Table 1

Comparison of primary prevention trials of aspirin that enrolled patients with diabetes (N = 11,787)

Study/year (ref.)Aspirin dose (study design)Follow-up (years)Number enrolled with diabetes% FemaleAge (years) (minimum/mean)CHD endpointCHD endpoint event rate (control vs. aspirin)10-year extrapolated CHD event rates[i]RR (95% CI)[ii]Stroke events for aspirin vs. control: RR (95% CI)
PHS DM/1989 (12)325 mg every other day (2 × 2 factorial design with 50 mg beta carotene)5.05330>40/NAFatal + nonfatal MI10.5% vs. 6.2%[iii] (27/258 vs. 17/275)21% vs. 12.4%0.59 (0.33–1.06)16 vs. 10: 1.50 (0.69–3.25)
ETDRS/1992 (18)650 mg daily5.03,71144>18/NAFatal + nonfatal MI15.3% vs. 13.0% (283/1,855 vs. 241/1,856)30.6% vs. 26.0%0.85 (0.73–1.00)92 vs. 78: 1.18 (0.88–1.58)
PPP DM/2003[iv] (16)100 mg daily (2 × 2 design with 30 mg vitamin E)3.71,03152>50/64Fatal + nonfatal MI2.0% vs. 1.0% (10/512 vs. 5/519)5.4% vs. 2.7%0.49 (0.17–1.43)10 vs. 11: 0.90 (0.38–2.09)
WHS DM/2005 (17)100 mg every other day (2 × 2 factorial design with 600 IU Vitamin E every other day)10.11,027100>45/55Fatal + nonfatal MI[v]5.9% vs. 7.9% (29/494 vs. 42/533)5.9% vs. 7.9%1.34 (0.85–2.12)15 vs. 31: 0.45 (0.25–0.82)
JPAD/2008 (10)81–100 mg daily (open label treatment assignment, blinded end-point assessment)4.42,53946>30/65Fatal + nonfatal MI1.1% vs. 1.0% (14/1,277 vs. 12/1,262)2.5% vs. 2.3%0.87 (0.40–1.87)28 vs. 32: 0.89 (0.54–1.46)
POPADAD/2008 (9)100 mg daily (2 × 2 factorial design including anti-oxidants)6.71,27656>40/60CHD death + nonfatal MI12.9% vs. 13.9% (82/638 vs. 89/638)19.3% vs. 20.7%1.09 (0.82–1.44)37 vs. 50: 0.74 (0.49–1.12)
TPT DM/1998 (data from ATT) (5)75 mg daily6.7680>45/58MCE15.4% vs. 13.8% (6/39 vs. 4/29)23.0% vs. 20.6%0.90 (0.28 – 2.89)1 vs. 2: 0.67 (0.06–7.06)
BMD/1988 (data from ATT) (5)500 mg daily5.61010>50/NAMCE18.8% vs. 18.8% (6/32 vs. 13/69)33.48% vs. 33.6%1.00 (0.42–2.40)3 vs. 1: 1.39 (0.15–12.86)
HOT DM/1998 (data from ATT) (5)75 mg daily (co-randomized to one of three diastolic BP goals)3.81,50147>50/62MCE3.6% vs. 2.8% (27/749 vs. 21/752)9.5% vs. 7.3%0.77 (0.44–1.36)22 vs. 24: 0.91 (0.52–1.61)
  • DM, diabetes mellitus; MCE, major coronary event (CHD death + nonfatal MI + sudden death); NA, not available.

  • i10-year extrapolated CHD event rate calculated by (10 ÷ study duration) × event rate.

  • iiCalculated based on event counts.

  • iiiValues slightly different from original PHS report based on updated ICD-9 coding information obtained by the ATT trialists.

  • ivData used from 2003 PPP diabetic substudy (16); number with diabetes is discrepant from original PPP publication (15) due to continued enrollment and follow-up of diabetic patients beyond the original study period.

  • vEvent rates slightly different than original 2005 report due to 11 extra MI/CHD deaths (6 in aspirin group and 5 in placebo) reported to the ATT study group vs. original publication.