Table 2.

Characteristics of participants and non-participants in the two study samples

General population sampleHigh-risk sample
Non-participants (n = 338), n (%)Participants (n = 118), n (%)P-valueaNon-participants (n = 449), n (%)Participants (n = 264), n (%)P-valuea
Age, years (mean ± SD)47 (±17)55 (±15)<0.00167 (±14)69 (±10)0.106
Age category, years
18–40138 (41)23 (19)<0.00124 (5)3 (1)0.004
41–60122 (36)45 (38)0.69298 (22)44 (17)0.096
61–8072 (21)48 (41)<0.001250 (56)178 (67)0.002
>806 (2)2 (2)0.95477 (17)39 (15)0.406
Female176 (52)71 (60)0.022215 (48)128 (49)0.877
High gastrointestinal risk55 (16)31 (26)0.017413 (92)249 (94)0.242
  History of peptic ulcer/ UGI complication4 (1)3 (3)0.301117 (26)46 (17)0.008
  Age >70 years42 (12)22 (19)0.094199 (44)110 (42)0.490
  Two or more minor risk factorsb14 (4)9 (8)0.136212 (47)149 (56)0.017
High cardiovascular risk14 (4)5 (4)0.964190 (42)115 (44)0.746
  History of myocardial infarction10 (3)3 (3)0.81583 (18)48 (18)0.919
  History of stroke5 (1)1 (1)0.60451 (11)38 (14)0.236
  Heart failure2 (1)1 (1)0.76780 (18)37 (14)0.186
High renal risk: chronic renal insufficiency0 (0)0 (0)NA29 (7)8 (3)0.046
  • UGI = upper gastrointestinal. NA = non applicable.

  • a Participants versus non-participants, χ2 test for dichotomous variables and independent t-test for age as a continuous variable.

  • b Two or more of the following minor risk factors: use of anticoagulant, use of aspirin, use of corticosteroid, use of selective serotonin reuptake inhibitor, age 60–70 years, history of severe rheumatoid arthritis, diabetes mellitus, or heart failure.