Table 1.

Phase I (derivation cohort) distribution of baseline variables

Individuals who underwent colonoscopy and filled some part of baseline questionnaire, by adenoma detectionIndividuals included in final analysis, by adenoma detection
Overalln = 621n = 541
N (%) or mean ± SDAdenoma detectedNo adenoma detectedAdenoma detectedNo adenoma detected
Baseline variablesn = 691n = 116n = 505n = 106n = 435
Age at baseline, y
 40–4970 (10%)5 (4%)51 (10%)01 (0.2%)
 50–59346 (50%)58 (50%)258 (51%)54 (51%)190 (44%)
 60–69275 (40%)53 (46%)196 (39%)52 (49%)244 (56%)
Sex
 Male317 (46%)66 (57%)227 (45%)60 (57%)204 (47%)
 Female374 (54%)50 (43%)278 (55%)46 (43%)231 (53%)
Race
 White non-hispanic572 (83%)101 (88%)421 (83%)96 (91%)383 (88%)
 Other116 (17%)14 (12%)82 (16%)10 (9%)52 (12%)
 Missing3 (0.5%)1 (0.9%)2 (0.4%)
Center location
 Minnesota290 (42%)53 (46%)223 (44%)49 (46%)214 (49%)
 Louisiana200 (29%)22 (19%)146 (29%)17 (16%)93 (21%)
 Washington201 (29%)41 (35%)136 (27%)40 (38%)128 (29%)
BMI
 <2015 (2%)2 (2%)9 (2%)2 (2%)7 (2%)
 20–24198 (29%)23 (20%)153 (30%)21 (20%)143 (33%)
 25–29273 (40%)50 (43%)198 (39%)47 (44%)178 (41%)
 ≥30187 (27%)38 (33%)130 (26%)36 (34%)107 (25%)
 Missing18 (3%)3 (3%)15 (3%)
Colorectal cancer in at least one first-degree relative
 Yes90 (13%)21 (18%)61 (12%)20 (19%)54 (12%)
 No599 (87%)94 (81%)443 (88%)86 (81%)381 (88%)
 Missing2 (0.3%)1 (0.9%)1 (0.2%)
Colorectal cancer in at least one second-degree relative
 Yes82 (12%)21 (18%)55 (11%)20 (19%)50 (11%)
 No607 (88%)94 (81%)449 (89%)86 (81%)385 (89%)
 Missing2 (0.3%)1 (0.9%)1 (0.2%)
Smoking
 Ever379 (55%)69 (59%)272 (54%)65 (61%)242 (56%)
 Never312 (45%)47 (41%)233 (46%)41 (39%)193 (44%)
Pack-years for ever smokers17.2 ± 18.217.8 ± 20.017.0 ± 17.718.4 ± 20.417.5 ± 17.9
Regular intake of aspirin
 Yes254 (37%)41 (35%)196 (39%)40 (38%)174 (40%)
 No436 (63%)75 (65%)308 (61%)66 (62%)261 (60%)
 Missing1 (0.1%)01 (0.2%)
Regular intake of NSAIDS
 Yes175 (25%)22 (19%)132 (26%)22 (21%)113 (26%)
 No514 (74%)94 (81%)371 (73%)84 (79%)322 (74%)
 Missing2 (0.3%)02 (0.4%)