Table 1.

Baseline characteristics of ASPIRED trial participants (N = 180).

PlaceboAspirin, 81 mgAspirin, 325 mg
(n = 60)(n = 60)(n = 60)
Age, year, mean (SD)57.1 (9.2)56.1 (8.7)57.5 (8.3)
Sex, n (%)a
 Female28 (46.7)29 (48.3)28 (46.7)
Race, n (%)
 White55 (91.7)52 (86.7)53 (88.3)
 Black/African American3 (5.0)4 (6.7)3 (5.0)
 Asian1 (1.7)0 (0)2 (3.3)
 More than one race0 (0)4 (6.7)2 (3.3)
 Did not report1 (1.7)0 (0)0 (0)
Ethnicity, n (%)
 Hispanic2 (3.3)2 (3.3)1 (1.7)
Marital status, n (%)
 Married40 (66.7)39 (65.0)37 (61.7)
 Never married6 (10.0)12 (20.0)11 (18.3)
 Separated2 (3.3)0 (0.0)1 (1.7)
 Divorced8 (13.3)7 (11.7)7 (11.7)
 Widowed4 (6.7)2 (3.3)4 (6.7)
BMI, kg/m2, mean (SD)26.8 (5.0)28.4 (4.9)27.5 (5.7)
 Normal, <18.5–24.921 (35.0)16 (26.7)21 (35.0)
 Overweight, 25.0–29.926 (43.3)26 (43.3)23 (38.3)
 Obese, ≥30.013 (21.7)18 (30.0)16 (26.7)
Smoking status, n (%)
 Never38 (63.3)36 (60.0)32 (53.3)
 Former18 (30.0)20 (33.3)19 (31.7)
 Current4 (6.7)3 (5.0)8 (13.3)
 Missing0 (0.0)1 (1.7)1 (1.7)
Alcohol consumption, n (%)
 Never7 (11.7)11 (18.3)11 (18.3)
 Rarely14 (23.3)16 (26.7)18 (30.0)
 1–5 times/week29 (48.3)24 (40.0)23 (38.3)
 Daily10 (16.7)8 (13.3)6 (10.0)
 More than daily0 (0.0)1 (1.7)2 (3.3)
Personal cancer history, yes, n (%)10 (17.0)6 (10.0)4 (6.8)
Family history of CRC, yes, n (%)13 (21.7)10 (16.7)12 (20.0)
Type II diabetes, yes, n (%)2 (3.4)3 (5.0)2 (3.3)
Menopause status (n = 85)b
 Premenopausal3 (10.7)9 (31.0)5 (17.9)
 Perimenopausal4 (14.3)1 (3.4)2 (7.1)
 Postmenopausal20 (71.4)17 (58.6)18 (64.3)
 Missing1 (3.6)2 (6.9)3 (10.7)
History of 81 mg aspirin use, n (%)
 Never55 (91.7)50 (83.3)53 (88.3)
 Intermittently (<2 ×/week)2 (3.3)5 (8.3)5 (8.3)
 Regularly (>2 ×/week)2 (3.3)2 (3.3)2 (3.3)
 Missing1 (1.7)3 (5.0)0 (0.0)
History of 325 mg aspirin use, n (%)
 Never40 (66.7)42 (70.0)42 (70.0)
 Intermittently (<2 ×/week)17 (28.3)15 (25.0)17 (28.3)
 Regularly (>2 ×/week)1 (1.7)1 (1.7)1 (1.7)
 Missing2 (3.3)2 (3.3)0 (0.0)
History of NSAID use, n (%)
 Never18 (30.0)13 (21.7)19 (31.7)
 Intermittently (<2 ×/week)31 (51.7)36 (60.0)32 (53.3)
 Regularly (>2 ×/week)10 (16.7)9 (15.0)8 (13.3)
 Missing1 (1.7)2 (3.3)1 (1.7)
PPI use, n (%)
 Current and regular5 (8.3)6 (10.0)8 (13.3)
 Missing7 (11.7)5 (8.3)4 (6.7)
H2-blocker use, n (%)
 Current and regular2 (3.3)5 (8.3)2 (3.3)
 Missing2 (3.3)1 (1.7)1 (1.7)
Antacid use, n (%)
 Current and regular5 (8.3)3 (5.0)3 (5.0)
 Missing1 (1.7)0 (0.0)0 (0.0)
Statin use, n (%)
 Current and regular14 (23.3)11 (18.3)16 (26.7)
 Missing2 (3.3)1 (1.7)1 (1.7)
Indication for previous endoscopy, n (%)
 Screening35 (58.3)33 (55.0)30 (50.0)
 Surveillance15 (25.0)13 (21.7)16 (26.7)
 Diagnostic3 (5.0)5 (8.3)3 (5.0)
 Other/unknown7 (11.7)9 (15.0)11 (18.3)
Polyp history by location, n (%)
 Right23 (38.3)25 (41.7)26 (43.3)
 Left24 (40.0)14 (23.3)17 (28.3)
 Both13 (21.7)21 (35.0)16 (26.7)
 Unknown0 (0.0)0 (0.0)1 (1.7)
Days on treatment, mean (SD)c68.6 (6.5)68.5 (7.5)69.6 (6.9)
Pill count adherence, n (%)c
 95.0%–100%52 (89.7)45 (79.3)49 (90.7)
 90.0%–94.9%3 (5.2)9 (15.5)3 (5.6)
 80.0%–89.9%1 (1.7)3 (5.2)2 (3.7)
 <80.0%1 (1.7)0 (0.0)0 (0.0)
 Missing1 (1.7)0 (0.0)0 (0.0)
  • Note: Baseline characteristics of subjects were compared between treatment arms by using Fisher exact test for categorical variables and one-way ANOVA and unpaired two sample t tests for continuous variables. Missing represents one individual who completed the study, but did not return their pill bottle to the study staff.

  • Abbreviation: CRC, colorectal cancer; PPI, Proton Pump Inhibitor.

  • aBiological sex at birth.

  • bQuestion posed only to women.

  • cOnly available for individuals who completed the study and provided a pre- and posttreatment sample (n = 169).