95% CI)	OR (95% CI)
Adequate baseline FSG	35834	32390	3444	0.10 (0.09, 0.10)	1.0 (reference)
Inadequate baseline FSG	3551	1974	1577	0.44 (0.43, 0.46)	6.24 (5.77, 6.75)
Age group in years
55–59	13097	11599	1498	0.11 (0.11, 0.12)	1.0 (reference)
60–64	12618	11123	1495	0.12 (0.11, 0.12)	1.06 (0.98, 1.15)
65–69	8843	7590	1253	0.14 (0.14, 0.15)	1.31 (1.20, 1.43)
70–74	4827	4052	775	0.16 (0.15, 0.17)	1.53 (1.38, 1.70)
Male	21803	19888	1915	0.08 (0.08, 0.09)	1.0 (reference)
Female	17582	14476	3106	0.18 (0.17, 0.18)	2.16 (2.02, 2.31)
High School or Less	16009	13731	2278	0.14 (0.14, 0.15)	1.0 (reference)
Some/Graduated College	15488	13570	1918	0.12 (0.12, 0.13)	0.94 (0.88, 1.01)
Postgraduate	7840	7021	819	0.11 (0.10, 0.11)	0.88 (0.80, 0.97)
Smoking status
Never	19293	16764	2529	0.13 (0.13, 0.14)	1.0 (reference)
Former	16892	14822	2070	0.12 (0.12, 0.13)	1.05 (0.98, 1.12)
Current	3189	2769	420	0.13 (0.12, 0.14)	1.05 (0.93, 1.18)
White, non-Hispanic	35131	30458	4673	0.13 (0.13, 0.14)	1.0 (reference)
Black, non-Hispanic	1629	1431	198	0.12 (0.11, 0.14)	0.95 (0.80, 1.13)
Hispanic	663	575	88	0.13 (0.11, 0.16)	1.31 (1.03, 1.68)
Asian	1653	1609	44	0.03 (0.02, 0.04)	0.91 (0.63, 1.32)
American Indians/Pacific Islanders	294	276	18	0.06 (0.04, 0.10)	1.34 (0.79, 2.27)
Body mass index, kg/m2
≤25	12848	10978	1870	0.15 (0.14, 0.15)	1.0 (reference)
25–29	17213	15109	2104	0.12 (0.12, 0.13)	0.92 (0.85, 0.98)
≥30	8961	7962	999	0.11 (0.11, 0.12)	0.79 (0.72, 0.86)

^aModel included all the variables in the table and screening center